xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/tree-complex.c (revision 07ece4eabb6d327c320416d49d51617a7c0fb3be)
1 /* Lower complex number operations to scalar operations.
2    Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010
3    Free Software Foundation, Inc.
4 
5 This file is part of GCC.
6 
7 GCC is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by the
9 Free Software Foundation; either version 3, or (at your option) any
10 later version.
11 
12 GCC is distributed in the hope that it will be useful, but WITHOUT
13 ANY 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 #include "config.h"
22 #include "system.h"
23 #include "coretypes.h"
24 #include "tm.h"
25 #include "tree.h"
26 #include "rtl.h"
27 #include "real.h"
28 #include "flags.h"
29 #include "tree-flow.h"
30 #include "gimple.h"
31 #include "tree-iterator.h"
32 #include "tree-pass.h"
33 #include "tree-ssa-propagate.h"
34 #include "diagnostic.h"
35 
36 
37 /* For each complex ssa name, a lattice value.  We're interested in finding
38    out whether a complex number is degenerate in some way, having only real
39    or only complex parts.  */
40 
41 enum
42 {
43   UNINITIALIZED = 0,
44   ONLY_REAL = 1,
45   ONLY_IMAG = 2,
46   VARYING = 3
47 };
48 
49 /* The type complex_lattice_t holds combinations of the above
50    constants.  */
51 typedef int complex_lattice_t;
52 
53 #define PAIR(a, b)  ((a) << 2 | (b))
54 
55 DEF_VEC_I(complex_lattice_t);
56 DEF_VEC_ALLOC_I(complex_lattice_t, heap);
57 
58 static VEC(complex_lattice_t, heap) *complex_lattice_values;
59 
60 /* For each complex variable, a pair of variables for the components exists in
61    the hashtable.  */
62 static htab_t complex_variable_components;
63 
64 /* For each complex SSA_NAME, a pair of ssa names for the components.  */
65 static VEC(tree, heap) *complex_ssa_name_components;
66 
67 /* Lookup UID in the complex_variable_components hashtable and return the
68    associated tree.  */
69 static tree
70 cvc_lookup (unsigned int uid)
71 {
72   struct int_tree_map *h, in;
73   in.uid = uid;
74   h = (struct int_tree_map *) htab_find_with_hash (complex_variable_components, &in, uid);
75   return h ? h->to : NULL;
76 }
77 
78 /* Insert the pair UID, TO into the complex_variable_components hashtable.  */
79 
80 static void
81 cvc_insert (unsigned int uid, tree to)
82 {
83   struct int_tree_map *h;
84   void **loc;
85 
86   h = XNEW (struct int_tree_map);
87   h->uid = uid;
88   h->to = to;
89   loc = htab_find_slot_with_hash (complex_variable_components, h,
90 				  uid, INSERT);
91   *(struct int_tree_map **) loc = h;
92 }
93 
94 /* Return true if T is not a zero constant.  In the case of real values,
95    we're only interested in +0.0.  */
96 
97 static int
98 some_nonzerop (tree t)
99 {
100   int zerop = false;
101 
102   /* Operations with real or imaginary part of a complex number zero
103      cannot be treated the same as operations with a real or imaginary
104      operand if we care about the signs of zeros in the result.  */
105   if (TREE_CODE (t) == REAL_CST && !flag_signed_zeros)
106     zerop = REAL_VALUES_IDENTICAL (TREE_REAL_CST (t), dconst0);
107   else if (TREE_CODE (t) == FIXED_CST)
108     zerop = fixed_zerop (t);
109   else if (TREE_CODE (t) == INTEGER_CST)
110     zerop = integer_zerop (t);
111 
112   return !zerop;
113 }
114 
115 
116 /* Compute a lattice value from the components of a complex type REAL
117    and IMAG.  */
118 
119 static complex_lattice_t
120 find_lattice_value_parts (tree real, tree imag)
121 {
122   int r, i;
123   complex_lattice_t ret;
124 
125   r = some_nonzerop (real);
126   i = some_nonzerop (imag);
127   ret = r * ONLY_REAL + i * ONLY_IMAG;
128 
129   /* ??? On occasion we could do better than mapping 0+0i to real, but we
130      certainly don't want to leave it UNINITIALIZED, which eventually gets
131      mapped to VARYING.  */
132   if (ret == UNINITIALIZED)
133     ret = ONLY_REAL;
134 
135   return ret;
136 }
137 
138 
139 /* Compute a lattice value from gimple_val T.  */
140 
141 static complex_lattice_t
142 find_lattice_value (tree t)
143 {
144   tree real, imag;
145 
146   switch (TREE_CODE (t))
147     {
148     case SSA_NAME:
149       return VEC_index (complex_lattice_t, complex_lattice_values,
150 			SSA_NAME_VERSION (t));
151 
152     case COMPLEX_CST:
153       real = TREE_REALPART (t);
154       imag = TREE_IMAGPART (t);
155       break;
156 
157     default:
158       gcc_unreachable ();
159     }
160 
161   return find_lattice_value_parts (real, imag);
162 }
163 
164 /* Determine if LHS is something for which we're interested in seeing
165    simulation results.  */
166 
167 static bool
168 is_complex_reg (tree lhs)
169 {
170   return TREE_CODE (TREE_TYPE (lhs)) == COMPLEX_TYPE && is_gimple_reg (lhs);
171 }
172 
173 /* Mark the incoming parameters to the function as VARYING.  */
174 
175 static void
176 init_parameter_lattice_values (void)
177 {
178   tree parm, ssa_name;
179 
180   for (parm = DECL_ARGUMENTS (cfun->decl); parm ; parm = TREE_CHAIN (parm))
181     if (is_complex_reg (parm)
182 	&& var_ann (parm) != NULL
183 	&& (ssa_name = gimple_default_def (cfun, parm)) != NULL_TREE)
184       VEC_replace (complex_lattice_t, complex_lattice_values,
185 		   SSA_NAME_VERSION (ssa_name), VARYING);
186 }
187 
188 /* Initialize simulation state for each statement.  Return false if we
189    found no statements we want to simulate, and thus there's nothing
190    for the entire pass to do.  */
191 
192 static bool
193 init_dont_simulate_again (void)
194 {
195   basic_block bb;
196   gimple_stmt_iterator gsi;
197   gimple phi;
198   bool saw_a_complex_op = false;
199 
200   FOR_EACH_BB (bb)
201     {
202       for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
203 	{
204 	  phi = gsi_stmt (gsi);
205 	  prop_set_simulate_again (phi,
206 				   is_complex_reg (gimple_phi_result (phi)));
207 	}
208 
209       for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
210 	{
211 	  gimple stmt;
212 	  tree op0, op1;
213 	  bool sim_again_p;
214 
215 	  stmt = gsi_stmt (gsi);
216 	  op0 = op1 = NULL_TREE;
217 
218 	  /* Most control-altering statements must be initially
219 	     simulated, else we won't cover the entire cfg.  */
220 	  sim_again_p = stmt_ends_bb_p (stmt);
221 
222 	  switch (gimple_code (stmt))
223 	    {
224 	    case GIMPLE_CALL:
225 	      if (gimple_call_lhs (stmt))
226 	        sim_again_p = is_complex_reg (gimple_call_lhs (stmt));
227 	      break;
228 
229 	    case GIMPLE_ASSIGN:
230 	      sim_again_p = is_complex_reg (gimple_assign_lhs (stmt));
231 	      if (gimple_assign_rhs_code (stmt) == REALPART_EXPR
232 		  || gimple_assign_rhs_code (stmt) == IMAGPART_EXPR)
233 		op0 = TREE_OPERAND (gimple_assign_rhs1 (stmt), 0);
234 	      else
235 		op0 = gimple_assign_rhs1 (stmt);
236 	      if (gimple_num_ops (stmt) > 2)
237 		op1 = gimple_assign_rhs2 (stmt);
238 	      break;
239 
240 	    case GIMPLE_COND:
241 	      op0 = gimple_cond_lhs (stmt);
242 	      op1 = gimple_cond_rhs (stmt);
243 	      break;
244 
245 	    default:
246 	      break;
247 	    }
248 
249 	  if (op0 || op1)
250 	    switch (gimple_expr_code (stmt))
251 	      {
252 	      case EQ_EXPR:
253 	      case NE_EXPR:
254 	      case PLUS_EXPR:
255 	      case MINUS_EXPR:
256 	      case MULT_EXPR:
257 	      case TRUNC_DIV_EXPR:
258 	      case CEIL_DIV_EXPR:
259 	      case FLOOR_DIV_EXPR:
260 	      case ROUND_DIV_EXPR:
261 	      case RDIV_EXPR:
262 		if (TREE_CODE (TREE_TYPE (op0)) == COMPLEX_TYPE
263 		    || TREE_CODE (TREE_TYPE (op1)) == COMPLEX_TYPE)
264 		  saw_a_complex_op = true;
265 		break;
266 
267 	      case NEGATE_EXPR:
268 	      case CONJ_EXPR:
269 		if (TREE_CODE (TREE_TYPE (op0)) == COMPLEX_TYPE)
270 		  saw_a_complex_op = true;
271 		break;
272 
273 	      case REALPART_EXPR:
274 	      case IMAGPART_EXPR:
275 		/* The total store transformation performed during
276 		  gimplification creates such uninitialized loads
277 		  and we need to lower the statement to be able
278 		  to fix things up.  */
279 		if (TREE_CODE (op0) == SSA_NAME
280 		    && ssa_undefined_value_p (op0))
281 		  saw_a_complex_op = true;
282 		break;
283 
284 	      default:
285 		break;
286 	      }
287 
288 	  prop_set_simulate_again (stmt, sim_again_p);
289 	}
290     }
291 
292   return saw_a_complex_op;
293 }
294 
295 
296 /* Evaluate statement STMT against the complex lattice defined above.  */
297 
298 static enum ssa_prop_result
299 complex_visit_stmt (gimple stmt, edge *taken_edge_p ATTRIBUTE_UNUSED,
300 		    tree *result_p)
301 {
302   complex_lattice_t new_l, old_l, op1_l, op2_l;
303   unsigned int ver;
304   tree lhs;
305 
306   lhs = gimple_get_lhs (stmt);
307   /* Skip anything but GIMPLE_ASSIGN and GIMPLE_CALL with a lhs.  */
308   if (!lhs)
309     return SSA_PROP_VARYING;
310 
311   /* These conditions should be satisfied due to the initial filter
312      set up in init_dont_simulate_again.  */
313   gcc_assert (TREE_CODE (lhs) == SSA_NAME);
314   gcc_assert (TREE_CODE (TREE_TYPE (lhs)) == COMPLEX_TYPE);
315 
316   *result_p = lhs;
317   ver = SSA_NAME_VERSION (lhs);
318   old_l = VEC_index (complex_lattice_t, complex_lattice_values, ver);
319 
320   switch (gimple_expr_code (stmt))
321     {
322     case SSA_NAME:
323     case COMPLEX_CST:
324       new_l = find_lattice_value (gimple_assign_rhs1 (stmt));
325       break;
326 
327     case COMPLEX_EXPR:
328       new_l = find_lattice_value_parts (gimple_assign_rhs1 (stmt),
329 				        gimple_assign_rhs2 (stmt));
330       break;
331 
332     case PLUS_EXPR:
333     case MINUS_EXPR:
334       op1_l = find_lattice_value (gimple_assign_rhs1 (stmt));
335       op2_l = find_lattice_value (gimple_assign_rhs2 (stmt));
336 
337       /* We've set up the lattice values such that IOR neatly
338 	 models addition.  */
339       new_l = op1_l | op2_l;
340       break;
341 
342     case MULT_EXPR:
343     case RDIV_EXPR:
344     case TRUNC_DIV_EXPR:
345     case CEIL_DIV_EXPR:
346     case FLOOR_DIV_EXPR:
347     case ROUND_DIV_EXPR:
348       op1_l = find_lattice_value (gimple_assign_rhs1 (stmt));
349       op2_l = find_lattice_value (gimple_assign_rhs2 (stmt));
350 
351       /* Obviously, if either varies, so does the result.  */
352       if (op1_l == VARYING || op2_l == VARYING)
353 	new_l = VARYING;
354       /* Don't prematurely promote variables if we've not yet seen
355 	 their inputs.  */
356       else if (op1_l == UNINITIALIZED)
357 	new_l = op2_l;
358       else if (op2_l == UNINITIALIZED)
359 	new_l = op1_l;
360       else
361 	{
362 	  /* At this point both numbers have only one component. If the
363 	     numbers are of opposite kind, the result is imaginary,
364 	     otherwise the result is real. The add/subtract translates
365 	     the real/imag from/to 0/1; the ^ performs the comparison.  */
366 	  new_l = ((op1_l - ONLY_REAL) ^ (op2_l - ONLY_REAL)) + ONLY_REAL;
367 
368 	  /* Don't allow the lattice value to flip-flop indefinitely.  */
369 	  new_l |= old_l;
370 	}
371       break;
372 
373     case NEGATE_EXPR:
374     case CONJ_EXPR:
375       new_l = find_lattice_value (gimple_assign_rhs1 (stmt));
376       break;
377 
378     default:
379       new_l = VARYING;
380       break;
381     }
382 
383   /* If nothing changed this round, let the propagator know.  */
384   if (new_l == old_l)
385     return SSA_PROP_NOT_INTERESTING;
386 
387   VEC_replace (complex_lattice_t, complex_lattice_values, ver, new_l);
388   return new_l == VARYING ? SSA_PROP_VARYING : SSA_PROP_INTERESTING;
389 }
390 
391 /* Evaluate a PHI node against the complex lattice defined above.  */
392 
393 static enum ssa_prop_result
394 complex_visit_phi (gimple phi)
395 {
396   complex_lattice_t new_l, old_l;
397   unsigned int ver;
398   tree lhs;
399   int i;
400 
401   lhs = gimple_phi_result (phi);
402 
403   /* This condition should be satisfied due to the initial filter
404      set up in init_dont_simulate_again.  */
405   gcc_assert (TREE_CODE (TREE_TYPE (lhs)) == COMPLEX_TYPE);
406 
407   /* We've set up the lattice values such that IOR neatly models PHI meet.  */
408   new_l = UNINITIALIZED;
409   for (i = gimple_phi_num_args (phi) - 1; i >= 0; --i)
410     new_l |= find_lattice_value (gimple_phi_arg_def (phi, i));
411 
412   ver = SSA_NAME_VERSION (lhs);
413   old_l = VEC_index (complex_lattice_t, complex_lattice_values, ver);
414 
415   if (new_l == old_l)
416     return SSA_PROP_NOT_INTERESTING;
417 
418   VEC_replace (complex_lattice_t, complex_lattice_values, ver, new_l);
419   return new_l == VARYING ? SSA_PROP_VARYING : SSA_PROP_INTERESTING;
420 }
421 
422 /* Create one backing variable for a complex component of ORIG.  */
423 
424 static tree
425 create_one_component_var (tree type, tree orig, const char *prefix,
426 			  const char *suffix, enum tree_code code)
427 {
428   tree r = create_tmp_var (type, prefix);
429   add_referenced_var (r);
430 
431   DECL_SOURCE_LOCATION (r) = DECL_SOURCE_LOCATION (orig);
432   DECL_ARTIFICIAL (r) = 1;
433 
434   if (DECL_NAME (orig) && !DECL_IGNORED_P (orig))
435     {
