Initial revision

From-SVN: r41

gcc/regs.h

+/* Define per-register tables for data flow info and register allocation.
+   Copyright (C) 1987 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, 675 Mass Ave, Cambridge, MA 02139, 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)
+
+/* 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;
+
+/* Indexed by n, gives number of times (REG n) is used or set.
+   References within loops may be counted more times.  */
+
+extern int *reg_n_refs;
+
+/* Indexed by n, gives number of times (REG n) is set.  */
+
+extern short *reg_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.  */
+
+extern short *reg_n_deaths;
+
+/* 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.  */
+
+extern int *reg_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-alloc.c makes an allocno for this but does
+   not try to assign a hard register to it.  */
+
+extern int *reg_live_length;
+
+/* Vector of substitutions of register numbers,
+   used to map pseudo regs into hardware regs.  */
+
+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];
+
+/* 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.  */
+
+extern short *regno_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.  */
+
+extern short *regno_last_uid;
+
+/* 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]
+
+/* 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