/* 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 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 "rtl.h"
#include "reload.h"
#include "expr.h"
-/* A mode for each hard register that we can save. This mode is wide enough
- to save the entire contents of the register and will be used whenever the
- register must be saved because it is live. */
+#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
-static enum machine_mode regno_save_mode[FIRST_PSEUDO_REGISTER];
+/* 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
+ register because it is live we first try to save in multi-register modes.
+ If that is not possible the save is done one register at a time. */
+
+static enum machine_mode
+ 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];
+static rtx
+ 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
when we emit them, the addresses might not be valid, so they might not
be recognized. */
-static enum insn_code reg_save_code[FIRST_PSEUDO_REGISTER];
-static enum insn_code reg_restore_code[FIRST_PSEUDO_REGISTER];
+static enum insn_code
+ reg_save_code[FIRST_PSEUDO_REGISTER][MAX_MOVE_MAX / MIN_UNITS_PER_WORD + 1];
+static enum insn_code
+ reg_restore_code[FIRST_PSEUDO_REGISTER][MAX_MOVE_MAX / MIN_UNITS_PER_WORD + 1];
/* Set of hard regs currently live (during scan of all insns). */
static HARD_REG_SET hard_regs_saved;
-/* Number of registers currently in hard_regs_saved. */
-
-int n_regs_saved;
-
-static void set_reg_live ();
-static void clear_reg_live ();
-static void restore_referenced_regs ();
-static void insert_save_restore ();
-\f
-/* Return a machine mode that is legitimate for hard reg REGNO and large
- enough to save the whole register. If we can't find one,
- return VOIDmode. */
-
-static enum machine_mode
-choose_hard_reg_mode (regno)
- int regno;
-{
- 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) == 1
- && HARD_REGNO_MODE_OK (regno, mode))
- found_mode = mode;
-
- if (found_mode != VOIDmode)
- return found_mode;
+/* Set of hard regs which need to be restored before referenced. */
- for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT); mode != VOIDmode;
- mode = GET_MODE_WIDER_MODE (mode))
- if (HARD_REGNO_NREGS (regno, mode) == 1
- && HARD_REGNO_MODE_OK (regno, mode))
- found_mode = mode;
+static HARD_REG_SET hard_regs_need_restore;
- if (found_mode != VOIDmode)
- return found_mode;
+/* Number of registers currently in hard_regs_saved. */
- if (HARD_REGNO_NREGS (regno, CCmode) == 1
- && HARD_REGNO_MODE_OK (regno, CCmode))
- return CCmode;
+int n_regs_saved;
- /* We can't find a mode valid for this register. */
- return VOIDmode;
-}
+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
/* Initialize for caller-save.
rtx addr_reg;
int offset;
rtx address;
- int i;
+ int i, j;
/* First find all the registers that we need to deal with and all
the modes that they can have. If we can't find a mode to use,
{
if (call_used_regs[i] && ! call_fixed_regs[i])
{
- regno_save_mode[i] = choose_hard_reg_mode (i);
- if (regno_save_mode[i] == VOIDmode)
+ for (j = 1; j <= MOVE_MAX / UNITS_PER_WORD; j++)
{
- call_fixed_regs[i] = 1;
- SET_HARD_REG_BIT (call_fixed_reg_set, i);
+ regno_save_mode[i][j] = choose_hard_reg_mode (i, j);
+ if (regno_save_mode[i][j] == VOIDmode && j == 1)
+ {
+ call_fixed_regs[i] = 1;
+ SET_HARD_REG_BIT (call_fixed_reg_set, i);
+ }
}
}
else
- regno_save_mode[i] = VOIDmode;
+ regno_save_mode[i][1] = VOIDmode;
}
/* The following code tries to approximate the conditions under which
for (offset = 1 << (HOST_BITS_PER_INT / 2); offset; offset >>= 1)
{
