https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121852
--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
--- gcc/rtlanal.cc.jj 2025-08-23 15:00:04.737781678 +0200
+++ gcc/rtlanal.cc 2025-12-09 19:11:33.519215100 +0100
@@ -1557,7 +1557,10 @@ single_set_2 (const rtx_insn *insn, cons
sets are found in the insn, we check them. */
if (!set_verified)
{
- if (find_reg_note (insn, REG_UNUSED, SET_DEST (set))
+ if ((df ? (REG_P (SET_DEST (set))
+ && REGNO (SET_DEST (set)) < df->regs_inited
+ && DF_REG_USE_COUNT (REGNO (SET_DEST (set))) == 0)
+ : !!find_reg_note (insn, REG_UNUSED, SET_DEST (set)))
&& !side_effects_p (set))
set = NULL;
else
@@ -1565,7 +1568,11 @@ single_set_2 (const rtx_insn *insn, cons
}
if (!set)
set = sub, set_verified = 0;
- else if (!find_reg_note (insn, REG_UNUSED, SET_DEST (sub))
+ else if (!(df ? (REG_P (SET_DEST (sub))
+ && REGNO (SET_DEST (sub)) < df->regs_inited
+ && (DF_REG_USE_COUNT (REGNO (SET_DEST (sub)))
+ == 0))
+ : !!find_reg_note (insn, REG_UNUSED, SET_DEST (sub)))
|| side_effects_p (sub))
return NULL_RTX;
break;
fixes this.
