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[official-gcc.git] / gcc / regs.h
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1 /* Define per-register tables for data flow info and register allocation.
2 Copyright (C) 1987-2021 Free Software Foundation, Inc.
4 This file is part of GCC.
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.
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.
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/>. */
20 #ifndef GCC_REGS_H
21 #define GCC_REGS_H
23 #define REG_BYTES(R) mode_size[(int) GET_MODE (R)]
25 /* When you only have the mode of a pseudo register before it has a hard
26 register chosen for it, this reports the size of each hard register
27 a pseudo in such a mode would get allocated to. A target may
28 override this. */
30 #ifndef REGMODE_NATURAL_SIZE
31 #define REGMODE_NATURAL_SIZE(MODE) UNITS_PER_WORD
32 #endif
34 /* Maximum register number used in this function, plus one. */
36 extern int max_regno;
38 /* REG_N_REFS and REG_N_SETS are initialized by a call to
39 regstat_init_n_sets_and_refs from the current values of
40 DF_REG_DEF_COUNT and DF_REG_USE_COUNT. REG_N_REFS and REG_N_SETS
41 should only be used if a pass need to change these values in some
42 magical way or the pass needs to have accurate values for these
43 and is not using incremental df scanning.
45 At the end of a pass that uses REG_N_REFS and REG_N_SETS, a call
46 should be made to regstat_free_n_sets_and_refs.
48 Local alloc seems to play pretty loose with these values.
49 REG_N_REFS is set to 0 if the register is used in an asm.
50 Furthermore, local_alloc calls regclass to hack both REG_N_REFS and
51 REG_N_SETS for three address insns. Other passes seem to have
52 other special values. */
56 /* Structure to hold values for REG_N_SETS (i) and REG_N_REFS (i). */
58 struct regstat_n_sets_and_refs_t
60 int sets; /* # of times (REG n) is set */
61 int refs; /* # of times (REG n) is used or set */
64 extern struct regstat_n_sets_and_refs_t *regstat_n_sets_and_refs;
66 /* Indexed by n, gives number of times (REG n) is used or set. */
67 static inline int
68 REG_N_REFS (int regno)
70 return regstat_n_sets_and_refs[regno].refs;
73 /* Indexed by n, gives number of times (REG n) is used or set. */
74 #define SET_REG_N_REFS(N,V) (regstat_n_sets_and_refs[N].refs = V)
75 #define INC_REG_N_REFS(N,V) (regstat_n_sets_and_refs[N].refs += V)
77 /* Indexed by n, gives number of times (REG n) is set. */
78 static inline int
79 REG_N_SETS (int regno)
81 return regstat_n_sets_and_refs[regno].sets;
84 /* Indexed by n, gives number of times (REG n) is set. */
85 #define SET_REG_N_SETS(N,V) (regstat_n_sets_and_refs[N].sets = V)
86 #define INC_REG_N_SETS(N,V) (regstat_n_sets_and_refs[N].sets += V)
88 /* Given a REG, return TRUE if the reg is a PARM_DECL, FALSE otherwise. */
89 extern bool reg_is_parm_p (rtx);
91 /* Functions defined in regstat.c. */
92 extern void regstat_init_n_sets_and_refs (void);
93 extern void regstat_free_n_sets_and_refs (void);
94 extern void regstat_compute_ri (void);
95 extern void regstat_free_ri (void);
96 extern bitmap regstat_get_setjmp_crosses (void);
97 extern void regstat_compute_calls_crossed (void);
98 extern void regstat_free_calls_crossed (void);
99 extern void dump_reg_info (FILE *);
101 /* Register information indexed by register number. This structure is
102 initialized by calling regstat_compute_ri and is destroyed by
103 calling regstat_free_ri. */
104 struct reg_info_t
106 int freq; /* # estimated frequency (REG n) is used or set */
107 int deaths; /* # of times (REG n) dies */
108 int calls_crossed; /* # of calls (REG n) is live across */
109 int basic_block; /* # of basic blocks (REG n) is used in */
112 extern struct reg_info_t *reg_info_p;
114 /* The number allocated elements of reg_info_p. */
115 extern size_t reg_info_p_size;
117 /* Estimate frequency of references to register N. */
119 #define REG_FREQ(N) (reg_info_p[N].freq)
121 /* The weights for each insn varies from 0 to REG_FREQ_BASE.
