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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, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2003, 2004, 2005, 2006, 2007, 2008, 2010 Free Software
4 Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 #ifndef GCC_REGS_H
23 #define GCC_REGS_H
25 #include "machmode.h"
26 #include "hard-reg-set.h"
27 #include "rtl.h"
29 #define REG_BYTES(R) mode_size[(int) GET_MODE (R)]
31 /* When you only have the mode of a pseudo register before it has a hard
32 register chosen for it, this reports the size of each hard register
33 a pseudo in such a mode would get allocated to. A target may
34 override this. */
36 #ifndef REGMODE_NATURAL_SIZE
37 #define REGMODE_NATURAL_SIZE(MODE) UNITS_PER_WORD
38 #endif
40 /* Maximum register number used in this function, plus one. */
42 extern int max_regno;
44 /* REG_N_REFS and REG_N_SETS are initialized by a call to
45 regstat_init_n_sets_and_refs from the current values of
46 DF_REG_DEF_COUNT and DF_REG_USE_COUNT. REG_N_REFS and REG_N_SETS
47 should only be used if a pass need to change these values in some
48 magical way or the pass needs to have accurate values for these
49 and is not using incremental df scanning.
51 At the end of a pass that uses REG_N_REFS and REG_N_SETS, a call
52 should be made to regstat_free_n_sets_and_refs.
54 Local alloc seems to play pretty loose with these values.
55 REG_N_REFS is set to 0 if the register is used in an asm.
56 Furthermore, local_alloc calls regclass to hack both REG_N_REFS and
57 REG_N_SETS for three address insns. Other passes seem to have
58 other special values. */
62 /* Structure to hold values for REG_N_SETS (i) and REG_N_REFS (i). */
64 struct regstat_n_sets_and_refs_t
66 int sets; /* # of times (REG n) is set */
67 int refs; /* # of times (REG n) is used or set */
70 extern struct regstat_n_sets_and_refs_t *regstat_n_sets_and_refs;
72 /* Indexed by n, gives number of times (REG n) is used or set. */
73 static inline int
74 REG_N_REFS(int regno)
76 return regstat_n_sets_and_refs[regno].refs;
79 /* Indexed by n, gives number of times (REG n) is used or set. */
80 #define SET_REG_N_REFS(N,V) (regstat_n_sets_and_refs[N].refs = V)
81 #define INC_REG_N_REFS(N,V) (regstat_n_sets_and_refs[N].refs += V)
83 /* Indexed by n, gives number of times (REG n) is set. */
84 static inline int
85 REG_N_SETS (int regno)
87 return regstat_n_sets_and_refs[regno].sets;
90 /* Indexed by n, gives number of times (REG n) is set. */
91 #define SET_REG_N_SETS(N,V) (regstat_n_sets_and_refs[N].sets = V)
92 #define INC_REG_N_SETS(N,V) (regstat_n_sets_and_refs[N].sets += V)
95 /* Functions defined in regstat.c. */
96 extern void regstat_init_n_sets_and_refs (void);
97 extern void regstat_free_n_sets_and_refs (void);
98 extern void regstat_compute_ri (void);
99 extern void regstat_free_ri (void);
100 extern bitmap regstat_get_setjmp_crosses (void);
101 extern void regstat_compute_calls_crossed (void);
102 extern void regstat_free_calls_crossed (void);
103 extern void dump_reg_info (FILE *);
105 /* Register information indexed by register number. This structure is
106 initialized by calling regstat_compute_ri and is destroyed by
107 calling regstat_free_ri. */
108 struct reg_info_t
110 int freq; /* # estimated frequency (REG n) is used or set */
111 int deaths; /* # of times (REG n) dies */
112 int live_length; /* # of instructions (REG n) is live */
113 int calls_crossed; /* # of calls (REG n) is live across */
114 int freq_calls_crossed; /* # estimated frequency (REG n) crosses call */
115 int throw_calls_crossed; /* # of calls that may throw (REG n) is live across */
116 int basic_block; /* # of basic blocks (REG n) is used in */
119 extern struct reg_info_t *reg_info_p;
121 /* The number allocated elements of reg_info_p. */
122 extern size_t reg_info_p_size;
124 /* Estimate frequency of references to register N. */
126 #define REG_FREQ(N) (reg_info_p[N].freq)
128 /* The weights for each insn varies from 0 to REG_FREQ_BASE.
