xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/ira.c (revision 63ce0b47aeb8b4c6792d02a0de9ecf8182e299ac)
1 /* Integrated Register Allocator (IRA) entry point.
2    Copyright (C) 2006-2016 Free Software Foundation, Inc.
3    Contributed by Vladimir Makarov <vmakarov@redhat.com>.
4 
5 This file is part of GCC.
6 
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
10 version.
11 
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15 for more details.
16 
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3.  If not see
19 <http://www.gnu.org/licenses/>.  */
20 
21 /* The integrated register allocator (IRA) is a
22    regional register allocator performing graph coloring on a top-down
23    traversal of nested regions.  Graph coloring in a region is based
24    on Chaitin-Briggs algorithm.  It is called integrated because
25    register coalescing, register live range splitting, and choosing a
26    better hard register are done on-the-fly during coloring.  Register
27    coalescing and choosing a cheaper hard register is done by hard
28    register preferencing during hard register assigning.  The live
29    range splitting is a byproduct of the regional register allocation.
30 
31    Major IRA notions are:
32 
33      o *Region* is a part of CFG where graph coloring based on
34        Chaitin-Briggs algorithm is done.  IRA can work on any set of
35        nested CFG regions forming a tree.  Currently the regions are
36        the entire function for the root region and natural loops for
37        the other regions.  Therefore data structure representing a
38        region is called loop_tree_node.
39 
40      o *Allocno class* is a register class used for allocation of
41        given allocno.  It means that only hard register of given
42        register class can be assigned to given allocno.  In reality,
43        even smaller subset of (*profitable*) hard registers can be
44        assigned.  In rare cases, the subset can be even smaller
45        because our modification of Chaitin-Briggs algorithm requires
46        that sets of hard registers can be assigned to allocnos forms a
47        forest, i.e. the sets can be ordered in a way where any
48        previous set is not intersected with given set or is a superset
49        of given set.
50 
51      o *Pressure class* is a register class belonging to a set of
52        register classes containing all of the hard-registers available
53        for register allocation.  The set of all pressure classes for a
54        target is defined in the corresponding machine-description file
55        according some criteria.  Register pressure is calculated only
56        for pressure classes and it affects some IRA decisions as
57        forming allocation regions.
58 
59      o *Allocno* represents the live range of a pseudo-register in a
60        region.  Besides the obvious attributes like the corresponding
61        pseudo-register number, allocno class, conflicting allocnos and
62        conflicting hard-registers, there are a few allocno attributes
63        which are important for understanding the allocation algorithm:
64 
65        - *Live ranges*.  This is a list of ranges of *program points*
66          where the allocno lives.  Program points represent places
67          where a pseudo can be born or become dead (there are
68          approximately two times more program points than the insns)
69          and they are represented by integers starting with 0.  The
70          live ranges are used to find conflicts between allocnos.
71          They also play very important role for the transformation of
72          the IRA internal representation of several regions into a one
73          region representation.  The later is used during the reload
74          pass work because each allocno represents all of the
75          corresponding pseudo-registers.
76 
77        - *Hard-register costs*.  This is a vector of size equal to the
78          number of available hard-registers of the allocno class.  The
79          cost of a callee-clobbered hard-register for an allocno is
80          increased by the cost of save/restore code around the calls
81          through the given allocno's life.  If the allocno is a move
82          instruction operand and another operand is a hard-register of
83          the allocno class, the cost of the hard-register is decreased
84          by the move cost.
85 
86          When an allocno is assigned, the hard-register with minimal
87          full cost is used.  Initially, a hard-register's full cost is
88          the corresponding value from the hard-register's cost vector.
89          If the allocno is connected by a *copy* (see below) to
90          another allocno which has just received a hard-register, the
91          cost of the hard-register is decreased.  Before choosing a
92          hard-register for an allocno, the allocno's current costs of
93          the hard-registers are modified by the conflict hard-register
94          costs of all of the conflicting allocnos which are not
95          assigned yet.
96 
97        - *Conflict hard-register costs*.  This is a vector of the same
98          size as the hard-register costs vector.  To permit an
99          unassigned allocno to get a better hard-register, IRA uses
100          this vector to calculate the final full cost of the
101          available hard-registers.  Conflict hard-register costs of an
102          unassigned allocno are also changed with a change of the
103          hard-register cost of the allocno when a copy involving the
104          allocno is processed as described above.  This is done to
105          show other unassigned allocnos that a given allocno prefers
106          some hard-registers in order to remove the move instruction
107          corresponding to the copy.
108 
109      o *Cap*.  If a pseudo-register does not live in a region but
110        lives in a nested region, IRA creates a special allocno called
111        a cap in the outer region.  A region cap is also created for a
112        subregion cap.
113 
114      o *Copy*.  Allocnos can be connected by copies.  Copies are used
115        to modify hard-register costs for allocnos during coloring.
116        Such modifications reflects a preference to use the same
117        hard-register for the allocnos connected by copies.  Usually
118        copies are created for move insns (in this case it results in
119        register coalescing).  But IRA also creates copies for operands
120        of an insn which should be assigned to the same hard-register
121        due to constraints in the machine description (it usually
122        results in removing a move generated in reload to satisfy
123        the constraints) and copies referring to the allocno which is
124        the output operand of an instruction and the allocno which is
125        an input operand dying in the instruction (creation of such
126        copies results in less register shuffling).  IRA *does not*
127        create copies between the same register allocnos from different
128        regions because we use another technique for propagating
129        hard-register preference on the borders of regions.
130 
131    Allocnos (including caps) for the upper region in the region tree
132    *accumulate* information important for coloring from allocnos with
133    the same pseudo-register from nested regions.  This includes
134    hard-register and memory costs, conflicts with hard-registers,
135    allocno conflicts, allocno copies and more.  *Thus, attributes for
136    allocnos in a region have the same values as if the region had no
137    subregions*.  It means that attributes for allocnos in the
138    outermost region corresponding to the function have the same values
139    as though the allocation used only one region which is the entire
140    function.  It also means that we can look at IRA work as if the
141    first IRA did allocation for all function then it improved the
142    allocation for loops then their subloops and so on.
143 
144    IRA major passes are:
145 
146      o Building IRA internal representation which consists of the
147        following subpasses:
148 
149        * First, IRA builds regions and creates allocnos (file
150          ira-build.c) and initializes most of their attributes.
151 
152        * Then IRA finds an allocno class for each allocno and
153          calculates its initial (non-accumulated) cost of memory and
154          each hard-register of its allocno class (file ira-cost.c).
155 
156        * IRA creates live ranges of each allocno, calculates register
157          pressure for each pressure class in each region, sets up
158          conflict hard registers for each allocno and info about calls
159          the allocno lives through (file ira-lives.c).
160 
161        * IRA removes low register pressure loops from the regions
162          mostly to speed IRA up (file ira-build.c).
163 
164        * IRA propagates accumulated allocno info from lower region
165          allocnos to corresponding upper region allocnos (file
166          ira-build.c).
167 
168        * IRA creates all caps (file ira-build.c).
169 
170        * Having live-ranges of allocnos and their classes, IRA creates
171          conflicting allocnos for each allocno.  Conflicting allocnos
172          are stored as a bit vector or array of pointers to the
173          conflicting allocnos whatever is more profitable (file
174          ira-conflicts.c).  At this point IRA creates allocno copies.
175 
176      o Coloring.  Now IRA has all necessary info to start graph coloring
177        process.  It is done in each region on top-down traverse of the
178        region tree (file ira-color.c).  There are following subpasses:
179 
180        * Finding profitable hard registers of corresponding allocno
181          class for each allocno.  For example, only callee-saved hard
182          registers are frequently profitable for allocnos living
183          through colors.  If the profitable hard register set of
184          allocno does not form a tree based on subset relation, we use
185          some approximation to form the tree.  This approximation is
186          used to figure out trivial colorability of allocnos.  The
187          approximation is a pretty rare case.
188 
189        * Putting allocnos onto the coloring stack.  IRA uses Briggs
190          optimistic coloring which is a major improvement over
191          Chaitin's coloring.  Therefore IRA does not spill allocnos at
192          this point.  There is some freedom in the order of putting
193          allocnos on the stack which can affect the final result of
194          the allocation.  IRA uses some heuristics to improve the
195          order.  The major one is to form *threads* from colorable
196          allocnos and push them on the stack by threads.  Thread is a
197          set of non-conflicting colorable allocnos connected by
198          copies.  The thread contains allocnos from the colorable
199          bucket or colorable allocnos already pushed onto the coloring
200          stack.  Pushing thread allocnos one after another onto the
201          stack increases chances of removing copies when the allocnos
202          get the same hard reg.
203 
204 	 We also use a modification of Chaitin-Briggs algorithm which
205          works for intersected register classes of allocnos.  To
206          figure out trivial colorability of allocnos, the mentioned
207          above tree of hard register sets is used.  To get an idea how
208          the algorithm works in i386 example, let us consider an
209          allocno to which any general hard register can be assigned.
210          If the allocno conflicts with eight allocnos to which only
211          EAX register can be assigned, given allocno is still
212          trivially colorable because all conflicting allocnos might be
213          assigned only to EAX and all other general hard registers are
214          still free.
215 
216 	 To get an idea of the used trivial colorability criterion, it
217 	 is also useful to read article "Graph-Coloring Register
218 	 Allocation for Irregular Architectures" by Michael D. Smith
219 	 and Glen Holloway.  Major difference between the article
220 	 approach and approach used in IRA is that Smith's approach
221 	 takes register classes only from machine description and IRA
222 	 calculate register classes from intermediate code too
223 	 (e.g. an explicit usage of hard registers in RTL code for
224 	 parameter passing can result in creation of additional
225 	 register classes which contain or exclude the hard
226 	 registers).  That makes IRA approach useful for improving
227 	 coloring even for architectures with regular register files
228 	 and in fact some benchmarking shows the improvement for
229 	 regular class architectures is even bigger than for irregular
230 	 ones.  Another difference is that Smith's approach chooses
231 	 intersection of classes of all insn operands in which a given
232 	 pseudo occurs.  IRA can use bigger classes if it is still
233 	 more profitable than memory usage.
234 
235        * Popping the allocnos from the stack and assigning them hard
236          registers.  If IRA can not assign a hard register to an
237          allocno and the allocno is coalesced, IRA undoes the
238          coalescing and puts the uncoalesced allocnos onto the stack in
239          the hope that some such allocnos will get a hard register
240          separately.  If IRA fails to assign hard register or memory
241          is more profitable for it, IRA spills the allocno.  IRA
242          assigns the allocno the hard-register with minimal full
243          allocation cost which reflects the cost of usage of the
244          hard-register for the allocno and cost of usage of the
245          hard-register for allocnos conflicting with given allocno.
246 
247        * Chaitin-Briggs coloring assigns as many pseudos as possible
248          to hard registers.  After coloring we try to improve
249          allocation with cost point of view.  We improve the
250          allocation by spilling some allocnos and assigning the freed
251          hard registers to other allocnos if it decreases the overall
252          allocation cost.
253 
254        * After allocno assigning in the region, IRA modifies the hard
255          register and memory costs for the corresponding allocnos in
256          the subregions to reflect the cost of possible loads, stores,
257          or moves on the border of the region and its subregions.
258          When default regional allocation algorithm is used
259          (-fira-algorithm=mixed), IRA just propagates the assignment
260          for allocnos if the register pressure in the region for the
261          corresponding pressure class is less than number of available
262          hard registers for given pressure class.
263 
264      o Spill/restore code moving.  When IRA performs an allocation
265        by traversing regions in top-down order, it does not know what
266        happens below in the region tree.  Therefore, sometimes IRA
267        misses opportunities to perform a better allocation.  A simple
268        optimization tries to improve allocation in a region having
269        subregions and containing in another region.  If the
270        corresponding allocnos in the subregion are spilled, it spills
271        the region allocno if it is profitable.  The optimization
272        implements a simple iterative algorithm performing profitable
273        transformations while they are still possible.  It is fast in
274        practice, so there is no real need for a better time complexity
275        algorithm.
276 
277      o Code change.  After coloring, two allocnos representing the
278        same pseudo-register outside and inside a region respectively
279        may be assigned to different locations (hard-registers or
280        memory).  In this case IRA creates and uses a new
281        pseudo-register inside the region and adds code to move allocno
282        values on the region's borders.  This is done during top-down
283        traversal of the regions (file ira-emit.c).  In some
284        complicated cases IRA can create a new allocno to move allocno
285        values (e.g. when a swap of values stored in two hard-registers
286        is needed).  At this stage, the new allocno is marked as
287        spilled.  IRA still creates the pseudo-register and the moves
288        on the region borders even when both allocnos were assigned to
289        the same hard-register.  If the reload pass spills a
290        pseudo-register for some reason, the effect will be smaller
291        because another allocno will still be in the hard-register.  In
292        most cases, this is better then spilling both allocnos.  If
293        reload does not change the allocation for the two
294        pseudo-registers, the trivial move will be removed by
295        post-reload optimizations.  IRA does not generate moves for
296        allocnos assigned to the same hard register when the default
297        regional allocation algorithm is used and the register pressure
298        in the region for the corresponding pressure class is less than
299        number of available hard registers for given pressure class.
300        IRA also does some optimizations to remove redundant stores and
301        to reduce code duplication on the region borders.
302 
303      o Flattening internal representation.  After changing code, IRA
304        transforms its internal representation for several regions into
305        one region representation (file ira-build.c).  This process is
306        called IR flattening.  Such process is more complicated than IR
307        rebuilding would be, but is much faster.
308 
309      o After IR flattening, IRA tries to assign hard registers to all
310        spilled allocnos.  This is implemented by a simple and fast
311        priority coloring algorithm (see function
312        ira_reassign_conflict_allocnos::ira-color.c).  Here new allocnos
313        created during the code change pass can be assigned to hard
314        registers.
315 
316      o At the end IRA calls the reload pass.  The reload pass
317        communicates with IRA through several functions in file
318        ira-color.c to improve its decisions in
319 
320        * sharing stack slots for the spilled pseudos based on IRA info
321          about pseudo-register conflicts.
322 
323        * reassigning hard-registers to all spilled pseudos at the end
324          of each reload iteration.
325 
326        * choosing a better hard-register to spill based on IRA info
327          about pseudo-register live ranges and the register pressure
328          in places where the pseudo-register lives.
329 
330    IRA uses a lot of data representing the target processors.  These
331    data are initialized in file ira.c.
332 
333    If function has no loops (or the loops are ignored when
334    -fira-algorithm=CB is used), we have classic Chaitin-Briggs
335    coloring (only instead of separate pass of coalescing, we use hard
336    register preferencing).  In such case, IRA works much faster
337    because many things are not made (like IR flattening, the
338    spill/restore optimization, and the code change).
339 
340    Literature is worth to read for better understanding the code:
341 
342    o Preston Briggs, Keith D. Cooper, Linda Torczon.  Improvements to
343      Graph Coloring Register Allocation.
344 
345    o David Callahan, Brian Koblenz.  Register allocation via
346      hierarchical graph coloring.
347 
348    o Keith Cooper, Anshuman Dasgupta, Jason Eckhardt. Revisiting Graph
349      Coloring Register Allocation: A Study of the Chaitin-Briggs and
350      Callahan-Koblenz Algorithms.
351 
352    o Guei-Yuan Lueh, Thomas Gross, and Ali-Reza Adl-Tabatabai. Global
353      Register Allocation Based on Graph Fusion.
354 
355    o Michael D. Smith and Glenn Holloway.  Graph-Coloring Register
356      Allocation for Irregular Architectures
357 
358    o Vladimir Makarov. The Integrated Register Allocator for GCC.
359 
360    o Vladimir Makarov.  The top-down register allocator for irregular
361      register file architectures.
362 
363 */
364 
365 
366 #include "config.h"
367 #include "system.h"
368 #include "coretypes.h"
369 #include "backend.h"
370 #include "target.h"
371 #include "rtl.h"
372 #include "tree.h"
373 #include "df.h"
374 #include "tm_p.h"
375 #include "insn-config.h"
376 #include "regs.h"
377 #include "ira.h"
378 #include "ira-int.h"
379 #include "diagnostic-core.h"
380 #include "cfgrtl.h"
381 #include "cfgbuild.h"
382 #include "cfgcleanup.h"
383 #include "expr.h"
384 #include "tree-pass.h"
385 #include "output.h"
386 #include "reload.h"
387 #include "cfgloop.h"
388 #include "lra.h"
389 #include "dce.h"
390 #include "dbgcnt.h"
391 #include "rtl-iter.h"
392 #include "shrink-wrap.h"
393 #include "print-rtl.h"
394 
395 struct target_ira default_target_ira;
396 struct target_ira_int default_target_ira_int;
397 #if SWITCHABLE_TARGET
398 struct target_ira *this_target_ira = &default_target_ira;
399 struct target_ira_int *this_target_ira_int = &default_target_ira_int;
400 #endif
401 
402 /* A modified value of flag `-fira-verbose' used internally.  */
403 int internal_flag_ira_verbose;
404 
405 /* Dump file of the allocator if it is not NULL.  */
406 FILE *ira_dump_file;
407 
408 /* The number of elements in the following array.  */
409 int ira_spilled_reg_stack_slots_num;
410 
411 /* The following array contains info about spilled pseudo-registers
412    stack slots used in current function so far.  */
413 struct ira_spilled_reg_stack_slot *ira_spilled_reg_stack_slots;
414 
415 /* Correspondingly overall cost of the allocation, overall cost before
416    reload, cost of the allocnos assigned to hard-registers, cost of
417    the allocnos assigned to memory, cost of loads, stores and register
418    move insns generated for pseudo-register live range splitting (see
419    ira-emit.c).  */
420 int64_t ira_overall_cost, overall_cost_before;
421 int64_t ira_reg_cost, ira_mem_cost;
422 int64_t ira_load_cost, ira_store_cost, ira_shuffle_cost;
423 int ira_move_loops_num, ira_additional_jumps_num;
424 
425 /* All registers that can be eliminated.  */
426 
427 HARD_REG_SET eliminable_regset;
428 
429 /* Value of max_reg_num () before IRA work start.  This value helps
430    us to recognize a situation when new pseudos were created during
431    IRA work.  */
432 static int max_regno_before_ira;
433 
434 /* Temporary hard reg set used for a different calculation.  */
435 static HARD_REG_SET temp_hard_regset;
436 
437 #define last_mode_for_init_move_cost \
438   (this_target_ira_int->x_last_mode_for_init_move_cost)
439 
440 
441 /* The function sets up the map IRA_REG_MODE_HARD_REGSET.  */
442 static void
443 setup_reg_mode_hard_regset (void)
444 {
445   int i, m, hard_regno;
446 
447   for (m = 0; m < NUM_MACHINE_MODES; m++)
448     for (hard_regno = 0; hard_regno < FIRST_PSEUDO_REGISTER; hard_regno++)
449       {
450 	CLEAR_HARD_REG_SET (ira_reg_mode_hard_regset[hard_regno][m]);
451 	for (i = hard_regno_nregs[hard_regno][m] - 1; i >= 0; i--)
452 	  if (hard_regno + i < FIRST_PSEUDO_REGISTER)
453 	    SET_HARD_REG_BIT (ira_reg_mode_hard_regset[hard_regno][m],
454 			      hard_regno + i);
455       }
456 }
457 
458 
459 #define no_unit_alloc_regs \
460   (this_target_ira_int->x_no_unit_alloc_regs)
461 
462 /* The function sets up the three arrays declared above.  */
463 static void
464 setup_class_hard_regs (void)
465 {
466   int cl, i, hard_regno, n;
467   HARD_REG_SET processed_hard_reg_set;
468 
469   ira_assert (SHRT_MAX >= FIRST_PSEUDO_REGISTER);
470   for (cl = (int) N_REG_CLASSES - 1; cl >= 0; cl--)
471     {
472       COPY_HARD_REG_SET (temp_hard_regset, reg_class_contents[cl]);
473       AND_COMPL_HARD_REG_SET (temp_hard_regset, no_unit_alloc_regs);
474       CLEAR_HARD_REG_SET (processed_hard_reg_set);
475       for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
476 	{
477 	  ira_non_ordered_class_hard_regs[cl][i] = -1;
478 	  ira_class_hard_reg_index[cl][i] = -1;
479 	}
480       for (n = 0, i = 0; i < FIRST_PSEUDO_REGISTER; i++)
481 	{
482 #ifdef REG_ALLOC_ORDER
483 	  hard_regno = reg_alloc_order[i];
484 #else
485 	  hard_regno = i;
486 #endif
487 	  if (TEST_HARD_REG_BIT (processed_hard_reg_set, hard_regno))
488 	    continue;
489 	  SET_HARD_REG_BIT (processed_hard_reg_set, hard_regno);
490       	  if (! TEST_HARD_REG_BIT (temp_hard_regset, hard_regno))
491 	    ira_class_hard_reg_index[cl][hard_regno] = -1;
492 	  else
493 	    {
494 	      ira_class_hard_reg_index[cl][hard_regno] = n;
495 	      ira_class_hard_regs[cl][n++] = hard_regno;
496 	    }
497 	}
498       ira_class_hard_regs_num[cl] = n;
499       for (n = 0, i = 0; i < FIRST_PSEUDO_REGISTER; i++)
500 	if (TEST_HARD_REG_BIT (temp_hard_regset, i))
501 	  ira_non_ordered_class_hard_regs[cl][n++] = i;
502       ira_assert (ira_class_hard_regs_num[cl] == n);
503     }
504 }
505 
506 /* Set up global variables defining info about hard registers for the
507    allocation.  These depend on USE_HARD_FRAME_P whose TRUE value means
508    that we can use the hard frame pointer for the allocation.  */
509 static void
510 setup_alloc_regs (bool use_hard_frame_p)
511 {
512 #ifdef ADJUST_REG_ALLOC_ORDER
513   ADJUST_REG_ALLOC_ORDER;
514 #endif
515   COPY_HARD_REG_SET (no_unit_alloc_regs, fixed_reg_set);
516   if (! use_hard_frame_p)
517     SET_HARD_REG_BIT (no_unit_alloc_regs, HARD_FRAME_POINTER_REGNUM);
518   setup_class_hard_regs ();
519 }
520 
521 
522 
523 #define alloc_reg_class_subclasses \
524   (this_target_ira_int->x_alloc_reg_class_subclasses)
525 
526 /* Initialize the table of subclasses of each reg class.  */
527 static void
528 setup_reg_subclasses (void)
529 {
530   int i, j;
531   HARD_REG_SET temp_hard_regset2;
532 
533   for (i = 0; i < N_REG_CLASSES; i++)
534     for (j = 0; j < N_REG_CLASSES; j++)
535       alloc_reg_class_subclasses[i][j] = LIM_REG_CLASSES;
536 
537   for (i = 0; i < N_REG_CLASSES; i++)
538     {
539       if (i == (int) NO_REGS)
540 	continue;
541 
542       COPY_HARD_REG_SET (temp_hard_regset, reg_class_contents[i]);
543       AND_COMPL_HARD_REG_SET (temp_hard_regset, no_unit_alloc_regs);
544       if (hard_reg_set_empty_p (temp_hard_regset))
545 	continue;
546       for (j = 0; j < N_REG_CLASSES; j++)
547 	if (i != j)
548 	  {
549 	    enum reg_class *p;
550 
551 	    COPY_HARD_REG_SET (temp_hard_regset2, reg_class_contents[j]);
552 	    AND_COMPL_HARD_REG_SET (temp_hard_regset2, no_unit_alloc_regs);
553 	    if (! hard_reg_set_subset_p (temp_hard_regset,
554 					 temp_hard_regset2))
555 	      continue;
556 	    p = &alloc_reg_class_subclasses[j][0];
557 	    while (*p != LIM_REG_CLASSES) p++;
558 	    *p = (enum reg_class) i;
559 	  }
560     }
561 }
562 
563 
564 
565 /* Set up IRA_MEMORY_MOVE_COST and IRA_MAX_MEMORY_MOVE_COST.  */
566 static void
567 setup_class_subset_and_memory_move_costs (void)
568 {
569   int cl, cl2, mode, cost;
570   HARD_REG_SET temp_hard_regset2;
571 
572   for (mode = 0; mode < MAX_MACHINE_MODE; mode++)
573     ira_memory_move_cost[mode][NO_REGS][0]
574       = ira_memory_move_cost[mode][NO_REGS][1] = SHRT_MAX;
575   for (cl = (int) N_REG_CLASSES - 1; cl >= 0; cl--)
576     {
577       if (cl != (int) NO_REGS)
578 	for (mode = 0; mode < MAX_MACHINE_MODE; mode++)
579 	  {
580 	    ira_max_memory_move_cost[mode][cl][0]
581 	      = ira_memory_move_cost[mode][cl][0]
582 	      = memory_move_cost ((machine_mode) mode,
583 				  (reg_class_t) cl, false);
584 	    ira_max_memory_move_cost[mode][cl][1]
585 	      = ira_memory_move_cost[mode][cl][1]
586 	      = memory_move_cost ((machine_mode) mode,
587 				  (reg_class_t) cl, true);
588 	    /* Costs for NO_REGS are used in cost calculation on the
589 	       1st pass when the preferred register classes are not
590 	       known yet.  In this case we take the best scenario.  */
591 	    if (ira_memory_move_cost[mode][NO_REGS][0]
592 		> ira_memory_move_cost[mode][cl][0])
593 	      ira_max_memory_move_cost[mode][NO_REGS][0]
594 		= ira_memory_move_cost[mode][NO_REGS][0]
595 		= ira_memory_move_cost[mode][cl][0];
596 	    if (ira_memory_move_cost[mode][NO_REGS][1]
597 		> ira_memory_move_cost[mode][cl][1])
598 	      ira_max_memory_move_cost[mode][NO_REGS][1]
599 		= ira_memory_move_cost[mode][NO_REGS][1]
600 		= ira_memory_move_cost[mode][cl][1];
601 	  }
602     }
603   for (cl = (int) N_REG_CLASSES - 1; cl >= 0; cl--)
604     for (cl2 = (int) N_REG_CLASSES - 1; cl2 >= 0; cl2--)
605       {
606 	COPY_HARD_REG_SET (temp_hard_regset, reg_class_contents[cl]);
607 	AND_COMPL_HARD_REG_SET (temp_hard_regset, no_unit_alloc_regs);
608 	COPY_HARD_REG_SET (temp_hard_regset2, reg_class_contents[cl2]);
609 	AND_COMPL_HARD_REG_SET (temp_hard_regset2, no_unit_alloc_regs);
610 	ira_class_subset_p[cl][cl2]
611 	  = hard_reg_set_subset_p (temp_hard_regset, temp_hard_regset2);
612 	if (! hard_reg_set_empty_p (temp_hard_regset2)
613 	    && hard_reg_set_subset_p (reg_class_contents[cl2],
614 				      reg_class_contents[cl]))
615 	  for (mode = 0; mode < MAX_MACHINE_MODE; mode++)
616 	    {
617 	      cost = ira_memory_move_cost[mode][cl2][0];
618 	      if (cost > ira_max_memory_move_cost[mode][cl][0])
619 		ira_max_memory_move_cost[mode][cl][0] = cost;
620 	      cost = ira_memory_move_cost[mode][cl2][1];
621 	      if (cost > ira_max_memory_move_cost[mode][cl][1])
622 		ira_max_memory_move_cost[mode][cl][1] = cost;
623 	    }
624       }
625   for (cl = (int) N_REG_CLASSES - 1; cl >= 0; cl--)
626     for (mode = 0; mode < MAX_MACHINE_MODE; mode++)
627       {
628 	ira_memory_move_cost[mode][cl][0]
629 	  = ira_max_memory_move_cost[mode][cl][0];
630 	ira_memory_move_cost[mode][cl][1]
631 	  = ira_max_memory_move_cost[mode][cl][1];
632       }
633   setup_reg_subclasses ();
634 }
635 
636 
637 
638 /* Define the following macro if allocation through malloc if
639    preferable.  */
640 #define IRA_NO_OBSTACK
641 
642 #ifndef IRA_NO_OBSTACK
643 /* Obstack used for storing all dynamic data (except bitmaps) of the
644    IRA.  */
645 static struct obstack ira_obstack;
646 #endif
647 
648 /* Obstack used for storing all bitmaps of the IRA.  */
649 static struct bitmap_obstack ira_bitmap_obstack;
650 
651 /* Allocate memory of size LEN for IRA data.  */
652 void *
653 ira_allocate (size_t len)
654 {
655   void *res;
656 
657 #ifndef IRA_NO_OBSTACK
658   res = obstack_alloc (&ira_obstack, len);
659 #else
660   res = xmalloc (len);
661 #endif
662   return res;
663 }
664 
665 /* Free memory ADDR allocated for IRA data.  */
666 void
667 ira_free (void *addr ATTRIBUTE_UNUSED)
668 {
669 #ifndef IRA_NO_OBSTACK
670   /* do nothing */
671 #else
672   free (addr);
673 #endif
674 }
675 
676 
677 /* Allocate and returns bitmap for IRA.  */
678 bitmap
679 ira_allocate_bitmap (void)
680 {
681   return BITMAP_ALLOC (&ira_bitmap_obstack);
682 }
683 
684 /* Free bitmap B allocated for IRA.  */
685 void
686 ira_free_bitmap (bitmap b ATTRIBUTE_UNUSED)
687 {
688   /* do nothing */
689 }
690 
691 
692 
693 /* Output information about allocation of all allocnos (except for
694    caps) into file F.  */
695 void
696 ira_print_disposition (FILE *f)
697 {
698   int i, n, max_regno;
699   ira_allocno_t a;
700   basic_block bb;
701 
702   fprintf (f, "Disposition:");
703   max_regno = max_reg_num ();
704   for (n = 0, i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
705     for (a = ira_regno_allocno_map[i];
706 	 a != NULL;
707 	 a = ALLOCNO_NEXT_REGNO_ALLOCNO (a))
708       {
709 	if (n % 4 == 0)
710 	  fprintf (f, "\n");
711 	n++;
712 	fprintf (f, " %4d:r%-4d", ALLOCNO_NUM (a), ALLOCNO_REGNO (a));
713 	if ((bb = ALLOCNO_LOOP_TREE_NODE (a)->bb) != NULL)
714 	  fprintf (f, "b%-3d", bb->index);
715 	else
716 	  fprintf (f, "l%-3d", ALLOCNO_LOOP_TREE_NODE (a)->loop_num);
717 	if (ALLOCNO_HARD_REGNO (a) >= 0)
718 	  fprintf (f, " %3d", ALLOCNO_HARD_REGNO (a));
719 	else
720 	  fprintf (f, " mem");
721       }
722   fprintf (f, "\n");
723 }
724 
725 /* Outputs information about allocation of all allocnos into
726    stderr.  */
727 void
728 ira_debug_disposition (void)
729 {
730   ira_print_disposition (stderr);
731 }
732 
733 
734 
735 /* Set up ira_stack_reg_pressure_class which is the biggest pressure
736    register class containing stack registers or NO_REGS if there are
737    no stack registers.  To find this class, we iterate through all
738    register pressure classes and choose the first register pressure
739    class containing all the stack registers and having the biggest
740    size.  */
741 static void
742 setup_stack_reg_pressure_class (void)
743 {
744   ira_stack_reg_pressure_class = NO_REGS;
745 #ifdef STACK_REGS
746   {
747     int i, best, size;
748     enum reg_class cl;
749     HARD_REG_SET temp_hard_regset2;
750 
751     CLEAR_HARD_REG_SET (temp_hard_regset);
752     for (i = FIRST_STACK_REG; i <= LAST_STACK_REG; i++)
753       SET_HARD_REG_BIT (temp_hard_regset, i);
754     best = 0;
755     for (i = 0; i < ira_pressure_classes_num; i++)
756       {
757 	cl = ira_pressure_classes[i];
758 	COPY_HARD_REG_SET (temp_hard_regset2, temp_hard_regset);
759 	AND_HARD_REG_SET (temp_hard_regset2, reg_class_contents[cl]);
760 	size = hard_reg_set_size (temp_hard_regset2);
761 	if (best < size)
762 	  {
763 	    best = size;
764 	    ira_stack_reg_pressure_class = cl;
765 	  }
766       }
767   }
768 #endif
769 }
770 
771 /* Find pressure classes which are register classes for which we
772    calculate register pressure in IRA, register pressure sensitive
773    insn scheduling, and register pressure sensitive loop invariant
774    motion.
