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-rw-r--r--gcc/combine.c81
1 files changed, 50 insertions, 31 deletions
diff --git a/gcc/combine.c b/gcc/combine.c
index d8d3baf982a..57f490da76b 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -860,16 +860,19 @@ combine_instructions (rtx f, unsigned int nregs)
rtx temp = XEXP (links, 0);
if ((set = single_set (temp)) != 0
&& (note = find_reg_equal_equiv_note (temp)) != 0
- && GET_CODE (XEXP (note, 0)) != EXPR_LIST
+ && (note = XEXP (note, 0), GET_CODE (note)) != EXPR_LIST
/* Avoid using a register that may already been marked
dead by an earlier instruction. */
- && ! unmentioned_reg_p (XEXP (note, 0), SET_SRC (set)))
+ && ! unmentioned_reg_p (note, SET_SRC (set))
+ && (GET_MODE (note) == VOIDmode
+ ? SCALAR_INT_MODE_P (GET_MODE (SET_DEST (set)))
+ : GET_MODE (SET_DEST (set)) == GET_MODE (note)))
{
/* Temporarily replace the set's source with the
contents of the REG_EQUAL note. The insn will
be deleted or recognized by try_combine. */
rtx orig = SET_SRC (set);
- SET_SRC (set) = XEXP (note, 0);
+ SET_SRC (set) = note;
next = try_combine (insn, temp, NULL_RTX,
&new_direct_jump_p);
if (next)
@@ -1663,6 +1666,29 @@ adjust_for_new_dest (rtx insn)
distribute_links (gen_rtx_INSN_LIST (VOIDmode, insn, NULL_RTX));
}
+/* Return TRUE if combine can reuse reg X in mode MODE.
+ ADDED_SETS is nonzero if the original set is still required. */
+static bool
+can_change_dest_mode (rtx x, int added_sets, enum machine_mode mode)
+{
+ unsigned int regno;
+
+ if (!REG_P(x))
+ return false;
+
+ regno = REGNO (x);
+ /* Allow hard registers if the new mode is legal, and occupies no more
+ registers than the old mode. */
+ if (regno < FIRST_PSEUDO_REGISTER)
+ return (HARD_REGNO_MODE_OK (regno, mode)
+ && (hard_regno_nregs[regno][GET_MODE (x)]
+ >= hard_regno_nregs[regno][mode]));
+
+ /* Or a pseudo that is only used once. */
+ return (REG_N_SETS (regno) == 1 && !added_sets
+ && !REG_USERVAR_P (x));
+}
+
/* Try to combine the insns I1 and I2 into I3.
Here I1 and I2 appear earlier than I3.
I1 can be zero; then we combine just I2 into I3.
@@ -2114,13 +2140,12 @@ try_combine (rtx i3, rtx i2, rtx i1, int *new_direct_jump_p)
i2src, const0_rtx))
!= GET_MODE (SET_DEST (newpat))))
{
- unsigned int regno = REGNO (SET_DEST (newpat));
- rtx new_dest = gen_rtx_REG (compare_mode, regno);
-
- if (regno < FIRST_PSEUDO_REGISTER
- || (REG_N_SETS (regno) == 1 && ! added_sets_2
- && ! REG_USERVAR_P (SET_DEST (newpat))))
+ if (can_change_dest_mode(SET_DEST (newpat), added_sets_2,
+ compare_mode))
{
+ unsigned int regno = REGNO (SET_DEST (newpat));
+ rtx new_dest = gen_rtx_REG (compare_mode, regno);
+
if (regno >= FIRST_PSEUDO_REGISTER)
SUBST (regno_reg_rtx[regno], new_dest);
@@ -2353,14 +2378,12 @@ try_combine (rtx i3, rtx i2, rtx i1, int *new_direct_jump_p)
if (m_split == 0 && ! reg_overlap_mentioned_p (ni2dest, 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 (GET_MODE (SET_DEST (newpat)) != GET_MODE (i2dest)
- && GET_MODE (SET_DEST (newpat)) != VOIDmode
- && REG_P (i2dest)
- && (REGNO (i2dest) < FIRST_PSEUDO_REGISTER
- || (REG_N_SETS (REGNO (i2dest)) == 1 && ! added_sets_2
- && ! REG_USERVAR_P (i2dest))))
+ 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));
@@ -2468,13 +2491,8 @@ try_combine (rtx i3, rtx i2, rtx i1, int *new_direct_jump_p)
isn't valid for it, or change the number of registers. */
&& (GET_MODE (*split) == GET_MODE (i2dest)
|| GET_MODE (*split) == VOIDmode
- || (REGNO (i2dest) < FIRST_PSEUDO_REGISTER
- && HARD_REGNO_MODE_OK (REGNO (i2dest), GET_MODE (*split))
- && (hard_regno_nregs[REGNO (i2dest)][GET_MODE (i2dest)]
- == hard_regno_nregs[REGNO (i2dest)][GET_MODE (*split)]))
- || (REGNO (i2dest) >= FIRST_PSEUDO_REGISTER
- && REG_N_SETS (REGNO (i2dest)) == 1 && ! added_sets_2
- && ! REG_USERVAR_P (i2dest)))
+ || can_change_dest_mode (i2dest, added_sets_2,
+ GET_MODE (*split)))
&& (next_real_insn (i2) == i3
|| ! use_crosses_set_p (*split, INSN_CUID (i2)))
/* We can't overwrite I2DEST if its value is still used by
@@ -5279,12 +5297,11 @@ simplify_set (rtx x)
which case we can safely change its mode. */
if (compare_mode != GET_MODE (dest))
{
- unsigned int regno = REGNO (dest);
- rtx new_dest = gen_rtx_REG (compare_mode, regno);
-
- if (regno < FIRST_PSEUDO_REGISTER
- || (REG_N_SETS (regno) == 1 && ! REG_USERVAR_P (dest)))
+ if (can_change_dest_mode (dest, 0, compare_mode))
{
+ unsigned int regno = REGNO (dest);
+ rtx new_dest = gen_rtx_REG (compare_mode, regno);
+
if (regno >= FIRST_PSEUDO_REGISTER)
SUBST (regno_reg_rtx[regno], new_dest);
@@ -6467,11 +6484,13 @@ make_extraction (enum machine_mode mode, rtx inner, HOST_WIDE_INT pos,
&& GET_MODE_SIZE (inner_mode) < GET_MODE_SIZE (is_mode))
offset -= GET_MODE_SIZE (is_mode) - GET_MODE_SIZE (inner_mode);
- /* If this is a constant position, we can move to the desired byte. */
+ /* If this is a constant position, we can move to the desired byte.
+ Be careful not to go beyond the original object. */
if (pos_rtx == 0)
{
- offset += pos / BITS_PER_UNIT;
- pos %= GET_MODE_BITSIZE (wanted_inner_mode);
+ enum machine_mode bfmode = smallest_mode_for_size (len, MODE_INT);
+ offset += pos / GET_MODE_BITSIZE (bfmode);
+ pos %= GET_MODE_BITSIZE (bfmode);
}
if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN
@@ -10222,7 +10241,7 @@ simplify_comparison (enum rtx_code code, rtx *pop0, rtx *pop1)
/* (A - C1) always sign-extends, like C2. */
&& num_sign_bit_copies (a, inner_mode)
> (unsigned int) (GET_MODE_BITSIZE (inner_mode)
- - mode_width - 1)))
+ - (mode_width - 1))))
{
op0 = SUBREG_REG (op0);
continue;
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-18 09:05:49 +0000