/* Save and restore call-clobbered registers which are live across a call.
- Copyright (C) 1989, 1992 Free Software Foundation, Inc.
+ Copyright (C) 1989, 1992, 1994, 1995, 1997, 1998,
+ 1999, 2000 Free Software Foundation, Inc.
This file is part of GNU CC.
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. */
+the Free Software Foundation, 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA. */
#include "config.h"
+#include "system.h"
#include "rtl.h"
#include "insn-config.h"
#include "flags.h"
#include "recog.h"
#include "basic-block.h"
#include "reload.h"
+#include "function.h"
#include "expr.h"
+#include "toplev.h"
+#include "tm_p.h"
+
+#ifndef MAX_MOVE_MAX
+#define MAX_MOVE_MAX MOVE_MAX
+#endif
+
+#ifndef MIN_UNITS_PER_WORD
+#define MIN_UNITS_PER_WORD UNITS_PER_WORD
+#endif
+
+#define MOVE_MAX_WORDS (MOVE_MAX / UNITS_PER_WORD)
/* Modes for each hard register that we can save. The smallest mode is wide
enough to save the entire contents of the register. When saving the
If that is not possible the save is done one register at a time. */
static enum machine_mode
- regno_save_mode[FIRST_PSEUDO_REGISTER][MOVE_MAX / UNITS_PER_WORD + 1];
+ regno_save_mode[FIRST_PSEUDO_REGISTER][MAX_MOVE_MAX / MIN_UNITS_PER_WORD + 1];
/* For each hard register, a place on the stack where it can be saved,
if needed. */
static rtx
- regno_save_mem[FIRST_PSEUDO_REGISTER][MOVE_MAX / UNITS_PER_WORD + 1];
+ regno_save_mem[FIRST_PSEUDO_REGISTER][MAX_MOVE_MAX / MIN_UNITS_PER_WORD + 1];
/* We will only make a register eligible for caller-save if it can be
saved in its widest mode with a simple SET insn as long as the memory
be recognized. */
static enum insn_code
- reg_save_code[FIRST_PSEUDO_REGISTER][MOVE_MAX / UNITS_PER_WORD + 1];
+ reg_save_code[FIRST_PSEUDO_REGISTER][MAX_MOVE_MAX / MIN_UNITS_PER_WORD + 1];
static enum insn_code
- reg_restore_code[FIRST_PSEUDO_REGISTER][MOVE_MAX / UNITS_PER_WORD + 1];
-
-/* Set of hard regs currently live (during scan of all insns). */
-
-static HARD_REG_SET hard_regs_live;
+ reg_restore_code[FIRST_PSEUDO_REGISTER][MAX_MOVE_MAX / MIN_UNITS_PER_WORD + 1];
/* Set of hard regs currently residing in save area (during insn scan). */
static HARD_REG_SET hard_regs_saved;
-/* Set of hard regs which need to be restored before referenced. */
-
-static HARD_REG_SET hard_regs_need_restore;
-
/* Number of registers currently in hard_regs_saved. */
-int n_regs_saved;
+static int n_regs_saved;
-static enum machine_mode choose_hard_reg_mode PROTO((int, int));
-static void set_reg_live PROTO((rtx, rtx));
-static void clear_reg_live PROTO((rtx));
-static void restore_referenced_regs PROTO((rtx, rtx, enum machine_mode));
-static int insert_save_restore PROTO((rtx, int, int,
- enum machine_mode, int));
-\f
-/* Return a machine mode that is legitimate for hard reg REGNO and large
- enough to save nregs. If we can't find one, return VOIDmode. */
+/* Computed by mark_referenced_regs, all regs referenced in a given
+ insn. */
+static HARD_REG_SET referenced_regs;
-static enum machine_mode
-choose_hard_reg_mode (regno, nregs)
- int regno;
- int nregs;
-{
- enum machine_mode found_mode = VOIDmode, mode;
-
- /* We first look for the largest integer mode that can be validly
- held in REGNO. If none, we look for the largest floating-point mode.
- If we still didn't find a valid mode, try CCmode. */
-
- for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT); mode != VOIDmode;
- mode = GET_MODE_WIDER_MODE (mode))
- if (HARD_REGNO_NREGS (regno, mode) == nregs
- && HARD_REGNO_MODE_OK (regno, mode))
- found_mode = mode;
-
- if (found_mode != VOIDmode)
- return found_mode;
-
- for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT); mode != VOIDmode;
- mode = GET_MODE_WIDER_MODE (mode))
- if (HARD_REGNO_NREGS (regno, mode) == nregs
- && HARD_REGNO_MODE_OK (regno, mode))
- found_mode = mode;
+/* Computed in mark_set_regs, holds all registers set by the current
+ instruction. */
+static HARD_REG_SET this_insn_sets;
- if (found_mode != VOIDmode)
- return found_mode;
- if (HARD_REGNO_NREGS (regno, CCmode) == nregs
- && HARD_REGNO_MODE_OK (regno, CCmode))
- return CCmode;
-
- /* We can't find a mode valid for this register. */
- return VOIDmode;
-}
+static void mark_set_regs PARAMS ((rtx, rtx, void *));
+static void mark_referenced_regs PARAMS ((rtx));
+static int insert_save PARAMS ((struct insn_chain *, int, int,
+ HARD_REG_SET *));
+static int insert_restore PARAMS ((struct insn_chain *, int, int,
+ int));
+static struct insn_chain *insert_one_insn PARAMS ((struct insn_chain *, int,
+ enum insn_code, rtx));
+static void add_stored_regs PARAMS ((rtx, rtx, void *));
\f
/* Initialize for caller-save.