775 
776    To make register pressure calculation easy, we always use
777    non-intersected register pressure classes.  A move of hard
778    registers from one register pressure class is not more expensive
779    than load and store of the hard registers.  Most likely an allocno
780    class will be a subset of a register pressure class and in many
781    cases a register pressure class.  That makes usage of register
782    pressure classes a good approximation to find a high register
783    pressure.  */
784 static void
785 setup_pressure_classes (void)
786 {
787   int cost, i, n, curr;
788   int cl, cl2;
789   enum reg_class pressure_classes[N_REG_CLASSES];
790   int m;
791   HARD_REG_SET temp_hard_regset2;
792   bool insert_p;
793 
794   n = 0;
795   for (cl = 0; cl < N_REG_CLASSES; cl++)
796     {
797       if (ira_class_hard_regs_num[cl] == 0)
798 	continue;
799       if (ira_class_hard_regs_num[cl] != 1
800 	  /* A register class without subclasses may contain a few
801 	     hard registers and movement between them is costly
802 	     (e.g. SPARC FPCC registers).  We still should consider it
803 	     as a candidate for a pressure class.  */
804 	  && alloc_reg_class_subclasses[cl][0] < cl)
805 	{
806 	  /* Check that the moves between any hard registers of the
807 	     current class are not more expensive for a legal mode
808 	     than load/store of the hard registers of the current
809 	     class.  Such class is a potential candidate to be a
810 	     register pressure class.  */
811 	  for (m = 0; m < NUM_MACHINE_MODES; m++)
812 	    {
813 	      COPY_HARD_REG_SET (temp_hard_regset, reg_class_contents[cl]);
814 	      AND_COMPL_HARD_REG_SET (temp_hard_regset, no_unit_alloc_regs);
815 	      AND_COMPL_HARD_REG_SET (temp_hard_regset,
816 				      ira_prohibited_class_mode_regs[cl][m]);
817 	      if (hard_reg_set_empty_p (temp_hard_regset))
818 		continue;
819 	      ira_init_register_move_cost_if_necessary ((machine_mode) m);
820 	      cost = ira_register_move_cost[m][cl][cl];
821 	      if (cost <= ira_max_memory_move_cost[m][cl][1]
822 		  || cost <= ira_max_memory_move_cost[m][cl][0])
823 		break;
824 	    }
825 	  if (m >= NUM_MACHINE_MODES)
826 	    continue;
827 	}
828       curr = 0;
829       insert_p = true;
830       COPY_HARD_REG_SET (temp_hard_regset, reg_class_contents[cl]);
831       AND_COMPL_HARD_REG_SET (temp_hard_regset, no_unit_alloc_regs);
832       /* Remove so far added pressure classes which are subset of the
833 	 current candidate class.  Prefer GENERAL_REGS as a pressure
834 	 register class to another class containing the same
835 	 allocatable hard registers.  We do this because machine
836 	 dependent cost hooks might give wrong costs for the latter
837 	 class but always give the right cost for the former class
838 	 (GENERAL_REGS).  */
839       for (i = 0; i < n; i++)
840 	{
841 	  cl2 = pressure_classes[i];
842 	  COPY_HARD_REG_SET (temp_hard_regset2, reg_class_contents[cl2]);
843 	  AND_COMPL_HARD_REG_SET (temp_hard_regset2, no_unit_alloc_regs);
844 	  if (hard_reg_set_subset_p (temp_hard_regset, temp_hard_regset2)
845 	      && (! hard_reg_set_equal_p (temp_hard_regset, temp_hard_regset2)
846 		  || cl2 == (int) GENERAL_REGS))
847 	    {
848 	      pressure_classes[curr++] = (enum reg_class) cl2;
849 	      insert_p = false;
850 	      continue;
851 	    }
852 	  if (hard_reg_set_subset_p (temp_hard_regset2, temp_hard_regset)
853 	      && (! hard_reg_set_equal_p (temp_hard_regset2, temp_hard_regset)
854 		  || cl == (int) GENERAL_REGS))
855 	    continue;
856 	  if (hard_reg_set_equal_p (temp_hard_regset2, temp_hard_regset))
857 	    insert_p = false;
858 	  pressure_classes[curr++] = (enum reg_class) cl2;
859 	}
860       /* If the current candidate is a subset of a so far added
861 	 pressure class, don't add it to the list of the pressure
862 	 classes.  */
863       if (insert_p)
864 	pressure_classes[curr++] = (enum reg_class) cl;
865       n = curr;
866     }
867 #ifdef ENABLE_IRA_CHECKING
868   {
869     HARD_REG_SET ignore_hard_regs;
870 
871     /* Check pressure classes correctness: here we check that hard
872        registers from all register pressure classes contains all hard
873        registers available for the allocation.  */
874     CLEAR_HARD_REG_SET (temp_hard_regset);
875     CLEAR_HARD_REG_SET (temp_hard_regset2);
876     COPY_HARD_REG_SET (ignore_hard_regs, no_unit_alloc_regs);
877     for (cl = 0; cl < LIM_REG_CLASSES; cl++)
878       {
879 	/* For some targets (like MIPS with MD_REGS), there are some
880 	   classes with hard registers available for allocation but
881 	   not able to hold value of any mode.  */
882 	for (m = 0; m < NUM_MACHINE_MODES; m++)
883 	  if (contains_reg_of_mode[cl][m])
884 	    break;
885 	if (m >= NUM_MACHINE_MODES)
886 	  {
887 	    IOR_HARD_REG_SET (ignore_hard_regs, reg_class_contents[cl]);
888 	    continue;
889 	  }
890 	for (i = 0; i < n; i++)
891 	  if ((int) pressure_classes[i] == cl)
892 	    break;
893 	IOR_HARD_REG_SET (temp_hard_regset2, reg_class_contents[cl]);
894 	if (i < n)
895 	  IOR_HARD_REG_SET (temp_hard_regset, reg_class_contents[cl]);
896       }
897     for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
898       /* Some targets (like SPARC with ICC reg) have allocatable regs
899 	 for which no reg class is defined.  */
900       if (REGNO_REG_CLASS (i) == NO_REGS)
901 	SET_HARD_REG_BIT (ignore_hard_regs, i);
902     AND_COMPL_HARD_REG_SET (temp_hard_regset, ignore_hard_regs);
903     AND_COMPL_HARD_REG_SET (temp_hard_regset2, ignore_hard_regs);
904     ira_assert (hard_reg_set_subset_p (temp_hard_regset2, temp_hard_regset));
905   }
906 #endif
907   ira_pressure_classes_num = 0;
908   for (i = 0; i < n; i++)
909     {
910       cl = (int) pressure_classes[i];
911       ira_reg_pressure_class_p[cl] = true;
912       ira_pressure_classes[ira_pressure_classes_num++] = (enum reg_class) cl;
913     }
914   setup_stack_reg_pressure_class ();
915 }
916 
917 /* Set up IRA_UNIFORM_CLASS_P.  Uniform class is a register class
918    whose register move cost between any registers of the class is the
919    same as for all its subclasses.  We use the data to speed up the
920    2nd pass of calculations of allocno costs.  */
921 static void
922 setup_uniform_class_p (void)
923 {
924   int i, cl, cl2, m;
925 
926   for (cl = 0; cl < N_REG_CLASSES; cl++)
927     {
928       ira_uniform_class_p[cl] = false;
929       if (ira_class_hard_regs_num[cl] == 0)
930 	continue;
931       /* We can not use alloc_reg_class_subclasses here because move
932 	 cost hooks does not take into account that some registers are
933 	 unavailable for the subtarget.  E.g. for i686, INT_SSE_REGS
934 	 is element of alloc_reg_class_subclasses for GENERAL_REGS
935 	 because SSE regs are unavailable.  */
936       for (i = 0; (cl2 = reg_class_subclasses[cl][i]) != LIM_REG_CLASSES; i++)
937 	{
938 	  if (ira_class_hard_regs_num[cl2] == 0)
939 	    continue;
940       	  for (m = 0; m < NUM_MACHINE_MODES; m++)
941 	    if (contains_reg_of_mode[cl][m] && contains_reg_of_mode[cl2][m])
942 	      {
943 		ira_init_register_move_cost_if_necessary ((machine_mode) m);
944 		if (ira_register_move_cost[m][cl][cl]
945 		    != ira_register_move_cost[m][cl2][cl2])
946 		  break;
947 	      }
948 	  if (m < NUM_MACHINE_MODES)
949 	    break;
950 	}
951       if (cl2 == LIM_REG_CLASSES)
952 	ira_uniform_class_p[cl] = true;
953     }
954 }
955 
956 /* Set up IRA_ALLOCNO_CLASSES, IRA_ALLOCNO_CLASSES_NUM,
957    IRA_IMPORTANT_CLASSES, and IRA_IMPORTANT_CLASSES_NUM.
958 
959    Target may have many subtargets and not all target hard registers can
960    be used for allocation, e.g. x86 port in 32-bit mode can not use
961    hard registers introduced in x86-64 like r8-r15).  Some classes
962    might have the same allocatable hard registers, e.g.  INDEX_REGS
963    and GENERAL_REGS in x86 port in 32-bit mode.  To decrease different
964    calculations efforts we introduce allocno classes which contain
965    unique non-empty sets of allocatable hard-registers.
966 
967    Pseudo class cost calculation in ira-costs.c is very expensive.
968    Therefore we are trying to decrease number of classes involved in
969    such calculation.  Register classes used in the cost calculation
970    are called important classes.  They are allocno classes and other
971    non-empty classes whose allocatable hard register sets are inside
972    of an allocno class hard register set.  From the first sight, it
973    looks like that they are just allocno classes.  It is not true.  In
974    example of x86-port in 32-bit mode, allocno classes will contain
975    GENERAL_REGS but not LEGACY_REGS (because allocatable hard
976    registers are the same for the both classes).  The important
977    classes will contain GENERAL_REGS and LEGACY_REGS.  It is done
978    because a machine description insn constraint may refers for
979    LEGACY_REGS and code in ira-costs.c is mostly base on investigation
980    of the insn constraints.  */
981 static void
982 setup_allocno_and_important_classes (void)
983 {
984   int i, j, n, cl;
985   bool set_p;
986   HARD_REG_SET temp_hard_regset2;
987   static enum reg_class classes[LIM_REG_CLASSES + 1];
988 
989   n = 0;
990   /* Collect classes which contain unique sets of allocatable hard
991      registers.  Prefer GENERAL_REGS to other classes containing the
992      same set of hard registers.  */
993   for (i = 0; i < LIM_REG_CLASSES; i++)
994     {
995       COPY_HARD_REG_SET (temp_hard_regset, reg_class_contents[i]);
996       AND_COMPL_HARD_REG_SET (temp_hard_regset, no_unit_alloc_regs);
997       for (j = 0; j < n; j++)
998 	{
999 	  cl = classes[j];
1000 	  COPY_HARD_REG_SET (temp_hard_regset2, reg_class_contents[cl]);
1001 	  AND_COMPL_HARD_REG_SET (temp_hard_regset2,
1002 				  no_unit_alloc_regs);
1003 	  if (hard_reg_set_equal_p (temp_hard_regset,
1004 				    temp_hard_regset2))
1005 	    break;
1006 	}
1007       if (j >= n)
1008 	classes[n++] = (enum reg_class) i;
1009       else if (i == GENERAL_REGS)
1010 	/* Prefer general regs.  For i386 example, it means that
1011 	   we prefer GENERAL_REGS over INDEX_REGS or LEGACY_REGS
1012 	   (all of them consists of the same available hard
1013 	   registers).  */
1014 	classes[j] = (enum reg_class) i;
1015     }
1016   classes[n] = LIM_REG_CLASSES;
1017 
1018   /* Set up classes which can be used for allocnos as classes
1019      containing non-empty unique sets of allocatable hard
1020      registers.  */
1021   ira_allocno_classes_num = 0;
1022   for (i = 0; (cl = classes[i]) != LIM_REG_CLASSES; i++)
1023     if (ira_class_hard_regs_num[cl] > 0)
1024       ira_allocno_classes[ira_allocno_classes_num++] = (enum reg_class) cl;
1025   ira_important_classes_num = 0;
1026   /* Add non-allocno classes containing to non-empty set of
1027      allocatable hard regs.  */
1028   for (cl = 0; cl < N_REG_CLASSES; cl++)
1029     if (ira_class_hard_regs_num[cl] > 0)
1030       {
1031 	COPY_HARD_REG_SET (temp_hard_regset, reg_class_contents[cl]);
1032 	AND_COMPL_HARD_REG_SET (temp_hard_regset, no_unit_alloc_regs);
1033 	set_p = false;
1034 	for (j = 0; j < ira_allocno_classes_num; j++)
1035 	  {
1036 	    COPY_HARD_REG_SET (temp_hard_regset2,
1037 			       reg_class_contents[ira_allocno_classes[j]]);
1038 	    AND_COMPL_HARD_REG_SET (temp_hard_regset2, no_unit_alloc_regs);
1039 	    if ((enum reg_class) cl == ira_allocno_classes[j])
1040 	      break;
1041 	    else if (hard_reg_set_subset_p (temp_hard_regset,
1042 					    temp_hard_regset2))
1043 	      set_p = true;
1044 	  }
1045 	if (set_p && j >= ira_allocno_classes_num)
1046 	  ira_important_classes[ira_important_classes_num++]
1047 	    = (enum reg_class) cl;
1048       }
1049   /* Now add allocno classes to the important classes.  */
1050   for (j = 0; j < ira_allocno_classes_num; j++)
1051     ira_important_classes[ira_important_classes_num++]
1052       = ira_allocno_classes[j];
1053   for (cl = 0; cl < N_REG_CLASSES; cl++)
1054     {
1055       ira_reg_allocno_class_p[cl] = false;
1056       ira_reg_pressure_class_p[cl] = false;
1057     }
1058   for (j = 0; j < ira_allocno_classes_num; j++)
1059     ira_reg_allocno_class_p[ira_allocno_classes[j]] = true;
1060   setup_pressure_classes ();
1061   setup_uniform_class_p ();
1062 }
1063 
1064 /* Setup translation in CLASS_TRANSLATE of all classes into a class
1065    given by array CLASSES of length CLASSES_NUM.  The function is used
1066    make translation any reg class to an allocno class or to an
1067    pressure class.  This translation is necessary for some
1068    calculations when we can use only allocno or pressure classes and
1069    such translation represents an approximate representation of all
1070    classes.
1071 
1072    The translation in case when allocatable hard register set of a
1073    given class is subset of allocatable hard register set of a class
1074    in CLASSES is pretty simple.  We use smallest classes from CLASSES
1075    containing a given class.  If allocatable hard register set of a
1076    given class is not a subset of any corresponding set of a class
1077    from CLASSES, we use the cheapest (with load/store point of view)
1078    class from CLASSES whose set intersects with given class set.  */
1079 static void
1080 setup_class_translate_array (enum reg_class *class_translate,
1081 			     int classes_num, enum reg_class *classes)
1082 {
1083   int cl, mode;
1084   enum reg_class aclass, best_class, *cl_ptr;
1085   int i, cost, min_cost, best_cost;
1086 
1087   for (cl = 0; cl < N_REG_CLASSES; cl++)
1088     class_translate[cl] = NO_REGS;
1089 
1090   for (i = 0; i < classes_num; i++)
1091     {
1092       aclass = classes[i];
1093       for (cl_ptr = &alloc_reg_class_subclasses[aclass][0];
1094 	   (cl = *cl_ptr) != LIM_REG_CLASSES;
1095 	   cl_ptr++)
1096 	if (class_translate[cl] == NO_REGS)
1097 	  class_translate[cl] = aclass;
1098       class_translate[aclass] = aclass;
1099     }
1100   /* For classes which are not fully covered by one of given classes
1101      (in other words covered by more one given class), use the
1102      cheapest class.  */
1103   for (cl = 0; cl < N_REG_CLASSES; cl++)
1104     {
1105       if (cl == NO_REGS || class_translate[cl] != NO_REGS)
1106 	continue;
1107       best_class = NO_REGS;
1108       best_cost = INT_MAX;
1109       for (i = 0; i < classes_num; i++)
1110 	{
1111 	  aclass = classes[i];
1112 	  COPY_HARD_REG_SET (temp_hard_regset,
1113 			     reg_class_contents[aclass]);
1114 	  AND_HARD_REG_SET (temp_hard_regset, reg_class_contents[cl]);
1115 	  AND_COMPL_HARD_REG_SET (temp_hard_regset, no_unit_alloc_regs);
1116 	  if (! hard_reg_set_empty_p (temp_hard_regset))
1117 	    {
1118 	      min_cost = INT_MAX;
1119 	      for (mode = 0; mode < MAX_MACHINE_MODE; mode++)
1120 		{
1121 		  cost = (ira_memory_move_cost[mode][aclass][0]
1122 			  + ira_memory_move_cost[mode][aclass][1]);
1123 		  if (min_cost > cost)
1124 		    min_cost = cost;
1125 		}
1126 	      if (best_class == NO_REGS || best_cost > min_cost)
1127 		{
1128 		  best_class = aclass;
1129 		  best_cost = min_cost;
1130 		}
1131 	    }
1132 	}
1133       class_translate[cl] = best_class;
1134     }
1135 }
1136 
1137 /* Set up array IRA_ALLOCNO_CLASS_TRANSLATE and
1138    IRA_PRESSURE_CLASS_TRANSLATE.  */
1139 static void
1140 setup_class_translate (void)
1141 {
1142   setup_class_translate_array (ira_allocno_class_translate,
1143 			       ira_allocno_classes_num, ira_allocno_classes);
1144   setup_class_translate_array (ira_pressure_class_translate,
1145 			       ira_pressure_classes_num, ira_pressure_classes);
1146 }
1147 
1148 /* Order numbers of allocno classes in original target allocno class
1149    array, -1 for non-allocno classes.  */
1150 static int allocno_class_order[N_REG_CLASSES];
1151 
1152 /* The function used to sort the important classes.  */
1153 static int
1154 comp_reg_classes_func (const void *v1p, const void *v2p)
1155 {
1156   enum reg_class cl1 = *(const enum reg_class *) v1p;
1157   enum reg_class cl2 = *(const enum reg_class *) v2p;
1158   enum reg_class tcl1, tcl2;
1159   int diff;
1160 
1161   tcl1 = ira_allocno_class_translate[cl1];
1162   tcl2 = ira_allocno_class_translate[cl2];
1163   if (tcl1 != NO_REGS && tcl2 != NO_REGS
1164       && (diff = allocno_class_order[tcl1] - allocno_class_order[tcl2]) != 0)
1165     return diff;
1166   return (int) cl1 - (int) cl2;
1167 }
1168 
1169 /* For correct work of function setup_reg_class_relation we need to
1170    reorder important classes according to the order of their allocno
1171    classes.  It places important classes containing the same
1172    allocatable hard register set adjacent to each other and allocno
1173    class with the allocatable hard register set right after the other
1174    important classes with the same set.