122 This constant does not need to be high, as in infrequently executed
123 regions we want to count instructions equivalently to optimize for
124 size instead of speed. */
125 #define REG_FREQ_MAX 1000
127 /* Compute register frequency from the BB frequency. When optimizing for size,
128 or profile driven feedback is available and the function is never executed,
129 frequency is always equivalent. Otherwise rescale the basic block
130 frequency. */
131 #define REG_FREQ_FROM_BB(bb) ((optimize_function_for_size_p (cfun) \
132 || !cfun->cfg->count_max.initialized_p ()) \
133 ? REG_FREQ_MAX \
134 : ((bb)->count.to_frequency (cfun) \
135 * REG_FREQ_MAX / BB_FREQ_MAX) \
136 ? ((bb)->count.to_frequency (cfun) \
137 * REG_FREQ_MAX / BB_FREQ_MAX) \
138 : 1)
140 /* Indexed by N, gives number of insns in which register N dies.
141 Note that if register N is live around loops, it can die
142 in transitions between basic blocks, and that is not counted here.
143 So this is only a reliable indicator of how many regions of life there are
144 for registers that are contained in one basic block. */
146 #define REG_N_DEATHS(N) (reg_info_p[N].deaths)
148 /* Get the number of consecutive words required to hold pseudo-reg N. */
150 #define PSEUDO_REGNO_SIZE(N) \
151 ((GET_MODE_SIZE (PSEUDO_REGNO_MODE (N)) + UNITS_PER_WORD - 1) \
152 / UNITS_PER_WORD)
154 /* Get the number of bytes required to hold pseudo-reg N. */
156 #define PSEUDO_REGNO_BYTES(N) \
157 GET_MODE_SIZE (PSEUDO_REGNO_MODE (N))
159 /* Get the machine mode of pseudo-reg N. */
161 #define PSEUDO_REGNO_MODE(N) GET_MODE (regno_reg_rtx[N])
163 /* Indexed by N, gives number of CALL_INSNS across which (REG n) is live. */
165 #define REG_N_CALLS_CROSSED(N) (reg_info_p[N].calls_crossed)
167 /* Indexed by n, gives number of basic block that (REG n) is used in.
168 If the value is REG_BLOCK_GLOBAL (-1),
169 it means (REG n) is used in more than one basic block.
170 REG_BLOCK_UNKNOWN (0) means it hasn't been seen yet so we don't know.
171 This information remains valid for the rest of the compilation
172 of the current function; it is used to control register allocation. */
174 #define REG_BLOCK_UNKNOWN 0
175 #define REG_BLOCK_GLOBAL -1
177 #define REG_BASIC_BLOCK(N) (reg_info_p[N].basic_block)
179 /* Vector of substitutions of register numbers,
180 used to map pseudo regs into hardware regs.
182 This can't be folded into reg_n_info without changing all of the
183 machine dependent directories, since the reload functions
184 in the machine dependent files access it. */
186 extern short *reg_renumber;
188 /* Flag set by local-alloc or global-alloc if they decide to allocate
189 something in a call-clobbered register. */
191 extern int caller_save_needed;
193 /* Select a register mode required for caller save of hard regno REGNO. */
194 #ifndef HARD_REGNO_CALLER_SAVE_MODE
195 #define HARD_REGNO_CALLER_SAVE_MODE(REGNO, NREGS, MODE) \
196 choose_hard_reg_mode (REGNO, NREGS, NULL)
197 #endif
199 /* Target-dependent globals. */
200 struct target_regs {
201 /* For each starting hard register, the number of consecutive hard
202 registers that a given machine mode occupies. */
203 unsigned char x_hard_regno_nregs[FIRST_PSEUDO_REGISTER][MAX_MACHINE_MODE];
205 /* For each hard register, the widest mode object that it can contain.