{
if (call_used_regs[i] && ! call_fixed_regs[i])
{
- for (j = 1; j <= MOVE_MAX / UNITS_PER_WORD; j++)
+ for (j = 1; j <= MOVE_MAX_WORDS; j++)
{
- regno_save_mode[i][j] = choose_hard_reg_mode (i, j);
+ regno_save_mode[i][j] = HARD_REGNO_CALLER_SAVE_MODE (i, j);
if (regno_save_mode[i][j] == VOIDmode && j == 1)
{
call_fixed_regs[i] = 1;
if (i == FIRST_PSEUDO_REGISTER)
abort ();
- addr_reg = gen_rtx (REG, Pmode, i);
+ addr_reg = gen_rtx_REG (Pmode, i);
for (offset = 1 << (HOST_BITS_PER_INT / 2); offset; offset >>= 1)
{
- address = gen_rtx (PLUS, Pmode, addr_reg, GEN_INT (offset));
+ address = gen_rtx_PLUS (Pmode, addr_reg, GEN_INT (offset));
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
if (regno_save_mode[i][1] != VOIDmode
start_sequence ();
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- for (j = 1; j <= MOVE_MAX / UNITS_PER_WORD; j++)
+ for (j = 1; j <= MOVE_MAX_WORDS; j++)
if (regno_save_mode[i][j] != VOIDmode)
{
- rtx mem = gen_rtx (MEM, regno_save_mode[i][j], address);
- rtx reg = gen_rtx (REG, regno_save_mode[i][j], i);
- rtx savepat = gen_rtx (SET, VOIDmode, mem, reg);
- rtx restpat = gen_rtx (SET, VOIDmode, reg, mem);
+ rtx mem = gen_rtx_MEM (regno_save_mode[i][j], address);
+ rtx reg = gen_rtx_REG (regno_save_mode[i][j], i);
+ rtx savepat = gen_rtx_SET (VOIDmode, mem, reg);
+ rtx restpat = gen_rtx_SET (VOIDmode, reg, mem);
rtx saveinsn = emit_insn (savepat);
rtx restinsn = emit_insn (restpat);
int ok;
reg_save_code[i][j] = recog_memoized (saveinsn);
reg_restore_code[i][j] = recog_memoized (restinsn);
- /* Now extract both insns and see if we can meet their constraints. */
- ok = (reg_save_code[i][j] != -1 && reg_restore_code[i][j] != -1);
+ /* Now extract both insns and see if we can meet their
+ constraints. */
+ ok = (reg_save_code[i][j] != (enum insn_code)-1
+ && reg_restore_code[i][j] != (enum insn_code)-1);
if (ok)
{
- insn_extract (saveinsn);
- ok = constrain_operands (reg_save_code[i][j], 1);
- insn_extract (restinsn);
- ok &= constrain_operands (reg_restore_code[i][j], 1);
+ extract_insn (saveinsn);
+ ok = constrain_operands (1);
+ extract_insn (restinsn);
+ ok &= constrain_operands (1);
}
if (! ok)
int i, j;
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- for (j = 1; j <= MOVE_MAX / UNITS_PER_WORD; j++)
+ for (j = 1; j <= MOVE_MAX_WORDS; j++)
regno_save_mem[i][j] = 0;
}
overestimate slightly (especially if some of these registers are later
used as spill registers), but it should not be significant.
- Then perform register elimination in the addresses of the save area
- locations; return 1 if all eliminated addresses are strictly valid.
- We assume that our caller has set up the elimination table to the
- worst (largest) possible offsets.
-
- Set *PCHANGED to 1 if we had to allocate some memory for the save area.