436       const char *name = IDENTIFIER_POINTER (DECL_NAME (orig));
437 
438       DECL_NAME (r) = get_identifier (ACONCAT ((name, suffix, NULL)));
439 
440       SET_DECL_DEBUG_EXPR (r, build1 (code, type, orig));
441       DECL_DEBUG_EXPR_IS_FROM (r) = 1;
442       DECL_IGNORED_P (r) = 0;
443       TREE_NO_WARNING (r) = TREE_NO_WARNING (orig);
444     }
445   else
446     {
447       DECL_IGNORED_P (r) = 1;
448       TREE_NO_WARNING (r) = 1;
449     }
450 
451   return r;
452 }
453 
454 /* Retrieve a value for a complex component of VAR.  */
455 
456 static tree
457 get_component_var (tree var, bool imag_p)
458 {
459   size_t decl_index = DECL_UID (var) * 2 + imag_p;
460   tree ret = cvc_lookup (decl_index);
461 
462   if (ret == NULL)
463     {
464       ret = create_one_component_var (TREE_TYPE (TREE_TYPE (var)), var,
465 				      imag_p ? "CI" : "CR",
466 				      imag_p ? "$imag" : "$real",
467 				      imag_p ? IMAGPART_EXPR : REALPART_EXPR);
468       cvc_insert (decl_index, ret);
469     }
470 
471   return ret;
472 }
473 
474 /* Retrieve a value for a complex component of SSA_NAME.  */
475 
476 static tree
477 get_component_ssa_name (tree ssa_name, bool imag_p)
478 {
479   complex_lattice_t lattice = find_lattice_value (ssa_name);
480   size_t ssa_name_index;
481   tree ret;
482 
483   if (lattice == (imag_p ? ONLY_REAL : ONLY_IMAG))
484     {
485       tree inner_type = TREE_TYPE (TREE_TYPE (ssa_name));
486       if (SCALAR_FLOAT_TYPE_P (inner_type))
487 	return build_real (inner_type, dconst0);
488       else
489 	return build_int_cst (inner_type, 0);
490     }
491 
492   ssa_name_index = SSA_NAME_VERSION (ssa_name) * 2 + imag_p;
493   ret = VEC_index (tree, complex_ssa_name_components, ssa_name_index);
494   if (ret == NULL)
495     {
496       ret = get_component_var (SSA_NAME_VAR (ssa_name), imag_p);
497       ret = make_ssa_name (ret, NULL);
498 
499       /* Copy some properties from the original.  In particular, whether it
500 	 is used in an abnormal phi, and whether it's uninitialized.  */
501       SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ret)
502 	= SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ssa_name);
503       if (TREE_CODE (SSA_NAME_VAR (ssa_name)) == VAR_DECL
504 	  && gimple_nop_p (SSA_NAME_DEF_STMT (ssa_name)))
505 	{
506 	  SSA_NAME_DEF_STMT (ret) = SSA_NAME_DEF_STMT (ssa_name);
507 	  set_default_def (SSA_NAME_VAR (ret), ret);
508 	}
509 
510       VEC_replace (tree, complex_ssa_name_components, ssa_name_index, ret);
511     }
512 
513   return ret;
514 }
515 
516 /* Set a value for a complex component of SSA_NAME, return a
517    gimple_seq of stuff that needs doing.  */
518 
519 static gimple_seq
520 set_component_ssa_name (tree ssa_name, bool imag_p, tree value)
521 {
522   complex_lattice_t lattice = find_lattice_value (ssa_name);
523   size_t ssa_name_index;
524   tree comp;
525   gimple last;
526   gimple_seq list;
527 
528   /* We know the value must be zero, else there's a bug in our lattice
529      analysis.  But the value may well be a variable known to contain
530      zero.  We should be safe ignoring it.  */
531   if (lattice == (imag_p ? ONLY_REAL : ONLY_IMAG))
532     return NULL;
533 
534   /* If we've already assigned an SSA_NAME to this component, then this
535      means that our walk of the basic blocks found a use before the set.
536      This is fine.  Now we should create an initialization for the value
537      we created earlier.  */
538   ssa_name_index = SSA_NAME_VERSION (ssa_name) * 2 + imag_p;
539   comp = VEC_index (tree, complex_ssa_name_components, ssa_name_index);
540   if (comp)
541     ;
542 
543   /* If we've nothing assigned, and the value we're given is already stable,
544      then install that as the value for this SSA_NAME.  This preemptively
545      copy-propagates the value, which avoids unnecessary memory allocation.  */
546   else if (is_gimple_min_invariant (value)
547 	   && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ssa_name))
548     {
549       VEC_replace (tree, complex_ssa_name_components, ssa_name_index, value);
550       return NULL;
551     }
552   else if (TREE_CODE (value) == SSA_NAME
553 	   && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ssa_name))
554     {
555       /* Replace an anonymous base value with the variable from cvc_lookup.
556 	 This should result in better debug info.  */
557       if (DECL_IGNORED_P (SSA_NAME_VAR (value))
558 	  && !DECL_IGNORED_P (SSA_NAME_VAR (ssa_name)))
559 	{
560 	  comp = get_component_var (SSA_NAME_VAR (ssa_name), imag_p);
561 	  replace_ssa_name_symbol (value, comp);
562 	}
563 
564       VEC_replace (tree, complex_ssa_name_components, ssa_name_index, value);
565       return NULL;
566     }
567 
568   /* Finally, we need to stabilize the result by installing the value into
569      a new ssa name.  */
570   else
571     comp = get_component_ssa_name (ssa_name, imag_p);
572 
573   /* Do all the work to assign VALUE to COMP.  */
574   list = NULL;
575   value = force_gimple_operand (value, &list, false, NULL);
576   last =  gimple_build_assign (comp, value);
577   gimple_seq_add_stmt (&list, last);
578   gcc_assert (SSA_NAME_DEF_STMT (comp) == last);
579 
580   return list;
581 }
582 
583 /* Extract the real or imaginary part of a complex variable or constant.
584    Make sure that it's a proper gimple_val and gimplify it if not.
585    Emit any new code before gsi.  */
586 
587 static tree
588 extract_component (gimple_stmt_iterator *gsi, tree t, bool imagpart_p,
589 		   bool gimple_p)
590 {
591   switch (TREE_CODE (t))
592     {
593     case COMPLEX_CST:
594       return imagpart_p ? TREE_IMAGPART (t) : TREE_REALPART (t);
595 
596     case COMPLEX_EXPR:
597       gcc_unreachable ();
598 
599     case VAR_DECL:
600     case RESULT_DECL:
601     case PARM_DECL:
602     case INDIRECT_REF:
603     case COMPONENT_REF:
604     case ARRAY_REF:
605     case VIEW_CONVERT_EXPR:
606       {
607 	tree inner_type = TREE_TYPE (TREE_TYPE (t));
608 
609 	t = build1 ((imagpart_p ? IMAGPART_EXPR : REALPART_EXPR),
610 		    inner_type, unshare_expr (t));
611 
612 	if (gimple_p)
613 	  t = force_gimple_operand_gsi (gsi, t, true, NULL, true,
614                                         GSI_SAME_STMT);
615 
616 	return t;
617       }
618 
619     case SSA_NAME:
620       return get_component_ssa_name (t, imagpart_p);
621 
622     default:
623       gcc_unreachable ();
624     }
625 }
626 
627 /* Update the complex components of the ssa name on the lhs of STMT.  */
628 
629 static void