- address = gen_rtx (PLUS, Pmode, addr_reg,
- gen_rtx (CONST_INT, VOIDmode, offset));
+ address = gen_rtx (PLUS, Pmode, addr_reg, GEN_INT (offset));
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- if (regno_save_mode[i] != VOIDmode
- && ! strict_memory_address_p (regno_save_mode[i], address))
+ if (regno_save_mode[i][1] != VOIDmode
+ && ! strict_memory_address_p (regno_save_mode[i][1], address))
break;
if (i == FIRST_PSEUDO_REGISTER)
start_sequence ();
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- if (regno_save_mode[i] != VOIDmode)
- {
- rtx mem = gen_rtx (MEM, regno_save_mode[i], address);
- rtx reg = gen_rtx (REG, regno_save_mode[i], 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] = recog_memoized (saveinsn);
- reg_restore_code[i] = recog_memoized (restinsn);
-
- /* Now extract both insns and see if we can meet their constraints. */
- ok = (reg_save_code[i] != -1 && reg_restore_code[i] != -1);
- if (ok)
- {
- insn_extract (saveinsn);
- ok = constrain_operands (reg_save_code[i], 1);
- insn_extract (restinsn);
- ok &= constrain_operands (reg_restore_code[i], 1);
- }
+ for (j = 1; j <= MOVE_MAX / UNITS_PER_WORD; 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 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);
+ 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);
+ }
- if (! ok)
- {
- call_fixed_regs[i] = 1;
- SET_HARD_REG_BIT (call_fixed_reg_set, i);
- }
+ if (! ok)
+ {
+ regno_save_mode[i][j] = VOIDmode;
+ if (j == 1)
+ {
+ call_fixed_regs[i] = 1;
+ SET_HARD_REG_BIT (call_fixed_reg_set, i);
+ }
+ }
}
end_sequence ();
void
init_save_areas ()
{
- int i;
+ int i, j;
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- regno_save_mem[i] = 0;
+ for (j = 1; j <= MOVE_MAX / UNITS_PER_WORD; j++)
+ regno_save_mem[i][j] = 0;
}
/* Allocate save areas for any hard registers that might need saving.
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. */
+ 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
+ modes for the save, choosing the largest available one instead of
+ falling back to the smallest mode immediately. (eg TF -> DF -> SF).
+
+ We do not try to use "move multiple" instructions that exist
+ on some machines (such as the 68k moveml). It could be a win to try
+ and use them when possible. The hard part is doing it in a way that is
+ 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;
{
+ int i, j, k;
+ HARD_REG_SET hard_regs_used;
int ok = 1;
- int i;
+
+ /* Allocate space in the save area for the largest multi-register
+ pseudos first, then work backwards to single register
+ pseudos. */
+
+ /* 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)
{
int regno = reg_renumber[i];
- int endregno
+ int endregno
= regno + HARD_REGNO_NREGS (regno, GET_MODE (regno_reg_rtx[i]));
- int j;
+ int nregs = endregno - regno;
+
+ for (j = 0; j < nregs; j++)
+ {
+ if (call_used_regs[regno+j])
+ SET_HARD_REG_BIT (hard_regs_used, regno+j);
+ }
+ }
+
+ /* Now run through all the call-used hard-registers and allocate
+ space for them in the caller-save area. Try to allocate space
+ in a manner which allows multi-register saves/restores to be done. */
- for (j = regno; j < endregno; j++)
- if (call_used_regs[j] && regno_save_mem[j] == 0)
+ for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
+ for (j = MOVE_MAX / UNITS_PER_WORD; j > 0; j--)
+ {
+ int ok = 1;
+ int do_save;
+
+ /* If no mode exists for this size, try another. Also break out
+ if we have already saved this hard register. */
+ if (regno_save_mode[i][j] == VOIDmode || regno_save_mem[i][1] != 0)
+ 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])