1175 
1176    In example from comments of function
1177    setup_allocno_and_important_classes, it places LEGACY_REGS and
1178    GENERAL_REGS close to each other and GENERAL_REGS is after
1179    LEGACY_REGS.  */
1180 static void
1181 reorder_important_classes (void)
1182 {
1183   int i;
1184 
1185   for (i = 0; i < N_REG_CLASSES; i++)
1186     allocno_class_order[i] = -1;
1187   for (i = 0; i < ira_allocno_classes_num; i++)
1188     allocno_class_order[ira_allocno_classes[i]] = i;
1189   qsort (ira_important_classes, ira_important_classes_num,
1190 	 sizeof (enum reg_class), comp_reg_classes_func);
1191   for (i = 0; i < ira_important_classes_num; i++)
1192     ira_important_class_nums[ira_important_classes[i]] = i;
1193 }
1194 
1195 /* Set up IRA_REG_CLASS_SUBUNION, IRA_REG_CLASS_SUPERUNION,
1196    IRA_REG_CLASS_SUPER_CLASSES, IRA_REG_CLASSES_INTERSECT, and
1197    IRA_REG_CLASSES_INTERSECT_P.  For the meaning of the relations,
1198    please see corresponding comments in ira-int.h.  */
1199 static void
1200 setup_reg_class_relations (void)
1201 {
1202   int i, cl1, cl2, cl3;
1203   HARD_REG_SET intersection_set, union_set, temp_set2;
1204   bool important_class_p[N_REG_CLASSES];
1205 
1206   memset (important_class_p, 0, sizeof (important_class_p));
1207   for (i = 0; i < ira_important_classes_num; i++)
1208     important_class_p[ira_important_classes[i]] = true;
1209   for (cl1 = 0; cl1 < N_REG_CLASSES; cl1++)
1210     {
1211       ira_reg_class_super_classes[cl1][0] = LIM_REG_CLASSES;
1212       for (cl2 = 0; cl2 < N_REG_CLASSES; cl2++)
1213 	{
1214 	  ira_reg_classes_intersect_p[cl1][cl2] = false;
1215 	  ira_reg_class_intersect[cl1][cl2] = NO_REGS;
1216 	  ira_reg_class_subset[cl1][cl2] = NO_REGS;
1217 	  COPY_HARD_REG_SET (temp_hard_regset, reg_class_contents[cl1]);
1218 	  AND_COMPL_HARD_REG_SET (temp_hard_regset, no_unit_alloc_regs);
1219 	  COPY_HARD_REG_SET (temp_set2, reg_class_contents[cl2]);
1220 	  AND_COMPL_HARD_REG_SET (temp_set2, no_unit_alloc_regs);
1221 	  if (hard_reg_set_empty_p (temp_hard_regset)
1222 	      && hard_reg_set_empty_p (temp_set2))
1223 	    {
1224 	      /* The both classes have no allocatable hard registers
1225 		 -- take all class hard registers into account and use
1226 		 reg_class_subunion and reg_class_superunion.  */
1227 	      for (i = 0;; i++)
1228 		{
1229 		  cl3 = reg_class_subclasses[cl1][i];
1230 		  if (cl3 == LIM_REG_CLASSES)
1231 		    break;
1232 		  if (reg_class_subset_p (ira_reg_class_intersect[cl1][cl2],
1233 					  (enum reg_class) cl3))
1234 		    ira_reg_class_intersect[cl1][cl2] = (enum reg_class) cl3;
1235 		}
1236 	      ira_reg_class_subunion[cl1][cl2] = reg_class_subunion[cl1][cl2];
1237 	      ira_reg_class_superunion[cl1][cl2] = reg_class_superunion[cl1][cl2];
1238 	      continue;
1239 	    }
1240 	  ira_reg_classes_intersect_p[cl1][cl2]
1241 	    = hard_reg_set_intersect_p (temp_hard_regset, temp_set2);
1242 	  if (important_class_p[cl1] && important_class_p[cl2]
1243 	      && hard_reg_set_subset_p (temp_hard_regset, temp_set2))
1244 	    {
1245 	      /* CL1 and CL2 are important classes and CL1 allocatable
1246 		 hard register set is inside of CL2 allocatable hard
1247 		 registers -- make CL1 a superset of CL2.  */
1248 	      enum reg_class *p;
1249 
1250 	      p = &ira_reg_class_super_classes[cl1][0];
1251 	      while (*p != LIM_REG_CLASSES)
1252 		p++;
1253 	      *p++ = (enum reg_class) cl2;
1254 	      *p = LIM_REG_CLASSES;
1255 	    }
1256 	  ira_reg_class_subunion[cl1][cl2] = NO_REGS;
1257 	  ira_reg_class_superunion[cl1][cl2] = NO_REGS;
1258 	  COPY_HARD_REG_SET (intersection_set, reg_class_contents[cl1]);
1259 	  AND_HARD_REG_SET (intersection_set, reg_class_contents[cl2]);
1260 	  AND_COMPL_HARD_REG_SET (intersection_set, no_unit_alloc_regs);
1261 	  COPY_HARD_REG_SET (union_set, reg_class_contents[cl1]);
1262 	  IOR_HARD_REG_SET (union_set, reg_class_contents[cl2]);
1263 	  AND_COMPL_HARD_REG_SET (union_set, no_unit_alloc_regs);
1264 	  for (cl3 = 0; cl3 < N_REG_CLASSES; cl3++)
1265 	    {
1266 	      COPY_HARD_REG_SET (temp_hard_regset, reg_class_contents[cl3]);
1267 	      AND_COMPL_HARD_REG_SET (temp_hard_regset, no_unit_alloc_regs);
1268 	      if (hard_reg_set_subset_p (temp_hard_regset, intersection_set))
1269 		{
1270 		  /* CL3 allocatable hard register set is inside of
1271 		     intersection of allocatable hard register sets
1272 		     of CL1 and CL2.  */
1273 		  if (important_class_p[cl3])
1274 		    {
1275 		      COPY_HARD_REG_SET
1276 			(temp_set2,
1277 			 reg_class_contents
1278 			 [(int) ira_reg_class_intersect[cl1][cl2]]);
1279 		      AND_COMPL_HARD_REG_SET (temp_set2, no_unit_alloc_regs);
1280 		      if (! hard_reg_set_subset_p (temp_hard_regset, temp_set2)
1281 			  /* If the allocatable hard register sets are
1282 			     the same, prefer GENERAL_REGS or the
1283 			     smallest class for debugging
1284 			     purposes.  */
1285 			  || (hard_reg_set_equal_p (temp_hard_regset, temp_set2)
1286 			      && (cl3 == GENERAL_REGS
1287 				  || ((ira_reg_class_intersect[cl1][cl2]
1288 				       != GENERAL_REGS)
1289 				      && hard_reg_set_subset_p
1290 				         (reg_class_contents[cl3],
1291 					  reg_class_contents
1292 					  [(int)
1293 					   ira_reg_class_intersect[cl1][cl2]])))))
1294 			ira_reg_class_intersect[cl1][cl2] = (enum reg_class) cl3;
1295 		    }
1296 		  COPY_HARD_REG_SET
1297 		    (temp_set2,
1298 		     reg_class_contents[(int) ira_reg_class_subset[cl1][cl2]]);
1299 		  AND_COMPL_HARD_REG_SET (temp_set2, no_unit_alloc_regs);
1300 		  if (! hard_reg_set_subset_p (temp_hard_regset, temp_set2)
1301 		      /* Ignore unavailable hard registers and prefer
1302 			 smallest class for debugging purposes.  */
1303 		      || (hard_reg_set_equal_p (temp_hard_regset, temp_set2)
1304 			  && hard_reg_set_subset_p
1305 			     (reg_class_contents[cl3],
1306 			      reg_class_contents
1307 			      [(int) ira_reg_class_subset[cl1][cl2]])))
1308 		    ira_reg_class_subset[cl1][cl2] = (enum reg_class) cl3;
1309 		}
1310 	      if (important_class_p[cl3]
1311 		  && hard_reg_set_subset_p (temp_hard_regset, union_set))
1312 		{
1313 		  /* CL3 allocatable hard register set is inside of
1314 		     union of allocatable hard register sets of CL1
1315 		     and CL2.  */
1316 		  COPY_HARD_REG_SET
1317 		    (temp_set2,
1318 		     reg_class_contents[(int) ira_reg_class_subunion[cl1][cl2]]);
1319 		  AND_COMPL_HARD_REG_SET (temp_set2, no_unit_alloc_regs);
1320 	 	  if (ira_reg_class_subunion[cl1][cl2] == NO_REGS
1321 		      || (hard_reg_set_subset_p (temp_set2, temp_hard_regset)
1322 
1323 			  && (! hard_reg_set_equal_p (temp_set2,
1324 						      temp_hard_regset)
1325 			      || cl3 == GENERAL_REGS
1326 			      /* If the allocatable hard register sets are the
1327 				 same, prefer GENERAL_REGS or the smallest
1328 				 class for debugging purposes.  */
1329 			      || (ira_reg_class_subunion[cl1][cl2] != GENERAL_REGS
1330 				  && hard_reg_set_subset_p
1331 				     (reg_class_contents[cl3],
1332 				      reg_class_contents
1333 				      [(int) ira_reg_class_subunion[cl1][cl2]])))))
1334 		    ira_reg_class_subunion[cl1][cl2] = (enum reg_class) cl3;
1335 		}
1336 	      if (hard_reg_set_subset_p (union_set, temp_hard_regset))
1337 		{
1338 		  /* CL3 allocatable hard register set contains union
1339 		     of allocatable hard register sets of CL1 and
1340 		     CL2.  */
1341 		  COPY_HARD_REG_SET
1342 		    (temp_set2,
1343 		     reg_class_contents[(int) ira_reg_class_superunion[cl1][cl2]]);
1344 		  AND_COMPL_HARD_REG_SET (temp_set2, no_unit_alloc_regs);
1345 	 	  if (ira_reg_class_superunion[cl1][cl2] == NO_REGS
1346 		      || (hard_reg_set_subset_p (temp_hard_regset, temp_set2)
1347 
1348 			  && (! hard_reg_set_equal_p (temp_set2,
1349 						      temp_hard_regset)
1350 			      || cl3 == GENERAL_REGS
1351 			      /* If the allocatable hard register sets are the
1352 				 same, prefer GENERAL_REGS or the smallest
1353 				 class for debugging purposes.  */
1354 			      || (ira_reg_class_superunion[cl1][cl2] != GENERAL_REGS
1355 				  && hard_reg_set_subset_p
1356 				     (reg_class_contents[cl3],
1357 				      reg_class_contents
1358 				      [(int) ira_reg_class_superunion[cl1][cl2]])))))
1359 		    ira_reg_class_superunion[cl1][cl2] = (enum reg_class) cl3;
1360 		}
1361 	    }
1362 	}
1363     }
1364 }
1365 
1366 /* Output all uniform and important classes into file F.  */
1367 static void
1368 print_uniform_and_important_classes (FILE *f)
1369 {
1370   int i, cl;
1371 
1372   fprintf (f, "Uniform classes:\n");
1373   for (cl = 0; cl < N_REG_CLASSES; cl++)
1374     if (ira_uniform_class_p[cl])
1375       fprintf (f, " %s", reg_class_names[cl]);
1376   fprintf (f, "\nImportant classes:\n");
1377   for (i = 0; i < ira_important_classes_num; i++)
1378     fprintf (f, " %s", reg_class_names[ira_important_classes[i]]);
1379   fprintf (f, "\n");
1380 }
1381 
1382 /* Output all possible allocno or pressure classes and their
1383    translation map into file F.  */
1384 static void
1385 print_translated_classes (FILE *f, bool pressure_p)
1386 {
1387   int classes_num = (pressure_p
1388 		     ? ira_pressure_classes_num : ira_allocno_classes_num);
1389   enum reg_class *classes = (pressure_p
1390 			     ? ira_pressure_classes : ira_allocno_classes);
1391   enum reg_class *class_translate = (pressure_p
1392 				     ? ira_pressure_class_translate
1393 				     : ira_allocno_class_translate);
1394   int i;
1395 
1396   fprintf (f, "%s classes:\n", pressure_p ? "Pressure" : "Allocno");
1397   for (i = 0; i < classes_num; i++)
1398     fprintf (f, " %s", reg_class_names[classes[i]]);
1399   fprintf (f, "\nClass translation:\n");
1400   for (i = 0; i < N_REG_CLASSES; i++)
1401     fprintf (f, " %s -> %s\n", reg_class_names[i],
1402 	     reg_class_names[class_translate[i]]);
1403 }
1404 
1405 /* Output all possible allocno and translation classes and the
1406    translation maps into stderr.  */
1407 void
1408 ira_debug_allocno_classes (void)
1409 {
1410   print_uniform_and_important_classes (stderr);
1411   print_translated_classes (stderr, false);
1412   print_translated_classes (stderr, true);
1413 }
1414 
1415 /* Set up different arrays concerning class subsets, allocno and
1416    important classes.  */
1417 static void
1418 find_reg_classes (void)
1419 {
1420   setup_allocno_and_important_classes ();
1421   setup_class_translate ();
1422   reorder_important_classes ();
1423   setup_reg_class_relations ();
1424 }
1425 
1426 
1427 
1428 /* Set up the array above.  */
1429 static void
1430 setup_hard_regno_aclass (void)
1431 {
1432   int i;
1433 
1434   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1435     {
1436 #if 1
1437       ira_hard_regno_allocno_class[i]
1438 	= (TEST_HARD_REG_BIT (no_unit_alloc_regs, i)
1439 	   ? NO_REGS
1440 	   : ira_allocno_class_translate[REGNO_REG_CLASS (i)]);
1441 #else
1442       int j;
1443       enum reg_class cl;
1444       ira_hard_regno_allocno_class[i] = NO_REGS;
1445       for (j = 0; j < ira_allocno_classes_num; j++)
1446  	{
1447 	  cl = ira_allocno_classes[j];
1448  	  if (ira_class_hard_reg_index[cl][i] >= 0)
1449  	    {
1450 	      ira_hard_regno_allocno_class[i] = cl;
1451  	      break;
1452  	    }
1453  	}
1454 #endif
1455     }
1456 }
1457 
1458 
1459 
1460 /* Form IRA_REG_CLASS_MAX_NREGS and IRA_REG_CLASS_MIN_NREGS maps.  */
1461 static void
1462 setup_reg_class_nregs (void)
1463 {
1464   int i, cl, cl2, m;
1465 
1466   for (m = 0; m < MAX_MACHINE_MODE; m++)
1467     {
1468       for (cl = 0; cl < N_REG_CLASSES; cl++)
1469 	ira_reg_class_max_nregs[cl][m]
1470 	  = ira_reg_class_min_nregs[cl][m]
1471 	  = targetm.class_max_nregs ((reg_class_t) cl, (machine_mode) m);
1472       for (cl = 0; cl < N_REG_CLASSES; cl++)
1473 	for (i = 0;
1474 	     (cl2 = alloc_reg_class_subclasses[cl][i]) != LIM_REG_CLASSES;
1475 	     i++)
1476 	  if (ira_reg_class_min_nregs[cl2][m]
1477 	      < ira_reg_class_min_nregs[cl][m])
1478 	    ira_reg_class_min_nregs[cl][m] = ira_reg_class_min_nregs[cl2][m];
1479     }
1480 }
1481 
1482 
1483 
1484 /* Set up IRA_PROHIBITED_CLASS_MODE_REGS and IRA_CLASS_SINGLETON.
1485    This function is called once IRA_CLASS_HARD_REGS has been initialized.  */
1486 static void
1487 setup_prohibited_class_mode_regs (void)
1488 {
1489   int j, k, hard_regno, cl, last_hard_regno, count;
1490 
1491   for (cl = (int) N_REG_CLASSES - 1; cl >= 0; cl--)
1492     {
1493       COPY_HARD_REG_SET (temp_hard_regset, reg_class_contents[cl]);
1494       AND_COMPL_HARD_REG_SET (temp_hard_regset, no_unit_alloc_regs);
1495       for (j = 0; j < NUM_MACHINE_MODES; j++)
1496 	{
1497 	  count = 0;
1498 	  last_hard_regno = -1;
1499 	  CLEAR_HARD_REG_SET (ira_prohibited_class_mode_regs[cl][j]);
1500 	  for (k = ira_class_hard_regs_num[cl] - 1; k >= 0; k--)
1501 	    {
1502 	      hard_regno = ira_class_hard_regs[cl][k];
1503 	      if (! HARD_REGNO_MODE_OK (hard_regno, (machine_mode) j))
1504 		SET_HARD_REG_BIT (ira_prohibited_class_mode_regs[cl][j],
1505 				  hard_regno);
1506 	      else if (in_hard_reg_set_p (temp_hard_regset,
1507 					  (machine_mode) j, hard_regno))
1508 		{
1509 		  last_hard_regno = hard_regno;
1510 		  count++;
1511 		}
1512 	    }
1513 	  ira_class_singleton[cl][j] = (count == 1 ? last_hard_regno : -1);
1514 	}
1515     }
1516 }
1517 
1518 /* Clarify IRA_PROHIBITED_CLASS_MODE_REGS by excluding hard registers
1519    spanning from one register pressure class to another one.  It is
1520    called after defining the pressure classes.  */
1521 static void
1522 clarify_prohibited_class_mode_regs (void)
1523 {
1524   int j, k, hard_regno, cl, pclass, nregs;
1525 
1526   for (cl = (int) N_REG_CLASSES - 1; cl >= 0; cl--)
1527     for (j = 0; j < NUM_MACHINE_MODES; j++)
1528       {
1529 	CLEAR_HARD_REG_SET (ira_useful_class_mode_regs[cl][j]);
1530 	for (k = ira_class_hard_regs_num[cl] - 1; k >= 0; k--)
1531 	  {
1532 	    hard_regno = ira_class_hard_regs[cl][k];
1533 	    if (TEST_HARD_REG_BIT (ira_prohibited_class_mode_regs[cl][j], hard_regno))
1534 	      continue;
1535 	    nregs = hard_regno_nregs[hard_regno][j];
1536 	    if (hard_regno + nregs > FIRST_PSEUDO_REGISTER)
1537 	      {
1538 		SET_HARD_REG_BIT (ira_prohibited_class_mode_regs[cl][j],
1539 				  hard_regno);
1540 		 continue;
1541 	      }
1542 	    pclass = ira_pressure_class_translate[REGNO_REG_CLASS (hard_regno)];
1543 	    for (nregs-- ;nregs >= 0; nregs--)
1544 	      if (((enum reg_class) pclass
1545 		   != ira_pressure_class_translate[REGNO_REG_CLASS
1546 						   (hard_regno + nregs)]))
1547 		{
1548 		  SET_HARD_REG_BIT (ira_prohibited_class_mode_regs[cl][j],
1549 				    hard_regno);
1550 		  break;
1551 		}
1552 	    if (!TEST_HARD_REG_BIT (ira_prohibited_class_mode_regs[cl][j],
1553 				    hard_regno))
1554 	      add_to_hard_reg_set (&ira_useful_class_mode_regs[cl][j],
1555 				   (machine_mode) j, hard_regno);
1556 	  }
1557       }
1558 }
1559 
1560 /* Allocate and initialize IRA_REGISTER_MOVE_COST, IRA_MAY_MOVE_IN_COST
1561    and IRA_MAY_MOVE_OUT_COST for MODE.  */
1562 void
1563 ira_init_register_move_cost (machine_mode mode)
1564 {
1565   static unsigned short last_move_cost[N_REG_CLASSES][N_REG_CLASSES];
1566   bool all_match = true;
1567   unsigned int cl1, cl2;
1568 
1569   ira_assert (ira_register_move_cost[mode] == NULL
1570 	      && ira_may_move_in_cost[mode] == NULL
1571 	      && ira_may_move_out_cost[mode] == NULL);
1572   ira_assert (have_regs_of_mode[mode]);
1573   for (cl1 = 0; cl1 < N_REG_CLASSES; cl1++)
1574     for (cl2 = 0; cl2 < N_REG_CLASSES; cl2++)
1575       {
1576 	int cost;
1577 	if (!contains_reg_of_mode[cl1][mode]
1578 	    || !contains_reg_of_mode[cl2][mode])
1579 	  {
1580 	    if ((ira_reg_class_max_nregs[cl1][mode]
1581 		 > ira_class_hard_regs_num[cl1])
1582 		|| (ira_reg_class_max_nregs[cl2][mode]
1583 		    > ira_class_hard_regs_num[cl2]))
1584 	      cost = 65535;
1585 	    else
1586 	      cost = (ira_memory_move_cost[mode][cl1][0]
1587 		      + ira_memory_move_cost[mode][cl2][1]) * 2;
1588 	  }
1589 	else
1590 	  {
1591 	    cost = register_move_cost (mode, (enum reg_class) cl1,
1592 				       (enum reg_class) cl2);
1593 	    ira_assert (cost < 65535);
1594 	  }
1595 	all_match &= (last_move_cost[cl1][cl2] == cost);
1596 	last_move_cost[cl1][cl2] = cost;
1597       }
1598   if (all_match && last_mode_for_init_move_cost != -1)
1599     {
1600       ira_register_move_cost[mode]
1601 	= ira_register_move_cost[last_mode_for_init_move_cost];
1602       ira_may_move_in_cost[mode]
1603 	= ira_may_move_in_cost[last_mode_for_init_move_cost];
1604       ira_may_move_out_cost[mode]
1605 	= ira_may_move_out_cost[last_mode_for_init_move_cost];
1606       return;
1607     }
1608   last_mode_for_init_move_cost = mode;
1609   ira_register_move_cost[mode] = XNEWVEC (move_table, N_REG_CLASSES);
1610   ira_may_move_in_cost[mode] = XNEWVEC (move_table, N_REG_CLASSES);
1611   ira_may_move_out_cost[mode] = XNEWVEC (move_table, N_REG_CLASSES);
1612   for (cl1 = 0; cl1 < N_REG_CLASSES; cl1++)
1613     for (cl2 = 0; cl2 < N_REG_CLASSES; cl2++)
1614       {
1615 	int cost;
1616 	enum reg_class *p1, *p2;
1617 
1618 	if (last_move_cost[cl1][cl2] == 65535)
1619 	  {
1620 	    ira_register_move_cost[mode][cl1][cl2] = 65535;
1621 	    ira_may_move_in_cost[mode][cl1][cl2] = 65535;
1622 	    ira_may_move_out_cost[mode][cl1][cl2] = 65535;
1623 	  }
1624 	else
1625 	  {
1626 	    cost = last_move_cost[cl1][cl2];
1627 
1628 	    for (p2 = &reg_class_subclasses[cl2][0];
1629 		 *p2 != LIM_REG_CLASSES; p2++)
1630 	      if (ira_class_hard_regs_num[*p2] > 0
1631 		  && (ira_reg_class_max_nregs[*p2][mode]
1632 		      <= ira_class_hard_regs_num[*p2]))
1633 		cost = MAX (cost, ira_register_move_cost[mode][cl1][*p2]);
1634 
1635 	    for (p1 = &reg_class_subclasses[cl1][0];
1636 		 *p1 != LIM_REG_CLASSES; p1++)
1637 	      if (ira_class_hard_regs_num[*p1] > 0
1638 		  && (ira_reg_class_max_nregs[*p1][mode]
1639 		      <= ira_class_hard_regs_num[*p1]))
1640 		cost = MAX (cost, ira_register_move_cost[mode][*p1][cl2]);
1641 
1642 	    ira_assert (cost <= 65535);
1643 	    ira_register_move_cost[mode][cl1][cl2] = cost;
1644 
1645 	    if (ira_class_subset_p[cl1][cl2])
1646 	      ira_may_move_in_cost[mode][cl1][cl2] = 0;
1647 	    else
1648 	      ira_may_move_in_cost[mode][cl1][cl2] = cost;
1649 
1650 	    if (ira_class_subset_p[cl2][cl1])
1651 	      ira_may_move_out_cost[mode][cl1][cl2] = 0;
1652 	    else
1653 	      ira_may_move_out_cost[mode][cl1][cl2] = cost;
1654 	  }
1655       }
1656 }
1657 
1658 
1659 
1660 /* This is called once during compiler work.  It sets up
1661    different arrays whose values don't depend on the compiled
1662    function.  */
1663 void
1664 ira_init_once (void)
1665 {
1666   ira_init_costs_once ();
1667   lra_init_once ();
1668 }
1669 
1670 /* Free ira_max_register_move_cost, ira_may_move_in_cost and
1671    ira_may_move_out_cost for each mode.  */
1672 void
1673 target_ira_int::free_register_move_costs (void)
1674 {
1675   int mode, i;
1676 
1677   /* Reset move_cost and friends, making sure we only free shared
1678      table entries once.  */
1679   for (mode = 0; mode < MAX_MACHINE_MODE; mode++)
1680     if (x_ira_register_move_cost[mode])
1681       {
1682 	for (i = 0;
1683 	     i < mode && (x_ira_register_move_cost[i]
1684 			  != x_ira_register_move_cost[mode]);
1685 	     i++)
1686 	  ;
1687 	if (i == mode)
1688 	  {
1689 	    free (x_ira_register_move_cost[mode]);
1690 	    free (x_ira_may_move_in_cost[mode]);
1691 	    free (x_ira_may_move_out_cost[mode]);
1692 	  }
1693       }
1694   memset (x_ira_register_move_cost, 0, sizeof x_ira_register_move_cost);
1695   memset (x_ira_may_move_in_cost, 0, sizeof x_ira_may_move_in_cost);
1696   memset (x_ira_may_move_out_cost, 0, sizeof x_ira_may_move_out_cost);
1697   last_mode_for_init_move_cost = -1;
1698 }
1699 
1700 target_ira_int::~target_ira_int ()
1701 {
1702   free_ira_costs ();
1703   free_register_move_costs ();
1704 }
1705 
1706 /* This is called every time when register related information is
1707    changed.  */
1708 void
1709 ira_init (void)
1710 {
1711   this_target_ira_int->free_register_move_costs ();
1712   setup_reg_mode_hard_regset ();
1713   setup_alloc_regs (flag_omit_frame_pointer != 0);
1714   setup_class_subset_and_memory_move_costs ();
1715   setup_reg_class_nregs ();
1716   setup_prohibited_class_mode_regs ();
1717   find_reg_classes ();
1718   clarify_prohibited_class_mode_regs ();
1719   setup_hard_regno_aclass ();
1720   ira_init_costs ();
1721 }
1722 
1723 
1724 #define ira_prohibited_mode_move_regs_initialized_p \
1725   (this_target_ira_int->x_ira_prohibited_mode_move_regs_initialized_p)
1726 
1727 /* Set up IRA_PROHIBITED_MODE_MOVE_REGS.  */
1728 static void
1729 setup_prohibited_mode_move_regs (void)
1730 {
1731   int i, j;
1732   rtx test_reg1, test_reg2, move_pat;
1733   rtx_insn *move_insn;
1734 
1735   if (ira_prohibited_mode_move_regs_initialized_p)
1736     return;
1737   ira_prohibited_mode_move_regs_initialized_p = true;
1738   test_reg1 = gen_rtx_REG (word_mode, LAST_VIRTUAL_REGISTER + 1);
1739   test_reg2 = gen_rtx_REG (word_mode, LAST_VIRTUAL_REGISTER + 2);
1740   move_pat = gen_rtx_SET (test_reg1, test_reg2);
1741   move_insn = gen_rtx_INSN (VOIDmode, 0, 0, 0, move_pat, 0, -1, 0);
1742   for (i = 0; i < NUM_MACHINE_MODES; i++)
1743     {
1744       SET_HARD_REG_SET (ira_prohibited_mode_move_regs[i]);
1745       for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)
1746 	{
1747 	  if (! HARD_REGNO_MODE_OK (j, (machine_mode) i))
1748 	    continue;
1749 	  set_mode_and_regno (test_reg1, (machine_mode) i, j);
1750 	  set_mode_and_regno (test_reg2, (machine_mode) i, j);
1751 	  INSN_CODE (move_insn) = -1;
1752 	  recog_memoized (move_insn);
1753 	  if (INSN_CODE (move_insn) < 0)
1754 	    continue;
1755 	  extract_insn (move_insn);
1756 	  /* We don't know whether the move will be in code that is optimized
1757 	     for size or speed, so consider all enabled alternatives.  */
1758 	  if (! constrain_operands (1, get_enabled_alternatives (move_insn)))
1759 	    continue;
1760 	  CLEAR_HARD_REG_BIT (ira_prohibited_mode_move_regs[i], j);
1761 	}
1762     }
1763 }
1764 
1765 
1766 
1767 /* Setup possible alternatives in ALTS for INSN.  */
1768 void
1769 ira_setup_alts (rtx_insn *insn, HARD_REG_SET &alts)
1770 {
1771   /* MAP nalt * nop -> start of constraints for given operand and
1772      alternative.  */
1773   static vec<const char *> insn_constraints;
1774   int nop, nalt;
1775   bool curr_swapped;
1776   const char *p;
1777   int commutative = -1;
1778 
1779   extract_insn (insn);
1780   alternative_mask preferred = get_preferred_alternatives (insn);
1781   CLEAR_HARD_REG_SET (alts);
1782   insn_constraints.release ();
1783   insn_constraints.safe_grow_cleared (recog_data.n_operands
1784 				      * recog_data.n_alternatives + 1);
1785   /* Check that the hard reg set is enough for holding all
1786      alternatives.  It is hard to imagine the situation when the
1787      assertion is wrong.  */
1788   ira_assert (recog_data.n_alternatives
1789 	      <= (int) MAX (sizeof (HARD_REG_ELT_TYPE) * CHAR_BIT,
1790 			    FIRST_PSEUDO_REGISTER));
1791   for (curr_swapped = false;; curr_swapped = true)
1792     {
1793       /* Calculate some data common for all alternatives to speed up the
1794 	 function.  */
1795       for (nop = 0; nop < recog_data.n_operands; nop++)
1796 	{
1797 	  for (nalt = 0, p = recog_data.constraints[nop];
1798 	       nalt < recog_data.n_alternatives;
1799 	       nalt++)
1800 	    {
1801 	      insn_constraints[nop * recog_data.n_alternatives + nalt] = p;
1802 	      while (*p && *p != ',')
1803 		{
1804 		  /* We only support one commutative marker, the first
1805 		     one.  We already set commutative above.  */
1806 		  if (*p == '%' && commutative < 0)
1807 		    commutative = nop;
1808 		  p++;
1809 		}
1810 	      if (*p)
1811 		p++;
1812 	    }
1813 	}
1814       for (nalt = 0; nalt < recog_data.n_alternatives; nalt++)
1815 	{
1816 	  if (!TEST_BIT (preferred, nalt)
1817 	      || TEST_HARD_REG_BIT (alts, nalt))
1818 	    continue;
1819 
1820 	  for (nop = 0; nop < recog_data.n_operands; nop++)
1821 	    {
1822 	      int c, len;
1823 
1824 	      rtx op = recog_data.operand[nop];
1825 	      p = insn_constraints[nop * recog_data.n_alternatives + nalt];
1826 	      if (*p == 0 || *p == ',')
1827 		continue;
1828 
1829 	      do
1830 		switch (c = *p, len = CONSTRAINT_LEN (c, p), c)
1831 		  {
1832 		  case '#':
1833 		  case ',':
1834 		    c = '\0';
1835 		  case '\0':
1836 		    len = 0;
1837 		    break;
1838 
1839 		  case '%':
1840 		    /* The commutative modifier is handled above.  */
1841 		    break;
1842 
1843 		  case '0':  case '1':  case '2':  case '3':  case '4':
1844 		  case '5':  case '6':  case '7':  case '8':  case '9':
1845 		    goto op_success;
1846 		    break;
1847 
1848 		  case 'g':
1849 		    goto op_success;
1850 		    break;
1851 
1852 		  default:
1853 		    {
1854 		      enum constraint_num cn = lookup_constraint (p);
1855 		      switch (get_constraint_type (cn))
1856 			{
1857 			case CT_REGISTER:
1858 			  if (reg_class_for_constraint (cn) != NO_REGS)
1859 			    goto op_success;
1860 			  break;
1861 
1862 			case CT_CONST_INT:
1863 			  if (CONST_INT_P (op)
1864 			      && (insn_const_int_ok_for_constraint
1865 				  (INTVAL (op), cn)))
1866 			    goto op_success;
1867 			  break;
1868 
1869 			case CT_ADDRESS:
1870 			case CT_MEMORY:
1871 			case CT_SPECIAL_MEMORY:
1872 			  goto op_success;
1873 
1874 			case CT_FIXED_FORM:
1875 			  if (constraint_satisfied_p (op, cn))
1876 			    goto op_success;
1877 			  break;
1878 			}
1879 		      break;
1880 		    }
1881 		  }
1882 	      while (p += len, c);
1883 	      break;
1884 	    op_success:
1885 	      ;
1886 	    }
1887 	  if (nop >= recog_data.n_operands)
1888 	    SET_HARD_REG_BIT (alts, nalt);
1889 	}
1890       if (commutative < 0)
1891 	break;
1892       /* Swap forth and back to avoid changing recog_data.  */
1893       std::swap (recog_data.operand[commutative],
1894 		 recog_data.operand[commutative + 1]);
1895       if (curr_swapped)
1896 	break;
1897     }
1898 }
1899 
1900 /* Return the number of the output non-early clobber operand which
1901    should be the same in any case as operand with number OP_NUM (or
1902    negative value if there is no such operand).  The function takes
1903    only really possible alternatives into consideration.  */
1904 int
1905 ira_get_dup_out_num (int op_num, HARD_REG_SET &alts)
1906 {
1907   int curr_alt, c, original, dup;
1908   bool ignore_p, use_commut_op_p;
1909   const char *str;
1910 
1911   if (op_num < 0 || recog_data.n_alternatives == 0)
1912     return -1;
1913   /* We should find duplications only for input operands.  */
1914   if (recog_data.operand_type[op_num] != OP_IN)
1915     return -1;
1916   str = recog_data.constraints[op_num];
1917   use_commut_op_p = false;
1918   for (;;)
1919     {
1920       rtx op = recog_data.operand[op_num];
1921 
1922       for (curr_alt = 0, ignore_p = !TEST_HARD_REG_BIT (alts, curr_alt),
1923 	   original = -1;;)
1924 	{
1925 	  c = *str;
1926 	  if (c == '\0')
1927 	    break;
1928 	  if (c == '#')
1929 	    ignore_p = true;
1930 	  else if (c == ',')
1931 	    {
1932 	      curr_alt++;
1933 	      ignore_p = !TEST_HARD_REG_BIT (alts, curr_alt);
1934 	    }
1935 	  else if (! ignore_p)
1936 	    switch (c)
1937 	      {
1938 	      case 'g':
1939 		goto fail;
1940 	      default:
1941 		{
1942 		  enum constraint_num cn = lookup_constraint (str);
1943 		  enum reg_class cl = reg_class_for_constraint (cn);
1944 		  if (cl != NO_REGS
1945 		      && !targetm.class_likely_spilled_p (cl))
1946 		    goto fail;
1947 		  if (constraint_satisfied_p (op, cn))
1948 		    goto fail;
1949 		  break;
1950 		}
1951 
1952 	      case '0': case '1': case '2': case '3': case '4':
1953 	      case '5': case '6': case '7': case '8': case '9':
1954 		if (original != -1 && original != c)
1955 		  goto fail;
1956 		original = c;
1957 		break;
1958 	      }
1959 	  str += CONSTRAINT_LEN (c, str);
1960 	}
1961       if (original == -1)
1962 	goto fail;
1963       dup = -1;
1964       for (ignore_p = false, str = recog_data.constraints[original - '0'];
1965 	   *str != 0;
1966 	   str++)
1967 	if (ignore_p)
1968 	  {
1969 	    if (*str == ',')
1970 	      ignore_p = false;
1971 	  }
1972 	else if (*str == '#')
1973 	  ignore_p = true;
1974 	else if (! ignore_p)
1975 	  {
1976 	    if (*str == '=')
1977 	      dup = original - '0';
1978 	    /* It is better ignore an alternative with early clobber.  */
1979 	    else if (*str == '&')
1980 	      goto fail;
1981 	  }
1982       if (dup >= 0)
1983 	return dup;
1984     fail:
1985       if (use_commut_op_p)
1986 	break;
1987       use_commut_op_p = true;
1988       if (recog_data.constraints[op_num][0] == '%')
1989 	str = recog_data.constraints[op_num + 1];
1990       else if (op_num > 0 && recog_data.constraints[op_num - 1][0] == '%')
1991 	str = recog_data.constraints[op_num - 1];
1992       else
1993 	break;
1994     }
1995   return -1;
1996 }
1997 
1998 
1999 
2000 /* Search forward to see if the source register of a copy insn dies
2001    before either it or the destination register is modified, but don't
2002    scan past the end of the basic block.  If so, we can replace the
2003    source with the destination and let the source die in the copy
2004    insn.