-
Future work:
In the fallback case we should iterate backwards across all possible
machine independent since they might be saving non-consecutive
registers. (imagine caller-saving d0,d1,a0,a1 on the 68k) */
-int
-setup_save_areas (pchanged)
- int *pchanged;
+void
+setup_save_areas ()
{
int i, j, k;
HARD_REG_SET hard_regs_used;
- int ok = 1;
-
/* Allocate space in the save area for the largest multi-register
pseudos first, then work backwards to single register
/* Find and record all call-used hard-registers in this function. */
CLEAR_HARD_REG_SET (hard_regs_used);
for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
- if (reg_renumber[i] >= 0 && reg_n_calls_crossed[i] > 0)
+ if (reg_renumber[i] >= 0 && REG_N_CALLS_CROSSED (i) > 0)
{
int regno = reg_renumber[i];
int endregno
in a manner which allows multi-register saves/restores to be done. */
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- for (j = MOVE_MAX / UNITS_PER_WORD; j > 0; j--)
+ for (j = MOVE_MAX_WORDS; j > 0; j--)
{
- int ok = 1;
- int do_save;
+ int do_save = 1;
/* If no mode exists for this size, try another. Also break out
if we have already saved this hard register. */
continue;
/* See if any register in this group has been saved. */
- do_save = 1;
for (k = 0; k < j; k++)
if (regno_save_mem[i + k][1])
{
continue;
for (k = 0; k < j; k++)
+ if (! TEST_HARD_REG_BIT (hard_regs_used, i + k))
{
- int regno = i + k;
- ok &= (TEST_HARD_REG_BIT (hard_regs_used, regno) != 0);
+ do_save = 0;
+ break;
}
+ if (! do_save)
+ continue;
- /* We have found an acceptable mode to store in. */
- if (ok)
- {
-
- regno_save_mem[i][j]
- = assign_stack_local (regno_save_mode[i][j],
- GET_MODE_SIZE (regno_save_mode[i][j]), 0);
+ /* We have found an acceptable mode to store in. */
+ regno_save_mem[i][j]
+ = assign_stack_local (regno_save_mode[i][j],
+ GET_MODE_SIZE (regno_save_mode[i][j]), 0);
- /* Setup single word save area just in case... */
- for (k = 0; k < j; k++)
- {
- /* This should not depend on WORDS_BIG_ENDIAN.
- The order of words in regs is the same as in memory. */
- rtx temp = gen_rtx (MEM, regno_save_mode[i+k][1],
+ /* Setup single word save area just in case... */
+ for (k = 0; k < j; k++)
+ {
+ /* This should not depend on WORDS_BIG_ENDIAN.
+ The order of words in regs is the same as in memory. */
+ rtx temp = gen_rtx_MEM (regno_save_mode[i+k][1],
XEXP (regno_save_mem[i][j], 0));
- regno_save_mem[i+k][1]
- = adj_offsettable_operand (temp, k * UNITS_PER_WORD);
- }
- *pchanged = 1;
+ regno_save_mem[i+k][1]
+ = adj_offsettable_operand (temp, k * UNITS_PER_WORD);
}
}
-
- for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- for (j = 1; j <= MOVE_MAX / UNITS_PER_WORD; j++)
- if (regno_save_mem[i][j] != 0)
- ok &= strict_memory_address_p (GET_MODE (regno_save_mem[i][j]),
- XEXP (eliminate_regs (regno_save_mem[i][j], 0, NULL_RTX), 0));
-
- return ok;
}
\f
-/* Find the places where hard regs are live across calls and save them.
-
- INSN_MODE is the mode to assign to any insns that we add. This is used
- by reload to determine whether or not reloads or register eliminations
- need be done on these insns. */
-
+/* Find the places where hard regs are live across calls and save them. */
void
-save_call_clobbered_regs (insn_mode)
- enum machine_mode insn_mode;
+save_call_clobbered_regs ()
{
- rtx insn;
- int b;
-
- for (b = 0; b < n_basic_blocks; b++)
- {
- regset regs_live = basic_block_live_at_start[b];
- rtx prev_block_last = PREV_INSN (basic_block_head[b]);
- REGSET_ELT_TYPE bit;
- int offset, i, j;
- int regno;
-
- /* Compute hard regs live at start of block -- this is the
- real hard regs marked live, plus live pseudo regs that
- have been renumbered to hard regs. No registers have yet been
- saved because we restore all of them before the end of the basic
- block. */
-
-#ifdef HARD_REG_SET
- hard_regs_live = *regs_live;
-#else
- COPY_HARD_REG_SET (hard_regs_live, regs_live);
-#endif
+ struct insn_chain *chain, *next;
- CLEAR_HARD_REG_SET (hard_regs_saved);
- CLEAR_HARD_REG_SET (hard_regs_need_restore);