630 update_complex_components (gimple_stmt_iterator *gsi, gimple stmt, tree r,
631 			   tree i)
632 {
633   tree lhs;
634   gimple_seq list;
635 
636   lhs = gimple_get_lhs (stmt);
637 
638   list = set_component_ssa_name (lhs, false, r);
639   if (list)
640     gsi_insert_seq_after (gsi, list, GSI_CONTINUE_LINKING);
641 
642   list = set_component_ssa_name (lhs, true, i);
643   if (list)
644     gsi_insert_seq_after (gsi, list, GSI_CONTINUE_LINKING);
645 }
646 
647 static void
648 update_complex_components_on_edge (edge e, tree lhs, tree r, tree i)
649 {
650   gimple_seq list;
651 
652   list = set_component_ssa_name (lhs, false, r);
653   if (list)
654     gsi_insert_seq_on_edge (e, list);
655 
656   list = set_component_ssa_name (lhs, true, i);
657   if (list)
658     gsi_insert_seq_on_edge (e, list);
659 }
660 
661 
662 /* Update an assignment to a complex variable in place.  */
663 
664 static void
665 update_complex_assignment (gimple_stmt_iterator *gsi, tree r, tree i)
666 {
667   gimple_stmt_iterator orig_si = *gsi;
668   gimple stmt;
669 
670   if (gimple_in_ssa_p (cfun))
671     update_complex_components (gsi, gsi_stmt (*gsi), r, i);
672 
673   gimple_assign_set_rhs_with_ops (&orig_si, COMPLEX_EXPR, r, i);
674   stmt = gsi_stmt (orig_si);
675   update_stmt (stmt);
676   if (maybe_clean_eh_stmt (stmt))
677     gimple_purge_dead_eh_edges (gimple_bb (stmt));
678 }
679 
680 
681 /* Generate code at the entry point of the function to initialize the
682    component variables for a complex parameter.  */
683 
684 static void
685 update_parameter_components (void)
686 {
687   edge entry_edge = single_succ_edge (ENTRY_BLOCK_PTR);
688   tree parm;
689 
690   for (parm = DECL_ARGUMENTS (cfun->decl); parm ; parm = TREE_CHAIN (parm))
691     {
692       tree type = TREE_TYPE (parm);
693       tree ssa_name, r, i;
694 
695       if (TREE_CODE (type) != COMPLEX_TYPE || !is_gimple_reg (parm))
696 	continue;
697 
698       type = TREE_TYPE (type);
699       ssa_name = gimple_default_def (cfun, parm);
700       if (!ssa_name)
701 	continue;
702 
703       r = build1 (REALPART_EXPR, type, ssa_name);
704       i = build1 (IMAGPART_EXPR, type, ssa_name);
705       update_complex_components_on_edge (entry_edge, ssa_name, r, i);
706     }
707 }
708 
709 /* Generate code to set the component variables of a complex variable
710    to match the PHI statements in block BB.  */
711 
712 static void
713 update_phi_components (basic_block bb)
714 {
715   gimple_stmt_iterator gsi;
716 
717   for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
718     {
719       gimple phi = gsi_stmt (gsi);
720 
721       if (is_complex_reg (gimple_phi_result (phi)))
722 	{
723 	  tree lr, li;
724 	  gimple pr = NULL, pi = NULL;
725 	  unsigned int i, n;
726 
727 	  lr = get_component_ssa_name (gimple_phi_result (phi), false);
728 	  if (TREE_CODE (lr) == SSA_NAME)
729 	    {
730 	      pr = create_phi_node (lr, bb);
731 	      SSA_NAME_DEF_STMT (lr) = pr;
732 	    }
733 
734 	  li = get_component_ssa_name (gimple_phi_result (phi), true);
735 	  if (TREE_CODE (li) == SSA_NAME)
736 	    {
737 	      pi = create_phi_node (li, bb);
738 	      SSA_NAME_DEF_STMT (li) = pi;
739 	    }
740 
741 	  for (i = 0, n = gimple_phi_num_args (phi); i < n; ++i)
742 	    {
743 	      tree comp, arg = gimple_phi_arg_def (phi, i);
744 	      if (pr)
745 		{
746 		  comp = extract_component (NULL, arg, false, false);
747 		  SET_PHI_ARG_DEF (pr, i, comp);
748 		}
749 	      if (pi)
750 		{
751 		  comp = extract_component (NULL, arg, true, false);
752 		  SET_PHI_ARG_DEF (pi, i, comp);
753 		}
754 	    }
755 	}
756     }
757 }
758 
759 /* Expand a complex move to scalars.  */
760 
761 static void
762 expand_complex_move (gimple_stmt_iterator *gsi, tree type)
763 {
764   tree inner_type = TREE_TYPE (type);
765   tree r, i, lhs, rhs;
766   gimple stmt = gsi_stmt (*gsi);
767 
768   if (is_gimple_assign (stmt))
769     {
770       lhs = gimple_assign_lhs (stmt);
771       if (gimple_num_ops (stmt) == 2)
772 	rhs = gimple_assign_rhs1 (stmt);
773       else
774 	rhs = NULL_TREE;
775     }
776   else if (is_gimple_call (stmt))
777     {
778       lhs = gimple_call_lhs (stmt);
779       rhs = NULL_TREE;
780     }
781   else
782     gcc_unreachable ();
783 
784   if (TREE_CODE (lhs) == SSA_NAME)
785     {
786       if (is_ctrl_altering_stmt (stmt))
787 	{
788 	  edge_iterator ei;
789 	  edge e;
790 
791 	  /* The value is not assigned on the exception edges, so we need not
792 	     concern ourselves there.  We do need to update on the fallthru
793 	     edge.  Find it.  */
794 	  FOR_EACH_EDGE (e, ei, gsi_bb (*gsi)->succs)
795 	    if (e->flags & EDGE_FALLTHRU)
796 	      goto found_fallthru;
797 	  gcc_unreachable ();
798 	found_fallthru:
799 
800 	  r = build1 (REALPART_EXPR, inner_type, lhs);
801 	  i = build1 (IMAGPART_EXPR, inner_type, lhs);
802 	  update_complex_components_on_edge (e, lhs, r, i);
803 	}
804       else if (is_gimple_call (stmt)
805 	       || gimple_has_side_effects (stmt)
806 	       || gimple_assign_rhs_code (stmt) == PAREN_EXPR)
807 	{
808 	  r = build1 (REALPART_EXPR, inner_type, lhs);
809 	  i = build1 (IMAGPART_EXPR, inner_type, lhs);
810 	  update_complex_components (gsi, stmt, r, i);
811 	}
812       else
813 	{
814 	  if (gimple_assign_rhs_code (stmt) != COMPLEX_EXPR)
815 	    {
816 	      r = extract_component (gsi, rhs, 0, true);
817 	      i = extract_component (gsi, rhs, 1, true);
818 	    }
819 	  else
820 	    {
821 	      r = gimple_assign_rhs1 (stmt);
822 	      i = gimple_assign_rhs2 (stmt);
823 	    }
824 	  update_complex_assignment (gsi, r, i);
825 	}
826     }
827   else if (rhs && TREE_CODE (rhs) == SSA_NAME && !TREE_SIDE_EFFECTS (lhs))
828     {
829       tree x;
830       gimple t;
831 
832       r = extract_component (gsi, rhs, 0, false);
833       i = extract_component (gsi, rhs, 1, false);
834 
835       x = build1 (REALPART_EXPR, inner_type, unshare_expr (lhs));
836       t = gimple_build_assign (x, r);
837       gsi_insert_before (gsi, t, GSI_SAME_STMT);
838 
839       if (stmt == gsi_stmt (*gsi))
840 	{
841 	  x = build1 (IMAGPART_EXPR, inner_type, unshare_expr (lhs));
842 	  gimple_assign_set_lhs (stmt, x);
843 	  gimple_assign_set_rhs1 (stmt, i);
844 	}
845       else
846 	{
847 	  x = build1 (IMAGPART_EXPR, inner_type, unshare_expr (lhs));
848 	  t = gimple_build_assign (x, i);
849 	  gsi_insert_before (gsi, t, GSI_SAME_STMT);
850 
851 	  stmt = gsi_stmt (*gsi);
852 	  gcc_assert (gimple_code (stmt) == GIMPLE_RETURN);
853 	  gimple_return_set_retval (stmt, lhs);