2005 
2006    This will reduce the number of registers live in that range and may
2007    enable the destination and the source coalescing, thus often saving
2008    one register in addition to a register-register copy.  */
2009 
2010 static void
2011 decrease_live_ranges_number (void)
2012 {
2013   basic_block bb;
2014   rtx_insn *insn;
2015   rtx set, src, dest, dest_death, note;
2016   rtx_insn *p, *q;
2017   int sregno, dregno;
2018 
2019   if (! flag_expensive_optimizations)
2020     return;
2021 
2022   if (ira_dump_file)
2023     fprintf (ira_dump_file, "Starting decreasing number of live ranges...\n");
2024 
2025   FOR_EACH_BB_FN (bb, cfun)
2026     FOR_BB_INSNS (bb, insn)
2027       {
2028 	set = single_set (insn);
2029 	if (! set)
2030 	  continue;
2031 	src = SET_SRC (set);
2032 	dest = SET_DEST (set);
2033 	if (! REG_P (src) || ! REG_P (dest)
2034 	    || find_reg_note (insn, REG_DEAD, src))
2035 	  continue;
2036 	sregno = REGNO (src);
2037 	dregno = REGNO (dest);
2038 
2039 	/* We don't want to mess with hard regs if register classes
2040 	   are small.  */
2041 	if (sregno == dregno
2042 	    || (targetm.small_register_classes_for_mode_p (GET_MODE (src))
2043 		&& (sregno < FIRST_PSEUDO_REGISTER
2044 		    || dregno < FIRST_PSEUDO_REGISTER))
2045 	    /* We don't see all updates to SP if they are in an
2046 	       auto-inc memory reference, so we must disallow this
2047 	       optimization on them.  */
2048 	    || sregno == STACK_POINTER_REGNUM
2049 	    || dregno == STACK_POINTER_REGNUM)
2050 	  continue;
2051 
2052 	dest_death = NULL_RTX;
2053 
2054 	for (p = NEXT_INSN (insn); p; p = NEXT_INSN (p))
2055 	  {
2056 	    if (! INSN_P (p))
2057 	      continue;
2058 	    if (BLOCK_FOR_INSN (p) != bb)
2059 	      break;
2060 
2061 	    if (reg_set_p (src, p) || reg_set_p (dest, p)
2062 		/* If SRC is an asm-declared register, it must not be
2063 		   replaced in any asm.  Unfortunately, the REG_EXPR
2064 		   tree for the asm variable may be absent in the SRC
2065 		   rtx, so we can't check the actual register
2066 		   declaration easily (the asm operand will have it,
2067 		   though).  To avoid complicating the test for a rare
2068 		   case, we just don't perform register replacement
2069 		   for a hard reg mentioned in an asm.  */
2070 		|| (sregno < FIRST_PSEUDO_REGISTER
2071 		    && asm_noperands (PATTERN (p)) >= 0
2072 		    && reg_overlap_mentioned_p (src, PATTERN (p)))
2073 		/* Don't change hard registers used by a call.  */
2074 		|| (CALL_P (p) && sregno < FIRST_PSEUDO_REGISTER
2075 		    && find_reg_fusage (p, USE, src))
2076 		/* Don't change a USE of a register.  */
2077 		|| (GET_CODE (PATTERN (p)) == USE
2078 		    && reg_overlap_mentioned_p (src, XEXP (PATTERN (p), 0))))
2079 	      break;
2080 
2081 	    /* See if all of SRC dies in P.  This test is slightly
2082 	       more conservative than it needs to be.  */
2083 	    if ((note = find_regno_note (p, REG_DEAD, sregno))
2084 		&& GET_MODE (XEXP (note, 0)) == GET_MODE (src))
2085 	      {
2086 		int failed = 0;
2087 
2088 		/* We can do the optimization.  Scan forward from INSN
2089 		   again, replacing regs as we go.  Set FAILED if a
2090 		   replacement can't be done.  In that case, we can't
2091 		   move the death note for SRC.  This should be
2092 		   rare.  */
2093 
2094 		/* Set to stop at next insn.  */
2095 		for (q = next_real_insn (insn);
2096 		     q != next_real_insn (p);
2097 		     q = next_real_insn (q))
2098 		  {
2099 		    if (reg_overlap_mentioned_p (src, PATTERN (q)))
2100 		      {
2101 			/* If SRC is a hard register, we might miss
2102 			   some overlapping registers with
2103 			   validate_replace_rtx, so we would have to
2104 			   undo it.  We can't if DEST is present in
2105 			   the insn, so fail in that combination of
2106 			   cases.  */
2107 			if (sregno < FIRST_PSEUDO_REGISTER
2108 			    && reg_mentioned_p (dest, PATTERN (q)))
2109 			  failed = 1;
2110 
2111 			/* Attempt to replace all uses.  */
2112 			else if (!validate_replace_rtx (src, dest, q))
2113 			  failed = 1;
2114 
2115 			/* If this succeeded, but some part of the
2116 			   register is still present, undo the
2117 			   replacement.  */
2118 			else if (sregno < FIRST_PSEUDO_REGISTER
2119 				 && reg_overlap_mentioned_p (src, PATTERN (q)))
2120 			  {
2121 			    validate_replace_rtx (dest, src, q);
2122 			    failed = 1;
2123 			  }
2124 		      }
2125 
2126 		    /* If DEST dies here, remove the death note and
2127 		       save it for later.  Make sure ALL of DEST dies
2128 		       here; again, this is overly conservative.  */
2129 		    if (! dest_death
2130 			&& (dest_death = find_regno_note (q, REG_DEAD, dregno)))
2131 		      {
2132 			if (GET_MODE (XEXP (dest_death, 0)) == GET_MODE (dest))
2133 			  remove_note (q, dest_death);
2134 			else
2135 			  {
2136 			    failed = 1;
2137 			    dest_death = 0;
2138 			  }
2139 		      }
2140 		  }
2141 
2142 		if (! failed)
2143 		  {
2144 		    /* Move death note of SRC from P to INSN.  */
2145 		    remove_note (p, note);
2146 		    XEXP (note, 1) = REG_NOTES (insn);
2147 		    REG_NOTES (insn) = note;
2148 		  }
2149 
2150 		/* DEST is also dead if INSN has a REG_UNUSED note for
2151 		   DEST.  */
2152 		if (! dest_death
2153 		    && (dest_death
2154 			= find_regno_note (insn, REG_UNUSED, dregno)))
2155 		  {
2156 		    PUT_REG_NOTE_KIND (dest_death, REG_DEAD);
2157 		    remove_note (insn, dest_death);
2158 		  }
2159 
2160 		/* Put death note of DEST on P if we saw it die.  */
2161 		if (dest_death)
2162 		  {
2163 		    XEXP (dest_death, 1) = REG_NOTES (p);
2164 		    REG_NOTES (p) = dest_death;
2165 		  }
2166 		break;
2167 	      }
2168 
2169 	    /* If SRC is a hard register which is set or killed in
2170 	       some other way, we can't do this optimization.  */
2171 	    else if (sregno < FIRST_PSEUDO_REGISTER && dead_or_set_p (p, src))
2172 	      break;
2173 	  }
2174       }
2175 }
2176 
2177 
2178 
2179 /* Return nonzero if REGNO is a particularly bad choice for reloading X.  */
2180 static bool
2181 ira_bad_reload_regno_1 (int regno, rtx x)
2182 {
2183   int x_regno, n, i;
2184   ira_allocno_t a;
2185   enum reg_class pref;
2186 
2187   /* We only deal with pseudo regs.  */
2188   if (! x || GET_CODE (x) != REG)
2189     return false;
2190 
2191   x_regno = REGNO (x);
2192   if (x_regno < FIRST_PSEUDO_REGISTER)
2193     return false;
2194 
2195   /* If the pseudo prefers REGNO explicitly, then do not consider
2196      REGNO a bad spill choice.  */
2197   pref = reg_preferred_class (x_regno);
2198   if (reg_class_size[pref] == 1)
2199     return !TEST_HARD_REG_BIT (reg_class_contents[pref], regno);
2200 
2201   /* If the pseudo conflicts with REGNO, then we consider REGNO a
2202      poor choice for a reload regno.  */
2203   a = ira_regno_allocno_map[x_regno];
2204   n = ALLOCNO_NUM_OBJECTS (a);
2205   for (i = 0; i < n; i++)
2206     {
2207       ira_object_t obj = ALLOCNO_OBJECT (a, i);
2208       if (TEST_HARD_REG_BIT (OBJECT_TOTAL_CONFLICT_HARD_REGS (obj), regno))
2209 	return true;
2210     }
2211   return false;
2212 }
2213 
2214 /* Return nonzero if REGNO is a particularly bad choice for reloading
2215    IN or OUT.  */
2216 bool
2217 ira_bad_reload_regno (int regno, rtx in, rtx out)
2218 {
2219   return (ira_bad_reload_regno_1 (regno, in)
2220 	  || ira_bad_reload_regno_1 (regno, out));
2221 }
2222 
2223 /* Add register clobbers from asm statements.  */
2224 static void
2225 compute_regs_asm_clobbered (void)
2226 {
2227   basic_block bb;
2228 
2229   FOR_EACH_BB_FN (bb, cfun)
2230     {
2231       rtx_insn *insn;
2232       FOR_BB_INSNS_REVERSE (bb, insn)
2233 	{
2234 	  df_ref def;
2235 
2236 	  if (NONDEBUG_INSN_P (insn) && extract_asm_operands (PATTERN (insn)))
2237 	    FOR_EACH_INSN_DEF (def, insn)
2238 	      {
2239 		unsigned int dregno = DF_REF_REGNO (def);
2240 		if (HARD_REGISTER_NUM_P (dregno))
2241 		  add_to_hard_reg_set (&crtl->asm_clobbers,
2242 				       GET_MODE (DF_REF_REAL_REG (def)),
2243 				       dregno);
2244 	      }
2245 	}
2246     }
2247 }
2248 
2249 
2250 /* Set up ELIMINABLE_REGSET, IRA_NO_ALLOC_REGS, and
2251    REGS_EVER_LIVE.  */
2252 void
2253 ira_setup_eliminable_regset (void)
2254 {
2255 #ifdef ELIMINABLE_REGS
2256   int i;
2257   static const struct {const int from, to; } eliminables[] = ELIMINABLE_REGS;
2258 #endif
2259   /* FIXME: If EXIT_IGNORE_STACK is set, we will not save and restore
2260      sp for alloca.  So we can't eliminate the frame pointer in that
2261      case.  At some point, we should improve this by emitting the
2262      sp-adjusting insns for this case.  */
2263   frame_pointer_needed
2264     = (! flag_omit_frame_pointer
2265        || (cfun->calls_alloca && EXIT_IGNORE_STACK)
2266        /* We need the frame pointer to catch stack overflow exceptions if
2267 	  the stack pointer is moving (as for the alloca case just above).  */
2268        || (STACK_CHECK_MOVING_SP
2269 	   && flag_stack_check
2270 	   && flag_exceptions
2271 	   && cfun->can_throw_non_call_exceptions)
2272        || crtl->accesses_prior_frames
2273        || (SUPPORTS_STACK_ALIGNMENT && crtl->stack_realign_needed)
2274        /* We need a frame pointer for all Cilk Plus functions that use
2275 	  Cilk keywords.  */
2276        || (flag_cilkplus && cfun->is_cilk_function)
2277        || targetm.frame_pointer_required ());
2278 
2279     /* The chance that FRAME_POINTER_NEEDED is changed from inspecting
2280        RTL is very small.  So if we use frame pointer for RA and RTL
2281        actually prevents this, we will spill pseudos assigned to the
2282        frame pointer in LRA.  */
2283 
2284   if (frame_pointer_needed)
2285     df_set_regs_ever_live (HARD_FRAME_POINTER_REGNUM, true);
2286 
2287   COPY_HARD_REG_SET (ira_no_alloc_regs, no_unit_alloc_regs);
2288   CLEAR_HARD_REG_SET (eliminable_regset);
2289 
2290   compute_regs_asm_clobbered ();
2291 
2292   /* Build the regset of all eliminable registers and show we can't
2293      use those that we already know won't be eliminated.  */
2294 #ifdef ELIMINABLE_REGS
2295   for (i = 0; i < (int) ARRAY_SIZE (eliminables); i++)
2296     {
2297       bool cannot_elim
2298 	= (! targetm.can_eliminate (eliminables[i].from, eliminables[i].to)
2299 	   || (eliminables[i].to == STACK_POINTER_REGNUM && frame_pointer_needed));
2300 
2301       if (!TEST_HARD_REG_BIT (crtl->asm_clobbers, eliminables[i].from))
2302 	{
2303 	    SET_HARD_REG_BIT (eliminable_regset, eliminables[i].from);
2304 
2305 	    if (cannot_elim)
2306 	      SET_HARD_REG_BIT (ira_no_alloc_regs, eliminables[i].from);
2307 	}
2308       else if (cannot_elim)
2309 	error ("%s cannot be used in asm here",
2310 	       reg_names[eliminables[i].from]);
2311       else
2312 	df_set_regs_ever_live (eliminables[i].from, true);
2313     }
2314   if (!HARD_FRAME_POINTER_IS_FRAME_POINTER)
2315     {
2316       if (!TEST_HARD_REG_BIT (crtl->asm_clobbers, HARD_FRAME_POINTER_REGNUM))
2317 	{
2318 	  SET_HARD_REG_BIT (eliminable_regset, HARD_FRAME_POINTER_REGNUM);
2319 	  if (frame_pointer_needed)
2320 	    SET_HARD_REG_BIT (ira_no_alloc_regs, HARD_FRAME_POINTER_REGNUM);
2321 	}
2322       else if (frame_pointer_needed)
2323 	error ("%s cannot be used in asm here",
2324 	       reg_names[HARD_FRAME_POINTER_REGNUM]);
2325       else
2326 	df_set_regs_ever_live (HARD_FRAME_POINTER_REGNUM, true);
2327     }
2328 
2329 #else
2330   if (!TEST_HARD_REG_BIT (crtl->asm_clobbers, HARD_FRAME_POINTER_REGNUM))
2331     {
2332       SET_HARD_REG_BIT (eliminable_regset, FRAME_POINTER_REGNUM);
2333       if (frame_pointer_needed)
2334 	SET_HARD_REG_BIT (ira_no_alloc_regs, FRAME_POINTER_REGNUM);
2335     }
2336   else if (frame_pointer_needed)
2337     error ("%s cannot be used in asm here", reg_names[FRAME_POINTER_REGNUM]);
2338   else
2339     df_set_regs_ever_live (FRAME_POINTER_REGNUM, true);
2340 #endif
2341 }
2342 
2343 
2344 
2345 /* Vector of substitutions of register numbers,
2346    used to map pseudo regs into hardware regs.
2347    This is set up as a result of register allocation.
2348    Element N is the hard reg assigned to pseudo reg N,
2349    or is -1 if no hard reg was assigned.
2350    If N is a hard reg number, element N is N.  */
2351 short *reg_renumber;
2352 
2353 /* Set up REG_RENUMBER and CALLER_SAVE_NEEDED (used by reload) from
2354    the allocation found by IRA.  */
2355 static void
2356 setup_reg_renumber (void)
2357 {
2358   int regno, hard_regno;
2359   ira_allocno_t a;
2360   ira_allocno_iterator ai;
2361 
2362   caller_save_needed = 0;
2363   FOR_EACH_ALLOCNO (a, ai)
2364     {
2365       if (ira_use_lra_p && ALLOCNO_CAP_MEMBER (a) != NULL)
2366 	continue;
2367       /* There are no caps at this point.  */
2368       ira_assert (ALLOCNO_CAP_MEMBER (a) == NULL);
2369       if (! ALLOCNO_ASSIGNED_P (a))
2370 	/* It can happen if A is not referenced but partially anticipated
2371 	   somewhere in a region.  */
2372 	ALLOCNO_ASSIGNED_P (a) = true;
2373       ira_free_allocno_updated_costs (a);
2374       hard_regno = ALLOCNO_HARD_REGNO (a);
2375       regno = ALLOCNO_REGNO (a);
2376       reg_renumber[regno] = (hard_regno < 0 ? -1 : hard_regno);
2377       if (hard_regno >= 0)
2378 	{
2379 	  int i, nwords;
2380 	  enum reg_class pclass;
2381 	  ira_object_t obj;
2382 
2383 	  pclass = ira_pressure_class_translate[REGNO_REG_CLASS (hard_regno)];
2384 	  nwords = ALLOCNO_NUM_OBJECTS (a);
2385 	  for (i = 0; i < nwords; i++)
2386 	    {
2387 	      obj = ALLOCNO_OBJECT (a, i);
2388 	      IOR_COMPL_HARD_REG_SET (OBJECT_TOTAL_CONFLICT_HARD_REGS (obj),
2389 				      reg_class_contents[pclass]);
2390 	    }
2391 	  if (ALLOCNO_CALLS_CROSSED_NUM (a) != 0
2392 	      && ira_hard_reg_set_intersection_p (hard_regno, ALLOCNO_MODE (a),
2393 						  call_used_reg_set))
2394 	    {
2395 	      ira_assert (!optimize || flag_caller_saves
2396 			  || (ALLOCNO_CALLS_CROSSED_NUM (a)
2397 			      == ALLOCNO_CHEAP_CALLS_CROSSED_NUM (a))
2398 			  || regno >= ira_reg_equiv_len
2399 			  || ira_equiv_no_lvalue_p (regno));
2400 	      caller_save_needed = 1;
2401 	    }
2402 	}
2403     }
2404 }
2405 
2406 /* Set up allocno assignment flags for further allocation
2407    improvements.  */
2408 static void
2409 setup_allocno_assignment_flags (void)
2410 {
2411   int hard_regno;
2412   ira_allocno_t a;
2413   ira_allocno_iterator ai;
2414 
2415   FOR_EACH_ALLOCNO (a, ai)
2416     {
2417       if (! ALLOCNO_ASSIGNED_P (a))
2418 	/* It can happen if A is not referenced but partially anticipated
2419 	   somewhere in a region.  */
2420 	ira_free_allocno_updated_costs (a);
2421       hard_regno = ALLOCNO_HARD_REGNO (a);
2422       /* Don't assign hard registers to allocnos which are destination
2423 	 of removed store at the end of loop.  It has no sense to keep
2424 	 the same value in different hard registers.  It is also
2425 	 impossible to assign hard registers correctly to such
2426 	 allocnos because the cost info and info about intersected
2427 	 calls are incorrect for them.  */
2428       ALLOCNO_ASSIGNED_P (a) = (hard_regno >= 0
2429 				|| ALLOCNO_EMIT_DATA (a)->mem_optimized_dest_p
2430 				|| (ALLOCNO_MEMORY_COST (a)
2431 				    - ALLOCNO_CLASS_COST (a)) < 0);
2432       ira_assert
2433 	(hard_regno < 0
2434 	 || ira_hard_reg_in_set_p (hard_regno, ALLOCNO_MODE (a),
2435 				   reg_class_contents[ALLOCNO_CLASS (a)]));
2436     }
2437 }
2438 
2439 /* Evaluate overall allocation cost and the costs for using hard
2440    registers and memory for allocnos.  */
2441 static void
2442 calculate_allocation_cost (void)
2443 {
2444   int hard_regno, cost;
2445   ira_allocno_t a;
2446   ira_allocno_iterator ai;
2447 
2448   ira_overall_cost = ira_reg_cost = ira_mem_cost = 0;
2449   FOR_EACH_ALLOCNO (a, ai)
2450     {
2451       hard_regno = ALLOCNO_HARD_REGNO (a);
2452       ira_assert (hard_regno < 0
2453 		  || (ira_hard_reg_in_set_p
2454 		      (hard_regno, ALLOCNO_MODE (a),
2455 		       reg_class_contents[ALLOCNO_CLASS (a)])));
2456       if (hard_regno < 0)
2457 	{
2458 	  cost = ALLOCNO_MEMORY_COST (a);
2459 	  ira_mem_cost += cost;
2460 	}
2461       else if (ALLOCNO_HARD_REG_COSTS (a) != NULL)
2462 	{
2463 	  cost = (ALLOCNO_HARD_REG_COSTS (a)
2464 		  [ira_class_hard_reg_index
2465 		   [ALLOCNO_CLASS (a)][hard_regno]]);
2466 	  ira_reg_cost += cost;
2467 	}
2468       else
2469 	{
2470 	  cost = ALLOCNO_CLASS_COST (a);
2471 	  ira_reg_cost += cost;
2472 	}
2473       ira_overall_cost += cost;
2474     }
2475 
2476   if (internal_flag_ira_verbose > 0 && ira_dump_file != NULL)
2477     {
2478       fprintf (ira_dump_file,
2479 	       "+++Costs: overall %" PRId64
2480 	       ", reg %" PRId64
2481 	       ", mem %" PRId64
2482 	       ", ld %" PRId64
2483 	       ", st %" PRId64
2484 	       ", move %" PRId64,
2485 	       ira_overall_cost, ira_reg_cost, ira_mem_cost,
2486 	       ira_load_cost, ira_store_cost, ira_shuffle_cost);
2487       fprintf (ira_dump_file, "\n+++       move loops %d, new jumps %d\n",
2488 	       ira_move_loops_num, ira_additional_jumps_num);
2489     }
2490 
2491 }
2492 
2493 #ifdef ENABLE_IRA_CHECKING
2494 /* Check the correctness of the allocation.  We do need this because
2495    of complicated code to transform more one region internal
2496    representation into one region representation.  */
2497 static void
2498 check_allocation (void)
2499 {
2500   ira_allocno_t a;
2501   int hard_regno, nregs, conflict_nregs;
2502   ira_allocno_iterator ai;
2503 
2504   FOR_EACH_ALLOCNO (a, ai)
2505     {
2506       int n = ALLOCNO_NUM_OBJECTS (a);
2507       int i;
2508 
2509       if (ALLOCNO_CAP_MEMBER (a) != NULL
2510 	  || (hard_regno = ALLOCNO_HARD_REGNO (a)) < 0)
2511 	continue;
2512       nregs = hard_regno_nregs[hard_regno][ALLOCNO_MODE (a)];
2513       if (nregs == 1)
2514 	/* We allocated a single hard register.  */
2515 	n = 1;
2516       else if (n > 1)
2517 	/* We allocated multiple hard registers, and we will test
2518 	   conflicts in a granularity of single hard regs.  */
2519 	nregs = 1;
2520 
2521       for (i = 0; i < n; i++)
2522 	{
2523 	  ira_object_t obj = ALLOCNO_OBJECT (a, i);
2524 	  ira_object_t conflict_obj;
2525 	  ira_object_conflict_iterator oci;
2526 	  int this_regno = hard_regno;
2527 	  if (n > 1)
2528 	    {
2529 	      if (REG_WORDS_BIG_ENDIAN)
2530 		this_regno += n - i - 1;
2531 	      else
2532 		this_regno += i;
2533 	    }
2534 	  FOR_EACH_OBJECT_CONFLICT (obj, conflict_obj, oci)
2535 	    {
2536 	      ira_allocno_t conflict_a = OBJECT_ALLOCNO (conflict_obj);
2537 	      int conflict_hard_regno = ALLOCNO_HARD_REGNO (conflict_a);
2538 	      if (conflict_hard_regno < 0)
2539 		continue;
2540 
2541 	      conflict_nregs
2542 		= (hard_regno_nregs
2543 		   [conflict_hard_regno][ALLOCNO_MODE (conflict_a)]);
2544 
2545 	      if (ALLOCNO_NUM_OBJECTS (conflict_a) > 1
2546 		  && conflict_nregs == ALLOCNO_NUM_OBJECTS (conflict_a))
2547 		{
2548 		  if (REG_WORDS_BIG_ENDIAN)
2549 		    conflict_hard_regno += (ALLOCNO_NUM_OBJECTS (conflict_a)
2550 					    - OBJECT_SUBWORD (conflict_obj) - 1);
2551 		  else
2552 		    conflict_hard_regno += OBJECT_SUBWORD (conflict_obj);
2553 		  conflict_nregs = 1;
2554 		}
2555 
2556 	      if ((conflict_hard_regno <= this_regno
2557 		 && this_regno < conflict_hard_regno + conflict_nregs)
2558 		|| (this_regno <= conflict_hard_regno
2559 		    && conflict_hard_regno < this_regno + nregs))
2560 		{
2561 		  fprintf (stderr, "bad allocation for %d and %d\n",
2562 			   ALLOCNO_REGNO (a), ALLOCNO_REGNO (conflict_a));
2563 		  gcc_unreachable ();
2564 		}
2565 	    }
2566 	}
2567     }
2568 }
2569 #endif
2570 
2571 /* Allocate REG_EQUIV_INIT.  Set up it from IRA_REG_EQUIV which should
2572    be already calculated.  */
2573 static void
2574 setup_reg_equiv_init (void)
2575 {
2576   int i;
2577   int max_regno = max_reg_num ();
2578 
2579   for (i = 0; i < max_regno; i++)
2580     reg_equiv_init (i) = ira_reg_equiv[i].init_insns;
2581 }
2582 
2583 /* Update equiv regno from movement of FROM_REGNO to TO_REGNO.  INSNS
2584    are insns which were generated for such movement.  It is assumed
2585    that FROM_REGNO and TO_REGNO always have the same value at the
2586    point of any move containing such registers. This function is used
2587    to update equiv info for register shuffles on the region borders
2588    and for caller save/restore insns.  */
2589 void
2590 ira_update_equiv_info_by_shuffle_insn (int to_regno, int from_regno, rtx_insn *insns)
2591 {
2592   rtx_insn *insn;
2593   rtx x, note;
2594 
2595   if (! ira_reg_equiv[from_regno].defined_p
2596       && (! ira_reg_equiv[to_regno].defined_p
2597 	  || ((x = ira_reg_equiv[to_regno].memory) != NULL_RTX
2598 	      && ! MEM_READONLY_P (x))))
2599     return;
2600   insn = insns;
2601   if (NEXT_INSN (insn) != NULL_RTX)
2602     {
2603       if (! ira_reg_equiv[to_regno].defined_p)
2604 	{
2605 	  ira_assert (ira_reg_equiv[to_regno].init_insns == NULL_RTX);
2606 	  return;
2607 	}
2608       ira_reg_equiv[to_regno].defined_p = false;
2609       ira_reg_equiv[to_regno].memory
2610 	= ira_reg_equiv[to_regno].constant
2611 	= ira_reg_equiv[to_regno].invariant
2612 	= ira_reg_equiv[to_regno].init_insns = NULL;
2613       if (internal_flag_ira_verbose > 3 && ira_dump_file != NULL)
2614 	fprintf (ira_dump_file,
2615 		 "      Invalidating equiv info for reg %d\n", to_regno);
2616       return;
2617     }
2618   /* It is possible that FROM_REGNO still has no equivalence because
2619      in shuffles to_regno<-from_regno and from_regno<-to_regno the 2nd
2620      insn was not processed yet.  */
2621   if (ira_reg_equiv[from_regno].defined_p)
2622     {
2623       ira_reg_equiv[to_regno].defined_p = true;
2624       if ((x = ira_reg_equiv[from_regno].memory) != NULL_RTX)
2625 	{
2626 	  ira_assert (ira_reg_equiv[from_regno].invariant == NULL_RTX
2627 		      && ira_reg_equiv[from_regno].constant == NULL_RTX);
2628 	  ira_assert (ira_reg_equiv[to_regno].memory == NULL_RTX
2629 		      || rtx_equal_p (ira_reg_equiv[to_regno].memory, x));
2630 	  ira_reg_equiv[to_regno].memory = x;
2631 	  if (! MEM_READONLY_P (x))
2632 	    /* We don't add the insn to insn init list because memory
2633 	       equivalence is just to say what memory is better to use
2634 	       when the pseudo is spilled.  */
2635 	    return;
2636 	}
2637       else if ((x = ira_reg_equiv[from_regno].constant) != NULL_RTX)
2638 	{
2639 	  ira_assert (ira_reg_equiv[from_regno].invariant == NULL_RTX);
2640 	  ira_assert (ira_reg_equiv[to_regno].constant == NULL_RTX
2641 		      || rtx_equal_p (ira_reg_equiv[to_regno].constant, x));
2642 	  ira_reg_equiv[to_regno].constant = x;
2643 	}
2644       else
2645 	{
2646 	  x = ira_reg_equiv[from_regno].invariant;
2647 	  ira_assert (x != NULL_RTX);
2648 	  ira_assert (ira_reg_equiv[to_regno].invariant == NULL_RTX
2649 		      || rtx_equal_p (ira_reg_equiv[to_regno].invariant, x));
2650 	  ira_reg_equiv[to_regno].invariant = x;
2651 	}
2652       if (find_reg_note (insn, REG_EQUIV, x) == NULL_RTX)
2653 	{
2654 	  note = set_unique_reg_note (insn, REG_EQUIV, x);
2655 	  gcc_assert (note != NULL_RTX);
2656 	  if (internal_flag_ira_verbose > 3 && ira_dump_file != NULL)
2657 	    {
2658 	      fprintf (ira_dump_file,
2659 		       "      Adding equiv note to insn %u for reg %d ",
2660 		       INSN_UID (insn), to_regno);
2661 	      dump_value_slim (ira_dump_file, x, 1);
2662 	      fprintf (ira_dump_file, "\n");
2663 	    }
2664 	}
2665     }
2666   ira_reg_equiv[to_regno].init_insns
2667     = gen_rtx_INSN_LIST (VOIDmode, insn,
2668 			 ira_reg_equiv[to_regno].init_insns);
2669   if (internal_flag_ira_verbose > 3 && ira_dump_file != NULL)
2670     fprintf (ira_dump_file,
2671 	     "      Adding equiv init move insn %u to reg %d\n",
2672 	     INSN_UID (insn), to_regno);
2673 }
2674 
2675 /* Fix values of array REG_EQUIV_INIT after live range splitting done
2676    by IRA.  */
2677 static void
2678 fix_reg_equiv_init (void)
2679 {
2680   int max_regno = max_reg_num ();
2681   int i, new_regno, max;
2682   rtx set;
2683   rtx_insn_list *x, *next, *prev;
2684   rtx_insn *insn;
2685 
2686   if (max_regno_before_ira < max_regno)
2687     {
2688       max = vec_safe_length (reg_equivs);
2689       grow_reg_equivs ();
2690       for (i = FIRST_PSEUDO_REGISTER; i < max; i++)
2691 	for (prev = NULL, x = reg_equiv_init (i);
2692 	     x != NULL_RTX;
2693 	     x = next)
2694 	  {
2695 	    next = x->next ();
2696 	    insn = x->insn ();
2697 	    set = single_set (insn);
2698 	    ira_assert (set != NULL_RTX
2699 			&& (REG_P (SET_DEST (set)) || REG_P (SET_SRC (set))));
2700 	    if (REG_P (SET_DEST (set))
2701 		&& ((int) REGNO (SET_DEST (set)) == i
2702 		    || (int) ORIGINAL_REGNO (SET_DEST (set)) == i))
2703 	      new_regno = REGNO (SET_DEST (set));
2704 	    else if (REG_P (SET_SRC (set))
2705 		     && ((int) REGNO (SET_SRC (set)) == i
2706 			 || (int) ORIGINAL_REGNO (SET_SRC (set)) == i))
2707 	      new_regno = REGNO (SET_SRC (set));
2708 	    else
2709  	      gcc_unreachable ();
2710 	    if (new_regno == i)
2711 	      prev = x;
2712 	    else
2713 	      {
2714 		/* Remove the wrong list element.  */
2715 		if (prev == NULL_RTX)
2716 		  reg_equiv_init (i) = next;
2717 		else
2718 		  XEXP (prev, 1) = next;
2719 		XEXP (x, 1) = reg_equiv_init (new_regno);
2720 		reg_equiv_init (new_regno) = x;
2721 	      }
2722 	  }
2723     }
2724 }
2725 
2726 #ifdef ENABLE_IRA_CHECKING
2727 /* Print redundant memory-memory copies.  */
2728 static void
2729 print_redundant_copies (void)
2730 {
2731   int hard_regno;
2732   ira_allocno_t a;
2733   ira_copy_t cp, next_cp;
2734   ira_allocno_iterator ai;
2735 
2736   FOR_EACH_ALLOCNO (a, ai)
2737     {
2738       if (ALLOCNO_CAP_MEMBER (a) != NULL)
2739 	/* It is a cap.  */
2740 	continue;
2741       hard_regno = ALLOCNO_HARD_REGNO (a);
2742       if (hard_regno >= 0)
2743 	continue;
2744       for (cp = ALLOCNO_COPIES (a); cp != NULL; cp = next_cp)
2745 	if (cp->first == a)
2746 	  next_cp = cp->next_first_allocno_copy;
2747 	else
2748 	  {
2749 	    next_cp = cp->next_second_allocno_copy;
2750 	    if (internal_flag_ira_verbose > 4 && ira_dump_file != NULL
2751 		&& cp->insn != NULL_RTX
2752 		&& ALLOCNO_HARD_REGNO (cp->first) == hard_regno)
2753 	      fprintf (ira_dump_file,
2754 		       "        Redundant move from %d(freq %d):%d\n",
2755 		       INSN_UID (cp->insn), cp->freq, hard_regno);
2756 	  }
2757     }
2758 }
2759 #endif
2760 
2761 /* Setup preferred and alternative classes for new pseudo-registers
2762    created by IRA starting with START.  */
2763 static void
2764 setup_preferred_alternate_classes_for_new_pseudos (int start)
2765 {
2766   int i, old_regno;
2767   int max_regno = max_reg_num ();
2768 
2769   for (i = start; i < max_regno; i++)
2770     {
2771       old_regno = ORIGINAL_REGNO (regno_reg_rtx[i]);
2772       ira_assert (i != old_regno);
2773       setup_reg_classes (i, reg_preferred_class (old_regno),
2774 			 reg_alternate_class (old_regno),
2775 			 reg_allocno_class (old_regno));
2776       if (internal_flag_ira_verbose > 2 && ira_dump_file != NULL)
2777 	fprintf (ira_dump_file,
2778 		 "    New r%d: setting preferred %s, alternative %s\n",
2779 		 i, reg_class_names[reg_preferred_class (old_regno)],
2780 		 reg_class_names[reg_alternate_class (old_regno)]);
2781     }
2782 }
2783 
2784 
2785 /* The number of entries allocated in reg_info.  */
2786 static int allocated_reg_info_size;
2787 
2788 /* Regional allocation can create new pseudo-registers.  This function
2789    expands some arrays for pseudo-registers.  */
2790 static void
2791 expand_reg_info (void)
2792 {
2793   int i;
2794   int size = max_reg_num ();
2795 
2796   resize_reg_info ();
2797   for (i = allocated_reg_info_size; i < size; i++)
2798     setup_reg_classes (i, GENERAL_REGS, ALL_REGS, GENERAL_REGS);
2799   setup_preferred_alternate_classes_for_new_pseudos (allocated_reg_info_size);
2800   allocated_reg_info_size = size;
2801 }
2802 
2803 /* Return TRUE if there is too high register pressure in the function.