- n_regs_saved = 0;
+ CLEAR_HARD_REG_SET (hard_regs_saved);
+ n_regs_saved = 0;
- for (offset = 0, i = 0; offset < regset_size; offset++)
- {
- if (regs_live[offset] == 0)
- i += REGSET_ELT_BITS;
- else
- for (bit = 1; bit && i < max_regno; bit <<= 1, i++)
- if ((regs_live[offset] & bit)
- && (regno = reg_renumber[i]) >= 0)
- for (j = regno;
- j < regno + HARD_REGNO_NREGS (regno,
- PSEUDO_REGNO_MODE (i));
- j++)
- SET_HARD_REG_BIT (hard_regs_live, j);
+ for (chain = reload_insn_chain; chain != 0; chain = next)
+ {
+ rtx insn = chain->insn;
+ enum rtx_code code = GET_CODE (insn);
- }
+ next = chain->next;
- /* Now scan the insns in the block, keeping track of what hard
- regs are live as we go. When we see a call, save the live
- call-clobbered hard regs. */
+ if (chain->is_caller_save_insn)
+ abort ();
- for (insn = basic_block_head[b]; ; insn = NEXT_INSN (insn))
+ if (GET_RTX_CLASS (code) == 'i')
{
- RTX_CODE code = GET_CODE (insn);
+ /* If some registers have been saved, see if INSN references
+ any of them. We must restore them before the insn if so. */
- if (GET_RTX_CLASS (code) == 'i')
+ if (n_regs_saved)
{
- rtx link;
+ int regno;
- /* If some registers have been saved, see if INSN references
- any of them. We must restore them before the insn if so. */
-
- if (n_regs_saved)
- restore_referenced_regs (PATTERN (insn), insn, insn_mode);
-
- /* NB: the normal procedure is to first enliven any
- registers set by insn, then deaden any registers that
- had their last use at insn. This is incorrect now,
- since multiple pseudos may have been mapped to the
- same hard reg, and the death notes are ambiguous. So
- it must be done in the other, safe, order. */
-
- for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
- if (REG_NOTE_KIND (link) == REG_DEAD)
- clear_reg_live (XEXP (link, 0));
-
- /* When we reach a call, we need to save all registers that are
- live, call-used, not fixed, and not already saved. We must
- test at this point because registers that die in a CALL_INSN
- are not live across the call and likewise for registers that
- are born in the CALL_INSN. */
-
- if (code == CALL_INSN)
+ if (code == JUMP_INSN)
+ /* Restore all registers if this is a JUMP_INSN. */
+ COPY_HARD_REG_SET (referenced_regs, hard_regs_saved);
+ else
{
- for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
- if (call_used_regs[regno] && ! call_fixed_regs[regno]
- && TEST_HARD_REG_BIT (hard_regs_live, regno)
- && ! TEST_HARD_REG_BIT (hard_regs_saved, regno))
- regno += insert_save_restore (insn, 1, regno,
- insn_mode, 0);
-#ifdef HARD_REG_SET
- hard_regs_need_restore = hard_regs_saved;
-#else
- COPY_HARD_REG_SET (hard_regs_need_restore,
- hard_regs_saved);
-#endif
-
- /* Must recompute n_regs_saved. */
- n_regs_saved = 0;
- for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
- if (TEST_HARD_REG_BIT (hard_regs_saved, regno))
- n_regs_saved++;
-
+ CLEAR_HARD_REG_SET (referenced_regs);
+ mark_referenced_regs (PATTERN (insn));
+ AND_HARD_REG_SET (referenced_regs, hard_regs_saved);
}
-
- note_stores (PATTERN (insn), set_reg_live);
- for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
- if (REG_NOTE_KIND (link) == REG_UNUSED)
- clear_reg_live (XEXP (link, 0));
+ for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
+ if (TEST_HARD_REG_BIT (referenced_regs, regno))
+ regno += insert_restore (chain, 1, regno, MOVE_MAX_WORDS);
}
- if (insn == basic_block_end[b])
- break;
+ if (code == CALL_INSN)
+ {
+ int regno;
+ HARD_REG_SET hard_regs_to_save;
+
+ /* Use the register life information in CHAIN to compute which
+ regs are live during the call. */
+ REG_SET_TO_HARD_REG_SET (hard_regs_to_save,
+ &chain->live_throughout);
+ compute_use_by_pseudos (&hard_regs_to_save,
+ &chain->live_throughout);
+
+ /* Record all registers set in this call insn. These don't need
+ to be saved. N.B. the call insn might set a subreg of a
+ multi-hard-reg pseudo; then the pseudo is considered live
+ during the call, but the subreg that is set isn't. */
+ CLEAR_HARD_REG_SET (this_insn_sets);