854 	}
855 
856       update_stmt (stmt);
857     }
858 }
859 
860 /* Expand complex addition to scalars:
861 	a + b = (ar + br) + i(ai + bi)
862 	a - b = (ar - br) + i(ai + bi)
863 */
864 
865 static void
866 expand_complex_addition (gimple_stmt_iterator *gsi, tree inner_type,
867 			 tree ar, tree ai, tree br, tree bi,
868 			 enum tree_code code,
869 			 complex_lattice_t al, complex_lattice_t bl)
870 {
871   tree rr, ri;
872 
873   switch (PAIR (al, bl))
874     {
875     case PAIR (ONLY_REAL, ONLY_REAL):
876       rr = gimplify_build2 (gsi, code, inner_type, ar, br);
877       ri = ai;
878       break;
879 
880     case PAIR (ONLY_REAL, ONLY_IMAG):
881       rr = ar;
882       if (code == MINUS_EXPR)
883 	ri = gimplify_build2 (gsi, MINUS_EXPR, inner_type, ai, bi);
884       else
885 	ri = bi;
886       break;
887 
888     case PAIR (ONLY_IMAG, ONLY_REAL):
889       if (code == MINUS_EXPR)
890 	rr = gimplify_build2 (gsi, MINUS_EXPR, inner_type, ar, br);
891       else
892 	rr = br;
893       ri = ai;
894       break;
895 
896     case PAIR (ONLY_IMAG, ONLY_IMAG):
897       rr = ar;
898       ri = gimplify_build2 (gsi, code, inner_type, ai, bi);
899       break;
900 
901     case PAIR (VARYING, ONLY_REAL):
902       rr = gimplify_build2 (gsi, code, inner_type, ar, br);
903       ri = ai;
904       break;
905 
906     case PAIR (VARYING, ONLY_IMAG):
907       rr = ar;
908       ri = gimplify_build2 (gsi, code, inner_type, ai, bi);
909       break;
910 
911     case PAIR (ONLY_REAL, VARYING):
912       if (code == MINUS_EXPR)
913 	goto general;
914       rr = gimplify_build2 (gsi, code, inner_type, ar, br);
915       ri = bi;
916       break;
917 
918     case PAIR (ONLY_IMAG, VARYING):
919       if (code == MINUS_EXPR)
920 	goto general;
921       rr = br;
922       ri = gimplify_build2 (gsi, code, inner_type, ai, bi);
923       break;
924 
925     case PAIR (VARYING, VARYING):
926     general:
927       rr = gimplify_build2 (gsi, code, inner_type, ar, br);
928       ri = gimplify_build2 (gsi, code, inner_type, ai, bi);
929       break;
930 
931     default:
932       gcc_unreachable ();
933     }
934 
935   update_complex_assignment (gsi, rr, ri);
936 }
937 
938 /* Expand a complex multiplication or division to a libcall to the c99
939    compliant routines.  */
940 
941 static void
942 expand_complex_libcall (gimple_stmt_iterator *gsi, tree ar, tree ai,
943 			tree br, tree bi, enum tree_code code)
944 {
945   enum machine_mode mode;
946   enum built_in_function bcode;
947   tree fn, type, lhs;
948   gimple old_stmt, stmt;
949 
950   old_stmt = gsi_stmt (*gsi);
951   lhs = gimple_assign_lhs (old_stmt);
952   type = TREE_TYPE (lhs);
953 
954   mode = TYPE_MODE (type);
955   gcc_assert (GET_MODE_CLASS (mode) == MODE_COMPLEX_FLOAT);
956 
957   if (code == MULT_EXPR)
958     bcode = ((enum built_in_function)
959 	     (BUILT_IN_COMPLEX_MUL_MIN + mode - MIN_MODE_COMPLEX_FLOAT));
960   else if (code == RDIV_EXPR)
961     bcode = ((enum built_in_function)
962 	     (BUILT_IN_COMPLEX_DIV_MIN + mode - MIN_MODE_COMPLEX_FLOAT));
963   else
964     gcc_unreachable ();
965   fn = built_in_decls[bcode];
966 
967   stmt = gimple_build_call (fn, 4, ar, ai, br, bi);
968   gimple_call_set_lhs (stmt, lhs);
969   update_stmt (stmt);
970   gsi_replace (gsi, stmt, false);
971 
972   if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt))
973     gimple_purge_dead_eh_edges (gsi_bb (*gsi));
974 
975   if (gimple_in_ssa_p (cfun))
976     {
977       type = TREE_TYPE (type);
978       update_complex_components (gsi, stmt,
979 				 build1 (REALPART_EXPR, type, lhs),
980 				 build1 (IMAGPART_EXPR, type, lhs));
981       SSA_NAME_DEF_STMT (lhs) = stmt;
982     }
983 }
984 
985 /* Expand complex multiplication to scalars:
986 	a * b = (ar*br - ai*bi) + i(ar*bi + br*ai)
987 */
988 
989 static void
990 expand_complex_multiplication (gimple_stmt_iterator *gsi, tree inner_type,
991 			       tree ar, tree ai, tree br, tree bi,
992 			       complex_lattice_t al, complex_lattice_t bl)
993 {
994   tree rr, ri;
995 
996   if (al < bl)
997     {
998       complex_lattice_t tl;
999       rr = ar, ar = br, br = rr;
1000       ri = ai, ai = bi, bi = ri;
1001       tl = al, al = bl, bl = tl;
1002     }
1003 
1004   switch (PAIR (al, bl))
1005     {
1006     case PAIR (ONLY_REAL, ONLY_REAL):
1007       rr = gimplify_build2 (gsi, MULT_EXPR, inner_type, ar, br);
1008       ri = ai;
1009       break;
1010 
1011     case PAIR (ONLY_IMAG, ONLY_REAL):
1012       rr = ar;
1013       if (TREE_CODE (ai) == REAL_CST
1014 	  && REAL_VALUES_IDENTICAL (TREE_REAL_CST (ai), dconst1))
1015 	ri = br;
1016       else
1017 	ri = gimplify_build2 (gsi, MULT_EXPR, inner_type, ai, br);
1018       break;
1019 
1020     case PAIR (ONLY_IMAG, ONLY_IMAG):
1021       rr = gimplify_build2 (gsi, MULT_EXPR, inner_type, ai, bi);
1022       rr = gimplify_build1 (gsi, NEGATE_EXPR, inner_type, rr);
1023       ri = ar;
1024       break;
1025 
1026     case PAIR (VARYING, ONLY_REAL):
1027       rr = gimplify_build2 (gsi, MULT_EXPR, inner_type, ar, br);
1028       ri = gimplify_build2 (gsi, MULT_EXPR, inner_type, ai, br);
1029       break;
1030 
1031     case PAIR (VARYING, ONLY_IMAG):
1032       rr = gimplify_build2 (gsi, MULT_EXPR, inner_type, ai, bi);
1033       rr = gimplify_build1 (gsi, NEGATE_EXPR, inner_type, rr);
1034       ri = gimplify_build2 (gsi, MULT_EXPR, inner_type, ar, bi);
1035       break;
1036 
1037     case PAIR (VARYING, VARYING):
1038       if (flag_complex_method == 2 && SCALAR_FLOAT_TYPE_P (inner_type))
1039 	{
1040 	  expand_complex_libcall (gsi, ar, ai, br, bi, MULT_EXPR);
1041 	  return;
1042 	}
1043       else
1044 	{
1045 	  tree t1, t2, t3, t4;
1046 
1047 	  t1 = gimplify_build2 (gsi, MULT_EXPR, inner_type, ar, br);
1048 	  t2 = gimplify_build2 (gsi, MULT_EXPR, inner_type, ai, bi);
1049 	  t3 = gimplify_build2 (gsi, MULT_EXPR, inner_type, ar, bi);
1050 
1051 	  /* Avoid expanding redundant multiplication for the common
1052 	     case of squaring a complex number.  */
1053 	  if (ar == br && ai == bi)
1054 	    t4 = t3;
1055 	  else
1056 	    t4 = gimplify_build2 (gsi, MULT_EXPR, inner_type, ai, br);
1057 
1058 	  rr = gimplify_build2 (gsi, MINUS_EXPR, inner_type, t1, t2);
1059 	  ri = gimplify_build2 (gsi, PLUS_EXPR, inner_type, t3, t4);
1060 	}
1061       break;
1062 
1063     default:
1064       gcc_unreachable ();
1065     }
1066 
1067   update_complex_assignment (gsi, rr, ri);
1068 }
1069 
1070 /* Keep this algorithm in sync with fold-const.c:const_binop().