2804    It is used to decide when stack slot sharing is worth to do.  */
2805 static bool
2806 too_high_register_pressure_p (void)
2807 {
2808   int i;
2809   enum reg_class pclass;
2810 
2811   for (i = 0; i < ira_pressure_classes_num; i++)
2812     {
2813       pclass = ira_pressure_classes[i];
2814       if (ira_loop_tree_root->reg_pressure[pclass] > 10000)
2815 	return true;
2816     }
2817   return false;
2818 }
2819 
2820 
2821 
2822 /* Indicate that hard register number FROM was eliminated and replaced with
2823    an offset from hard register number TO.  The status of hard registers live
2824    at the start of a basic block is updated by replacing a use of FROM with
2825    a use of TO.  */
2826 
2827 void
2828 mark_elimination (int from, int to)
2829 {
2830   basic_block bb;
2831   bitmap r;
2832 
2833   FOR_EACH_BB_FN (bb, cfun)
2834     {
2835       r = DF_LR_IN (bb);
2836       if (bitmap_bit_p (r, from))
2837 	{
2838 	  bitmap_clear_bit (r, from);
2839 	  bitmap_set_bit (r, to);
2840 	}
2841       if (! df_live)
2842         continue;
2843       r = DF_LIVE_IN (bb);
2844       if (bitmap_bit_p (r, from))
2845 	{
2846 	  bitmap_clear_bit (r, from);
2847 	  bitmap_set_bit (r, to);
2848 	}
2849     }
2850 }
2851 
2852 
2853 
2854 /* The length of the following array.  */
2855 int ira_reg_equiv_len;
2856 
2857 /* Info about equiv. info for each register.  */
2858 struct ira_reg_equiv_s *ira_reg_equiv;
2859 
2860 /* Expand ira_reg_equiv if necessary.  */
2861 void
2862 ira_expand_reg_equiv (void)
2863 {
2864   int old = ira_reg_equiv_len;
2865 
2866   if (ira_reg_equiv_len > max_reg_num ())
2867     return;
2868   ira_reg_equiv_len = max_reg_num () * 3 / 2 + 1;
2869   ira_reg_equiv
2870     = (struct ira_reg_equiv_s *) xrealloc (ira_reg_equiv,
2871 					 ira_reg_equiv_len
2872 					 * sizeof (struct ira_reg_equiv_s));
2873   gcc_assert (old < ira_reg_equiv_len);
2874   memset (ira_reg_equiv + old, 0,
2875 	  sizeof (struct ira_reg_equiv_s) * (ira_reg_equiv_len - old));
2876 }
2877 
2878 static void
2879 init_reg_equiv (void)
2880 {
2881   ira_reg_equiv_len = 0;
2882   ira_reg_equiv = NULL;
2883   ira_expand_reg_equiv ();
2884 }
2885 
2886 static void
2887 finish_reg_equiv (void)
2888 {
2889   free (ira_reg_equiv);
2890 }
2891 
2892 
2893 
2894 struct equivalence
2895 {
2896   /* Set when a REG_EQUIV note is found or created.  Use to
2897      keep track of what memory accesses might be created later,
2898      e.g. by reload.  */
2899   rtx replacement;
2900   rtx *src_p;
2901 
2902   /* The list of each instruction which initializes this register.
2903 
2904      NULL indicates we know nothing about this register's equivalence
2905      properties.
2906 
2907      An INSN_LIST with a NULL insn indicates this pseudo is already
2908      known to not have a valid equivalence.  */
2909   rtx_insn_list *init_insns;
2910 
2911   /* Loop depth is used to recognize equivalences which appear
2912      to be present within the same loop (or in an inner loop).  */
2913   short loop_depth;
2914   /* Nonzero if this had a preexisting REG_EQUIV note.  */
2915   unsigned char is_arg_equivalence : 1;
2916   /* Set when an attempt should be made to replace a register
2917      with the associated src_p entry.  */
2918   unsigned char replace : 1;
2919   /* Set if this register has no known equivalence.  */
2920   unsigned char no_equiv : 1;
2921 };
2922 
2923 /* reg_equiv[N] (where N is a pseudo reg number) is the equivalence
2924    structure for that register.  */
2925 static struct equivalence *reg_equiv;
2926 
2927 /* Used for communication between the following two functions: contains
2928    a MEM that we wish to ensure remains unchanged.  */
2929 static rtx equiv_mem;
2930 
2931 /* Set nonzero if EQUIV_MEM is modified.  */
2932 static int equiv_mem_modified;
2933 
2934 /* If EQUIV_MEM is modified by modifying DEST, indicate that it is modified.
2935    Called via note_stores.  */
2936 static void
2937 validate_equiv_mem_from_store (rtx dest, const_rtx set ATTRIBUTE_UNUSED,
2938 			       void *data ATTRIBUTE_UNUSED)
2939 {
2940   if ((REG_P (dest)
2941        && reg_overlap_mentioned_p (dest, equiv_mem))
2942       || (MEM_P (dest)
2943 	  && anti_dependence (equiv_mem, dest)))
2944     equiv_mem_modified = 1;
2945 }
2946 
2947 /* Verify that no store between START and the death of REG invalidates
2948    MEMREF.  MEMREF is invalidated by modifying a register used in MEMREF,
2949    by storing into an overlapping memory location, or with a non-const
2950    CALL_INSN.
2951 
2952    Return 1 if MEMREF remains valid.  */
2953 static int
2954 validate_equiv_mem (rtx_insn *start, rtx reg, rtx memref)
2955 {
2956   rtx_insn *insn;
2957   rtx note;
2958 
2959   equiv_mem = memref;
2960   equiv_mem_modified = 0;
2961 
2962   /* If the memory reference has side effects or is volatile, it isn't a
2963      valid equivalence.  */
2964   if (side_effects_p (memref))
2965     return 0;
2966 
2967   for (insn = start; insn && ! equiv_mem_modified; insn = NEXT_INSN (insn))
2968     {
2969       if (! INSN_P (insn))
2970 	continue;
2971 
2972       if (find_reg_note (insn, REG_DEAD, reg))
2973 	return 1;
2974 
2975       /* This used to ignore readonly memory and const/pure calls.  The problem
2976 	 is the equivalent form may reference a pseudo which gets assigned a
2977 	 call clobbered hard reg.  When we later replace REG with its
2978 	 equivalent form, the value in the call-clobbered reg has been
2979 	 changed and all hell breaks loose.  */
2980       if (CALL_P (insn))
2981 	return 0;
2982 
2983       note_stores (PATTERN (insn), validate_equiv_mem_from_store, NULL);
2984 
2985       /* If a register mentioned in MEMREF is modified via an
2986 	 auto-increment, we lose the equivalence.  Do the same if one
2987 	 dies; although we could extend the life, it doesn't seem worth
2988 	 the trouble.  */
2989 
2990       for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
2991 	if ((REG_NOTE_KIND (note) == REG_INC
2992 	     || REG_NOTE_KIND (note) == REG_DEAD)
2993 	    && REG_P (XEXP (note, 0))
2994 	    && reg_overlap_mentioned_p (XEXP (note, 0), memref))
2995 	  return 0;
2996     }
2997 
2998   return 0;
2999 }
3000 
3001 /* Returns zero if X is known to be invariant.  */
3002 static int
3003 equiv_init_varies_p (rtx x)
3004 {
3005   RTX_CODE code = GET_CODE (x);
3006   int i;
3007   const char *fmt;
3008 
3009   switch (code)
3010     {
3011     case MEM:
3012       return !MEM_READONLY_P (x) || equiv_init_varies_p (XEXP (x, 0));
3013 
3014     case CONST:
3015     CASE_CONST_ANY:
3016     case SYMBOL_REF:
3017     case LABEL_REF:
3018       return 0;
3019 
3020     case REG:
3021       return reg_equiv[REGNO (x)].replace == 0 && rtx_varies_p (x, 0);
3022 
3023     case ASM_OPERANDS:
3024       if (MEM_VOLATILE_P (x))
3025 	return 1;
3026 
3027       /* Fall through.  */
3028 
3029     default:
3030       break;
3031     }
3032 
3033   fmt = GET_RTX_FORMAT (code);
3034   for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
3035     if (fmt[i] == 'e')
3036       {
3037 	if (equiv_init_varies_p (XEXP (x, i)))
3038 	  return 1;
3039       }
3040     else if (fmt[i] == 'E')
3041       {
3042 	int j;
3043 	for (j = 0; j < XVECLEN (x, i); j++)
3044 	  if (equiv_init_varies_p (XVECEXP (x, i, j)))
3045 	    return 1;
3046       }
3047 
3048   return 0;
3049 }
3050 
3051 /* Returns nonzero if X (used to initialize register REGNO) is movable.
3052    X is only movable if the registers it uses have equivalent initializations
3053    which appear to be within the same loop (or in an inner loop) and movable
3054    or if they are not candidates for local_alloc and don't vary.  */
3055 static int
3056 equiv_init_movable_p (rtx x, int regno)
3057 {
3058   int i, j;
3059   const char *fmt;
3060   enum rtx_code code = GET_CODE (x);
3061 
3062   switch (code)
3063     {
3064     case SET:
3065       return equiv_init_movable_p (SET_SRC (x), regno);
3066 
3067     case CC0:
3068     case CLOBBER:
3069       return 0;
3070 
3071     case PRE_INC:
3072     case PRE_DEC:
3073     case POST_INC:
3074     case POST_DEC:
3075     case PRE_MODIFY:
3076     case POST_MODIFY:
3077       return 0;
3078 
3079     case REG:
3080       return ((reg_equiv[REGNO (x)].loop_depth >= reg_equiv[regno].loop_depth
3081 	       && reg_equiv[REGNO (x)].replace)
3082 	      || (REG_BASIC_BLOCK (REGNO (x)) < NUM_FIXED_BLOCKS
3083 		  && ! rtx_varies_p (x, 0)));
3084 
3085     case UNSPEC_VOLATILE:
3086       return 0;
3087 
3088     case ASM_OPERANDS:
3089       if (MEM_VOLATILE_P (x))
3090 	return 0;
3091 
3092       /* Fall through.  */
3093 
3094     default:
3095       break;
3096     }
3097 
3098   fmt = GET_RTX_FORMAT (code);
3099   for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
3100     switch (fmt[i])
3101       {
3102       case 'e':
3103 	if (! equiv_init_movable_p (XEXP (x, i), regno))
3104 	  return 0;
3105 	break;
3106       case 'E':
3107 	for (j = XVECLEN (x, i) - 1; j >= 0; j--)
3108 	  if (! equiv_init_movable_p (XVECEXP (x, i, j), regno))
3109 	    return 0;
3110 	break;
3111       }
3112 
3113   return 1;
3114 }
3115 
3116 /* TRUE if X uses any registers for which reg_equiv[REGNO].replace is
3117    true.  */
3118 static int
3119 contains_replace_regs (rtx x)
3120 {
3121   int i, j;
3122   const char *fmt;
3123   enum rtx_code code = GET_CODE (x);
3124 
3125   switch (code)
3126     {
3127     case CONST:
3128     case LABEL_REF:
3129     case SYMBOL_REF:
3130     CASE_CONST_ANY:
3131     case PC:
3132     case CC0:
3133     case HIGH:
3134       return 0;
3135 
3136     case REG:
3137       return reg_equiv[REGNO (x)].replace;
3138 
3139     default:
3140       break;
3141     }
3142 
3143   fmt = GET_RTX_FORMAT (code);
3144   for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
3145     switch (fmt[i])
3146       {
3147       case 'e':
3148 	if (contains_replace_regs (XEXP (x, i)))
3149 	  return 1;
3150 	break;
3151       case 'E':
3152 	for (j = XVECLEN (x, i) - 1; j >= 0; j--)
3153 	  if (contains_replace_regs (XVECEXP (x, i, j)))
3154 	    return 1;
3155 	break;
3156       }
3157 
3158   return 0;
3159 }
3160 
3161 /* TRUE if X references a memory location that would be affected by a store
3162    to MEMREF.  */
3163 static int
3164 memref_referenced_p (rtx memref, rtx x)
3165 {
3166   int i, j;
3167   const char *fmt;
3168   enum rtx_code code = GET_CODE (x);
3169 
3170   switch (code)
3171     {
3172     case CONST:
3173     case LABEL_REF:
3174     case SYMBOL_REF:
3175     CASE_CONST_ANY:
3176     case PC:
3177     case CC0:
3178     case HIGH:
3179     case LO_SUM:
3180       return 0;
3181 
3182     case REG:
3183       return (reg_equiv[REGNO (x)].replacement
3184 	      && memref_referenced_p (memref,
3185 				      reg_equiv[REGNO (x)].replacement));
3186 
3187     case MEM:
3188       if (true_dependence (memref, VOIDmode, x))
3189 	return 1;
3190       break;
3191 
3192     case SET:
3193       /* If we are setting a MEM, it doesn't count (its address does), but any
3194 	 other SET_DEST that has a MEM in it is referencing the MEM.  */
3195       if (MEM_P (SET_DEST (x)))
3196 	{
3197 	  if (memref_referenced_p (memref, XEXP (SET_DEST (x), 0)))
3198 	    return 1;
3199 	}
3200       else if (memref_referenced_p (memref, SET_DEST (x)))
3201 	return 1;
3202 
3203       return memref_referenced_p (memref, SET_SRC (x));
3204 
3205     default:
3206       break;
3207     }
3208 
3209   fmt = GET_RTX_FORMAT (code);
3210   for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
3211     switch (fmt[i])
3212       {
3213       case 'e':
3214 	if (memref_referenced_p (memref, XEXP (x, i)))
3215 	  return 1;
3216 	break;
3217       case 'E':
3218 	for (j = XVECLEN (x, i) - 1; j >= 0; j--)
3219 	  if (memref_referenced_p (memref, XVECEXP (x, i, j)))
3220 	    return 1;
3221 	break;
3222       }
3223 
3224   return 0;
3225 }
3226 
3227 /* TRUE if some insn in the range (START, END] references a memory location
3228    that would be affected by a store to MEMREF.
3229 
3230    Callers should not call this routine if START is after END in the
3231    RTL chain.  */
3232 
3233 static int
3234 memref_used_between_p (rtx memref, rtx_insn *start, rtx_insn *end)
3235 {
3236   rtx_insn *insn;
3237 
3238   for (insn = NEXT_INSN (start);
3239        insn && insn != NEXT_INSN (end);
3240        insn = NEXT_INSN (insn))
3241     {
3242       if (!NONDEBUG_INSN_P (insn))
3243 	continue;
3244 
3245       if (memref_referenced_p (memref, PATTERN (insn)))
3246 	return 1;
3247 
3248       /* Nonconst functions may access memory.  */
3249       if (CALL_P (insn) && (! RTL_CONST_CALL_P (insn)))
3250 	return 1;
3251     }
3252 
3253   gcc_assert (insn == NEXT_INSN (end));
3254   return 0;
3255 }
3256 
3257 /* Mark REG as having no known equivalence.
3258    Some instructions might have been processed before and furnished
3259    with REG_EQUIV notes for this register; these notes will have to be
3260    removed.
3261    STORE is the piece of RTL that does the non-constant / conflicting
3262    assignment - a SET, CLOBBER or REG_INC note.  It is currently not used,
3263    but needs to be there because this function is called from note_stores.  */
3264 static void
3265 no_equiv (rtx reg, const_rtx store ATTRIBUTE_UNUSED,
3266 	  void *data ATTRIBUTE_UNUSED)
3267 {
3268   int regno;
3269   rtx_insn_list *list;
3270 
3271   if (!REG_P (reg))
3272     return;
3273   regno = REGNO (reg);
3274   reg_equiv[regno].no_equiv = 1;
3275   list = reg_equiv[regno].init_insns;
3276   if (list && list->insn () == NULL)
3277     return;
3278   reg_equiv[regno].init_insns = gen_rtx_INSN_LIST (VOIDmode, NULL_RTX, NULL);
3279   reg_equiv[regno].replacement = NULL_RTX;
3280   /* This doesn't matter for equivalences made for argument registers, we
3281      should keep their initialization insns.  */
3282   if (reg_equiv[regno].is_arg_equivalence)
3283     return;
3284   ira_reg_equiv[regno].defined_p = false;
3285   ira_reg_equiv[regno].init_insns = NULL;
3286   for (; list; list = list->next ())
3287     {
3288       rtx_insn *insn = list->insn ();
3289       remove_note (insn, find_reg_note (insn, REG_EQUIV, NULL_RTX));
3290     }
3291 }
3292 
3293 /* Check whether the SUBREG is a paradoxical subreg and set the result
3294    in PDX_SUBREGS.  */
3295 
3296 static void
3297 set_paradoxical_subreg (rtx_insn *insn, bool *pdx_subregs)
3298 {
3299   subrtx_iterator::array_type array;
3300   FOR_EACH_SUBRTX (iter, array, PATTERN (insn), NONCONST)
3301     {
3302       const_rtx subreg = *iter;
3303       if (GET_CODE (subreg) == SUBREG)
3304 	{
3305 	  const_rtx reg = SUBREG_REG (subreg);
3306 	  if (REG_P (reg) && paradoxical_subreg_p (subreg))
3307 	    pdx_subregs[REGNO (reg)] = true;
3308 	}
3309     }
3310 }
3311 
3312 /* In DEBUG_INSN location adjust REGs from CLEARED_REGS bitmap to the
3313    equivalent replacement.  */
3314 
3315 static rtx
3316 adjust_cleared_regs (rtx loc, const_rtx old_rtx ATTRIBUTE_UNUSED, void *data)
3317 {
3318   if (REG_P (loc))
3319     {
3320       bitmap cleared_regs = (bitmap) data;
3321       if (bitmap_bit_p (cleared_regs, REGNO (loc)))
3322 	return simplify_replace_fn_rtx (copy_rtx (*reg_equiv[REGNO (loc)].src_p),
3323 					NULL_RTX, adjust_cleared_regs, data);
3324     }
3325   return NULL_RTX;
3326 }
3327 
3328 /* Find registers that are equivalent to a single value throughout the
3329    compilation (either because they can be referenced in memory or are
3330    set once from a single constant).  Lower their priority for a
3331    register.
3332 
3333    If such a register is only referenced once, try substituting its
3334    value into the using insn.  If it succeeds, we can eliminate the
3335    register completely.
3336 
3337    Initialize init_insns in ira_reg_equiv array.  */
3338 static void
3339 update_equiv_regs (void)
3340 {
3341   rtx_insn *insn;
3342   basic_block bb;
3343   int loop_depth;
3344   bitmap cleared_regs;
3345   bool *pdx_subregs;
3346   bitmap_head seen_insns;
3347 
3348   /* Use pdx_subregs to show whether a reg is used in a paradoxical
3349      subreg.  */
3350   pdx_subregs = XCNEWVEC (bool, max_regno);
3351 
3352   reg_equiv = XCNEWVEC (struct equivalence, max_regno);
3353   grow_reg_equivs ();
3354 
3355   init_alias_analysis ();
3356 
3357   /* Scan insns and set pdx_subregs[regno] if the reg is used in a
3358      paradoxical subreg. Don't set such reg equivalent to a mem,
3359      because lra will not substitute such equiv memory in order to
3360      prevent access beyond allocated memory for paradoxical memory subreg.  */
3361   FOR_EACH_BB_FN (bb, cfun)
3362     FOR_BB_INSNS (bb, insn)
3363       if (NONDEBUG_INSN_P (insn))
3364 	set_paradoxical_subreg (insn, pdx_subregs);
3365 
3366   /* Scan the insns and find which registers have equivalences.  Do this
3367      in a separate scan of the insns because (due to -fcse-follow-jumps)
3368      a register can be set below its use.  */
3369   FOR_EACH_BB_FN (bb, cfun)
3370     {
3371       loop_depth = bb_loop_depth (bb);
3372 
3373       for (insn = BB_HEAD (bb);
3374 	   insn != NEXT_INSN (BB_END (bb));
3375 	   insn = NEXT_INSN (insn))
3376 	{
3377 	  rtx note;
3378 	  rtx set;
3379 	  rtx dest, src;
3380 	  int regno;
3381 
3382 	  if (! INSN_P (insn))
3383 	    continue;
3384 
3385 	  for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
3386 	    if (REG_NOTE_KIND (note) == REG_INC)
3387 	      no_equiv (XEXP (note, 0), note, NULL);
3388 
3389 	  set = single_set (insn);
3390 
3391 	  /* If this insn contains more (or less) than a single SET,
3392 	     only mark all destinations as having no known equivalence.  */
3393 	  if (set == NULL_RTX
3394 	      || side_effects_p (SET_SRC (set)))
3395 	    {
3396 	      note_stores (PATTERN (insn), no_equiv, NULL);
3397 	      continue;
3398 	    }
3399 	  else if (GET_CODE (PATTERN (insn)) == PARALLEL)
3400 	    {
3401 	      int i;
3402 
3403 	      for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
3404 		{
3405 		  rtx part = XVECEXP (PATTERN (insn), 0, i);
3406 		  if (part != set)
3407 		    note_stores (part, no_equiv, NULL);
3408 		}
3409 	    }
3410 
3411 	  dest = SET_DEST (set);
3412 	  src = SET_SRC (set);
3413 
3414 	  /* See if this is setting up the equivalence between an argument
3415 	     register and its stack slot.  */
3416 	  note = find_reg_note (insn, REG_EQUIV, NULL_RTX);
3417 	  if (note)
3418 	    {
3419 	      gcc_assert (REG_P (dest));
3420 	      regno = REGNO (dest);
3421 
3422 	      /* Note that we don't want to clear init_insns in
3423 		 ira_reg_equiv even if there are multiple sets of this
3424 		 register.  */
3425 	      reg_equiv[regno].is_arg_equivalence = 1;
3426 
3427 	      /* The insn result can have equivalence memory although
3428 		 the equivalence is not set up by the insn.  We add
3429 		 this insn to init insns as it is a flag for now that
3430 		 regno has an equivalence.  We will remove the insn
3431 		 from init insn list later.  */
3432 	      if (rtx_equal_p (src, XEXP (note, 0)) || MEM_P (XEXP (note, 0)))
3433 		ira_reg_equiv[regno].init_insns
3434 		  = gen_rtx_INSN_LIST (VOIDmode, insn,
3435 				       ira_reg_equiv[regno].init_insns);
3436 
3437 	      /* Continue normally in case this is a candidate for
3438 		 replacements.  */
3439 	    }
3440 
3441 	  if (!optimize)
3442 	    continue;
3443 
3444 	  /* We only handle the case of a pseudo register being set
3445 	     once, or always to the same value.  */
3446 	  /* ??? The mn10200 port breaks if we add equivalences for
3447 	     values that need an ADDRESS_REGS register and set them equivalent
3448 	     to a MEM of a pseudo.  The actual problem is in the over-conservative
3449 	     handling of INPADDR_ADDRESS / INPUT_ADDRESS / INPUT triples in
3450 	     calculate_needs, but we traditionally work around this problem
3451 	     here by rejecting equivalences when the destination is in a register
3452 	     that's likely spilled.  This is fragile, of course, since the
3453 	     preferred class of a pseudo depends on all instructions that set
3454 	     or use it.  */
3455 
3456 	  if (!REG_P (dest)
3457 	      || (regno = REGNO (dest)) < FIRST_PSEUDO_REGISTER
3458 	      || (reg_equiv[regno].init_insns
3459 		  && reg_equiv[regno].init_insns->insn () == NULL)
3460 	      || (targetm.class_likely_spilled_p (reg_preferred_class (regno))
3461 		  && MEM_P (src) && ! reg_equiv[regno].is_arg_equivalence))
3462 	    {
3463 	      /* This might be setting a SUBREG of a pseudo, a pseudo that is
3464 		 also set somewhere else to a constant.  */
3465 	      note_stores (set, no_equiv, NULL);
3466 	      continue;
3467 	    }
3468 
3469 	  /* Don't set reg (if pdx_subregs[regno] == true) equivalent to a mem.  */
3470 	  if (MEM_P (src) && pdx_subregs[regno])
3471 	    {
3472 	      note_stores (set, no_equiv, NULL);
3473 	      continue;
3474 	    }
3475 
3476 	  note = find_reg_note (insn, REG_EQUAL, NULL_RTX);
3477 
3478 	  /* cse sometimes generates function invariants, but doesn't put a
3479 	     REG_EQUAL note on the insn.  Since this note would be redundant,
3480 	     there's no point creating it earlier than here.  */
3481 	  if (! note && ! rtx_varies_p (src, 0))
3482 	    note = set_unique_reg_note (insn, REG_EQUAL, copy_rtx (src));
3483 
3484 	  /* Don't bother considering a REG_EQUAL note containing an EXPR_LIST
3485 	     since it represents a function call.  */
3486 	  if (note && GET_CODE (XEXP (note, 0)) == EXPR_LIST)
3487 	    note = NULL_RTX;
3488 
3489 	  if (DF_REG_DEF_COUNT (regno) != 1)
3490 	    {
3491 	      bool equal_p = true;
3492 	      rtx_insn_list *list;
3493 
3494 	      /* If we have already processed this pseudo and determined it
3495 		 can not have an equivalence, then honor that decision.  */
3496 	      if (reg_equiv[regno].no_equiv)
3497 		continue;
3498 
3499 	      if (! note
3500 		  || rtx_varies_p (XEXP (note, 0), 0)
3501 		  || (reg_equiv[regno].replacement
3502 		      && ! rtx_equal_p (XEXP (note, 0),
3503 					reg_equiv[regno].replacement)))
3504 		{
3505 		  no_equiv (dest, set, NULL);
3506 		  continue;
3507 		}
3508 
3509 	      list = reg_equiv[regno].init_insns;
3510 	      for (; list; list = list->next ())
3511 		{
3512 		  rtx note_tmp;
3513 		  rtx_insn *insn_tmp;
3514 
3515 		  insn_tmp = list->insn ();
3516 		  note_tmp = find_reg_note (insn_tmp, REG_EQUAL, NULL_RTX);
3517 		  gcc_assert (note_tmp);
3518 		  if (! rtx_equal_p (XEXP (note, 0), XEXP (note_tmp, 0)))
3519 		    {
3520 		      equal_p = false;
3521 		      break;
3522 		    }
3523 		}
3524 
3525 	      if (! equal_p)
3526 		{
3527 		  no_equiv (dest, set, NULL);
3528 		  continue;
3529 		}
3530 	    }
3531 
3532 	  /* Record this insn as initializing this register.  */
3533 	  reg_equiv[regno].init_insns
3534 	    = gen_rtx_INSN_LIST (VOIDmode, insn, reg_equiv[regno].init_insns);
3535 
3536 	  /* If this register is known to be equal to a constant, record that
3537 	     it is always equivalent to the constant.  */
3538 	  if (DF_REG_DEF_COUNT (regno) == 1
3539 	      && note && ! rtx_varies_p (XEXP (note, 0), 0))
3540 	    {
3541 	      rtx note_value = XEXP (note, 0);
3542 	      remove_note (insn, note);
3543 	      set_unique_reg_note (insn, REG_EQUIV, note_value);
3544 	    }
3545 
3546 	  /* If this insn introduces a "constant" register, decrease the priority
3547 	     of that register.  Record this insn if the register is only used once
3548 	     more and the equivalence value is the same as our source.