129 This constant does not need to be high, as in infrequently executed
130 regions we want to count instructions equivalently to optimize for
131 size instead of speed. */
132 #define REG_FREQ_MAX 1000
134 /* Compute register frequency from the BB frequency. When optimizing for size,
135 or profile driven feedback is available and the function is never executed,
136 frequency is always equivalent. Otherwise rescale the basic block
137 frequency. */
138 #define REG_FREQ_FROM_BB(bb) (optimize_size \
139 || (flag_branch_probabilities \
140 && !ENTRY_BLOCK_PTR->count) \
141 ? REG_FREQ_MAX \
142 : ((bb)->frequency * REG_FREQ_MAX / BB_FREQ_MAX)\
143 ? ((bb)->frequency * REG_FREQ_MAX / BB_FREQ_MAX)\
144 : 1)
146 /* Indexed by N, gives number of insns in which register N dies.
147 Note that if register N is live around loops, it can die
148 in transitions between basic blocks, and that is not counted here.
149 So this is only a reliable indicator of how many regions of life there are
150 for registers that are contained in one basic block. */
152 #define REG_N_DEATHS(N) (reg_info_p[N].deaths)
154 /* Get the number of consecutive words required to hold pseudo-reg N. */
156 #define PSEUDO_REGNO_SIZE(N) \
157 ((GET_MODE_SIZE (PSEUDO_REGNO_MODE (N)) + UNITS_PER_WORD - 1) \
158 / UNITS_PER_WORD)
160 /* Get the number of bytes required to hold pseudo-reg N. */
162 #define PSEUDO_REGNO_BYTES(N) \
163 GET_MODE_SIZE (PSEUDO_REGNO_MODE (N))
165 /* Get the machine mode of pseudo-reg N. */
167 #define PSEUDO_REGNO_MODE(N) GET_MODE (regno_reg_rtx[N])
169 /* Indexed by N, gives number of CALL_INSNS across which (REG n) is live. */
171 #define REG_N_CALLS_CROSSED(N) (reg_info_p[N].calls_crossed)
172 #define REG_FREQ_CALLS_CROSSED(N) (reg_info_p[N].freq_calls_crossed)
174 /* Indexed by N, gives number of CALL_INSNS that may throw, across which
175 (REG n) is live. */
177 #define REG_N_THROWING_CALLS_CROSSED(N) (reg_info_p[N].throw_calls_crossed)
179 /* Total number of instructions at which (REG n) is live. The larger
180 this is, the less priority (REG n) gets for allocation in a hard
181 register (in global-alloc). This is set in df-problems.c whenever
182 register info is requested and remains valid for the rest of the
183 compilation of the function; it is used to control register
184 allocation.
186 local-alloc.c may alter this number to change the priority.
188 Negative values are special.
189 -1 is used to mark a pseudo reg which has a constant or memory equivalent
190 and is used infrequently enough that it should not get a hard register.
191 -2 is used to mark a pseudo reg for a parameter, when a frame pointer
192 is not required. global.c makes an allocno for this but does
193 not try to assign a hard register to it. */
195 #define REG_LIVE_LENGTH(N) (reg_info_p[N].live_length)
197 /* Indexed by n, gives number of basic block that (REG n) is used in.
198 If the value is REG_BLOCK_GLOBAL (-1),
199 it means (REG n) is used in more than one basic block.