+ note_stores (PATTERN (insn), mark_set_regs, NULL);
+
+ /* Compute which hard regs must be saved before this call. */
+ AND_COMPL_HARD_REG_SET (hard_regs_to_save, call_fixed_reg_set);
+ AND_COMPL_HARD_REG_SET (hard_regs_to_save, this_insn_sets);
+ AND_COMPL_HARD_REG_SET (hard_regs_to_save, hard_regs_saved);
+ AND_HARD_REG_SET (hard_regs_to_save, call_used_reg_set);
+
+ for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
+ if (TEST_HARD_REG_BIT (hard_regs_to_save, regno))
+ regno += insert_save (chain, 1, regno, &hard_regs_to_save);
+
+ /* Must recompute n_regs_saved. */
+ n_regs_saved = 0;
+ for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
+ if (TEST_HARD_REG_BIT (hard_regs_saved, regno))
+ n_regs_saved++;
+ }
}
- /* At the end of the basic block, we must restore any registers that
- remain saved. If the last insn in the block is a JUMP_INSN, put
- the restore before the insn, otherwise, put it after the insn. */
-
- if (n_regs_saved)
- for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
- if (TEST_HARD_REG_BIT (hard_regs_need_restore, regno))
- regno += insert_save_restore ((GET_CODE (insn) == JUMP_INSN
- ? insn : NEXT_INSN (insn)), 0,
- regno, insn_mode, MOVE_MAX / UNITS_PER_WORD);
-
- /* If we added any insns at the start of the block, update the start
- of the block to point at those insns. */
- basic_block_head[b] = NEXT_INSN (prev_block_last);
- }
+ if (chain->next == 0 || chain->next->block > chain->block)
+ {
+ int regno;
+ /* At the end of the basic block, we must restore any registers that
+ remain saved. If the last insn in the block is a JUMP_INSN, put
+ the restore before the insn, otherwise, put it after the insn. */
+
+ if (n_regs_saved)
+ for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
+ if (TEST_HARD_REG_BIT (hard_regs_saved, regno))
+ regno += insert_restore (chain, GET_CODE (insn) == JUMP_INSN,
+ regno, MOVE_MAX_WORDS);
+ }
+ }
}
/* Here from note_stores when an insn stores a value in a register.
- Set the proper bit or bits in hard_regs_live. All pseudos that have
+ Set the proper bit or bits in this_insn_sets. All pseudos that have
been assigned hard regs have had their register number changed already,
so we can ignore pseudos. */
-
static void
-set_reg_live (reg, setter)
- rtx reg, setter;
+mark_set_regs (reg, setter, data)
+ rtx reg;
+ rtx setter ATTRIBUTE_UNUSED;
+ void *data ATTRIBUTE_UNUSED;
{
register int regno, endregno, i;
enum machine_mode mode = GET_MODE (reg);
endregno = regno + HARD_REGNO_NREGS (regno, mode);
for (i = regno; i < endregno; i++)
- {
- SET_HARD_REG_BIT (hard_regs_live, i);
- CLEAR_HARD_REG_BIT (hard_regs_saved, i);
- CLEAR_HARD_REG_BIT (hard_regs_need_restore, i);
- }
+ SET_HARD_REG_BIT (this_insn_sets, i);
}
-/* Here when a REG_DEAD note records the last use of a reg. Clear
- the appropriate bit or bits in hard_regs_live. Again we can ignore
- pseudos. */
-
+/* Here from note_stores when an insn stores a value in a register.
+ Set the proper bit or bits in the passed regset. All pseudos that have
+ been assigned hard regs have had their register number changed already,
+ so we can ignore pseudos. */
static void
-clear_reg_live (reg)
+add_stored_regs (reg, setter, data)
rtx reg;
+ rtx setter;
+ void *data;
{
register int regno, endregno, i;
+ enum machine_mode mode = GET_MODE (reg);
+ int word = 0;
+
+ if (GET_CODE (setter) == CLOBBER)
+ return;
+
+ while (GET_CODE (reg) == SUBREG)
+ {
+ word += SUBREG_WORD (reg);
+ reg = SUBREG_REG (reg);
+ }
if (GET_CODE (reg) != REG || REGNO (reg) >= FIRST_PSEUDO_REGISTER)
return;
- regno = REGNO (reg);
- endregno= regno + HARD_REGNO_NREGS (regno, GET_MODE (reg));
+ regno = REGNO (reg) + word;
+ endregno = regno + HARD_REGNO_NREGS (regno, mode);
for (i = regno; i < endregno; i++)
- {
- CLEAR_HARD_REG_BIT (hard_regs_live, i);
- CLEAR_HARD_REG_BIT (hard_regs_need_restore, i);
- CLEAR_HARD_REG_BIT (hard_regs_saved, i);
- }
-}
-\f
-/* If any register currently residing in the save area is referenced in X,
- which is part of INSN, emit code to restore the register in front of INSN.