3549 
3550 	     The latter condition is checked for two reasons:  First, it is an
3551 	     indication that it may be more efficient to actually emit the insn
3552 	     as written (if no registers are available, reload will substitute
3553 	     the equivalence).  Secondly, it avoids problems with any registers
3554 	     dying in this insn whose death notes would be missed.
3555 
3556 	     If we don't have a REG_EQUIV note, see if this insn is loading
3557 	     a register used only in one basic block from a MEM.  If so, and the
3558 	     MEM remains unchanged for the life of the register, add a REG_EQUIV
3559 	     note.  */
3560 	  note = find_reg_note (insn, REG_EQUIV, NULL_RTX);
3561 
3562 	  if (note == NULL_RTX && REG_BASIC_BLOCK (regno) >= NUM_FIXED_BLOCKS
3563 	      && MEM_P (SET_SRC (set))
3564 	      && validate_equiv_mem (insn, dest, SET_SRC (set)))
3565 	    note = set_unique_reg_note (insn, REG_EQUIV, copy_rtx (SET_SRC (set)));
3566 
3567 	  if (note)
3568 	    {
3569 	      int regno = REGNO (dest);
3570 	      rtx x = XEXP (note, 0);
3571 
3572 	      /* If we haven't done so, record for reload that this is an
3573 		 equivalencing insn.  */
3574 	      if (!reg_equiv[regno].is_arg_equivalence)
3575 		ira_reg_equiv[regno].init_insns
3576 		  = gen_rtx_INSN_LIST (VOIDmode, insn,
3577 				       ira_reg_equiv[regno].init_insns);
3578 
3579 	      reg_equiv[regno].replacement = x;
3580 	      reg_equiv[regno].src_p = &SET_SRC (set);
3581 	      reg_equiv[regno].loop_depth = (short) loop_depth;
3582 
3583 	      /* Don't mess with things live during setjmp.  */
3584 	      if (REG_LIVE_LENGTH (regno) >= 0 && optimize)
3585 		{
3586 		  /* Note that the statement below does not affect the priority
3587 		     in local-alloc!  */
3588 		  REG_LIVE_LENGTH (regno) *= 2;
3589 
3590 		  /* If the register is referenced exactly twice, meaning it is
3591 		     set once and used once, indicate that the reference may be
3592 		     replaced by the equivalence we computed above.  Do this
3593 		     even if the register is only used in one block so that
3594 		     dependencies can be handled where the last register is
3595 		     used in a different block (i.e. HIGH / LO_SUM sequences)
3596 		     and to reduce the number of registers alive across
3597 		     calls.  */
3598 
3599 		  if (REG_N_REFS (regno) == 2
3600 		      && (rtx_equal_p (x, src)
3601 			  || ! equiv_init_varies_p (src))
3602 		      && NONJUMP_INSN_P (insn)
3603 		      && equiv_init_movable_p (PATTERN (insn), regno))
3604 		    reg_equiv[regno].replace = 1;
3605 		}
3606 	    }
3607 	}
3608     }
3609 
3610   if (!optimize)
3611     goto out;
3612 
3613   /* A second pass, to gather additional equivalences with memory.  This needs
3614      to be done after we know which registers we are going to replace.  */
3615 
3616   bitmap_initialize (&seen_insns, NULL);
3617   for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3618     {
3619       rtx set, src, dest;
3620       unsigned regno;
3621 
3622       bitmap_set_bit (&seen_insns, INSN_UID (insn));
3623 
3624       if (! INSN_P (insn))
3625 	continue;
3626 
3627       set = single_set (insn);
3628       if (! set)
3629 	continue;
3630 
3631       dest = SET_DEST (set);
3632       src = SET_SRC (set);
3633 
3634       /* If this sets a MEM to the contents of a REG that is only used
3635 	 in a single basic block, see if the register is always equivalent
3636 	 to that memory location and if moving the store from INSN to the
3637 	 insn that set REG is safe.  If so, put a REG_EQUIV note on the
3638 	 initializing insn.
3639 
3640 	 Don't add a REG_EQUIV note if the insn already has one.  The existing
3641 	 REG_EQUIV is likely more useful than the one we are adding.
3642 
3643 	 If one of the regs in the address has reg_equiv[REGNO].replace set,
3644 	 then we can't add this REG_EQUIV note.  The reg_equiv[REGNO].replace
3645 	 optimization may move the set of this register immediately before
3646 	 insn, which puts it after reg_equiv[REGNO].init_insns, and hence
3647 	 the mention in the REG_EQUIV note would be to an uninitialized
3648 	 pseudo.  */
3649 
3650       if (MEM_P (dest) && REG_P (src)
3651 	  && (regno = REGNO (src)) >= FIRST_PSEUDO_REGISTER
3652 	  && REG_BASIC_BLOCK (regno) >= NUM_FIXED_BLOCKS
3653 	  && DF_REG_DEF_COUNT (regno) == 1
3654 	  && reg_equiv[regno].init_insns != NULL
3655 	  && reg_equiv[regno].init_insns->insn () != NULL
3656 	  && ! find_reg_note (XEXP (reg_equiv[regno].init_insns, 0),
3657 			      REG_EQUIV, NULL_RTX)
3658 	  && ! contains_replace_regs (XEXP (dest, 0))
3659 	  && ! pdx_subregs[regno])
3660 	{
3661 	  rtx_insn *init_insn =
3662 	    as_a <rtx_insn *> (XEXP (reg_equiv[regno].init_insns, 0));
3663 	  if (validate_equiv_mem (init_insn, src, dest)
3664 	      && bitmap_bit_p (&seen_insns, INSN_UID (init_insn))
3665 	      && ! memref_used_between_p (dest, init_insn, insn)
3666 	      /* Attaching a REG_EQUIV note will fail if INIT_INSN has
3667 		 multiple sets.  */
3668 	      && set_unique_reg_note (init_insn, REG_EQUIV, copy_rtx (dest)))
3669 	    {
3670 	      /* This insn makes the equivalence, not the one initializing
3671 		 the register.  */
3672 	      ira_reg_equiv[regno].init_insns
3673 		= gen_rtx_INSN_LIST (VOIDmode, insn, NULL_RTX);
3674 	      df_notes_rescan (init_insn);
3675 	      if (dump_file)
3676 		fprintf (dump_file,
3677 			 "Adding REG_EQUIV to insn %d for source of insn %d\n",
3678 			 INSN_UID (init_insn),
3679 			 INSN_UID (insn));
3680 	    }
3681 	}
3682     }
3683   bitmap_clear (&seen_insns);
3684 
3685   cleared_regs = BITMAP_ALLOC (NULL);
3686   /* Now scan all regs killed in an insn to see if any of them are
3687      registers only used that once.  If so, see if we can replace the
3688      reference with the equivalent form.  If we can, delete the
3689      initializing reference and this register will go away.  If we
3690      can't replace the reference, and the initializing reference is
3691      within the same loop (or in an inner loop), then move the register
3692      initialization just before the use, so that they are in the same
3693      basic block.  */
3694   FOR_EACH_BB_REVERSE_FN (bb, cfun)
3695     {
3696       loop_depth = bb_loop_depth (bb);
3697       for (insn = BB_END (bb);
3698 	   insn != PREV_INSN (BB_HEAD (bb));
3699 	   insn = PREV_INSN (insn))
3700 	{
3701 	  rtx link;
3702 
3703 	  if (! INSN_P (insn))
3704 	    continue;
3705 
3706 	  /* Don't substitute into jumps.  indirect_jump_optimize does
3707 	     this for anything we are prepared to handle.  */
3708 	  if (JUMP_P (insn))
3709 	    continue;
3710 
3711 	  for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
3712 	    {
3713 	      if (REG_NOTE_KIND (link) == REG_DEAD
3714 		  /* Make sure this insn still refers to the register.  */
3715 		  && reg_mentioned_p (XEXP (link, 0), PATTERN (insn)))
3716 		{
3717 		  int regno = REGNO (XEXP (link, 0));
3718 		  rtx equiv_insn;
3719 
3720 		  if (! reg_equiv[regno].replace
3721 		      || reg_equiv[regno].loop_depth < (short) loop_depth
3722 		      /* There is no sense to move insns if live range
3723 			 shrinkage or register pressure-sensitive
3724 			 scheduling were done because it will not
3725 			 improve allocation but worsen insn schedule
3726 			 with a big probability.  */
3727 		      || flag_live_range_shrinkage
3728 		      || (flag_sched_pressure && flag_schedule_insns))
3729 		    continue;
3730 
3731 		  /* reg_equiv[REGNO].replace gets set only when
3732 		     REG_N_REFS[REGNO] is 2, i.e. the register is set
3733 		     once and used once.  (If it were only set, but
3734 		     not used, flow would have deleted the setting
3735 		     insns.)  Hence there can only be one insn in
3736 		     reg_equiv[REGNO].init_insns.  */
3737 		  gcc_assert (reg_equiv[regno].init_insns
3738 			      && !XEXP (reg_equiv[regno].init_insns, 1));
3739 		  equiv_insn = XEXP (reg_equiv[regno].init_insns, 0);
3740 
3741 		  /* We may not move instructions that can throw, since
3742 		     that changes basic block boundaries and we are not
3743 		     prepared to adjust the CFG to match.  */
3744 		  if (can_throw_internal (equiv_insn))
3745 		    continue;
3746 
3747 		  if (asm_noperands (PATTERN (equiv_insn)) < 0
3748 		      && validate_replace_rtx (regno_reg_rtx[regno],
3749 					       *(reg_equiv[regno].src_p), insn))
3750 		    {
3751 		      rtx equiv_link;
3752 		      rtx last_link;
3753 		      rtx note;
3754 
3755 		      /* Find the last note.  */
3756 		      for (last_link = link; XEXP (last_link, 1);
3757 			   last_link = XEXP (last_link, 1))
3758 			;
3759 
3760 		      /* Append the REG_DEAD notes from equiv_insn.  */
3761 		      equiv_link = REG_NOTES (equiv_insn);
3762 		      while (equiv_link)
3763 			{
3764 			  note = equiv_link;
3765 			  equiv_link = XEXP (equiv_link, 1);
3766 			  if (REG_NOTE_KIND (note) == REG_DEAD)
3767 			    {
3768 			      remove_note (equiv_insn, note);
3769 			      XEXP (last_link, 1) = note;
3770 			      XEXP (note, 1) = NULL_RTX;
3771 			      last_link = note;
3772 			    }
3773 			}
3774 
3775 		      remove_death (regno, insn);
3776 		      SET_REG_N_REFS (regno, 0);
3777 		      REG_FREQ (regno) = 0;
3778 		      delete_insn (equiv_insn);
3779 
3780 		      reg_equiv[regno].init_insns
3781 			= reg_equiv[regno].init_insns->next ();
3782 
3783 		      ira_reg_equiv[regno].init_insns = NULL;
3784 		      bitmap_set_bit (cleared_regs, regno);
3785 		    }
3786 		  /* Move the initialization of the register to just before
3787 		     INSN.  Update the flow information.  */
3788 		  else if (prev_nondebug_insn (insn) != equiv_insn)
3789 		    {
3790 		      rtx_insn *new_insn;
3791 
3792 		      new_insn = emit_insn_before (PATTERN (equiv_insn), insn);
3793 		      REG_NOTES (new_insn) = REG_NOTES (equiv_insn);
3794 		      REG_NOTES (equiv_insn) = 0;
3795 		      /* Rescan it to process the notes.  */
3796 		      df_insn_rescan (new_insn);
3797 
3798 		      /* Make sure this insn is recognized before
3799 			 reload begins, otherwise
3800 			 eliminate_regs_in_insn will die.  */
3801 		      INSN_CODE (new_insn) = INSN_CODE (equiv_insn);
3802 
3803 		      delete_insn (equiv_insn);
3804 
3805 		      XEXP (reg_equiv[regno].init_insns, 0) = new_insn;
3806 
3807 		      REG_BASIC_BLOCK (regno) = bb->index;
3808 		      REG_N_CALLS_CROSSED (regno) = 0;
3809 		      REG_FREQ_CALLS_CROSSED (regno) = 0;
3810 		      REG_N_THROWING_CALLS_CROSSED (regno) = 0;
3811 		      REG_LIVE_LENGTH (regno) = 2;
3812 
3813 		      if (insn == BB_HEAD (bb))
3814 			BB_HEAD (bb) = PREV_INSN (insn);
3815 
3816 		      ira_reg_equiv[regno].init_insns
3817 			= gen_rtx_INSN_LIST (VOIDmode, new_insn, NULL_RTX);
3818 		      bitmap_set_bit (cleared_regs, regno);
3819 		    }
3820 		}
3821 	    }
3822 	}
3823     }
3824 
3825   if (!bitmap_empty_p (cleared_regs))
3826     {
3827       FOR_EACH_BB_FN (bb, cfun)
3828 	{
3829 	  bitmap_and_compl_into (DF_LR_IN (bb), cleared_regs);
3830 	  bitmap_and_compl_into (DF_LR_OUT (bb), cleared_regs);
3831 	  if (! df_live)
3832 	    continue;
3833 	  bitmap_and_compl_into (DF_LIVE_IN (bb), cleared_regs);
3834 	  bitmap_and_compl_into (DF_LIVE_OUT (bb), cleared_regs);
3835 	}
3836 
3837       /* Last pass - adjust debug insns referencing cleared regs.  */
3838       if (MAY_HAVE_DEBUG_INSNS)
3839 	for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3840 	  if (DEBUG_INSN_P (insn))
3841 	    {
3842 	      rtx old_loc = INSN_VAR_LOCATION_LOC (insn);
3843 	      INSN_VAR_LOCATION_LOC (insn)
3844 		= simplify_replace_fn_rtx (old_loc, NULL_RTX,
3845 					   adjust_cleared_regs,
3846 					   (void *) cleared_regs);
3847 	      if (old_loc != INSN_VAR_LOCATION_LOC (insn))
3848 		df_insn_rescan (insn);
3849 	    }
3850     }
3851 
3852   BITMAP_FREE (cleared_regs);
3853 
3854   out:
3855   /* Clean up.  */
3856 
3857   end_alias_analysis ();
3858   free (reg_equiv);
3859   free (pdx_subregs);
3860 }
3861 
3862 /* A pass over indirect jumps, converting simple cases to direct jumps.
3863    Combine does this optimization too, but only within a basic block.  */
3864 static void
3865 indirect_jump_optimize (void)
3866 {
3867   basic_block bb;
3868   bool rebuild_p = false;
3869 
3870   FOR_EACH_BB_REVERSE_FN (bb, cfun)
3871     {
3872       rtx_insn *insn = BB_END (bb);
3873       if (!JUMP_P (insn)
3874 	  || find_reg_note (insn, REG_NON_LOCAL_GOTO, NULL_RTX))
3875 	continue;
3876 
3877       rtx x = pc_set (insn);
3878       if (!x || !REG_P (SET_SRC (x)))
3879 	continue;
3880 
3881       int regno = REGNO (SET_SRC (x));
3882       if (DF_REG_DEF_COUNT (regno) == 1)
3883 	{
3884 	  df_ref def = DF_REG_DEF_CHAIN (regno);
3885 	  if (!DF_REF_IS_ARTIFICIAL (def))
3886 	    {
3887 	      rtx_insn *def_insn = DF_REF_INSN (def);
3888 	      rtx lab = NULL_RTX;
3889 	      rtx set = single_set (def_insn);
3890 	      if (set && GET_CODE (SET_SRC (set)) == LABEL_REF)
3891 		lab = SET_SRC (set);
3892 	      else
3893 		{
3894 		  rtx eqnote = find_reg_note (def_insn, REG_EQUAL, NULL_RTX);
3895 		  if (eqnote && GET_CODE (XEXP (eqnote, 0)) == LABEL_REF)
3896 		    lab = XEXP (eqnote, 0);
3897 		}
3898 	      if (lab && validate_replace_rtx (SET_SRC (x), lab, insn))
3899 		rebuild_p = true;
3900 	    }
3901 	}
3902     }
3903 
3904   if (rebuild_p)
3905     {
3906       timevar_push (TV_JUMP);
3907       rebuild_jump_labels (get_insns ());
3908       if (purge_all_dead_edges ())
3909 	delete_unreachable_blocks ();
3910       timevar_pop (TV_JUMP);
3911     }
3912 }
3913 
3914 /* Set up fields memory, constant, and invariant from init_insns in
3915    the structures of array ira_reg_equiv.  */
3916 static void
3917 setup_reg_equiv (void)
3918 {
3919   int i;
3920   rtx_insn_list *elem, *prev_elem, *next_elem;
3921   rtx_insn *insn;
3922   rtx set, x;
3923 
3924   for (i = FIRST_PSEUDO_REGISTER; i < ira_reg_equiv_len; i++)
3925     for (prev_elem = NULL, elem = ira_reg_equiv[i].init_insns;
3926 	 elem;
3927 	 prev_elem = elem, elem = next_elem)
3928       {
3929 	next_elem = elem->next ();
3930 	insn = elem->insn ();
3931 	set = single_set (insn);
3932 
3933 	/* Init insns can set up equivalence when the reg is a destination or
3934 	   a source (in this case the destination is memory).  */
3935 	if (set != 0 && (REG_P (SET_DEST (set)) || REG_P (SET_SRC (set))))
3936 	  {
3937 	    if ((x = find_reg_note (insn, REG_EQUIV, NULL_RTX)) != NULL)
3938 	      {
3939 		x = XEXP (x, 0);
3940 		if (REG_P (SET_DEST (set))
3941 		    && REGNO (SET_DEST (set)) == (unsigned int) i
3942 		    && ! rtx_equal_p (SET_SRC (set), x) && MEM_P (x))
3943 		  {
3944 		    /* This insn reporting the equivalence but
3945 		       actually not setting it.  Remove it from the
3946 		       list.  */
3947 		    if (prev_elem == NULL)
3948 		      ira_reg_equiv[i].init_insns = next_elem;
3949 		    else
3950 		      XEXP (prev_elem, 1) = next_elem;
3951 		    elem = prev_elem;
3952 		  }
3953 	      }
3954 	    else if (REG_P (SET_DEST (set))
3955 		     && REGNO (SET_DEST (set)) == (unsigned int) i)
3956 	      x = SET_SRC (set);
3957 	    else
3958 	      {
3959 		gcc_assert (REG_P (SET_SRC (set))
3960 			    && REGNO (SET_SRC (set)) == (unsigned int) i);
3961 		x = SET_DEST (set);
3962 	      }
3963 	    if (! function_invariant_p (x)
3964 		|| ! flag_pic
3965 		/* A function invariant is often CONSTANT_P but may
3966 		   include a register.  We promise to only pass
3967 		   CONSTANT_P objects to LEGITIMATE_PIC_OPERAND_P.  */
3968 		|| (CONSTANT_P (x) && LEGITIMATE_PIC_OPERAND_P (x)))
3969 	      {
3970 		/* It can happen that a REG_EQUIV note contains a MEM
3971 		   that is not a legitimate memory operand.  As later
3972 		   stages of reload assume that all addresses found in
3973 		   the lra_regno_equiv_* arrays were originally
3974 		   legitimate, we ignore such REG_EQUIV notes.  */
3975 		if (memory_operand (x, VOIDmode))
3976 		  {
3977 		    ira_reg_equiv[i].defined_p = true;
3978 		    ira_reg_equiv[i].memory = x;
3979 		    continue;
3980 		  }
3981 		else if (function_invariant_p (x))
3982 		  {
3983 		    machine_mode mode;
3984 
3985 		    mode = GET_MODE (SET_DEST (set));
3986 		    if (GET_CODE (x) == PLUS
3987 			|| x == frame_pointer_rtx || x == arg_pointer_rtx)
3988 		      /* This is PLUS of frame pointer and a constant,
3989 			 or fp, or argp.  */
3990 		      ira_reg_equiv[i].invariant = x;
3991 		    else if (targetm.legitimate_constant_p (mode, x))
3992 		      ira_reg_equiv[i].constant = x;
3993 		    else
3994 		      {
3995 			ira_reg_equiv[i].memory = force_const_mem (mode, x);
3996 			if (ira_reg_equiv[i].memory == NULL_RTX)
3997 			  {
3998 			    ira_reg_equiv[i].defined_p = false;
3999 			    ira_reg_equiv[i].init_insns = NULL;
4000 			    break;
4001 			  }
4002 		      }
4003 		    ira_reg_equiv[i].defined_p = true;
4004 		    continue;
4005 		  }
4006 	      }
4007 	  }
4008 	ira_reg_equiv[i].defined_p = false;
4009 	ira_reg_equiv[i].init_insns = NULL;
4010 	break;
4011       }
4012 }
4013 
4014 
4015 
4016 /* Print chain C to FILE.  */
4017 static void
4018 print_insn_chain (FILE *file, struct insn_chain *c)
4019 {
4020   fprintf (file, "insn=%d, ", INSN_UID (c->insn));
4021   bitmap_print (file, &c->live_throughout, "live_throughout: ", ", ");
4022   bitmap_print (file, &c->dead_or_set, "dead_or_set: ", "\n");
4023 }
4024 
4025 
4026 /* Print all reload_insn_chains to FILE.  */
4027 static void
4028 print_insn_chains (FILE *file)
4029 {
4030   struct insn_chain *c;
4031   for (c = reload_insn_chain; c ; c = c->next)
4032     print_insn_chain (file, c);
4033 }
4034 
4035 /* Return true if pseudo REGNO should be added to set live_throughout
4036    or dead_or_set of the insn chains for reload consideration.  */
4037 static bool
4038 pseudo_for_reload_consideration_p (int regno)
4039 {
4040   /* Consider spilled pseudos too for IRA because they still have a
4041      chance to get hard-registers in the reload when IRA is used.  */
4042   return (reg_renumber[regno] >= 0 || ira_conflicts_p);
4043 }
4044 
4045 /* Init LIVE_SUBREGS[ALLOCNUM] and LIVE_SUBREGS_USED[ALLOCNUM] using
4046    REG to the number of nregs, and INIT_VALUE to get the
4047    initialization.  ALLOCNUM need not be the regno of REG.  */
4048 static void
4049 init_live_subregs (bool init_value, sbitmap *live_subregs,
4050 		   bitmap live_subregs_used, int allocnum, rtx reg)
4051 {
4052   unsigned int regno = REGNO (SUBREG_REG (reg));
4053   int size = GET_MODE_SIZE (GET_MODE (regno_reg_rtx[regno]));
4054 
4055   gcc_assert (size > 0);
4056 
4057   /* Been there, done that.  */
4058   if (bitmap_bit_p (live_subregs_used, allocnum))
4059     return;
4060 
4061   /* Create a new one.  */
4062   if (live_subregs[allocnum] == NULL)
4063     live_subregs[allocnum] = sbitmap_alloc (size);
4064 
4065   /* If the entire reg was live before blasting into subregs, we need
4066      to init all of the subregs to ones else init to 0.  */
4067   if (init_value)
4068     bitmap_ones (live_subregs[allocnum]);
4069   else
4070     bitmap_clear (live_subregs[allocnum]);
4071 
4072   bitmap_set_bit (live_subregs_used, allocnum);
4073 }
4074 
4075 /* Walk the insns of the current function and build reload_insn_chain,
4076    and record register life information.  */
4077 static void
4078 build_insn_chain (void)
4079 {
4080   unsigned int i;
4081   struct insn_chain **p = &reload_insn_chain;
4082   basic_block bb;
4083   struct insn_chain *c = NULL;
4084   struct insn_chain *next = NULL;
4085   bitmap live_relevant_regs = BITMAP_ALLOC (NULL);
4086   bitmap elim_regset = BITMAP_ALLOC (NULL);
4087   /* live_subregs is a vector used to keep accurate information about
4088      which hardregs are live in multiword pseudos.  live_subregs and
4089      live_subregs_used are indexed by pseudo number.  The live_subreg
4090      entry for a particular pseudo is only used if the corresponding
4091      element is non zero in live_subregs_used.  The sbitmap size of
4092      live_subreg[allocno] is number of bytes that the pseudo can
4093      occupy.  */
4094   sbitmap *live_subregs = XCNEWVEC (sbitmap, max_regno);
4095   bitmap live_subregs_used = BITMAP_ALLOC (NULL);
4096 
4097   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
4098     if (TEST_HARD_REG_BIT (eliminable_regset, i))
4099       bitmap_set_bit (elim_regset, i);
4100   FOR_EACH_BB_REVERSE_FN (bb, cfun)
4101     {
4102       bitmap_iterator bi;
4103       rtx_insn *insn;
4104 
4105       CLEAR_REG_SET (live_relevant_regs);
4106       bitmap_clear (live_subregs_used);
4107 
4108       EXECUTE_IF_SET_IN_BITMAP (df_get_live_out (bb), 0, i, bi)
4109 	{
4110 	  if (i >= FIRST_PSEUDO_REGISTER)
4111 	    break;
4112 	  bitmap_set_bit (live_relevant_regs, i);
4113 	}
4114 
4115       EXECUTE_IF_SET_IN_BITMAP (df_get_live_out (bb),
4116 				FIRST_PSEUDO_REGISTER, i, bi)
4117 	{
4118 	  if (pseudo_for_reload_consideration_p (i))
4119 	    bitmap_set_bit (live_relevant_regs, i);
4120 	}
4121 
4122       FOR_BB_INSNS_REVERSE (bb, insn)
4123 	{
4124 	  if (!NOTE_P (insn) && !BARRIER_P (insn))
4125 	    {
4126 	      struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
4127 	      df_ref def, use;
4128 
4129 	      c = new_insn_chain ();
4130 	      c->next = next;
4131 	      next = c;
4132 	      *p = c;
4133 	      p = &c->prev;
4134 
4135 	      c->insn = insn;
4136 	      c->block = bb->index;
4137 
4138 	      if (NONDEBUG_INSN_P (insn))
4139 		FOR_EACH_INSN_INFO_DEF (def, insn_info)
4140 		  {
4141 		    unsigned int regno = DF_REF_REGNO (def);
4142 
4143 		    /* Ignore may clobbers because these are generated
4144 		       from calls. However, every other kind of def is
4145 		       added to dead_or_set.  */
4146 		    if (!DF_REF_FLAGS_IS_SET (def, DF_REF_MAY_CLOBBER))
4147 		      {
4148 			if (regno < FIRST_PSEUDO_REGISTER)
4149 			  {
4150 			    if (!fixed_regs[regno])
4151 			      bitmap_set_bit (&c->dead_or_set, regno);
4152 			  }
4153 			else if (pseudo_for_reload_consideration_p (regno))
4154 			  bitmap_set_bit (&c->dead_or_set, regno);
4155 		      }
4156 
4157 		    if ((regno < FIRST_PSEUDO_REGISTER
4158 			 || reg_renumber[regno] >= 0
4159 			 || ira_conflicts_p)
4160 			&& (!DF_REF_FLAGS_IS_SET (def, DF_REF_CONDITIONAL)))
4161 		      {
4162 			rtx reg = DF_REF_REG (def);
4163 
4164 			/* We can model subregs, but not if they are
4165 			   wrapped in ZERO_EXTRACTS.  */
4166 			if (GET_CODE (reg) == SUBREG
4167 			    && !DF_REF_FLAGS_IS_SET (def, DF_REF_ZERO_EXTRACT))
4168 			  {
4169 			    unsigned int start = SUBREG_BYTE (reg);
4170 			    unsigned int last = start
4171 			      + GET_MODE_SIZE (GET_MODE (reg));
4172 
4173 			    init_live_subregs
4174 			      (bitmap_bit_p (live_relevant_regs, regno),
4175 			       live_subregs, live_subregs_used, regno, reg);
4176 
4177 			    if (!DF_REF_FLAGS_IS_SET
4178 				(def, DF_REF_STRICT_LOW_PART))
4179 			      {
4180 				/* Expand the range to cover entire words.