+ {
+ do_save = 0;
+ break;
+ }
+ if (! do_save)
+ continue;
+
+ for (k = 0; k < j; k++)
{
- regno_save_mem[j]
- = assign_stack_local (regno_save_mode[j],
- GET_MODE_SIZE (regno_save_mode[j]), 0);
- *pchanged = 1;
+ int regno = i + k;
+ ok &= (TEST_HARD_REG_BIT (hard_regs_used, regno) != 0);
}
+
+ /* 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);
+
+ /* 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;
+ }
}
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- if (regno_save_mem[i] != 0)
- ok &= strict_memory_address_p (regno_save_mode[i],
- XEXP (eliminate_regs (regno_save_mem[i],
- 0, 0),
- 0));
+ 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, 1), 0));
return ok;
}
for (b = 0; b < n_basic_blocks; b++)
{
regset regs_live = basic_block_live_at_start[b];
- int offset, bit, i, j;
+ 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
#endif
CLEAR_HARD_REG_SET (hard_regs_saved);
+ CLEAR_HARD_REG_SET (hard_regs_need_restore);
n_regs_saved = 0;
for (offset = 0, i = 0; offset < regset_size; offset++)
{
if (regs_live[offset] == 0)
- i += HOST_BITS_PER_INT;
+ i += REGSET_ELT_BITS;
else
for (bit = 1; bit && i < max_regno; bit <<= 1, i++)
if ((regs_live[offset] & bit)
PSEUDO_REGNO_MODE (i));
j++)
SET_HARD_REG_BIT (hard_regs_live, j);
+
}
/* Now scan the insns in the block, keeping track of what hard
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. */
+ are born in the CALL_INSN.
+
+ If registers are filled with parameters for this function,
+ and some of these are also being set by this function, then
+ they will not appear to die (no REG_DEAD note for them),
+ to check if in fact they do, collect the set registers in
+ hard_regs_live first. */
if (code == CALL_INSN)
- 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))
- insert_save_restore (insn, 1, regno, insn_mode);
-
- note_stores (PATTERN (insn), set_reg_live);
+ {
+ HARD_REG_SET this_call_sets;
+ {
+ HARD_REG_SET old_hard_regs_live;
+
+ /* Save the hard_regs_live information. */
+ COPY_HARD_REG_SET (old_hard_regs_live, hard_regs_live);
+
+ /* Now calculate hard_regs_live for this CALL_INSN
+ only. */
+ CLEAR_HARD_REG_SET (hard_regs_live);
+ note_stores (PATTERN (insn), set_reg_live);
+ COPY_HARD_REG_SET (this_call_sets, hard_regs_live);
+
+ /* Restore the hard_regs_live information. */
+ COPY_HARD_REG_SET (hard_regs_live, old_hard_regs_live);
+ }
+
+ 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)
+ /* It must not be set by this instruction. */
+ && ! TEST_HARD_REG_BIT (this_call_sets, regno)
+ && ! TEST_HARD_REG_BIT (hard_regs_saved, regno))
+ regno += insert_save_restore (insn, 1, regno,
+ insn_mode, 0);
+
+ /* Put the information for this CALL_INSN on top of what
+ we already had. */
+ IOR_HARD_REG_SET (hard_regs_live, this_call_sets);
+ COPY_HARD_REG_SET (hard_regs_need_restore, hard_regs_saved);
+
+ /* 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++;
+ }
+ else
+ {
+ note_stores (PATTERN (insn), set_reg_live);
+#ifdef AUTO_INC_DEC
+ for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
+ if (REG_NOTE_KIND (link) == REG_INC)
+ set_reg_live (XEXP (link, 0), NULL_RTX);
+#endif
+ }
for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
if (REG_NOTE_KIND (link) == REG_UNUSED)
if (n_regs_saved)
for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
- if (TEST_HARD_REG_BIT (hard_regs_saved, regno))
- insert_save_restore ((GET_CODE (insn) == JUMP_INSN
- ? insn : NEXT_INSN (insn)),
- 0, regno, insn_mode);
+ 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);
}
}
rtx reg, setter;
{