200 REG_BLOCK_UNKNOWN (0) means it hasn't been seen yet so we don't know.
201 This information remains valid for the rest of the compilation
202 of the current function; it is used to control register allocation. */
204 #define REG_BLOCK_UNKNOWN 0
205 #define REG_BLOCK_GLOBAL -1
207 #define REG_BASIC_BLOCK(N) (reg_info_p[N].basic_block)
209 /* Vector of substitutions of register numbers,
210 used to map pseudo regs into hardware regs.
212 This can't be folded into reg_n_info without changing all of the
213 machine dependent directories, since the reload functions
214 in the machine dependent files access it. */
216 extern short *reg_renumber;
218 /* Flag set by local-alloc or global-alloc if they decide to allocate
219 something in a call-clobbered register. */
221 extern int caller_save_needed;
223 /* Predicate to decide whether to give a hard reg to a pseudo which
224 is referenced REFS times and would need to be saved and restored
225 around a call CALLS times. */
227 #ifndef CALLER_SAVE_PROFITABLE
228 #define CALLER_SAVE_PROFITABLE(REFS, CALLS) (4 * (CALLS) < (REFS))
229 #endif
231 /* Select a register mode required for caller save of hard regno REGNO. */
232 #ifndef HARD_REGNO_CALLER_SAVE_MODE
233 #define HARD_REGNO_CALLER_SAVE_MODE(REGNO, NREGS, MODE) \
234 choose_hard_reg_mode (REGNO, NREGS, false)
235 #endif
237 /* Registers that get partially clobbered by a call in a given mode.
238 These must not be call used registers. */
239 #ifndef HARD_REGNO_CALL_PART_CLOBBERED
240 #define HARD_REGNO_CALL_PART_CLOBBERED(REGNO, MODE) 0
241 #endif
243 /* Target-dependent globals. */
244 struct target_regs {
245 /* For each starting hard register, the number of consecutive hard
246 registers that a given machine mode occupies. */
247 unsigned char x_hard_regno_nregs[FIRST_PSEUDO_REGISTER][MAX_MACHINE_MODE];
249 /* For each hard register, the widest mode object that it can contain.
250 This will be a MODE_INT mode if the register can hold integers. Otherwise
251 it will be a MODE_FLOAT or a MODE_CC mode, whichever is valid for the
252 register. */
253 enum machine_mode x_reg_raw_mode[FIRST_PSEUDO_REGISTER];
255 /* Vector indexed by machine mode saying whether there are regs of
256 that mode. */
257 bool x_have_regs_of_mode[MAX_MACHINE_MODE];
259 /* 1 if the corresponding class contains a register of the given mode. */
260 char x_contains_reg_of_mode[N_REG_CLASSES][MAX_MACHINE_MODE];
262 /* Record for each mode whether we can move a register directly to or
263 from an object of that mode in memory. If we can't, we won't try
264 to use that mode directly when accessing a field of that mode. */
265 char x_direct_load[NUM_MACHINE_MODES];
266 char x_direct_store[NUM_MACHINE_MODES];
268 /* Record for each mode whether we can float-extend from memory. */
269 bool x_float_extend_from_mem[NUM_MACHINE_MODES][NUM_MACHINE_MODES];
272 extern struct target_regs default_target_regs;
273 #if SWITCHABLE_TARGET
274 extern struct target_regs *this_target_regs;
275 #else
276 #define this_target_regs (&default_target_regs)
277 #endif
279 #define hard_regno_nregs \
280 (this_target_regs->x_hard_regno_nregs)
281 #define reg_raw_mode \
282 (this_target_regs->x_reg_raw_mode)
283 #define have_regs_of_mode \
284 (this_target_regs->x_have_regs_of_mode)
285 #define contains_reg_of_mode \
286 (this_target_regs->x_contains_reg_of_mode)
287 #define direct_load \
288 (this_target_regs->x_direct_load)
289 #define direct_store \