1071 
1072    Expand complex division to scalars, straightforward algorithm.
1073 	a / b = ((ar*br + ai*bi)/t) + i((ai*br - ar*bi)/t)
1074 	    t = br*br + bi*bi
1075 */
1076 
1077 static void
1078 expand_complex_div_straight (gimple_stmt_iterator *gsi, tree inner_type,
1079 			     tree ar, tree ai, tree br, tree bi,
1080 			     enum tree_code code)
1081 {
1082   tree rr, ri, div, t1, t2, t3;
1083 
1084   t1 = gimplify_build2 (gsi, MULT_EXPR, inner_type, br, br);
1085   t2 = gimplify_build2 (gsi, MULT_EXPR, inner_type, bi, bi);
1086   div = gimplify_build2 (gsi, PLUS_EXPR, inner_type, t1, t2);
1087 
1088   t1 = gimplify_build2 (gsi, MULT_EXPR, inner_type, ar, br);
1089   t2 = gimplify_build2 (gsi, MULT_EXPR, inner_type, ai, bi);
1090   t3 = gimplify_build2 (gsi, PLUS_EXPR, inner_type, t1, t2);
1091   rr = gimplify_build2 (gsi, code, inner_type, t3, div);
1092 
1093   t1 = gimplify_build2 (gsi, MULT_EXPR, inner_type, ai, br);
1094   t2 = gimplify_build2 (gsi, MULT_EXPR, inner_type, ar, bi);
1095   t3 = gimplify_build2 (gsi, MINUS_EXPR, inner_type, t1, t2);
1096   ri = gimplify_build2 (gsi, code, inner_type, t3, div);
1097 
1098   update_complex_assignment (gsi, rr, ri);
1099 }
1100 
1101 /* Keep this algorithm in sync with fold-const.c:const_binop().
1102 
1103    Expand complex division to scalars, modified algorithm to minimize
1104    overflow with wide input ranges.  */
1105 
1106 static void
1107 expand_complex_div_wide (gimple_stmt_iterator *gsi, tree inner_type,
1108 			 tree ar, tree ai, tree br, tree bi,
1109 			 enum tree_code code)
1110 {
1111   tree rr, ri, ratio, div, t1, t2, tr, ti, compare;
1112   basic_block bb_cond, bb_true, bb_false, bb_join;
1113   gimple stmt;
1114 
1115   /* Examine |br| < |bi|, and branch.  */
1116   t1 = gimplify_build1 (gsi, ABS_EXPR, inner_type, br);
1117   t2 = gimplify_build1 (gsi, ABS_EXPR, inner_type, bi);
1118   compare = fold_build2_loc (gimple_location (gsi_stmt (*gsi)),
1119 			     LT_EXPR, boolean_type_node, t1, t2);
1120   STRIP_NOPS (compare);
1121 
1122   bb_cond = bb_true = bb_false = bb_join = NULL;
1123   rr = ri = tr = ti = NULL;
1124   if (TREE_CODE (compare) != INTEGER_CST)
1125     {
1126       edge e;
1127       gimple stmt;
1128       tree cond, tmp;
1129 
1130       tmp = create_tmp_var (boolean_type_node, NULL);
1131       stmt = gimple_build_assign (tmp, compare);
1132       if (gimple_in_ssa_p (cfun))
1133 	{
1134 	  tmp = make_ssa_name (tmp,  stmt);
1135 	  gimple_assign_set_lhs (stmt, tmp);
1136 	}
1137 
1138       gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
1139 
1140       cond = fold_build2_loc (gimple_location (stmt),
1141 			  EQ_EXPR, boolean_type_node, tmp, boolean_true_node);
1142       stmt = gimple_build_cond_from_tree (cond, NULL_TREE, NULL_TREE);
1143       gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
1144 
1145       /* Split the original block, and create the TRUE and FALSE blocks.  */
1146       e = split_block (gsi_bb (*gsi), stmt);
1147       bb_cond = e->src;
1148       bb_join = e->dest;
1149       bb_true = create_empty_bb (bb_cond);
1150       bb_false = create_empty_bb (bb_true);
1151 
1152       /* Wire the blocks together.  */
1153       e->flags = EDGE_TRUE_VALUE;
1154       redirect_edge_succ (e, bb_true);
1155       make_edge (bb_cond, bb_false, EDGE_FALSE_VALUE);
1156       make_edge (bb_true, bb_join, EDGE_FALLTHRU);
1157       make_edge (bb_false, bb_join, EDGE_FALLTHRU);
1158 
1159       /* Update dominance info.  Note that bb_join's data was
1160          updated by split_block.  */
1161       if (dom_info_available_p (CDI_DOMINATORS))
1162         {
1163           set_immediate_dominator (CDI_DOMINATORS, bb_true, bb_cond);
1164           set_immediate_dominator (CDI_DOMINATORS, bb_false, bb_cond);
1165         }
1166 
1167       rr = make_rename_temp (inner_type, NULL);
1168       ri = make_rename_temp (inner_type, NULL);
1169     }
1170 
1171   /* In the TRUE branch, we compute
1172       ratio = br/bi;
1173       div = (br * ratio) + bi;
1174       tr = (ar * ratio) + ai;
1175       ti = (ai * ratio) - ar;
1176       tr = tr / div;
1177       ti = ti / div;  */
1178   if (bb_true || integer_nonzerop (compare))
1179     {
1180       if (bb_true)
1181 	{
1182 	  *gsi = gsi_last_bb (bb_true);
1183 	  gsi_insert_after (gsi, gimple_build_nop (), GSI_NEW_STMT);
1184 	}
1185 
1186       ratio = gimplify_build2 (gsi, code, inner_type, br, bi);
1187 
1188       t1 = gimplify_build2 (gsi, MULT_EXPR, inner_type, br, ratio);
1189       div = gimplify_build2 (gsi, PLUS_EXPR, inner_type, t1, bi);
1190 
1191       t1 = gimplify_build2 (gsi, MULT_EXPR, inner_type, ar, ratio);
1192       tr = gimplify_build2 (gsi, PLUS_EXPR, inner_type, t1, ai);
1193 
1194       t1 = gimplify_build2 (gsi, MULT_EXPR, inner_type, ai, ratio);
1195       ti = gimplify_build2 (gsi, MINUS_EXPR, inner_type, t1, ar);
1196 
1197       tr = gimplify_build2 (gsi, code, inner_type, tr, div);
1198       ti = gimplify_build2 (gsi, code, inner_type, ti, div);
1199 
1200      if (bb_true)
1201        {
1202 	 stmt = gimple_build_assign (rr, tr);
1203 	 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
1204 	 stmt = gimple_build_assign (ri, ti);
1205 	 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
1206 	 gsi_remove (gsi, true);
1207        }
1208     }
1209 
1210   /* In the FALSE branch, we compute
1211       ratio = d/c;
1212       divisor = (d * ratio) + c;
1213       tr = (b * ratio) + a;
1214       ti = b - (a * ratio);
1215       tr = tr / div;
1216       ti = ti / div;  */
1217   if (bb_false || integer_zerop (compare))
1218     {
1219       if (bb_false)
1220 	{
1221 	  *gsi = gsi_last_bb (bb_false);
1222 	  gsi_insert_after (gsi, gimple_build_nop (), GSI_NEW_STMT);
1223 	}
1224 
1225       ratio = gimplify_build2 (gsi, code, inner_type, bi, br);
1226 
1227       t1 = gimplify_build2 (gsi, MULT_EXPR, inner_type, bi, ratio);
1228       div = gimplify_build2 (gsi, PLUS_EXPR, inner_type, t1, br);
1229 
1230       t1 = gimplify_build2 (gsi, MULT_EXPR, inner_type, ai, ratio);
1231       tr = gimplify_build2 (gsi, PLUS_EXPR, inner_type, t1, ar);
1232 
1233       t1 = gimplify_build2 (gsi, MULT_EXPR, inner_type, ar, ratio);
1234       ti = gimplify_build2 (gsi, MINUS_EXPR, inner_type, ai, t1);
1235 
1236       tr = gimplify_build2 (gsi, code, inner_type, tr, div);
1237       ti = gimplify_build2 (gsi, code, inner_type, ti, div);