register int regno, endregno, i;
+ enum machine_mode mode = GET_MODE (reg);
int word = 0;
if (GET_CODE (reg) == SUBREG)
return;
regno = REGNO (reg) + word;
- endregno = regno + HARD_REGNO_NREGS (regno, GET_MODE (reg));
+ endregno = regno + HARD_REGNO_NREGS (regno, mode);
for (i = regno; i < endregno; i++)
- SET_HARD_REG_BIT (hard_regs_live, 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);
+ }
}
/* Here when a REG_DEAD note records the last use of a reg. Clear
endregno= regno + HARD_REGNO_NREGS (regno, GET_MODE (reg));
for (i = regno; i < endregno; i++)
- CLEAR_HARD_REG_BIT (hard_regs_live, 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,
char *fmt;
int i, j;
+ if (code == CLOBBER)
+ return;
+
if (code == REG)
{
int regno = REGNO (x);
insn, insn_mode);
else if (regno >= FIRST_PSEUDO_REGISTER
&& reg_equiv_address[regno] != 0)
- restore_referenced_regs (XEXP (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
else if (regno < FIRST_PSEUDO_REGISTER)
{
- int endregno = regno + HARD_REGNO_NREGS (regno, GET_MODE (x));
-
- for (i = regno; i < endregno; i ++)
- if (TEST_HARD_REG_BIT (hard_regs_saved, i))
- insert_save_restore (insn, 0, i, insn_mode);
+ 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);
}
return;
\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.
+ 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.
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
since the address might not be valid so the insn might not be recognized.
These insns will be reloaded and have register elimination done by
- find_reload, so we need not worry about that here. */
+ find_reload, so we need not worry about that here.
-static void
-insert_save_restore (insn, save_p, regno, insn_mode)
+ Return the extra number of registers saved. */
+
+static int
+insert_save_restore (insn, save_p, regno, insn_mode, maxrestore)
rtx insn;
int save_p;
int regno;
enum machine_mode insn_mode;
+ int maxrestore;
{
rtx pat;
enum insn_code code;
- int i;
+ int i, numregs;
- /* If INSN is a CALL_INSN, we must insert our insns before any
- USE insns in front of the CALL_INSN. */
+ /* 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 (GET_CODE (insn) == CALL_INSN)
- while (GET_CODE (PREV_INSN (insn)) == INSN
- && GET_CODE (PATTERN (PREV_INSN (insn))) == USE)
- insn = PREV_INSN (insn);
+ if (regno_save_mem[regno][1] == 0)
+ abort ();
#ifdef HAVE_cc0
/* If INSN references CC0, put our insns in front of the insn that sets
/* Get the pattern to emit and update our status. */
if (save_p)
{
- pat = gen_rtx (SET, VOIDmode, regno_save_mem[regno],
- gen_rtx (REG, regno_save_mode[regno], regno));
- code = reg_save_code[regno];
- SET_HARD_REG_BIT (hard_regs_saved, regno);
- n_regs_saved++;
+ int i, j, k;
+ int ok;
+
+ /* 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--)
+ {
+ 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++)
+ {
+ SET_HARD_REG_BIT (hard_regs_saved, regno + k);
+ SET_HARD_REG_BIT (hard_regs_need_restore, regno + k);
+ n_regs_saved++;
+ }
+
+ numregs = i;
+ break;
+ }
}
else
{
- pat = gen_rtx (SET, VOIDmode,
- gen_rtx (REG, regno_save_mode[regno], regno),
- regno_save_mem[regno]);
- code = reg_restore_code[regno];
- CLEAR_HARD_REG_BIT (hard_regs_saved, regno);
- n_regs_saved--;
- }
+ 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;
+ }
+ }
/* Emit the insn and set the code and mode. */
insn = emit_insn_before (pat, insn);
PUT_MODE (insn, insn_mode);
INSN_CODE (insn) = code;
+
+ /* Tell our callers how many extra registers we saved/restored */
+ return numregs - 1;
}
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