- INSN_MODE is the mode to assign to any insns that we add. */
+ SET_REGNO_REG_SET ((regset) data, i);
+}
+/* Walk X and record all referenced registers in REFERENCED_REGS. */
static void
-restore_referenced_regs (x, insn, insn_mode)
+mark_referenced_regs (x)
rtx x;
- rtx insn;
- enum machine_mode insn_mode;
{
enum rtx_code code = GET_CODE (x);
- char *fmt;
+ const char *fmt;
int i, j;
- if (code == CLOBBER)
- return;
+ if (code == SET)
+ mark_referenced_regs (SET_SRC (x));
+ if (code == SET || code == CLOBBER)
+ {
+ x = SET_DEST (x);
+ code = GET_CODE (x);
+ if (code == REG || code == PC || code == CC0
+ || (code == SUBREG && GET_CODE (SUBREG_REG (x)) == REG))
+ return;
+ }
+ if (code == MEM || code == SUBREG)
+ {
+ x = XEXP (x, 0);
+ code = GET_CODE (x);
+ }
if (code == REG)
{
int regno = REGNO (x);
+ int hardregno = (regno < FIRST_PSEUDO_REGISTER ? regno
+ : reg_renumber[regno]);
- /* If this is a pseudo, scan its memory location, since it might
- involve the use of another register, which might be saved. */
-
- if (regno >= FIRST_PSEUDO_REGISTER
- && reg_equiv_mem[regno] != 0)
- restore_referenced_regs (XEXP (reg_equiv_mem[regno], 0),
- insn, insn_mode);
- else if (regno >= FIRST_PSEUDO_REGISTER
- && reg_equiv_address[regno] != 0)
- restore_referenced_regs (reg_equiv_address[regno],
- insn, insn_mode);
-
- /* Otherwise if this is a hard register, restore any piece of it that
- is currently saved. */
-
- else if (regno < FIRST_PSEUDO_REGISTER)
+ if (hardregno >= 0)
{
- int numregs = HARD_REGNO_NREGS (regno, GET_MODE (x));
- /* Save at most SAVEREGS at a time. This can not be larger than
- MOVE_MAX, because that causes insert_save_restore to fail. */
- int saveregs = MIN (numregs, MOVE_MAX / UNITS_PER_WORD);
- int endregno = regno + numregs;
-
- for (i = regno; i < endregno; i++)
- if (TEST_HARD_REG_BIT (hard_regs_need_restore, i))
- i += insert_save_restore (insn, 0, i, insn_mode, saveregs);
+ int nregs = HARD_REGNO_NREGS (hardregno, GET_MODE (x));
+ while (nregs-- > 0)
+ SET_HARD_REG_BIT (referenced_regs, hardregno + nregs);
}
-
+ /* If this is a pseudo that did not get a hard register, scan its
+ memory location, since it might involve the use of another
+ register, which might be saved. */
+ else if (reg_equiv_mem[regno] != 0)
+ mark_referenced_regs (XEXP (reg_equiv_mem[regno], 0));
+ else if (reg_equiv_address[regno] != 0)
+ mark_referenced_regs (reg_equiv_address[regno]);
return;
}
-
+
fmt = GET_RTX_FORMAT (code);
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
if (fmt[i] == 'e')
- restore_referenced_regs (XEXP (x, i), insn, insn_mode);
+ mark_referenced_regs (XEXP (x, i));
else if (fmt[i] == 'E')
for (j = XVECLEN (x, i) - 1; j >= 0; j--)
- restore_referenced_regs (XVECEXP (x, i, j), insn, insn_mode);
+ mark_referenced_regs (XVECEXP (x, i, j));
}
}
\f
-/* Insert a sequence of insns to save or restore, SAVE_P says which,
- REGNO. Place these insns in front of INSN. INSN_MODE is the mode
- to assign to these insns. MAXRESTORE is the maximum number of registers
- which should be restored during this call (when SAVE_P == 0). It should
- never be less than 1 since we only work with entire registers.
+/* Insert a sequence of insns to restore. Place these insns in front of
+ CHAIN if BEFORE_P is nonzero, behind the insn otherwise. MAXRESTORE is
+ the maximum number of registers which should be restored during this call.
+ It should never be less than 1 since we only work with entire registers.
Note that we have verified in init_caller_save that we can do this
with a simple SET, so use it. Set INSN_CODE to what we save there
Return the extra number of registers saved. */
static int
-insert_save_restore (insn, save_p, regno, insn_mode, maxrestore)
- rtx insn;
- int save_p;
+insert_restore (chain, before_p, regno, maxrestore)
+ struct insn_chain *chain;
+ int before_p;
int regno;
- enum machine_mode insn_mode;
int maxrestore;
{
- rtx pat;
- enum insn_code code;
- int i, numregs;
+ int i, k;
+ rtx pat = NULL_RTX;
+ enum insn_code code = CODE_FOR_nothing;
+ int numregs = 0;
+ struct insn_chain *new;
+
+ /* A common failure mode if register status is not correct in the RTL
+ is for this routine to be called with a REGNO we didn't expect to
+ save. That will cause us to write an insn with a (nil) SET_DEST
+ or SET_SRC. Instead of doing so and causing a crash later, check
+ for this common case and abort here instead. This will remove one
+ step in debugging such problems. */
+
+ if (regno_save_mem[regno][1] == 0)
+ abort ();
+
+ /* Get the pattern to emit and update our status.
