aboutsummaryrefslogtreecommitdiff
path: root/gcc/combine.c
diff options
context:
space:
mode:
Diffstat (limited to 'gcc/combine.c')
-rw-r--r--gcc/combine.c158
1 files changed, 108 insertions, 50 deletions
diff --git a/gcc/combine.c b/gcc/combine.c
index ab91989..e2e7258 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -321,15 +321,14 @@ static int nonzero_sign_valid;
/* Record one modification to rtl structure
- to be undone by storing old_contents into *where.
- is_int is 1 if the contents are an int. */
+ to be undone by storing old_contents into *where. */
struct undo
{
struct undo *next;
- int is_int;
- union {rtx r; int i;} old_contents;
- union {rtx *r; int *i;} where;
+ enum { UNDO_RTX, UNDO_INT, UNDO_MODE } kind;
+ union { rtx r; int i; enum machine_mode m; } old_contents;
+ union { rtx *r; int *i; } where;
};
/* Record a bunch of changes to be undone, up to MAX_UNDO of them.
@@ -490,7 +489,7 @@ do_SUBST (rtx *into, rtx newval)
else
buf = xmalloc (sizeof (struct undo));
- buf->is_int = 0;
+ buf->kind = UNDO_RTX;
buf->where.r = into;
buf->old_contents.r = oldval;
*into = newval;
@@ -518,7 +517,7 @@ do_SUBST_INT (int *into, int newval)
else
buf = xmalloc (sizeof (struct undo));
- buf->is_int = 1;
+ buf->kind = UNDO_INT;
buf->where.i = into;
buf->old_contents.i = oldval;
*into = newval;
@@ -527,6 +526,35 @@ do_SUBST_INT (int *into, int newval)
}
#define SUBST_INT(INTO, NEWVAL) do_SUBST_INT(&(INTO), (NEWVAL))
+
+/* Similar to SUBST, but just substitute the mode. This is used when
+ changing the mode of a pseudo-register, so that any other
+ references to the entry in the regno_reg_rtx array will change as
+ well. */
+
+static void
+do_SUBST_MODE (rtx *into, enum machine_mode newval)
+{
+ struct undo *buf;
+ enum machine_mode oldval = GET_MODE (*into);
+
+ if (oldval == newval)
+ return;
+
+ if (undobuf.frees)
+ buf = undobuf.frees, undobuf.frees = buf->next;
+ else
+ buf = xmalloc (sizeof (struct undo));
+
+ buf->kind = UNDO_MODE;
+ buf->where.r = into;
+ buf->old_contents.m = oldval;
+ PUT_MODE (*into, newval);
+
+ buf->next = undobuf.undos, undobuf.undos = buf;
+}
+
+#define SUBST_MODE(INTO, NEWVAL) do_SUBST_MODE(&(INTO), (NEWVAL))
/* Subroutine of try_combine. Determine whether the combine replacement
patterns NEWPAT and NEWI2PAT are cheaper according to insn_rtx_cost
@@ -2224,10 +2252,15 @@ try_combine (rtx i3, rtx i2, rtx i1, int *new_direct_jump_p)
compare_mode))
{
unsigned int regno = REGNO (SET_DEST (newpat));
- rtx new_dest = gen_rtx_REG (compare_mode, regno);
+ rtx new_dest;
- if (regno >= FIRST_PSEUDO_REGISTER)
- SUBST (regno_reg_rtx[regno], new_dest);
+ if (regno < FIRST_PSEUDO_REGISTER)
+ new_dest = gen_rtx_REG (compare_mode, regno);
+ else
+ {
+ SUBST_MODE (regno_reg_rtx[regno], compare_mode);
+ new_dest = regno_reg_rtx[regno];
+ }
SUBST (SET_DEST (newpat), new_dest);
SUBST (XEXP (*cc_use, 0), new_dest);
@@ -2476,7 +2509,6 @@ try_combine (rtx i3, rtx i2, rtx i1, int *new_direct_jump_p)
&& asm_noperands (newpat) < 0)
{
rtx m_split, *split;
- rtx ni2dest = i2dest;
/* See if the MD file can split NEWPAT. If it can't, see if letting it
use I2DEST as a scratch register will help. In the latter case,
@@ -2491,34 +2523,55 @@ try_combine (rtx i3, rtx i2, rtx i1, int *new_direct_jump_p)
possible to try that as a scratch reg. This would require adding
more code to make it work though. */
- if (m_split == 0 && ! reg_overlap_mentioned_p (ni2dest, newpat))
+ if (m_split == 0 && ! reg_overlap_mentioned_p (i2dest, newpat))
{
- enum machine_mode new_mode = GET_MODE (SET_DEST (newpat));
- /* If I2DEST is a hard register or the only use of a pseudo,
- we can change its mode. */
- if (new_mode != GET_MODE (i2dest)
- && new_mode != VOIDmode
- && can_change_dest_mode (i2dest, added_sets_2, new_mode))
- ni2dest = gen_rtx_REG (GET_MODE (SET_DEST (newpat)),
- REGNO (i2dest));
+ enum machine_mode new_mode = GET_MODE (SET_DEST (newpat));
+ /* First try to split using the original register as a