206 This will be a MODE_INT mode if the register can hold integers. Otherwise
207 it will be a MODE_FLOAT or a MODE_CC mode, whichever is valid for the
208 register. */
209 machine_mode x_reg_raw_mode[FIRST_PSEUDO_REGISTER];
211 /* Vector indexed by machine mode saying whether there are regs of
212 that mode. */
213 bool x_have_regs_of_mode[MAX_MACHINE_MODE];
215 /* 1 if the corresponding class contains a register of the given mode. */
216 char x_contains_reg_of_mode[N_REG_CLASSES][MAX_MACHINE_MODE];
218 /* 1 if the corresponding class contains a register of the given mode
219 which is not global and can therefore be allocated. */
220 char x_contains_allocatable_reg_of_mode[N_REG_CLASSES][MAX_MACHINE_MODE];
222 /* Record for each mode whether we can move a register directly to or
223 from an object of that mode in memory. If we can't, we won't try
224 to use that mode directly when accessing a field of that mode. */
225 char x_direct_load[NUM_MACHINE_MODES];
226 char x_direct_store[NUM_MACHINE_MODES];
228 /* Record for each mode whether we can float-extend from memory. */
229 bool x_float_extend_from_mem[NUM_MACHINE_MODES][NUM_MACHINE_MODES];
232 extern struct target_regs default_target_regs;
233 #if SWITCHABLE_TARGET
234 extern struct target_regs *this_target_regs;
235 #else
236 #define this_target_regs (&default_target_regs)
237 #endif
238 #define reg_raw_mode \
239 (this_target_regs->x_reg_raw_mode)
240 #define have_regs_of_mode \
241 (this_target_regs->x_have_regs_of_mode)
242 #define contains_reg_of_mode \
243 (this_target_regs->x_contains_reg_of_mode)
244 #define contains_allocatable_reg_of_mode \
245 (this_target_regs->x_contains_allocatable_reg_of_mode)
246 #define direct_load \
247 (this_target_regs->x_direct_load)
248 #define direct_store \
249 (this_target_regs->x_direct_store)
250 #define float_extend_from_mem \
251 (this_target_regs->x_float_extend_from_mem)
253 /* Return the number of hard registers in (reg:MODE REGNO). */
255 ALWAYS_INLINE unsigned char
256 hard_regno_nregs (unsigned int regno, machine_mode mode)
258 return this_target_regs->x_hard_regno_nregs[regno][mode];
261 /* Return an exclusive upper bound on the registers occupied by hard
262 register (reg:MODE REGNO). */
264 static inline unsigned int
265 end_hard_regno (machine_mode mode, unsigned int regno)
267 return regno + hard_regno_nregs (regno, mode);
270 /* Add to REGS all the registers required to store a value of mode MODE
271 in register REGNO. */
273 static inline void
274 add_to_hard_reg_set (HARD_REG_SET *regs, machine_mode mode,
275 unsigned int regno)
277 unsigned int end_regno;
279 end_regno = end_hard_regno (mode, regno);
281 SET_HARD_REG_BIT (*regs, regno);
282 while (++regno < end_regno);
285 /* Likewise, but remove the registers. */
287 static inline void
288 remove_from_hard_reg_set (HARD_REG_SET *regs, machine_mode mode,
289 unsigned int regno)
291 unsigned int end_regno;
293 end_regno = end_hard_regno (mode, regno);
295 CLEAR_HARD_REG_BIT (*regs, regno);
296 while (++regno < end_regno);
299 /* Return true if REGS contains the whole of (reg:MODE REGNO). */
301 static inline bool
302 in_hard_reg_set_p (const_hard_reg_set regs, machine_mode mode,
303 unsigned int regno)
305 unsigned int end_regno;
307 gcc_assert (HARD_REGISTER_NUM_P (regno));
309 if (!TEST_HARD_REG_BIT (regs, regno))
310 return false;
312 end_regno = end_hard_regno (mode, regno);
314 if (!HARD_REGISTER_NUM_P (end_regno - 1))
315 return false;
317 while (++regno < end_regno)
318 if (!TEST_HARD_REG_BIT (regs, regno))
319 return false;
321 return true;
324 /* Return true if (reg:MODE REGNO) includes an element of REGS. */
326 static inline bool
327 overlaps_hard_reg_set_p (const_hard_reg_set regs, machine_mode mode,
328 unsigned int regno)
330 unsigned int end_regno;
332 if (TEST_HARD_REG_BIT (regs, regno))
333 return true;
335 end_regno = end_hard_regno (mode, regno);
336 while (++regno < end_regno)
337 if (TEST_HARD_REG_BIT (regs, regno))
338 return true;
340 return false;
343 /* Like add_to_hard_reg_set, but use a REGNO/NREGS range instead of
344 REGNO and MODE. */
346 static inline void
347 add_range_to_hard_reg_set (HARD_REG_SET *regs, unsigned int regno,
348 int nregs)
350 while (nregs-- > 0)
351 SET_HARD_REG_BIT (*regs, regno + nregs);
354 /* Likewise, but remove the registers. */
356 static inline void
357 remove_range_from_hard_reg_set (HARD_REG_SET *regs, unsigned int regno,
358 int nregs)
360 while (nregs-- > 0)
361 CLEAR_HARD_REG_BIT (*regs, regno + nregs);
364 /* Like overlaps_hard_reg_set_p, but use a REGNO/NREGS range instead of
365 REGNO and MODE. */
366 static inline bool
367 range_overlaps_hard_reg_set_p (const_hard_reg_set set, unsigned regno,
368 int nregs)
370 while (nregs-- > 0)
371 if (TEST_HARD_REG_BIT (set, regno + nregs))
372 return true;
373 return false;
376 /* Like in_hard_reg_set_p, but use a REGNO/NREGS range instead of
377 REGNO and MODE. */
378 static inline bool
379 range_in_hard_reg_set_p (const_hard_reg_set set, unsigned regno, int nregs)
381 while (nregs-- > 0)
382 if (!TEST_HARD_REG_BIT (set, regno + nregs))
383 return false;
384 return true;
387 #endif /* GCC_REGS_H */