+
+ See if we can restore `maxrestore' registers at once. Work
+ backwards to the single register case. */
+ for (i = maxrestore; i > 0; i--)
+ {
+ int j;
+ int ok = 1;
+
+ if (regno_save_mem[regno][i] == 0)
+ continue;
+
+ for (j = 0; j < i; j++)
+ if (! TEST_HARD_REG_BIT (hard_regs_saved, regno + j))
+ {
+ ok = 0;
+ break;
+ }
+ /* Must do this one restore at a time */
+ if (! ok)
+ continue;
+
+ numregs = i;
+ break;
+ }
+
+ pat = gen_rtx_SET (VOIDmode,
+ gen_rtx_REG (GET_MODE (regno_save_mem[regno][numregs]),
+ regno),
+ regno_save_mem[regno][numregs]);
+ code = reg_restore_code[regno][numregs];
+ new = insert_one_insn (chain, before_p, code, pat);
+
+ /* Clear status for all registers we restored. */
+ for (k = 0; k < i; k++)
+ {
+ CLEAR_HARD_REG_BIT (hard_regs_saved, regno + k);
+ SET_REGNO_REG_SET (&new->dead_or_set, regno + k);
+ n_regs_saved--;
+ }
+
+
+
+ /* Tell our callers how many extra registers we saved/restored */
+ return numregs - 1;
+}
+
+/* Like insert_restore above, but save registers instead. */
+static int
+insert_save (chain, before_p, regno, to_save)
+ struct insn_chain *chain;
+ int before_p;
+ int regno;
+ HARD_REG_SET *to_save;
+{
+ int i, k;
+ rtx pat = NULL_RTX;
+ enum insn_code code = CODE_FOR_nothing;
+ int numregs = 0;
+ struct insn_chain *new;
/* A common failure mode if register status is not correct in the RTL
is for this routine to be called with a REGNO we didn't expect to
if (regno_save_mem[regno][1] == 0)
abort ();
- /* If INSN is a CALL_INSN, we must insert our insns before any
- USE insns in front of the CALL_INSN. */
+ /* Get the pattern to emit and update our status.
+
+ See if we can save several registers with a single instruction.
+ Work backwards to the single register case. */
+ for (i = MOVE_MAX_WORDS; i > 0; i--)
+ {
+ int j;
+ int ok = 1;
+ if (regno_save_mem[regno][i] == 0)
+ continue;
+
+ for (j = 0; j < i; j++)
+ if (! TEST_HARD_REG_BIT (*to_save, regno + j))
+ {
+ ok = 0;
+ break;
+ }
+ /* Must do this one save at a time */
+ if (! ok)
+ continue;
+
+ numregs = i;
+ break;
+ }
+
+ pat = gen_rtx_SET (VOIDmode, regno_save_mem[regno][numregs],
+ gen_rtx_REG (GET_MODE (regno_save_mem[regno][numregs]),
+ regno));
+ code = reg_save_code[regno][numregs];
+ new = insert_one_insn (chain, before_p, code, pat);
+
+ /* Set hard_regs_saved and dead_or_set for all the registers we saved. */
+ for (k = 0; k < numregs; k++)
+ {
+ SET_HARD_REG_BIT (hard_regs_saved, regno + k);
+ SET_REGNO_REG_SET (&new->dead_or_set, regno + k);
+ n_regs_saved++;
+ }
- if (GET_CODE (insn) == CALL_INSN)
- while (GET_CODE (PREV_INSN (insn)) == INSN
- && GET_CODE (PATTERN (PREV_INSN (insn))) == USE)
- insn = PREV_INSN (insn);
+ /* Tell our callers how many extra registers we saved/restored */
+ return numregs - 1;
+}
+/* Emit a new caller-save insn and set the code. */
+static struct insn_chain *
+insert_one_insn (chain, before_p, code, pat)
+ struct insn_chain *chain;
+ int before_p;
+ enum insn_code code;
+ rtx pat;
+{
+ rtx insn = chain->insn;
+ struct insn_chain *new;
+
#ifdef HAVE_cc0
/* If INSN references CC0, put our insns in front of the insn that sets
CC0. This is always safe, since the only way we could be passed an
reference CC0. Guard against non-INSN's like CODE_LABEL. */
if ((GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN)
+ && before_p
&& reg_referenced_p (cc0_rtx, PATTERN (insn)))
- insn = prev_nonnote_insn (insn);
+ chain = chain->prev, insn = chain->insn;
#endif
- /* Get the pattern to emit and update our status. */
- if (save_p)
+ new = new_insn_chain ();
+ if (before_p)
{
- int i, j, k;
- int ok;
+ rtx link;
- /* See if we can save several registers with a single instruction.
