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-rw-r--r--gcc/sched.c22
1 files changed, 10 insertions, 12 deletions
diff --git a/gcc/sched.c b/gcc/sched.c
index b539569dfb6..a44002e12a7 100644
--- a/gcc/sched.c
+++ b/gcc/sched.c
@@ -2343,12 +2343,7 @@ attach_deaths (x, insn, set_p)
#endif
&& regno != STACK_POINTER_REGNUM)
{
- /* ??? It is perhaps a dead_or_set_p bug that it does
- not check for REG_UNUSED notes itself. This is necessary
- for the case where the SET_DEST is a subreg of regno, as
- dead_or_set_p handles subregs specially. */
- if (! all_needed && ! dead_or_set_p (insn, x)
- && ! find_reg_note (insn, REG_UNUSED, x))
+ if (! all_needed && ! dead_or_set_p (insn, x))
{
/* Check for the case where the register dying partially
overlaps the register set by this insn. */
@@ -2406,17 +2401,20 @@ attach_deaths (x, insn, set_p)
return;
case SUBREG:
+ attach_deaths (SUBREG_REG (x), insn,
+ set_p && ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))
+ <= UNITS_PER_WORD)
+ || (GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))
+ == GET_MODE_SIZE (GET_MODE ((x))))));
+ return;
+
case STRICT_LOW_PART:
- /* These two cases preserve the value of SET_P, so handle them
- separately. */
- attach_deaths (XEXP (x, 0), insn, set_p);
+ attach_deaths (XEXP (x, 0), insn, 0);
return;
case ZERO_EXTRACT:
case SIGN_EXTRACT:
- /* This case preserves the value of SET_P for the first operand, but
- clears it for the other two. */
- attach_deaths (XEXP (x, 0), insn, set_p);
+ attach_deaths (XEXP (x, 0), insn, 0);
attach_deaths (XEXP (x, 1), insn, 0);
attach_deaths (XEXP (x, 2), insn, 0);
return;