4181 				   Bytes added here are "don't care".  */
4182 				start
4183 				  = start / UNITS_PER_WORD * UNITS_PER_WORD;
4184 				last = ((last + UNITS_PER_WORD - 1)
4185 					/ UNITS_PER_WORD * UNITS_PER_WORD);
4186 			      }
4187 
4188 			    /* Ignore the paradoxical bits.  */
4189 			    if (last > SBITMAP_SIZE (live_subregs[regno]))
4190 			      last = SBITMAP_SIZE (live_subregs[regno]);
4191 
4192 			    while (start < last)
4193 			      {
4194 				bitmap_clear_bit (live_subregs[regno], start);
4195 				start++;
4196 			      }
4197 
4198 			    if (bitmap_empty_p (live_subregs[regno]))
4199 			      {
4200 				bitmap_clear_bit (live_subregs_used, regno);
4201 				bitmap_clear_bit (live_relevant_regs, regno);
4202 			      }
4203 			    else
4204 			      /* Set live_relevant_regs here because
4205 				 that bit has to be true to get us to
4206 				 look at the live_subregs fields.  */
4207 			      bitmap_set_bit (live_relevant_regs, regno);
4208 			  }
4209 			else
4210 			  {
4211 			    /* DF_REF_PARTIAL is generated for
4212 			       subregs, STRICT_LOW_PART, and
4213 			       ZERO_EXTRACT.  We handle the subreg
4214 			       case above so here we have to keep from
4215 			       modeling the def as a killing def.  */
4216 			    if (!DF_REF_FLAGS_IS_SET (def, DF_REF_PARTIAL))
4217 			      {
4218 				bitmap_clear_bit (live_subregs_used, regno);
4219 				bitmap_clear_bit (live_relevant_regs, regno);
4220 			      }
4221 			  }
4222 		      }
4223 		  }
4224 
4225 	      bitmap_and_compl_into (live_relevant_regs, elim_regset);
4226 	      bitmap_copy (&c->live_throughout, live_relevant_regs);
4227 
4228 	      if (NONDEBUG_INSN_P (insn))
4229 		FOR_EACH_INSN_INFO_USE (use, insn_info)
4230 		  {
4231 		    unsigned int regno = DF_REF_REGNO (use);
4232 		    rtx reg = DF_REF_REG (use);
4233 
4234 		    /* DF_REF_READ_WRITE on a use means that this use
4235 		       is fabricated from a def that is a partial set
4236 		       to a multiword reg.  Here, we only model the
4237 		       subreg case that is not wrapped in ZERO_EXTRACT
4238 		       precisely so we do not need to look at the
4239 		       fabricated use.  */
4240 		    if (DF_REF_FLAGS_IS_SET (use, DF_REF_READ_WRITE)
4241 			&& !DF_REF_FLAGS_IS_SET (use, DF_REF_ZERO_EXTRACT)
4242 			&& DF_REF_FLAGS_IS_SET (use, DF_REF_SUBREG))
4243 		      continue;
4244 
4245 		    /* Add the last use of each var to dead_or_set.  */
4246 		    if (!bitmap_bit_p (live_relevant_regs, regno))
4247 		      {
4248 			if (regno < FIRST_PSEUDO_REGISTER)
4249 			  {
4250 			    if (!fixed_regs[regno])
4251 			      bitmap_set_bit (&c->dead_or_set, regno);
4252 			  }
4253 			else if (pseudo_for_reload_consideration_p (regno))
4254 			  bitmap_set_bit (&c->dead_or_set, regno);
4255 		      }
4256 
4257 		    if (regno < FIRST_PSEUDO_REGISTER
4258 			|| pseudo_for_reload_consideration_p (regno))
4259 		      {
4260 			if (GET_CODE (reg) == SUBREG
4261 			    && !DF_REF_FLAGS_IS_SET (use,
4262 						     DF_REF_SIGN_EXTRACT
4263 						     | DF_REF_ZERO_EXTRACT))
4264 			  {
4265 			    unsigned int start = SUBREG_BYTE (reg);
4266 			    unsigned int last = start
4267 			      + GET_MODE_SIZE (GET_MODE (reg));
4268 
4269 			    init_live_subregs
4270 			      (bitmap_bit_p (live_relevant_regs, regno),
4271 			       live_subregs, live_subregs_used, regno, reg);
4272 
4273 			    /* Ignore the paradoxical bits.  */
4274 			    if (last > SBITMAP_SIZE (live_subregs[regno]))
4275 			      last = SBITMAP_SIZE (live_subregs[regno]);
4276 
4277 			    while (start < last)
4278 			      {
4279 				bitmap_set_bit (live_subregs[regno], start);
4280 				start++;
4281 			      }
4282 			  }
4283 			else
4284 			  /* Resetting the live_subregs_used is
4285 			     effectively saying do not use the subregs
4286 			     because we are reading the whole
4287 			     pseudo.  */
4288 			  bitmap_clear_bit (live_subregs_used, regno);
4289 			bitmap_set_bit (live_relevant_regs, regno);
4290 		      }
4291 		  }
4292 	    }
4293 	}
4294 
4295       /* FIXME!! The following code is a disaster.  Reload needs to see the
4296 	 labels and jump tables that are just hanging out in between
4297 	 the basic blocks.  See pr33676.  */
4298       insn = BB_HEAD (bb);
4299 
4300       /* Skip over the barriers and cruft.  */
4301       while (insn && (BARRIER_P (insn) || NOTE_P (insn)
4302 		      || BLOCK_FOR_INSN (insn) == bb))
4303 	insn = PREV_INSN (insn);
4304 
4305       /* While we add anything except barriers and notes, the focus is
4306 	 to get the labels and jump tables into the
4307 	 reload_insn_chain.  */
4308       while (insn)
4309 	{
4310 	  if (!NOTE_P (insn) && !BARRIER_P (insn))
4311 	    {
4312 	      if (BLOCK_FOR_INSN (insn))
4313 		break;
4314 
4315 	      c = new_insn_chain ();
4316 	      c->next = next;
4317 	      next = c;
4318 	      *p = c;
4319 	      p = &c->prev;
4320 
4321 	      /* The block makes no sense here, but it is what the old
4322 		 code did.  */
4323 	      c->block = bb->index;
4324 	      c->insn = insn;
4325 	      bitmap_copy (&c->live_throughout, live_relevant_regs);
4326 	    }
4327 	  insn = PREV_INSN (insn);
4328 	}
4329     }
4330 
4331   reload_insn_chain = c;
4332   *p = NULL;
4333 
4334   for (i = 0; i < (unsigned int) max_regno; i++)
4335     if (live_subregs[i] != NULL)
4336       sbitmap_free (live_subregs[i]);
4337   free (live_subregs);
4338   BITMAP_FREE (live_subregs_used);
4339   BITMAP_FREE (live_relevant_regs);
4340   BITMAP_FREE (elim_regset);
4341 
4342   if (dump_file)
4343     print_insn_chains (dump_file);
4344 }
4345 
4346 /* Examine the rtx found in *LOC, which is read or written to as determined
4347    by TYPE.  Return false if we find a reason why an insn containing this
4348    rtx should not be moved (such as accesses to non-constant memory), true
4349    otherwise.  */
4350 static bool
4351 rtx_moveable_p (rtx *loc, enum op_type type)
4352 {
4353   const char *fmt;
4354   rtx x = *loc;
4355   enum rtx_code code = GET_CODE (x);
4356   int i, j;
4357 
4358   code = GET_CODE (x);
4359   switch (code)
4360     {
4361     case CONST:
4362     CASE_CONST_ANY:
4363     case SYMBOL_REF:
4364     case LABEL_REF:
4365       return true;
4366 
4367     case PC:
4368       return type == OP_IN;
4369 
4370     case CC0:
4371       return false;
4372 
4373     case REG:
4374       if (x == frame_pointer_rtx)
4375 	return true;
4376       if (HARD_REGISTER_P (x))
4377 	return false;
4378 
4379       return true;
4380 
4381     case MEM:
4382       if (type == OP_IN && MEM_READONLY_P (x))
4383 	return rtx_moveable_p (&XEXP (x, 0), OP_IN);
4384       return false;
4385 
4386     case SET:
4387       return (rtx_moveable_p (&SET_SRC (x), OP_IN)
4388 	      && rtx_moveable_p (&SET_DEST (x), OP_OUT));
4389 
4390     case STRICT_LOW_PART:
4391       return rtx_moveable_p (&XEXP (x, 0), OP_OUT);
4392 
4393     case ZERO_EXTRACT:
4394     case SIGN_EXTRACT:
4395       return (rtx_moveable_p (&XEXP (x, 0), type)
4396 	      && rtx_moveable_p (&XEXP (x, 1), OP_IN)
4397 	      && rtx_moveable_p (&XEXP (x, 2), OP_IN));
4398 
4399     case CLOBBER:
4400       return rtx_moveable_p (&SET_DEST (x), OP_OUT);
4401 
4402     case UNSPEC_VOLATILE:
4403       /* It is a bad idea to consider insns with such rtl
4404 	 as moveable ones.  The insn scheduler also considers them as barrier
4405 	 for a reason.  */
4406       return false;
4407 
4408     default:
4409       break;
4410     }
4411 
4412   fmt = GET_RTX_FORMAT (code);
4413   for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
4414     {
4415       if (fmt[i] == 'e')
4416 	{
4417 	  if (!rtx_moveable_p (&XEXP (x, i), type))
4418 	    return false;
4419 	}
4420       else if (fmt[i] == 'E')
4421 	for (j = XVECLEN (x, i) - 1; j >= 0; j--)
4422 	  {
4423 	    if (!rtx_moveable_p (&XVECEXP (x, i, j), type))
4424 	      return false;
4425 	  }
4426     }
4427   return true;
4428 }
4429 
4430 /* A wrapper around dominated_by_p, which uses the information in UID_LUID
4431    to give dominance relationships between two insns I1 and I2.  */
4432 static bool
4433 insn_dominated_by_p (rtx i1, rtx i2, int *uid_luid)
4434 {
4435   basic_block bb1 = BLOCK_FOR_INSN (i1);
4436   basic_block bb2 = BLOCK_FOR_INSN (i2);
4437 
4438   if (bb1 == bb2)
4439     return uid_luid[INSN_UID (i2)] < uid_luid[INSN_UID (i1)];
4440   return dominated_by_p (CDI_DOMINATORS, bb1, bb2);
4441 }
4442 
4443 /* Record the range of register numbers added by find_moveable_pseudos.  */
4444 int first_moveable_pseudo, last_moveable_pseudo;
4445 
4446 /* These two vectors hold data for every register added by
4447    find_movable_pseudos, with index 0 holding data for the
4448    first_moveable_pseudo.  */
4449 /* The original home register.  */
4450 static vec<rtx> pseudo_replaced_reg;
4451 
4452 /* Look for instances where we have an instruction that is known to increase
4453    register pressure, and whose result is not used immediately.  If it is
4454    possible to move the instruction downwards to just before its first use,
4455    split its lifetime into two ranges.  We create a new pseudo to compute the
4456    value, and emit a move instruction just before the first use.  If, after
4457    register allocation, the new pseudo remains unallocated, the function
4458    move_unallocated_pseudos then deletes the move instruction and places
4459    the computation just before the first use.
4460 
4461    Such a move is safe and profitable if all the input registers remain live
4462    and unchanged between the original computation and its first use.  In such
4463    a situation, the computation is known to increase register pressure, and
4464    moving it is known to at least not worsen it.
4465 
4466    We restrict moves to only those cases where a register remains unallocated,
4467    in order to avoid interfering too much with the instruction schedule.  As
4468    an exception, we may move insns which only modify their input register
4469    (typically induction variables), as this increases the freedom for our
4470    intended transformation, and does not limit the second instruction
4471    scheduler pass.  */
4472 
4473 static void
4474 find_moveable_pseudos (void)
4475 {
4476   unsigned i;
4477   int max_regs = max_reg_num ();
4478   int max_uid = get_max_uid ();
4479   basic_block bb;
4480   int *uid_luid = XNEWVEC (int, max_uid);
4481   rtx_insn **closest_uses = XNEWVEC (rtx_insn *, max_regs);
4482   /* A set of registers which are live but not modified throughout a block.  */
4483   bitmap_head *bb_transp_live = XNEWVEC (bitmap_head,
4484 					 last_basic_block_for_fn (cfun));
4485   /* A set of registers which only exist in a given basic block.  */
4486   bitmap_head *bb_local = XNEWVEC (bitmap_head,
4487 				   last_basic_block_for_fn (cfun));
4488   /* A set of registers which are set once, in an instruction that can be
4489      moved freely downwards, but are otherwise transparent to a block.  */
4490   bitmap_head *bb_moveable_reg_sets = XNEWVEC (bitmap_head,
4491 					       last_basic_block_for_fn (cfun));
4492   bitmap_head live, used, set, interesting, unusable_as_input;
4493   bitmap_iterator bi;
4494   bitmap_initialize (&interesting, 0);
4495 
4496   first_moveable_pseudo = max_regs;
4497   pseudo_replaced_reg.release ();
4498   pseudo_replaced_reg.safe_grow_cleared (max_regs);
4499 
4500   df_analyze ();
4501   calculate_dominance_info (CDI_DOMINATORS);
4502 
4503   i = 0;
4504   bitmap_initialize (&live, 0);
4505   bitmap_initialize (&used, 0);
4506   bitmap_initialize (&set, 0);
4507   bitmap_initialize (&unusable_as_input, 0);
4508   FOR_EACH_BB_FN (bb, cfun)
4509     {
4510       rtx_insn *insn;
4511       bitmap transp = bb_transp_live + bb->index;
4512       bitmap moveable = bb_moveable_reg_sets + bb->index;
4513       bitmap local = bb_local + bb->index;
4514 
4515       bitmap_initialize (local, 0);
4516       bitmap_initialize (transp, 0);
4517       bitmap_initialize (moveable, 0);
4518       bitmap_copy (&live, df_get_live_out (bb));
4519       bitmap_and_into (&live, df_get_live_in (bb));
4520       bitmap_copy (transp, &live);
4521       bitmap_clear (moveable);
4522       bitmap_clear (&live);
4523       bitmap_clear (&used);
4524       bitmap_clear (&set);
4525       FOR_BB_INSNS (bb, insn)
4526 	if (NONDEBUG_INSN_P (insn))
4527 	  {
4528 	    df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
4529 	    df_ref def, use;
4530 
4531 	    uid_luid[INSN_UID (insn)] = i++;
4532 
4533 	    def = df_single_def (insn_info);
4534 	    use = df_single_use (insn_info);
4535 	    if (use
4536 		&& def
4537 		&& DF_REF_REGNO (use) == DF_REF_REGNO (def)
4538 		&& !bitmap_bit_p (&set, DF_REF_REGNO (use))
4539 		&& rtx_moveable_p (&PATTERN (insn), OP_IN))
4540 	      {
4541 		unsigned regno = DF_REF_REGNO (use);
4542 		bitmap_set_bit (moveable, regno);
4543 		bitmap_set_bit (&set, regno);
4544 		bitmap_set_bit (&used, regno);
4545 		bitmap_clear_bit (transp, regno);
4546 		continue;
4547 	      }
4548 	    FOR_EACH_INSN_INFO_USE (use, insn_info)
4549 	      {
4550 		unsigned regno = DF_REF_REGNO (use);
4551 		bitmap_set_bit (&used, regno);
4552 		if (bitmap_clear_bit (moveable, regno))
4553 		  bitmap_clear_bit (transp, regno);
4554 	      }
4555 
4556 	    FOR_EACH_INSN_INFO_DEF (def, insn_info)
4557 	      {
4558 		unsigned regno = DF_REF_REGNO (def);
4559 		bitmap_set_bit (&set, regno);
4560 		bitmap_clear_bit (transp, regno);
4561 		bitmap_clear_bit (moveable, regno);
4562 	      }
4563 	  }
4564     }
4565 
4566   bitmap_clear (&live);
4567   bitmap_clear (&used);
4568   bitmap_clear (&set);
4569 
4570   FOR_EACH_BB_FN (bb, cfun)
4571     {
4572       bitmap local = bb_local + bb->index;
4573       rtx_insn *insn;
4574 
4575       FOR_BB_INSNS (bb, insn)
4576 	if (NONDEBUG_INSN_P (insn))
4577 	  {
4578 	    df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
4579 	    rtx_insn *def_insn;
4580 	    rtx closest_use, note;
4581 	    df_ref def, use;
4582 	    unsigned regno;
4583 	    bool all_dominated, all_local;
4584 	    machine_mode mode;
4585 
4586 	    def = df_single_def (insn_info);
4587 	    /* There must be exactly one def in this insn.  */
4588 	    if (!def || !single_set (insn))
4589 	      continue;
4590 	    /* This must be the only definition of the reg.  We also limit
4591 	       which modes we deal with so that we can assume we can generate
4592 	       move instructions.  */
4593 	    regno = DF_REF_REGNO (def);
4594 	    mode = GET_MODE (DF_REF_REG (def));
4595 	    if (DF_REG_DEF_COUNT (regno) != 1
4596 		|| !DF_REF_INSN_INFO (def)
4597 		|| HARD_REGISTER_NUM_P (regno)
4598 		|| DF_REG_EQ_USE_COUNT (regno) > 0
4599 		|| (!INTEGRAL_MODE_P (mode) && !FLOAT_MODE_P (mode)))
4600 	      continue;
4601 	    def_insn = DF_REF_INSN (def);
4602 
4603 	    for (note = REG_NOTES (def_insn); note; note = XEXP (note, 1))
4604 	      if (REG_NOTE_KIND (note) == REG_EQUIV && MEM_P (XEXP (note, 0)))
4605 		break;
4606 
4607 	    if (note)
4608 	      {
4609 		if (dump_file)
4610 		  fprintf (dump_file, "Ignoring reg %d, has equiv memory\n",
4611 			   regno);
4612 		bitmap_set_bit (&unusable_as_input, regno);
4613 		continue;
4614 	      }
4615 
4616 	    use = DF_REG_USE_CHAIN (regno);
4617 	    all_dominated = true;
4618 	    all_local = true;
4619 	    closest_use = NULL_RTX;
4620 	    for (; use; use = DF_REF_NEXT_REG (use))
4621 	      {
4622 		rtx_insn *insn;
4623 		if (!DF_REF_INSN_INFO (use))
4624 		  {
4625 		    all_dominated = false;
4626 		    all_local = false;
4627 		    break;
4628 		  }
4629 		insn = DF_REF_INSN (use);
4630 		if (DEBUG_INSN_P (insn))
4631 		  continue;
4632 		if (BLOCK_FOR_INSN (insn) != BLOCK_FOR_INSN (def_insn))
4633 		  all_local = false;
4634 		if (!insn_dominated_by_p (insn, def_insn, uid_luid))
4635 		  all_dominated = false;
4636 		if (closest_use != insn && closest_use != const0_rtx)
4637 		  {
4638 		    if (closest_use == NULL_RTX)
4639 		      closest_use = insn;
4640 		    else if (insn_dominated_by_p (closest_use, insn, uid_luid))
4641 		      closest_use = insn;
4642 		    else if (!insn_dominated_by_p (insn, closest_use, uid_luid))
4643 		      closest_use = const0_rtx;
4644 		  }
4645 	      }
4646 	    if (!all_dominated)
4647 	      {
4648 		if (dump_file)
4649 		  fprintf (dump_file, "Reg %d not all uses dominated by set\n",
4650 			   regno);
4651 		continue;
4652 	      }
4653 	    if (all_local)
4654 	      bitmap_set_bit (local, regno);
4655 	    if (closest_use == const0_rtx || closest_use == NULL
4656 		|| next_nonnote_nondebug_insn (def_insn) == closest_use)
4657 	      {
4658 		if (dump_file)
4659 		  fprintf (dump_file, "Reg %d uninteresting%s\n", regno,
4660 			   closest_use == const0_rtx || closest_use == NULL
4661 			   ? " (no unique first use)" : "");
4662 		continue;
4663 	      }
4664 	    if (HAVE_cc0 && reg_referenced_p (cc0_rtx, PATTERN (closest_use)))
4665 	      {
4666 		if (dump_file)
4667 		  fprintf (dump_file, "Reg %d: closest user uses cc0\n",
4668 			   regno);
4669 		continue;
4670 	      }
4671 
4672 	    bitmap_set_bit (&interesting, regno);
4673 	    /* If we get here, we know closest_use is a non-NULL insn
4674 	       (as opposed to const_0_rtx).  */
4675 	    closest_uses[regno] = as_a <rtx_insn *> (closest_use);
4676 
4677 	    if (dump_file && (all_local || all_dominated))
4678 	      {
4679 		fprintf (dump_file, "Reg %u:", regno);
4680 		if (all_local)
4681 		  fprintf (dump_file, " local to bb %d", bb->index);
4682 		if (all_dominated)
4683 		  fprintf (dump_file, " def dominates all uses");
4684 		if (closest_use != const0_rtx)
4685 		  fprintf (dump_file, " has unique first use");
4686 		fputs ("\n", dump_file);
4687 	      }
4688 	  }
4689     }
4690 
4691   EXECUTE_IF_SET_IN_BITMAP (&interesting, 0, i, bi)
4692     {
4693       df_ref def = DF_REG_DEF_CHAIN (i);
4694       rtx_insn *def_insn = DF_REF_INSN (def);
4695       basic_block def_block = BLOCK_FOR_INSN (def_insn);
4696       bitmap def_bb_local = bb_local + def_block->index;
4697       bitmap def_bb_moveable = bb_moveable_reg_sets + def_block->index;
4698       bitmap def_bb_transp = bb_transp_live + def_block->index;
4699       bool local_to_bb_p = bitmap_bit_p (def_bb_local, i);
4700       rtx_insn *use_insn = closest_uses[i];
4701       df_ref use;
4702       bool all_ok = true;
4703       bool all_transp = true;
4704 
4705       if (!REG_P (DF_REF_REG (def)))
4706 	continue;
4707 
4708       if (!local_to_bb_p)
4709 	{
4710 	  if (dump_file)
4711 	    fprintf (dump_file, "Reg %u not local to one basic block\n",
4712 		     i);
4713 	  continue;
4714 	}
4715       if (reg_equiv_init (i) != NULL_RTX)
4716 	{
4717 	  if (dump_file)
4718 	    fprintf (dump_file, "Ignoring reg %u with equiv init insn\n",
4719 		     i);
4720 	  continue;
4721 	}
4722       if (!rtx_moveable_p (&PATTERN (def_insn), OP_IN))
4723 	{
4724 	  if (dump_file)
4725 	    fprintf (dump_file, "Found def insn %d for %d to be not moveable\n",
4726 		     INSN_UID (def_insn), i);
4727 	  continue;
4728 	}
4729       if (dump_file)
4730 	fprintf (dump_file, "Examining insn %d, def for %d\n",
4731 		 INSN_UID (def_insn), i);
4732       FOR_EACH_INSN_USE (use, def_insn)
4733 	{
4734 	  unsigned regno = DF_REF_REGNO (use);
4735 	  if (bitmap_bit_p (&unusable_as_input, regno))
4736 	    {
4737 	      all_ok = false;
4738 	      if (dump_file)
4739 		fprintf (dump_file, "  found unusable input reg %u.\n", regno);
4740 	      break;
4741 	    }
4742 	  if (!bitmap_bit_p (def_bb_transp, regno))
4743 	    {
4744 	      if (bitmap_bit_p (def_bb_moveable, regno)
4745 		  && !control_flow_insn_p (use_insn)
4746 		  && (!HAVE_cc0 || !sets_cc0_p (use_insn)))
4747 		{
4748 		  if (modified_between_p (DF_REF_REG (use), def_insn, use_insn))
4749 		    {
4750 		      rtx_insn *x = NEXT_INSN (def_insn);
4751 		      while (!modified_in_p (DF_REF_REG (use), x))
4752 			{
4753 			  gcc_assert (x != use_insn);
4754 			  x = NEXT_INSN (x);
4755 			}
4756 		      if (dump_file)
4757 			fprintf (dump_file, "  input reg %u modified but insn %d moveable\n",
4758 				 regno, INSN_UID (x));
4759 		      emit_insn_after (PATTERN (x), use_insn);
4760 		      set_insn_deleted (x);
4761 		    }
4762 		  else
4763 		    {
4764 		      if (dump_file)
4765 			fprintf (dump_file, "  input reg %u modified between def and use\n",
4766 				 regno);
4767 		      all_transp = false;
4768 		    }
4769 		}
4770 	      else
4771 		all_transp = false;
4772 	    }
4773 	}
4774       if (!all_ok)
4775 	continue;
4776       if (!dbg_cnt (ira_move))
4777 	break;
4778       if (dump_file)
4779 	fprintf (dump_file, "  all ok%s\n", all_transp ? " and transp" : "");
4780 
4781       if (all_transp)
4782 	{
4783 	  rtx def_reg = DF_REF_REG (def);
4784 	  rtx newreg = ira_create_new_reg (def_reg);
4785 	  if (validate_change (def_insn, DF_REF_REAL_LOC (def), newreg, 0))
4786 	    {
4787 	      unsigned nregno = REGNO (newreg);
4788 	      emit_insn_before (gen_move_insn (def_reg, newreg), use_insn);
4789 	      nregno -= max_regs;
4790 	      pseudo_replaced_reg[nregno] = def_reg;
4791 	    }
4792 	}
4793     }
4794 
4795   FOR_EACH_BB_FN (bb, cfun)
4796     {
4797       bitmap_clear (bb_local + bb->index);
4798       bitmap_clear (bb_transp_live + bb->index);
4799       bitmap_clear (bb_moveable_reg_sets + bb->index);
4800     }
4801   bitmap_clear (&interesting);
4802   bitmap_clear (&unusable_as_input);
4803   free (uid_luid);
4804   free (closest_uses);
4805   free (bb_local);
4806   free (bb_transp_live);
4807   free (bb_moveable_reg_sets);
4808 
4809   last_moveable_pseudo = max_reg_num ();
4810 
4811   fix_reg_equiv_init ();
4812   expand_reg_info ();
4813   regstat_free_n_sets_and_refs ();
4814   regstat_free_ri ();
4815   regstat_init_n_sets_and_refs ();
4816   regstat_compute_ri ();
4817   free_dominance_info (CDI_DOMINATORS);
4818 }
4819 
4820 /* If SET pattern SET is an assignment from a hard register to a pseudo which
4821    is live at CALL_DOM (if non-NULL, otherwise this check is omitted), return
4822    the destination.  Otherwise return NULL.  */
4823 
4824 static rtx
4825 interesting_dest_for_shprep_1 (rtx set, basic_block call_dom)
4826 {
4827   rtx src = SET_SRC (set);
4828   rtx dest = SET_DEST (set);
4829   if (!REG_P (src) || !HARD_REGISTER_P (src)
4830       || !REG_P (dest) || HARD_REGISTER_P (dest)
4831       || (call_dom && !bitmap_bit_p (df_get_live_in (call_dom), REGNO (dest))))
4832     return NULL;
4833   return dest;
4834 }
4835 
4836 /* If insn is interesting for parameter range-splitting shrink-wrapping
4837    preparation, i.e. it is a single set from a hard register to a pseudo, which
4838    is live at CALL_DOM (if non-NULL, otherwise this check is omitted), or a
4839    parallel statement with only one such statement, return the destination.