+ scratch register. */
m_split = split_insns (gen_rtx_PARALLEL
(VOIDmode,
gen_rtvec (2, newpat,
gen_rtx_CLOBBER (VOIDmode,
- ni2dest))),
+ i2dest))),
i3);
- /* If the split with the mode-changed register didn't work, try
- the original register. */
- if (! m_split && ni2dest != i2dest)
+
+ /* If that didn't work, try changing the mode of I2DEST if
+ we can. */
+ if (m_split == 0
+ && new_mode != GET_MODE (i2dest)
+ && new_mode != VOIDmode
+ && can_change_dest_mode (i2dest, added_sets_2, new_mode))
{
- ni2dest = i2dest;
+ enum machine_mode old_mode = GET_MODE (i2dest);
+ rtx ni2dest;
+
+ if (REGNO (i2dest) < FIRST_PSEUDO_REGISTER)
+ ni2dest = gen_rtx_REG (new_mode, REGNO (i2dest));
+ else
+ {
+ SUBST_MODE (regno_reg_rtx[REGNO (i2dest)], new_mode);
+ ni2dest = regno_reg_rtx[REGNO (i2dest)];
+ }
+
m_split = split_insns (gen_rtx_PARALLEL
(VOIDmode,
gen_rtvec (2, newpat,
gen_rtx_CLOBBER (VOIDmode,
- i2dest))),
+ ni2dest))),
i3);
+
+ if (m_split == 0
+ && REGNO (i2dest) >= FIRST_PSEUDO_REGISTER)
+ {
+ struct undo *buf;
+
+ PUT_MODE (regno_reg_rtx[REGNO (i2dest)], old_mode);
+ buf = undobuf.undos;
+ undobuf.undos = buf->next;
+ buf->next = undobuf.frees;
+ undobuf.frees = buf;
+ }
}
}
@@ -2547,13 +2600,6 @@ try_combine (rtx i3, rtx i2, rtx i1, int *new_direct_jump_p)
i3set = single_set (NEXT_INSN (m_split));
i2set = single_set (m_split);
- /* In case we changed the mode of I2DEST, replace it in the
- pseudo-register table here. We can't do it above in case this
- code doesn't get executed and we do a split the other way. */
-
- if (REGNO (i2dest) >= FIRST_PSEUDO_REGISTER)
- SUBST (regno_reg_rtx[REGNO (i2dest)], ni2dest);
-
i2_code_number = recog_for_combine (&newi2pat, i2, &new_i2_notes);
/* If I2 or I3 has multiple SETs, we won't know how to track
@@ -2624,10 +2670,13 @@ try_combine (rtx i3, rtx i2, rtx i1, int *new_direct_jump_p)
validated that we can do this. */
if (GET_MODE (i2dest) != split_mode && split_mode != VOIDmode)
{
- newdest = gen_rtx_REG (split_mode, REGNO (i2dest));
-
- if (REGNO (i2dest) >= FIRST_PSEUDO_REGISTER)
- SUBST (regno_reg_rtx[REGNO (i2dest)], newdest);
+ if (REGNO (i2dest) < FIRST_PSEUDO_REGISTER)
+ newdest = gen_rtx_REG (split_mode, REGNO (i2dest));
+ else
+ {
+ SUBST_MODE (regno_reg_rtx[REGNO (i2dest)], split_mode);
+ newdest = regno_reg_rtx[REGNO (i2dest)];
+ }
}
/* If *SPLIT is a (mult FOO (const_int pow2)), convert it to
@@ -3328,10 +3377,20 @@ undo_all (void)
for (undo = undobuf.undos; undo; undo = next)
{
next = undo->next;
- if (undo->is_int)
- *undo->where.i = undo->old_contents.i;
- else
- *undo->where.r = undo->old_contents.r;
+ switch (undo->kind)
+ {
+ case UNDO_RTX:
+ *undo->where.r = undo->old_contents.r;
+ break;
+ case UNDO_INT:
+ *undo->where.i = undo->old_contents.i;
+ break;
+ case UNDO_MODE:
+ PUT_MODE (*undo->where.r, undo->old_contents.m);
+ break;
+ default:
+ gcc_unreachable ();
+ }
undo->next = undobuf.frees;
undobuf.frees = undo;
@@ -5160,10 +5219,15 @@ simplify_set (rtx x)
if (can_change_dest_mode (dest, 0, compare_mode))
{
unsigned int regno = REGNO (dest);
- rtx new_dest = gen_rtx_REG (compare_mode, regno);
+ rtx new_dest;
- if (regno >= FIRST_PSEUDO_REGISTER)
- SUBST (regno_reg_rtx[regno], new_dest);
+ if (regno < FIRST_PSEUDO_REGISTER)
+ new_dest = gen_rtx_REG (compare_mode, regno);
+ else
+ {
+ SUBST_MODE (regno_reg_rtx[regno], compare_mode);
+ new_dest = regno_reg_rtx[regno];
+ }
SUBST (SET_DEST (x), new_dest);
SUBST (XEXP (*cc_use, 0), new_dest);
@@ -11709,12 +11773,6 @@ distribute_notes (rtx notes, rtx from_insn, rtx i3, rtx i2, rtx elim_i2,
{
rtx place = 0, place2 = 0;
- /* If this NOTE references a pseudo register, ensure it references
- the latest copy of that register. */
- if (XEXP (note, 0) && REG_P (XEXP (note, 0))
- && REGNO (XEXP (note, 0)) >= FIRST_PSEUDO_REGISTER)
- XEXP (note, 0) = regno_reg_rtx[REGNO (XEXP (note, 0))];
-
next_note = XEXP (note, 1);
switch (REG_NOTE_KIND (note))
{
generated by cgit v1.1 at 2025-05-01 09:57:54 +0000