1238 
1239      if (bb_false)
1240        {
1241 	 stmt = gimple_build_assign (rr, tr);
1242 	 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
1243 	 stmt = gimple_build_assign (ri, ti);
1244 	 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
1245 	 gsi_remove (gsi, true);
1246        }
1247     }
1248 
1249   if (bb_join)
1250     *gsi = gsi_start_bb (bb_join);
1251   else
1252     rr = tr, ri = ti;
1253 
1254   update_complex_assignment (gsi, rr, ri);
1255 }
1256 
1257 /* Expand complex division to scalars.  */
1258 
1259 static void
1260 expand_complex_division (gimple_stmt_iterator *gsi, tree inner_type,
1261 			 tree ar, tree ai, tree br, tree bi,
1262 			 enum tree_code code,
1263 			 complex_lattice_t al, complex_lattice_t bl)
1264 {
1265   tree rr, ri;
1266 
1267   switch (PAIR (al, bl))
1268     {
1269     case PAIR (ONLY_REAL, ONLY_REAL):
1270       rr = gimplify_build2 (gsi, code, inner_type, ar, br);
1271       ri = ai;
1272       break;
1273 
1274     case PAIR (ONLY_REAL, ONLY_IMAG):
1275       rr = ai;
1276       ri = gimplify_build2 (gsi, code, inner_type, ar, bi);
1277       ri = gimplify_build1 (gsi, NEGATE_EXPR, inner_type, ri);
1278       break;
1279 
1280     case PAIR (ONLY_IMAG, ONLY_REAL):
1281       rr = ar;
1282       ri = gimplify_build2 (gsi, code, inner_type, ai, br);
1283       break;
1284 
1285     case PAIR (ONLY_IMAG, ONLY_IMAG):
1286       rr = gimplify_build2 (gsi, code, inner_type, ai, bi);
1287       ri = ar;
1288       break;
1289 
1290     case PAIR (VARYING, ONLY_REAL):
1291       rr = gimplify_build2 (gsi, code, inner_type, ar, br);
1292       ri = gimplify_build2 (gsi, code, inner_type, ai, br);
1293       break;
1294 
1295     case PAIR (VARYING, ONLY_IMAG):
1296       rr = gimplify_build2 (gsi, code, inner_type, ai, bi);
1297       ri = gimplify_build2 (gsi, code, inner_type, ar, bi);
1298       ri = gimplify_build1 (gsi, NEGATE_EXPR, inner_type, ri);
1299 
1300     case PAIR (ONLY_REAL, VARYING):
1301     case PAIR (ONLY_IMAG, VARYING):
1302     case PAIR (VARYING, VARYING):
1303       switch (flag_complex_method)
1304 	{
1305 	case 0:
1306 	  /* straightforward implementation of complex divide acceptable.  */
1307 	  expand_complex_div_straight (gsi, inner_type, ar, ai, br, bi, code);
1308 	  break;
1309 
1310 	case 2:
1311 	  if (SCALAR_FLOAT_TYPE_P (inner_type))
1312 	    {
1313 	      expand_complex_libcall (gsi, ar, ai, br, bi, code);
1314 	      break;
1315 	    }
1316 	  /* FALLTHRU */
1317 
1318 	case 1:
1319 	  /* wide ranges of inputs must work for complex divide.  */
1320 	  expand_complex_div_wide (gsi, inner_type, ar, ai, br, bi, code);
1321 	  break;
1322 
1323 	default:
1324 	  gcc_unreachable ();
1325 	}
1326       return;
1327 
1328     default:
1329       gcc_unreachable ();
1330     }
1331 
1332   update_complex_assignment (gsi, rr, ri);
1333 }
1334 
1335 /* Expand complex negation to scalars:
1336 	-a = (-ar) + i(-ai)
1337 */
1338 
1339 static void
1340 expand_complex_negation (gimple_stmt_iterator *gsi, tree inner_type,
1341 			 tree ar, tree ai)
1342 {
1343   tree rr, ri;
1344 
1345   rr = gimplify_build1 (gsi, NEGATE_EXPR, inner_type, ar);
1346   ri = gimplify_build1 (gsi, NEGATE_EXPR, inner_type, ai);
1347 
1348   update_complex_assignment (gsi, rr, ri);
1349 }
1350 
1351 /* Expand complex conjugate to scalars:
1352 	~a = (ar) + i(-ai)
1353 */
1354 
1355 static void
1356 expand_complex_conjugate (gimple_stmt_iterator *gsi, tree inner_type,
1357 			  tree ar, tree ai)
1358 {
1359   tree ri;
1360 
1361   ri = gimplify_build1 (gsi, NEGATE_EXPR, inner_type, ai);
1362 
1363   update_complex_assignment (gsi, ar, ri);
1364 }
1365 
1366 /* Expand complex comparison (EQ or NE only).  */
1367 
1368 static void
1369 expand_complex_comparison (gimple_stmt_iterator *gsi, tree ar, tree ai,
1370 			   tree br, tree bi, enum tree_code code)
1371 {
1372   tree cr, ci, cc, type;
1373   gimple stmt;
1374 
1375   cr = gimplify_build2 (gsi, code, boolean_type_node, ar, br);
1376   ci = gimplify_build2 (gsi, code, boolean_type_node, ai, bi);
1377   cc = gimplify_build2 (gsi,
1378 			(code == EQ_EXPR ? TRUTH_AND_EXPR : TRUTH_OR_EXPR),
1379 			boolean_type_node, cr, ci);
1380 
1381   stmt = gsi_stmt (*gsi);
1382 
1383   switch (gimple_code (stmt))
1384     {
1385     case GIMPLE_RETURN:
1386       type = TREE_TYPE (gimple_return_retval (stmt));
1387       gimple_return_set_retval (stmt, fold_convert (type, cc));
1388       break;
1389 
1390     case GIMPLE_ASSIGN:
1391       type = TREE_TYPE (gimple_assign_lhs (stmt));
1392       gimple_assign_set_rhs_from_tree (gsi, fold_convert (type, cc));
1393       stmt = gsi_stmt (*gsi);
1394       break;
1395 
1396     case GIMPLE_COND:
1397       gimple_cond_set_code (stmt, EQ_EXPR);
1398       gimple_cond_set_lhs (stmt, cc);
1399       gimple_cond_set_rhs (stmt, boolean_true_node);
1400       break;
1401 
1402     default:
1403       gcc_unreachable ();
1404     }
1405 
1406   update_stmt (stmt);
1407 }
1408 
1409 
1410 /* Process one statement.  If we identify a complex operation, expand it.  */
1411 
1412 static void
1413 expand_complex_operations_1 (gimple_stmt_iterator *gsi)
1414 {
1415   gimple stmt = gsi_stmt (*gsi);
1416   tree type, inner_type, lhs;
1417   tree ac, ar, ai, bc, br, bi;
1418   complex_lattice_t al, bl;
1419   enum tree_code code;
1420 
1421   lhs = gimple_get_lhs (stmt);
1422   if (!lhs && gimple_code (stmt) != GIMPLE_COND)
1423     return;
1424 
1425   type = TREE_TYPE (gimple_op (stmt, 0));
1426   code = gimple_expr_code (stmt);
1427 
1428   /* Initial filter for operations we handle.  */
1429   switch (code)
1430     {
1431     case PLUS_EXPR:
1432     case MINUS_EXPR:
1433     case MULT_EXPR:
1434     case TRUNC_DIV_EXPR:
1435     case CEIL_DIV_EXPR:
1436     case FLOOR_DIV_EXPR:
1437     case ROUND_DIV_EXPR:
1438     case RDIV_EXPR:
1439     case NEGATE_EXPR:
1440     case CONJ_EXPR:
1441       if (TREE_CODE (type) != COMPLEX_TYPE)
1442 	return;
1443       inner_type = TREE_TYPE (type);
1444       break;
1445 
1446     case EQ_EXPR:
1447     case NE_EXPR:
1448       /* Note, both GIMPLE_ASSIGN and GIMPLE_COND may have an EQ_EXPR
1449 	 subocde, so we need to access the operands using gimple_op.  */
1450       inner_type = TREE_TYPE (gimple_op (stmt, 1));
1451       if (TREE_CODE (inner_type) != COMPLEX_TYPE)
1452 	return;
1453       break;
1454 
1455     default:
1456       {
1457 	tree rhs;
1458 
1459 	/* GIMPLE_COND may also fallthru here, but we do not need to
1460 	   do anything with it.  */
1461 	if (gimple_code (stmt) == GIMPLE_COND)
1462 	  return;
1463 
1464 	if (TREE_CODE (type) == COMPLEX_TYPE)
1465 	  expand_complex_move (gsi, type);
1466 	else if (is_gimple_assign (stmt)
1467 		 && (gimple_assign_rhs_code (stmt) == REALPART_EXPR
1468 		     || gimple_assign_rhs_code (stmt) == IMAGPART_EXPR)
1469 		 && TREE_CODE (lhs) == SSA_NAME)
1470 	  {
1471 	    rhs = gimple_assign_rhs1 (stmt);
1472 	    rhs = extract_component (gsi, TREE_OPERAND (rhs, 0),
1473 		                     gimple_assign_rhs_code (stmt)
1474 				       == IMAGPART_EXPR,
1475 				     false);
1476 	    gimple_assign_set_rhs_from_tree (gsi, rhs);
1477 	    stmt = gsi_stmt (*gsi);
1478 	    update_stmt (stmt);
1479 	  }
1480       }
1481       return;
1482     }
1483 
1484   /* Extract the components of the two complex values.  Make sure and
1485      handle the common case of the same value used twice specially.  */
1486   if (is_gimple_assign (stmt))
1487     {
1488       ac = gimple_assign_rhs1 (stmt);
1489       bc = (gimple_num_ops (stmt) > 2) ? gimple_assign_rhs2 (stmt) : NULL;
1490     }
1491   /* GIMPLE_CALL can not get here.  */
1492   else
1493     {
1494       ac = gimple_cond_lhs (stmt);
1495       bc = gimple_cond_rhs (stmt);
1496     }
1497 
1498   ar = extract_component (gsi, ac, false, true);
1499   ai = extract_component (gsi, ac, true, true);
1500 
1501   if (ac == bc)
1502     br = ar, bi = ai;
1503   else if (bc)
1504     {
1505       br = extract_component (gsi, bc, 0, true);
1506       bi = extract_component (gsi, bc, 1, true);
1507     }
1508   else
1509     br = bi = NULL_TREE;
1510 
1511   if (gimple_in_ssa_p (cfun))
1512     {
1513       al = find_lattice_value (ac);
1514       if (al == UNINITIALIZED)
1515 	al = VARYING;
1516 
1517       if (TREE_CODE_CLASS (code) == tcc_unary)
1518 	bl = UNINITIALIZED;
1519       else if (ac == bc)
1520 	bl = al;
1521       else
1522 	{
1523 	  bl = find_lattice_value (bc);
1524 	  if (bl == UNINITIALIZED)
1525 	    bl = VARYING;
1526 	}
1527     }
1528   else
1529     al = bl = VARYING;
1530 
1531   switch (code)
1532     {
1533     case PLUS_EXPR:
1534     case MINUS_EXPR:
1535       expand_complex_addition (gsi, inner_type, ar, ai, br, bi, code, al, bl);
1536       break;
1537 
1538     case MULT_EXPR:
1539       expand_complex_multiplication (gsi, inner_type, ar, ai, br, bi, al, bl);
1540       break;
1541 
1542     case TRUNC_DIV_EXPR:
1543     case CEIL_DIV_EXPR:
1544     case FLOOR_DIV_EXPR:
1545     case ROUND_DIV_EXPR:
1546     case RDIV_EXPR:
1547       expand_complex_division (gsi, inner_type, ar, ai, br, bi, code, al, bl);
1548       break;
1549 
1550     case NEGATE_EXPR:
1551       expand_complex_negation (gsi, inner_type, ar, ai);
1552       break;
1553 
1554     case CONJ_EXPR:
1555       expand_complex_conjugate (gsi, inner_type, ar, ai);
1556       break;
1557 
1558     case EQ_EXPR:
1559     case NE_EXPR:
1560       expand_complex_comparison (gsi, ar, ai, br, bi, code);
1561       break;
1562 
1563     default:
1564       gcc_unreachable ();
1565     }
1566 }
1567 
1568 
1569 /* Entry point for complex operation lowering during optimization.  */
1570 
1571 static unsigned int
1572 tree_lower_complex (void)
1573 {
1574   int old_last_basic_block;
1575   gimple_stmt_iterator gsi;
1576   basic_block bb;
1577 
1578   if (!init_dont_simulate_again ())
1579     return 0;
1580 
1581   complex_lattice_values = VEC_alloc (complex_lattice_t, heap, num_ssa_names);
1582   VEC_safe_grow_cleared (complex_lattice_t, heap,
1583 			 complex_lattice_values, num_ssa_names);
1584 
1585   init_parameter_lattice_values ();
1586   ssa_propagate (complex_visit_stmt, complex_visit_phi);
1587 
1588   complex_variable_components = htab_create (10,  int_tree_map_hash,
1589 					     int_tree_map_eq, free);
1590 
1591   complex_ssa_name_components = VEC_alloc (tree, heap, 2*num_ssa_names);
1592   VEC_safe_grow_cleared (tree, heap, complex_ssa_name_components,
1593 			 2 * num_ssa_names);
1594 
1595   update_parameter_components ();
1596 
1597   /* ??? Ideally we'd traverse the blocks in breadth-first order.  */
1598   old_last_basic_block = last_basic_block;
1599   FOR_EACH_BB (bb)
1600     {
1601       if (bb->index >= old_last_basic_block)
1602 	continue;
1603 
1604       update_phi_components (bb);
1605       for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1606 	expand_complex_operations_1 (&gsi);
1607     }
1608 
1609   gsi_commit_edge_inserts ();
1610 
1611   htab_delete (complex_variable_components);
1612   VEC_free (tree, heap, complex_ssa_name_components);
1613   VEC_free (complex_lattice_t, heap, complex_lattice_values);
1614   return 0;
1615 }
1616 
1617 struct gimple_opt_pass pass_lower_complex =
1618 {
1619  {
1620   GIMPLE_PASS,
1621   "cplxlower",				/* name */
1622   0,					/* gate */
1623   tree_lower_complex,			/* execute */
1624   NULL,					/* sub */
1625   NULL,					/* next */
1626   0,					/* static_pass_number */
1627   TV_NONE,				/* tv_id */
1628   PROP_ssa,				/* properties_required */
1629   PROP_gimple_lcx,			/* properties_provided */
1630   0,                       		/* properties_destroyed */
1631   0,					/* todo_flags_start */
1632   TODO_dump_func
1633     | TODO_ggc_collect
1634     | TODO_update_ssa
1635     | TODO_verify_stmts	 		/* todo_flags_finish */
1636  }
1637 };
1638 
1639 
1640 static bool
1641 gate_no_optimization (void)
1642 {
1643   /* With errors, normal optimization passes are not run.  If we don't
1644      lower complex operations at all, rtl expansion will abort.  */
1645   return !(cfun->curr_properties & PROP_gimple_lcx);
1646 }
1647 
1648 struct gimple_opt_pass pass_lower_complex_O0 =
1649 {
1650  {
1651   GIMPLE_PASS,
1652   "cplxlower0",				/* name */
1653   gate_no_optimization,			/* gate */
1654   tree_lower_complex,			/* execute */
1655   NULL,					/* sub */
1656   NULL,					/* next */
1657   0,					/* static_pass_number */
1658   TV_NONE,				/* tv_id */
1659   PROP_cfg,				/* properties_required */
1660   PROP_gimple_lcx,			/* properties_provided */
1661   0,					/* properties_destroyed */
1662   0,					/* todo_flags_start */
1663   TODO_dump_func
1664     | TODO_ggc_collect
1665     | TODO_update_ssa
1666     | TODO_verify_stmts	 		/* todo_flags_finish */
1667  }
1668 };
1669