4840    Otherwise return NULL.  */
4841 
4842 static rtx
4843 interesting_dest_for_shprep (rtx_insn *insn, basic_block call_dom)
4844 {
4845   if (!INSN_P (insn))
4846     return NULL;
4847   rtx pat = PATTERN (insn);
4848   if (GET_CODE (pat) == SET)
4849     return interesting_dest_for_shprep_1 (pat, call_dom);
4850 
4851   if (GET_CODE (pat) != PARALLEL)
4852     return NULL;
4853   rtx ret = NULL;
4854   for (int i = 0; i < XVECLEN (pat, 0); i++)
4855     {
4856       rtx sub = XVECEXP (pat, 0, i);
4857       if (GET_CODE (sub) == USE || GET_CODE (sub) == CLOBBER)
4858 	continue;
4859       if (GET_CODE (sub) != SET
4860 	  || side_effects_p (sub))
4861 	return NULL;
4862       rtx dest = interesting_dest_for_shprep_1 (sub, call_dom);
4863       if (dest && ret)
4864 	return NULL;
4865       if (dest)
4866 	ret = dest;
4867     }
4868   return ret;
4869 }
4870 
4871 /* Split live ranges of pseudos that are loaded from hard registers in the
4872    first BB in a BB that dominates all non-sibling call if such a BB can be
4873    found and is not in a loop.  Return true if the function has made any
4874    changes.  */
4875 
4876 static bool
4877 split_live_ranges_for_shrink_wrap (void)
4878 {
4879   basic_block bb, call_dom = NULL;
4880   basic_block first = single_succ (ENTRY_BLOCK_PTR_FOR_FN (cfun));
4881   rtx_insn *insn, *last_interesting_insn = NULL;
4882   bitmap_head need_new, reachable;
4883   vec<basic_block> queue;
4884 
4885   if (!SHRINK_WRAPPING_ENABLED)
4886     return false;
4887 
4888   bitmap_initialize (&need_new, 0);
4889   bitmap_initialize (&reachable, 0);
4890   queue.create (n_basic_blocks_for_fn (cfun));
4891 
4892   FOR_EACH_BB_FN (bb, cfun)
4893     FOR_BB_INSNS (bb, insn)
4894       if (CALL_P (insn) && !SIBLING_CALL_P (insn))
4895 	{
4896 	  if (bb == first)
4897 	    {
4898 	      bitmap_clear (&need_new);
4899 	      bitmap_clear (&reachable);
4900 	      queue.release ();
4901 	      return false;
4902 	    }
4903 
4904 	  bitmap_set_bit (&need_new, bb->index);
4905 	  bitmap_set_bit (&reachable, bb->index);
4906 	  queue.quick_push (bb);
4907 	  break;
4908 	}
4909 
4910   if (queue.is_empty ())
4911     {
4912       bitmap_clear (&need_new);
4913       bitmap_clear (&reachable);
4914       queue.release ();
4915       return false;
4916     }
4917 
4918   while (!queue.is_empty ())
4919     {
4920       edge e;
4921       edge_iterator ei;
4922 
4923       bb = queue.pop ();
4924       FOR_EACH_EDGE (e, ei, bb->succs)
4925 	if (e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)
4926 	    && bitmap_set_bit (&reachable, e->dest->index))
4927 	  queue.quick_push (e->dest);
4928     }
4929   queue.release ();
4930 
4931   FOR_BB_INSNS (first, insn)
4932     {
4933       rtx dest = interesting_dest_for_shprep (insn, NULL);
4934       if (!dest)
4935 	continue;
4936 
4937       if (DF_REG_DEF_COUNT (REGNO (dest)) > 1)
4938 	{
4939 	  bitmap_clear (&need_new);
4940 	  bitmap_clear (&reachable);
4941 	  return false;
4942 	}
4943 
4944       for (df_ref use = DF_REG_USE_CHAIN (REGNO(dest));
4945 	   use;
4946 	   use = DF_REF_NEXT_REG (use))
4947 	{
4948 	  int ubbi = DF_REF_BB (use)->index;
4949 	  if (bitmap_bit_p (&reachable, ubbi))
4950 	    bitmap_set_bit (&need_new, ubbi);
4951 	}
4952       last_interesting_insn = insn;
4953     }
4954 
4955   bitmap_clear (&reachable);
4956   if (!last_interesting_insn)
4957     {
4958       bitmap_clear (&need_new);
4959       return false;
4960     }
4961 
4962   call_dom = nearest_common_dominator_for_set (CDI_DOMINATORS, &need_new);
4963   bitmap_clear (&need_new);
4964   if (call_dom == first)
4965     return false;
4966 
4967   loop_optimizer_init (AVOID_CFG_MODIFICATIONS);
4968   while (bb_loop_depth (call_dom) > 0)
4969     call_dom = get_immediate_dominator (CDI_DOMINATORS, call_dom);
4970   loop_optimizer_finalize ();
4971 
4972   if (call_dom == first)
4973     return false;
4974 
4975   calculate_dominance_info (CDI_POST_DOMINATORS);
4976   if (dominated_by_p (CDI_POST_DOMINATORS, first, call_dom))
4977     {
4978       free_dominance_info (CDI_POST_DOMINATORS);
4979       return false;
4980     }
4981   free_dominance_info (CDI_POST_DOMINATORS);
4982 
4983   if (dump_file)
4984     fprintf (dump_file, "Will split live ranges of parameters at BB %i\n",
4985 	     call_dom->index);
4986 
4987   bool ret = false;
4988   FOR_BB_INSNS (first, insn)
4989     {
4990       rtx dest = interesting_dest_for_shprep (insn, call_dom);
4991       if (!dest || dest == pic_offset_table_rtx)
4992 	continue;
4993 
4994       bool need_newreg = false;
4995       df_ref use, next;
4996       for (use = DF_REG_USE_CHAIN (REGNO (dest)); use; use = next)
4997 	{
4998 	  rtx_insn *uin = DF_REF_INSN (use);
4999 	  next = DF_REF_NEXT_REG (use);
5000 
5001 	  if (DEBUG_INSN_P (uin))
5002 	    continue;
5003 
5004 	  basic_block ubb = BLOCK_FOR_INSN (uin);
5005 	  if (ubb == call_dom
5006 	      || dominated_by_p (CDI_DOMINATORS, ubb, call_dom))
5007 	    {
5008 	      need_newreg = true;
5009 	      break;
5010 	    }
5011 	}
5012 
5013       if (need_newreg)
5014 	{
5015 	  rtx newreg = ira_create_new_reg (dest);
5016 
5017 	  for (use = DF_REG_USE_CHAIN (REGNO (dest)); use; use = next)
5018 	    {
5019 	      rtx_insn *uin = DF_REF_INSN (use);
5020 	      next = DF_REF_NEXT_REG (use);
5021 
5022 	      basic_block ubb = BLOCK_FOR_INSN (uin);
5023 	      if (ubb == call_dom
5024 		  || dominated_by_p (CDI_DOMINATORS, ubb, call_dom))
5025 		validate_change (uin, DF_REF_REAL_LOC (use), newreg, true);
5026 	    }
5027 
5028 	  rtx_insn *new_move = gen_move_insn (newreg, dest);
5029 	  emit_insn_after (new_move, bb_note (call_dom));
5030 	  if (dump_file)
5031 	    {
5032 	      fprintf (dump_file, "Split live-range of register ");
5033 	      print_rtl_single (dump_file, dest);
5034 	    }
5035 	  ret = true;
5036 	}
5037 
5038       if (insn == last_interesting_insn)
5039 	break;
5040     }
5041   apply_change_group ();
5042   return ret;
5043 }
5044 
5045 /* Perform the second half of the transformation started in
5046    find_moveable_pseudos.  We look for instances where the newly introduced
5047    pseudo remains unallocated, and remove it by moving the definition to
5048    just before its use, replacing the move instruction generated by
5049    find_moveable_pseudos.  */
5050 static void
5051 move_unallocated_pseudos (void)
5052 {
5053   int i;
5054   for (i = first_moveable_pseudo; i < last_moveable_pseudo; i++)
5055     if (reg_renumber[i] < 0)
5056       {
5057 	int idx = i - first_moveable_pseudo;
5058 	rtx other_reg = pseudo_replaced_reg[idx];
5059 	rtx_insn *def_insn = DF_REF_INSN (DF_REG_DEF_CHAIN (i));
5060 	/* The use must follow all definitions of OTHER_REG, so we can
5061 	   insert the new definition immediately after any of them.  */
5062 	df_ref other_def = DF_REG_DEF_CHAIN (REGNO (other_reg));
5063 	rtx_insn *move_insn = DF_REF_INSN (other_def);
5064 	rtx_insn *newinsn = emit_insn_after (PATTERN (def_insn), move_insn);
5065 	rtx set;
5066 	int success;
5067 
5068 	if (dump_file)
5069 	  fprintf (dump_file, "moving def of %d (insn %d now) ",
5070 		   REGNO (other_reg), INSN_UID (def_insn));
5071 
5072 	delete_insn (move_insn);
5073 	while ((other_def = DF_REG_DEF_CHAIN (REGNO (other_reg))))
5074 	  delete_insn (DF_REF_INSN (other_def));
5075 	delete_insn (def_insn);
5076 
5077 	set = single_set (newinsn);
5078 	success = validate_change (newinsn, &SET_DEST (set), other_reg, 0);
5079 	gcc_assert (success);
5080 	if (dump_file)
5081 	  fprintf (dump_file, " %d) rather than keep unallocated replacement %d\n",
5082 		   INSN_UID (newinsn), i);
5083 	SET_REG_N_REFS (i, 0);
5084       }
5085 }
5086 
5087 /* If the backend knows where to allocate pseudos for hard
5088    register initial values, register these allocations now.  */
5089 static void
5090 allocate_initial_values (void)
5091 {
5092   if (targetm.allocate_initial_value)
5093     {
5094       rtx hreg, preg, x;
5095       int i, regno;
5096 
5097       for (i = 0; HARD_REGISTER_NUM_P (i); i++)
5098 	{
5099 	  if (! initial_value_entry (i, &hreg, &preg))
5100 	    break;
5101 
5102 	  x = targetm.allocate_initial_value (hreg);
5103 	  regno = REGNO (preg);
5104 	  if (x && REG_N_SETS (regno) <= 1)
5105 	    {
5106 	      if (MEM_P (x))
5107 		reg_equiv_memory_loc (regno) = x;
5108 	      else
5109 		{
5110 		  basic_block bb;
5111 		  int new_regno;
5112 
5113 		  gcc_assert (REG_P (x));
5114 		  new_regno = REGNO (x);
5115 		  reg_renumber[regno] = new_regno;
5116 		  /* Poke the regno right into regno_reg_rtx so that even
5117 		     fixed regs are accepted.  */
5118 		  SET_REGNO (preg, new_regno);
5119 		  /* Update global register liveness information.  */
5120 		  FOR_EACH_BB_FN (bb, cfun)
5121 		    {
5122 		      if (REGNO_REG_SET_P (df_get_live_in (bb), regno))
5123 			SET_REGNO_REG_SET (df_get_live_in (bb), new_regno);
5124 		      if (REGNO_REG_SET_P (df_get_live_out (bb), regno))
5125 			SET_REGNO_REG_SET (df_get_live_out (bb), new_regno);
5126 		    }
5127 		}
5128 	    }
5129 	}
5130 
5131       gcc_checking_assert (! initial_value_entry (FIRST_PSEUDO_REGISTER,
5132 						  &hreg, &preg));
5133     }
5134 }
5135 
5136 
5137 /* True when we use LRA instead of reload pass for the current
5138    function.  */
5139 bool ira_use_lra_p;
5140 
5141 /* True if we have allocno conflicts.  It is false for non-optimized
5142    mode or when the conflict table is too big.  */
5143 bool ira_conflicts_p;
5144 
5145 /* Saved between IRA and reload.  */
5146 static int saved_flag_ira_share_spill_slots;
5147 
5148 /* This is the main entry of IRA.  */
5149 static void
5150 ira (FILE *f)
5151 {
5152   bool loops_p;
5153   int ira_max_point_before_emit;
5154   bool saved_flag_caller_saves = flag_caller_saves;
5155   enum ira_region saved_flag_ira_region = flag_ira_region;
5156 
5157   /* Perform target specific PIC register initialization.  */
5158   targetm.init_pic_reg ();
5159 
5160   ira_conflicts_p = optimize > 0;
5161 
5162   ira_use_lra_p = targetm.lra_p ();
5163   /* If there are too many pseudos and/or basic blocks (e.g. 10K
5164      pseudos and 10K blocks or 100K pseudos and 1K blocks), we will
5165      use simplified and faster algorithms in LRA.  */
5166   lra_simple_p
5167     = (ira_use_lra_p
5168        && max_reg_num () >= (1 << 26) / last_basic_block_for_fn (cfun));
5169   if (lra_simple_p)
5170     {
5171       /* It permits to skip live range splitting in LRA.  */
5172       flag_caller_saves = false;
5173       /* There is no sense to do regional allocation when we use
5174 	 simplified LRA.  */
5175       flag_ira_region = IRA_REGION_ONE;
5176       ira_conflicts_p = false;
5177     }
5178 
5179 #ifndef IRA_NO_OBSTACK
5180   gcc_obstack_init (&ira_obstack);
5181 #endif
5182   bitmap_obstack_initialize (&ira_bitmap_obstack);
5183 
5184   /* LRA uses its own infrastructure to handle caller save registers.  */
5185   if (flag_caller_saves && !ira_use_lra_p)
5186     init_caller_save ();
5187 
5188   if (flag_ira_verbose < 10)
5189     {
5190       internal_flag_ira_verbose = flag_ira_verbose;
5191       ira_dump_file = f;
5192     }
5193   else
5194     {
5195       internal_flag_ira_verbose = flag_ira_verbose - 10;
5196       ira_dump_file = stderr;
5197     }
5198 
5199   setup_prohibited_mode_move_regs ();
5200   decrease_live_ranges_number ();
5201   df_note_add_problem ();
5202 
5203   /* DF_LIVE can't be used in the register allocator, too many other
5204      parts of the compiler depend on using the "classic" liveness
5205      interpretation of the DF_LR problem.  See PR38711.
5206      Remove the problem, so that we don't spend time updating it in
5207      any of the df_analyze() calls during IRA/LRA.  */
5208   if (optimize > 1)
5209     df_remove_problem (df_live);
5210   gcc_checking_assert (df_live == NULL);
5211 
5212   if (flag_checking)
5213     df->changeable_flags |= DF_VERIFY_SCHEDULED;
5214 
5215   df_analyze ();
5216 
5217   init_reg_equiv ();
5218   if (ira_conflicts_p)
5219     {
5220       calculate_dominance_info (CDI_DOMINATORS);
5221 
5222       if (split_live_ranges_for_shrink_wrap ())
5223 	df_analyze ();
5224 
5225       free_dominance_info (CDI_DOMINATORS);
5226     }
5227 
5228   df_clear_flags (DF_NO_INSN_RESCAN);
5229 
5230   indirect_jump_optimize ();
5231   if (delete_trivially_dead_insns (get_insns (), max_reg_num ()))
5232     df_analyze ();
5233 
5234   regstat_init_n_sets_and_refs ();
5235   regstat_compute_ri ();
5236 
5237   /* If we are not optimizing, then this is the only place before
5238      register allocation where dataflow is done.  And that is needed
5239      to generate these warnings.  */
5240   if (warn_clobbered)
5241     generate_setjmp_warnings ();
5242 
5243   /* Determine if the current function is a leaf before running IRA
5244      since this can impact optimizations done by the prologue and
5245      epilogue thus changing register elimination offsets.  */
5246   crtl->is_leaf = leaf_function_p ();
5247 
5248   if (resize_reg_info () && flag_ira_loop_pressure)
5249     ira_set_pseudo_classes (true, ira_dump_file);
5250 
5251   update_equiv_regs ();
5252   setup_reg_equiv ();
5253   setup_reg_equiv_init ();
5254 
5255   allocated_reg_info_size = max_reg_num ();
5256 
5257   /* It is not worth to do such improvement when we use a simple
5258      allocation because of -O0 usage or because the function is too
5259      big.  */
5260   if (ira_conflicts_p)
5261     find_moveable_pseudos ();
5262 
5263   max_regno_before_ira = max_reg_num ();
5264   ira_setup_eliminable_regset ();
5265 
5266   ira_overall_cost = ira_reg_cost = ira_mem_cost = 0;
5267   ira_load_cost = ira_store_cost = ira_shuffle_cost = 0;
5268   ira_move_loops_num = ira_additional_jumps_num = 0;
5269 
5270   ira_assert (current_loops == NULL);
5271   if (flag_ira_region == IRA_REGION_ALL || flag_ira_region == IRA_REGION_MIXED)
5272     loop_optimizer_init (AVOID_CFG_MODIFICATIONS | LOOPS_HAVE_RECORDED_EXITS);
5273 
5274   if (internal_flag_ira_verbose > 0 && ira_dump_file != NULL)
5275     fprintf (ira_dump_file, "Building IRA IR\n");
5276   loops_p = ira_build ();
5277 
5278   ira_assert (ira_conflicts_p || !loops_p);
5279 
5280   saved_flag_ira_share_spill_slots = flag_ira_share_spill_slots;
5281   if (too_high_register_pressure_p () || cfun->calls_setjmp)
5282     /* It is just wasting compiler's time to pack spilled pseudos into
5283        stack slots in this case -- prohibit it.  We also do this if
5284        there is setjmp call because a variable not modified between
5285        setjmp and longjmp the compiler is required to preserve its
5286        value and sharing slots does not guarantee it.  */
5287     flag_ira_share_spill_slots = FALSE;
5288 
5289   ira_color ();
5290 
5291   ira_max_point_before_emit = ira_max_point;
5292 
5293   ira_initiate_emit_data ();
5294 
5295   ira_emit (loops_p);
5296 
5297   max_regno = max_reg_num ();
5298   if (ira_conflicts_p)
5299     {
5300       if (! loops_p)
5301 	{
5302 	  if (! ira_use_lra_p)
5303 	    ira_initiate_assign ();
5304 	}
5305       else
5306 	{
5307 	  expand_reg_info ();
5308 
5309 	  if (ira_use_lra_p)
5310 	    {
5311 	      ira_allocno_t a;
5312 	      ira_allocno_iterator ai;
5313 
5314 	      FOR_EACH_ALLOCNO (a, ai)
5315                 {
5316                   int old_regno = ALLOCNO_REGNO (a);
5317                   int new_regno = REGNO (ALLOCNO_EMIT_DATA (a)->reg);
5318 
5319                   ALLOCNO_REGNO (a) = new_regno;
5320 
5321                   if (old_regno != new_regno)
5322                     setup_reg_classes (new_regno, reg_preferred_class (old_regno),
5323                                        reg_alternate_class (old_regno),
5324                                        reg_allocno_class (old_regno));
5325                 }
5326 
5327 	    }
5328 	  else
5329 	    {
5330 	      if (internal_flag_ira_verbose > 0 && ira_dump_file != NULL)
5331 		fprintf (ira_dump_file, "Flattening IR\n");
5332 	      ira_flattening (max_regno_before_ira, ira_max_point_before_emit);
5333 	    }
5334 	  /* New insns were generated: add notes and recalculate live
5335 	     info.  */
5336 	  df_analyze ();
5337 
5338 	  /* ??? Rebuild the loop tree, but why?  Does the loop tree
5339 	     change if new insns were generated?  Can that be handled
5340 	     by updating the loop tree incrementally?  */
5341 	  loop_optimizer_finalize ();
5342 	  free_dominance_info (CDI_DOMINATORS);
5343 	  loop_optimizer_init (AVOID_CFG_MODIFICATIONS
5344 			       | LOOPS_HAVE_RECORDED_EXITS);
5345 
5346 	  if (! ira_use_lra_p)
5347 	    {
5348 	      setup_allocno_assignment_flags ();
5349 	      ira_initiate_assign ();
5350 	      ira_reassign_conflict_allocnos (max_regno);
5351 	    }
5352 	}
5353     }
5354 
5355   ira_finish_emit_data ();
5356 
5357   setup_reg_renumber ();
5358 
5359   calculate_allocation_cost ();
5360 
5361 #ifdef ENABLE_IRA_CHECKING
5362   if (ira_conflicts_p)
5363     check_allocation ();
5364 #endif
5365 
5366   if (max_regno != max_regno_before_ira)
5367     {
5368       regstat_free_n_sets_and_refs ();
5369       regstat_free_ri ();
5370       regstat_init_n_sets_and_refs ();
5371       regstat_compute_ri ();
5372     }
5373 
5374   overall_cost_before = ira_overall_cost;
5375   if (! ira_conflicts_p)
5376     grow_reg_equivs ();
5377   else
5378     {
5379       fix_reg_equiv_init ();
5380 
5381 #ifdef ENABLE_IRA_CHECKING
5382       print_redundant_copies ();
5383 #endif
5384       if (! ira_use_lra_p)
5385 	{
5386 	  ira_spilled_reg_stack_slots_num = 0;
5387 	  ira_spilled_reg_stack_slots
5388 	    = ((struct ira_spilled_reg_stack_slot *)
5389 	       ira_allocate (max_regno
5390 			     * sizeof (struct ira_spilled_reg_stack_slot)));
5391 	  memset (ira_spilled_reg_stack_slots, 0,
5392 		  max_regno * sizeof (struct ira_spilled_reg_stack_slot));
5393 	}
5394     }
5395   allocate_initial_values ();
5396 
5397   /* See comment for find_moveable_pseudos call.  */
5398   if (ira_conflicts_p)
5399     move_unallocated_pseudos ();
5400 
5401   /* Restore original values.  */
5402   if (lra_simple_p)
5403     {
5404       flag_caller_saves = saved_flag_caller_saves;
5405       flag_ira_region = saved_flag_ira_region;
5406     }
5407 }
5408 
5409 static void
5410 do_reload (void)
5411 {
5412   basic_block bb;
5413   bool need_dce;
5414   unsigned pic_offset_table_regno = INVALID_REGNUM;
5415 
5416   if (flag_ira_verbose < 10)
5417     ira_dump_file = dump_file;
5418 
5419   /* If pic_offset_table_rtx is a pseudo register, then keep it so
5420      after reload to avoid possible wrong usages of hard reg assigned
5421      to it.  */
5422   if (pic_offset_table_rtx
5423       && REGNO (pic_offset_table_rtx) >= FIRST_PSEUDO_REGISTER)
5424     pic_offset_table_regno = REGNO (pic_offset_table_rtx);
5425 
5426   timevar_push (TV_RELOAD);
5427   if (ira_use_lra_p)
5428     {
5429       if (current_loops != NULL)
5430 	{
5431 	  loop_optimizer_finalize ();
5432 	  free_dominance_info (CDI_DOMINATORS);
5433 	}
5434       FOR_ALL_BB_FN (bb, cfun)
5435 	bb->loop_father = NULL;
5436       current_loops = NULL;
5437 
5438       ira_destroy ();
5439 
5440       lra (ira_dump_file);
5441       /* ???!!! Move it before lra () when we use ira_reg_equiv in
5442 	 LRA.  */
5443       vec_free (reg_equivs);
5444       reg_equivs = NULL;
5445       need_dce = false;
5446     }
5447   else
5448     {
5449       df_set_flags (DF_NO_INSN_RESCAN);
5450       build_insn_chain ();
5451 
5452       need_dce = reload (get_insns (), ira_conflicts_p);
5453     }
5454 
5455   timevar_pop (TV_RELOAD);
5456 
5457   timevar_push (TV_IRA);
5458 
5459   if (ira_conflicts_p && ! ira_use_lra_p)
5460     {
5461       ira_free (ira_spilled_reg_stack_slots);
5462       ira_finish_assign ();
5463     }
5464 
5465   if (internal_flag_ira_verbose > 0 && ira_dump_file != NULL
5466       && overall_cost_before != ira_overall_cost)
5467     fprintf (ira_dump_file, "+++Overall after reload %" PRId64 "\n",
5468 	     ira_overall_cost);
5469 
5470   flag_ira_share_spill_slots = saved_flag_ira_share_spill_slots;
5471 
5472   if (! ira_use_lra_p)
5473     {
5474       ira_destroy ();
5475       if (current_loops != NULL)
5476 	{
5477 	  loop_optimizer_finalize ();
5478 	  free_dominance_info (CDI_DOMINATORS);
5479 	}
5480       FOR_ALL_BB_FN (bb, cfun)
5481 	bb->loop_father = NULL;
5482       current_loops = NULL;
5483 
5484       regstat_free_ri ();
5485       regstat_free_n_sets_and_refs ();
5486     }
5487 
5488   if (optimize)
5489     cleanup_cfg (CLEANUP_EXPENSIVE);
5490 
5491   finish_reg_equiv ();
5492 
5493   bitmap_obstack_release (&ira_bitmap_obstack);
5494 #ifndef IRA_NO_OBSTACK
5495   obstack_free (&ira_obstack, NULL);
5496 #endif
5497 
5498   /* The code after the reload has changed so much that at this point
5499      we might as well just rescan everything.  Note that
5500      df_rescan_all_insns is not going to help here because it does not
5501      touch the artificial uses and defs.  */
5502   df_finish_pass (true);
5503   df_scan_alloc (NULL);
5504   df_scan_blocks ();
5505 
5506   if (optimize > 1)
5507     {
5508       df_live_add_problem ();
5509       df_live_set_all_dirty ();
5510     }
5511 
5512   if (optimize)
5513     df_analyze ();
5514 
5515   if (need_dce && optimize)
5516     run_fast_dce ();
5517 
5518   /* Diagnose uses of the hard frame pointer when it is used as a global
5519      register.  Often we can get away with letting the user appropriate
5520      the frame pointer, but we should let them know when code generation
5521      makes that impossible.  */
5522   if (global_regs[HARD_FRAME_POINTER_REGNUM] && frame_pointer_needed)
5523     {
5524       tree decl = global_regs_decl[HARD_FRAME_POINTER_REGNUM];
5525       error_at (DECL_SOURCE_LOCATION (current_function_decl),
5526                 "frame pointer required, but reserved");
5527       inform (DECL_SOURCE_LOCATION (decl), "for %qD", decl);
5528     }
5529 
5530   /* If we are doing generic stack checking, give a warning if this
5531      function's frame size is larger than we expect.  */
5532   if (flag_stack_check == GENERIC_STACK_CHECK)
5533     {
5534       HOST_WIDE_INT size = get_frame_size () + STACK_CHECK_FIXED_FRAME_SIZE;
5535 
5536       for (int i = 0; i < FIRST_PSEUDO_REGISTER; i++)
5537 	if (df_regs_ever_live_p (i) && !fixed_regs[i] && call_used_regs[i])
5538 	  size += UNITS_PER_WORD;
5539 
5540       if (size > STACK_CHECK_MAX_FRAME_SIZE)
5541 	warning (0, "frame size too large for reliable stack checking");
5542     }
5543 
5544   if (pic_offset_table_regno != INVALID_REGNUM)
5545     pic_offset_table_rtx = gen_rtx_REG (Pmode, pic_offset_table_regno);
5546 
5547   timevar_pop (TV_IRA);
5548 }
5549 
5550 /* Run the integrated register allocator.  */
5551 
5552 namespace {
5553 
5554 const pass_data pass_data_ira =
5555 {
5556   RTL_PASS, /* type */
5557   "ira", /* name */
5558   OPTGROUP_NONE, /* optinfo_flags */
5559   TV_IRA, /* tv_id */
5560   0, /* properties_required */
5561   0, /* properties_provided */
5562   0, /* properties_destroyed */
5563   0, /* todo_flags_start */
5564   TODO_do_not_ggc_collect, /* todo_flags_finish */
5565 };
5566 
5567 class pass_ira : public rtl_opt_pass
5568 {
5569 public:
5570   pass_ira (gcc::context *ctxt)
5571     : rtl_opt_pass (pass_data_ira, ctxt)
5572   {}
5573 
5574   /* opt_pass methods: */
5575   virtual bool gate (function *)
5576     {
5577       return !targetm.no_register_allocation;
5578     }
5579   virtual unsigned int execute (function *)
5580     {
5581       ira (dump_file);
5582       return 0;
5583     }
5584 
5585 }; // class pass_ira
5586 
5587 } // anon namespace
5588 
5589 rtl_opt_pass *
5590 make_pass_ira (gcc::context *ctxt)
5591 {
5592   return new pass_ira (ctxt);
5593 }
5594 
5595 namespace {
5596 
5597 const pass_data pass_data_reload =
5598 {
5599   RTL_PASS, /* type */
5600   "reload", /* name */
5601   OPTGROUP_NONE, /* optinfo_flags */
5602   TV_RELOAD, /* tv_id */
5603   0, /* properties_required */
5604   0, /* properties_provided */
5605   0, /* properties_destroyed */
5606   0, /* todo_flags_start */
5607   0, /* todo_flags_finish */
5608 };
5609 
5610 class pass_reload : public rtl_opt_pass
5611 {
5612 public:
5613   pass_reload (gcc::context *ctxt)
5614     : rtl_opt_pass (pass_data_reload, ctxt)
5615   {}
5616 
5617   /* opt_pass methods: */
5618   virtual bool gate (function *)
5619     {
5620       return !targetm.no_register_allocation;
5621     }
5622   virtual unsigned int execute (function *)
5623     {
5624       do_reload ();
5625       return 0;
5626     }
5627 
5628 }; // class pass_reload
5629 
5630 } // anon namespace
5631 
5632 rtl_opt_pass *
5633 make_pass_reload (gcc::context *ctxt)
5634 {
5635   return new pass_reload (ctxt);
5636 }
5637