| /* Define per-register tables for data flow info and register allocation. |
| Copyright (C) 1987, 1993, 1994, 1995, 1997 Free Software Foundation, Inc. |
| |
| This file is part of GNU CC. |
| |
| GNU CC is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU CC is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU CC; see the file COPYING. If not, write to |
| the Free Software Foundation, 59 Temple Place - Suite 330, |
| Boston, MA 02111-1307, USA. */ |
| |
| |
| |
| #define REG_BYTES(R) mode_size[(int) GET_MODE (R)] |
| |
| /* Get the number of consecutive hard regs required to hold the REG rtx R. |
| When something may be an explicit hard reg, REG_SIZE is the only |
| valid way to get this value. You cannot get it from the regno. */ |
| |
| #define REG_SIZE(R) \ |
| ((mode_size[(int) GET_MODE (R)] + UNITS_PER_WORD - 1) / UNITS_PER_WORD) |
| |
| #ifndef SMALL_REGISTER_CLASSES |
| #define SMALL_REGISTER_CLASSES 0 |
| #endif |
| |
| /* Maximum register number used in this function, plus one. */ |
| |
| extern int max_regno; |
| |
| /* Maximum number of SCRATCH rtx's in each block of this function. */ |
| |
| extern int max_scratch; |
| |
| /* Register information indexed by register number */ |
| typedef struct reg_info_def { |
| /* fields set by reg_scan */ |
| int first_uid; /* UID of first insn to use (REG n) */ |
| int last_uid; /* UID of last insn to use (REG n) */ |
| int last_note_uid; /* UID of last note to use (REG n) */ |
| |
| /* fields set by both reg_scan and flow_analysis */ |
| int sets; /* # of times (REG n) is set */ |
| |
| /* fields set by flow_analysis */ |
| int refs; /* # of times (REG n) is used or set */ |
| int deaths; /* # of times (REG n) dies */ |
| int live_length; /* # of instructions (REG n) is live */ |
| int calls_crossed; /* # of calls (REG n) is live across */ |
| int basic_block; /* # of basic blocks (REG n) is used in */ |
| char changes_size; /* whether (SUBREG (REG n)) changes size */ |
| } reg_info; |
| |
| extern reg_info *reg_n_info; |
| |
| /* Indexed by n, gives number of times (REG n) is used or set. |
| References within loops may be counted more times. */ |
| |
| #define REG_N_REFS(N) (reg_n_info[(N)].refs) |
| |
| /* Indexed by n, gives number of times (REG n) is set. |
| ??? both regscan and flow allocate space for this. We should settle |
| on just copy. */ |
| |
| #define REG_N_SETS(N) (reg_n_info[(N)].sets) |
| |
| /* Indexed by N, gives number of insns in which register N dies. |
| Note that if register N is live around loops, it can die |
| in transitions between basic blocks, and that is not counted here. |
| So this is only a reliable indicator of how many regions of life there are |
| for registers that are contained in one basic block. */ |
| |
| #define REG_N_DEATHS(N) (reg_n_info[(N)].deaths) |
| |
| /* Indexed by N; says whether a pseudo register N was ever used |
| within a SUBREG that changes the size of the reg. Some machines prohibit |
| such objects to be in certain (usually floating-point) registers. */ |
| |
| #define REG_CHANGES_SIZE(N) (reg_n_info[(N)].changes_size) |
| |
| /* Get the number of consecutive words required to hold pseudo-reg N. */ |
| |
| #define PSEUDO_REGNO_SIZE(N) \ |
| ((GET_MODE_SIZE (PSEUDO_REGNO_MODE (N)) + UNITS_PER_WORD - 1) \ |
| / UNITS_PER_WORD) |
| |
| /* Get the number of bytes required to hold pseudo-reg N. */ |
| |
| #define PSEUDO_REGNO_BYTES(N) \ |
| GET_MODE_SIZE (PSEUDO_REGNO_MODE (N)) |
| |
| /* Get the machine mode of pseudo-reg N. */ |
| |
| #define PSEUDO_REGNO_MODE(N) GET_MODE (regno_reg_rtx[N]) |
| |
| /* Indexed by N, gives number of CALL_INSNS across which (REG n) is live. */ |
| |
| #define REG_N_CALLS_CROSSED(N) (reg_n_info[(N)].calls_crossed) |
| |
| /* Total number of instructions at which (REG n) is live. |
| The larger this is, the less priority (REG n) gets for |
| allocation in a hard register (in global-alloc). |
| This is set in flow.c and remains valid for the rest of the compilation |
| of the function; it is used to control register allocation. |
| |
| local-alloc.c may alter this number to change the priority. |
| |
| Negative values are special. |