- Work backwards to the single register case. */
- for (i = MOVE_MAX / UNITS_PER_WORD; i > 0; i--)
+ new->prev = chain->prev;
+ if (new->prev != 0)
+ new->prev->next = new;
+ else
+ reload_insn_chain = new;
+
+ chain->prev = new;
+ new->next = chain;
+ new->insn = emit_insn_before (pat, insn);
+ /* ??? It would be nice if we could exclude the already / still saved
+ registers from the live sets. */
+ COPY_REG_SET (&new->live_throughout, &chain->live_throughout);
+ /* Registers that die in CHAIN->INSN still live in the new insn. */
+ for (link = REG_NOTES (chain->insn); link; link = XEXP (link, 1))
{
- ok = 1;
- if (regno_save_mem[regno][i] != 0)
- for (j = 0; j < i; j++)
- {
- if (! call_used_regs[regno + j] || call_fixed_regs[regno + j]
- || ! TEST_HARD_REG_BIT (hard_regs_live, regno + j)
- || TEST_HARD_REG_BIT (hard_regs_saved, regno + j))
- ok = 0;
- }
- else
- continue;
-
- /* Must do this one save at a time */
- if (! ok)
- continue;
-
- pat = gen_rtx (SET, VOIDmode, regno_save_mem[regno][i],
- gen_rtx (REG, GET_MODE (regno_save_mem[regno][i]), regno));
- code = reg_save_code[regno][i];
-
- /* Set hard_regs_saved for all the registers we saved. */
- for (k = 0; k < i; k++)
+ if (REG_NOTE_KIND (link) == REG_DEAD)
{
- SET_HARD_REG_BIT (hard_regs_saved, regno + k);
- SET_HARD_REG_BIT (hard_regs_need_restore, regno + k);
- n_regs_saved++;
+ rtx reg = XEXP (link, 0);
+ int regno, i;
+
+ if (GET_CODE (reg) != REG)
+ abort ();
+
+ regno = REGNO (reg);
+ if (regno >= FIRST_PSEUDO_REGISTER)
+ regno = reg_renumber[regno];
+ if (regno < 0)
+ continue;
+ for (i = HARD_REGNO_NREGS (regno, GET_MODE (reg)) - 1;
+ i >= 0; i--)
+ SET_REGNO_REG_SET (&new->live_throughout, regno + i);
}
-
- numregs = i;
- break;
- }
+ }
+ CLEAR_REG_SET (&new->dead_or_set);
+ if (chain->insn == BLOCK_HEAD (chain->block))
+ BLOCK_HEAD (chain->block) = new->insn;
}
else
{
- int i, j, k;
- int ok;
-
- /* See if we can restore `maxrestore' registers at once. Work
- backwards to the single register case. */
- for (i = maxrestore; i > 0; i--)
- {
- ok = 1;
- if (regno_save_mem[regno][i])
- for (j = 0; j < i; j++)
- {
- if (! TEST_HARD_REG_BIT (hard_regs_need_restore, regno + j))
- ok = 0;
- }
- else
- continue;
-
- /* Must do this one restore at a time */
- if (! ok)
- continue;
-
- pat = gen_rtx (SET, VOIDmode,
- gen_rtx (REG, GET_MODE (regno_save_mem[regno][i]),
- regno),
- regno_save_mem[regno][i]);
- code = reg_restore_code[regno][i];
-
-
- /* Clear status for all registers we restored. */
- for (k = 0; k < i; k++)
- {
- CLEAR_HARD_REG_BIT (hard_regs_need_restore, regno + k);
- n_regs_saved--;
- }
-
- numregs = i;
- break;
- }
+ new->next = chain->next;
+ if (new->next != 0)
+ new->next->prev = new;
+ chain->next = new;
+ new->prev = chain;
+ new->insn = emit_insn_after (pat, insn);
+ /* ??? It would be nice if we could exclude the already / still saved
+ registers from the live sets, and observe REG_UNUSED notes. */
+ COPY_REG_SET (&new->live_throughout, &chain->live_throughout);
+ /* Registers that are set in CHAIN->INSN live in the new insn.
+ (Unless there is a REG_UNUSED note for them, but we don't
+ look for them here.) */
+ note_stores (PATTERN (chain->insn), add_stored_regs,
+ &new->live_throughout);
+ CLEAR_REG_SET (&new->dead_or_set);
+ if (chain->insn == BLOCK_END (chain->block))
+ BLOCK_END (chain->block) = new->insn;
}
- /* Emit the insn and set the code and mode. */
-
- insn = emit_insn_before (pat, insn);
- PUT_MODE (insn, insn_mode);
- INSN_CODE (insn) = code;
+ new->block = chain->block;
+ new->is_caller_save_insn = 1;
- /* Tell our callers how many extra registers we saved/restored */
- return numregs - 1;
+ INSN_CODE (new->insn) = code;
+ return new;
}
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