290 (this_target_regs->x_direct_store)
291 #define float_extend_from_mem \
292 (this_target_regs->x_float_extend_from_mem)
294 /* Return an exclusive upper bound on the registers occupied by hard
295 register (reg:MODE REGNO). */
297 static inline unsigned int
298 end_hard_regno (enum machine_mode mode, unsigned int regno)
300 return regno + hard_regno_nregs[regno][(int) mode];
303 /* Likewise for hard register X. */
305 #define END_HARD_REGNO(X) end_hard_regno (GET_MODE (X), REGNO (X))
307 /* Likewise for hard or pseudo register X. */
309 #define END_REGNO(X) (HARD_REGISTER_P (X) ? END_HARD_REGNO (X) : REGNO (X) + 1)
311 /* Add to REGS all the registers required to store a value of mode MODE
312 in register REGNO. */
314 static inline void
315 add_to_hard_reg_set (HARD_REG_SET *regs, enum machine_mode mode,
316 unsigned int regno)
318 unsigned int end_regno;
320 end_regno = end_hard_regno (mode, regno);
322 SET_HARD_REG_BIT (*regs, regno);
323 while (++regno < end_regno);
326 /* Likewise, but remove the registers. */
328 static inline void
329 remove_from_hard_reg_set (HARD_REG_SET *regs, enum machine_mode mode,
330 unsigned int regno)
332 unsigned int end_regno;
334 end_regno = end_hard_regno (mode, regno);
336 CLEAR_HARD_REG_BIT (*regs, regno);
337 while (++regno < end_regno);
340 /* Return true if REGS contains the whole of (reg:MODE REGNO). */
342 static inline bool
343 in_hard_reg_set_p (const HARD_REG_SET regs, enum machine_mode mode,
344 unsigned int regno)
346 unsigned int end_regno;
348 gcc_assert (HARD_REGISTER_NUM_P (regno));
350 if (!TEST_HARD_REG_BIT (regs, regno))
351 return false;
353 end_regno = end_hard_regno (mode, regno);
355 if (!HARD_REGISTER_NUM_P (end_regno - 1))
356 return false;
358 while (++regno < end_regno)
359 if (!TEST_HARD_REG_BIT (regs, regno))
360 return false;
362 return true;
365 /* Return true if (reg:MODE REGNO) includes an element of REGS. */
367 static inline bool
368 overlaps_hard_reg_set_p (const HARD_REG_SET regs, enum machine_mode mode,
369 unsigned int regno)
371 unsigned int end_regno;
373 if (TEST_HARD_REG_BIT (regs, regno))
374 return true;
376 end_regno = end_hard_regno (mode, regno);
377 while (++regno < end_regno)
378 if (TEST_HARD_REG_BIT (regs, regno))
379 return true;
381 return false;
384 /* Like add_to_hard_reg_set, but use a REGNO/NREGS range instead of
385 REGNO and MODE. */
387 static inline void
388 add_range_to_hard_reg_set (HARD_REG_SET *regs, unsigned int regno,
389 int nregs)
391 while (nregs-- > 0)
392 SET_HARD_REG_BIT (*regs, regno + nregs);
395 /* Likewise, but remove the registers. */
397 static inline void
398 remove_range_from_hard_reg_set (HARD_REG_SET *regs, unsigned int regno,
399 int nregs)
401 while (nregs-- > 0)
402 CLEAR_HARD_REG_BIT (*regs, regno + nregs);
405 /* Like overlaps_hard_reg_set_p, but use a REGNO/NREGS range instead of
406 REGNO and MODE. */
407 static inline bool
408 range_overlaps_hard_reg_set_p (const HARD_REG_SET set, unsigned regno,
409 int nregs)
411 while (nregs-- > 0)
412 if (TEST_HARD_REG_BIT (set, regno + nregs))
413 return true;
414 return false;
417 /* Like in_hard_reg_set_p, but use a REGNO/NREGS range instead of
418 REGNO and MODE. */
419 static inline bool
420 range_in_hard_reg_set_p (const HARD_REG_SET set, unsigned regno, int nregs)
422 while (nregs-- > 0)
423 if (!TEST_HARD_REG_BIT (set, regno + nregs))
424 return false;
425 return true;
428 #endif /* GCC_REGS_H */