| -1 is used to mark a pseudo reg which has a constant or memory equivalent |
| and is used infrequently enough that it should not get a hard register. |
| -2 is used to mark a pseudo reg for a parameter, when a frame pointer |
| is not required. global.c makes an allocno for this but does |
| not try to assign a hard register to it. */ |
| |
| #define REG_LIVE_LENGTH(N) (reg_n_info[(N)].live_length) |
| |
| /* Vector of substitutions of register numbers, |
| used to map pseudo regs into hardware regs. |
| |
| This can't be folded into reg_n_info without changing all of the |
| machine dependent directories, since the reload functions |
| in the machine dependent files access it. */ |
| |
| extern short *reg_renumber; |
| |
| /* Vector indexed by hardware reg |
| saying whether that reg is ever used. */ |
| |
| extern char regs_ever_live[FIRST_PSEUDO_REGISTER]; |
| |
| /* Vector indexed by hardware reg giving its name. */ |
| |
| extern char *reg_names[FIRST_PSEUDO_REGISTER]; |
| |
| /* For each hard register, the widest mode object that it can contain. |
| This will be a MODE_INT mode if the register can hold integers. Otherwise |
| it will be a MODE_FLOAT or a MODE_CC mode, whichever is valid for the |
| register. */ |
| |
| extern enum machine_mode reg_raw_mode[FIRST_PSEUDO_REGISTER]; |
| |
| /* Vector indexed by regno; gives uid of first insn using that reg. |
| This is computed by reg_scan for use by cse and loop. |
| It is sometimes adjusted for subsequent changes during loop, |
| but not adjusted by cse even if cse invalidates it. */ |
| |
| #define REGNO_FIRST_UID(N) (reg_n_info[(N)].first_uid) |
| |
| /* Vector indexed by regno; gives uid of last insn using that reg. |
| This is computed by reg_scan for use by cse and loop. |
| It is sometimes adjusted for subsequent changes during loop, |
| but not adjusted by cse even if cse invalidates it. |
| This is harmless since cse won't scan through a loop end. */ |
| |
| #define REGNO_LAST_UID(N) (reg_n_info[(N)].last_uid) |
| |
| /* Similar, but includes insns that mention the reg in their notes. */ |
| |
| #define REGNO_LAST_NOTE_UID(N) (reg_n_info[(N)].last_note_uid) |
| |
| /* This is reset to LAST_VIRTUAL_REGISTER + 1 at the start of each function. |
| After rtl generation, it is 1 plus the largest register number used. */ |
| |
| extern int reg_rtx_no; |
| |
| /* Vector indexed by regno; contains 1 for a register is considered a pointer. |
| Reloading, etc. will use a pointer register rather than a non-pointer |
| as the base register in an address, when there is a choice of two regs. */ |
| |
| extern char *regno_pointer_flag; |
| #define REGNO_POINTER_FLAG(REGNO) regno_pointer_flag[REGNO] |
| extern int regno_pointer_flag_length; |
| |
| /* List made of EXPR_LIST rtx's which gives pairs of pseudo registers |
| that have to go in the same hard reg. */ |
| extern rtx regs_may_share; |
| |
| /* Vector mapping pseudo regno into the REG rtx for that register. |
| This is computed by reg_scan. */ |
| |
| extern rtx *regno_reg_rtx; |
| |
| /* Flag set by local-alloc or global-alloc if they decide to allocate |
| something in a call-clobbered register. */ |
| |
| extern int caller_save_needed; |
| |
| /* Predicate to decide whether to give a hard reg to a pseudo which |
| is referenced REFS times and would need to be saved and restored |
| around a call CALLS times. */ |
| |
| #ifndef CALLER_SAVE_PROFITABLE |
| #define CALLER_SAVE_PROFITABLE(REFS, CALLS) (4 * (CALLS) < (REFS)) |
| #endif |
| |
| /* On most machines a register class is likely to be spilled if it |
| only has one register. */ |
| #ifndef CLASS_LIKELY_SPILLED_P |
| #define CLASS_LIKELY_SPILLED_P(CLASS) (reg_class_size[(int) (CLASS)] == 1) |
| #endif |
| |
| /* Allocated in local_alloc. */ |
| |
| /* A list of SCRATCH rtl allocated by local-alloc. */ |
| extern rtx *scratch_list; |
| /* The basic block in which each SCRATCH is used. */ |
| extern int *scratch_block; |
| /* The length of the arrays pointed to by scratch_block and scratch_list. */ |
| extern int scratch_list_length; |
| |
| /* Allocate reg_n_info tables */ |
| extern void allocate_reg_info PROTO((int, int, int)); |