xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/regrename.h (revision 8feb0f0b7eaff0608f8350bbfa3098827b4bb91b)
1 /* This file contains definitions for the register renamer.
2    Copyright (C) 2011-2020 Free Software Foundation, Inc.
3 
4 This file is part of GCC.
5 
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
10 
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 for more details.
15 
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3.  If not see
18 <http://www.gnu.org/licenses/>.  */
19 
20 #ifndef GCC_REGRENAME_H
21 #define GCC_REGRENAME_H
22 
23 /* We keep linked lists of DU_HEAD structures, each of which describes
24    a chain of occurrences of a reg.  */
25 class du_head
26 {
27 public:
28   /* The next chain.  */
29   class du_head *next_chain;
30   /* The first and last elements of this chain.  */
31   struct du_chain *first, *last;
32   /* The chain that this chain is tied to.  */
33   class du_head *tied_chain;
34   /* Describes the register being tracked.  */
35   unsigned regno;
36   int nregs;
37 
38   /* A unique id to be used as an index into the conflicts bitmaps.  */
39   unsigned id;
40   /* A bitmap to record conflicts with other chains.  */
41   bitmap_head conflicts;
42   /* Conflicts with untracked hard registers.  */
43   HARD_REG_SET hard_conflicts;
44   /* Which registers are fully or partially clobbered by the calls that
45      the chain crosses.  */
46   HARD_REG_SET call_clobber_mask;
47 
48   /* A bitmask of ABIs used by the calls that the chain crosses.  */
49   unsigned int call_abis : NUM_ABI_IDS;
50   /* Nonzero if the register is used in a way that prevents renaming,
51      such as the SET_DEST of a CALL_INSN or an asm operand that used
52      to be a hard register.  */
53   unsigned int cannot_rename:1;
54   /* Nonzero if the chain has already been renamed.  */
55   unsigned int renamed:1;
56 
57   /* Fields for use by target code.  */
58   unsigned int target_data_1;
59   unsigned int target_data_2;
60 };
61 
62 typedef class du_head *du_head_p;
63 
64 /* This struct describes a single occurrence of a register.  */
65 struct du_chain
66 {
67   /* Links to the next occurrence of the register.  */
68   struct du_chain *next_use;
69 
70   /* The insn where the register appears.  */
71   rtx_insn *insn;
72   /* The location inside the insn.  */
73   rtx *loc;
74   /* The register class required by the insn at this location.  */
75   ENUM_BITFIELD(reg_class) cl : 16;
76 };
77 
78 /* This struct describes data gathered during regrename_analyze about
79    a single operand of an insn.  */
80 struct operand_rr_info
81 {
82   /* The number of chains recorded for this operand.  */
83   short n_chains;
84   bool failed;
85   /* Holds either the chain for the operand itself, or for the registers in
86      a memory operand.  */
87   struct du_chain *chains[MAX_REGS_PER_ADDRESS];
88   class du_head *heads[MAX_REGS_PER_ADDRESS];
89 };
90 
91 /* A struct to hold a vector of operand_rr_info structures describing the
92    operands of an insn.  */
93 struct insn_rr_info
94 {
95   operand_rr_info *op_info;
96 };
97 
98 
99 extern vec<insn_rr_info> insn_rr;
100 
101 extern void regrename_init (bool);
102 extern void regrename_finish (void);
103 extern void regrename_analyze (bitmap);
104 extern du_head_p regrename_chain_from_id (unsigned int);
105 extern int find_rename_reg (du_head_p, enum reg_class, HARD_REG_SET *, int,
106 			    bool);
107 extern bool regrename_do_replace (du_head_p, int);
108 extern reg_class regrename_find_superclass (du_head_p, int *,
109 					    HARD_REG_SET *);
110 
111 #endif
112