https://gcc.gnu.org/g:eaccdba315b86d374a4e72b9dd8fefb0fc3cc5ee
commit r14-9847-geaccdba315b86d374a4e72b9dd8fefb0fc3cc5ee
Author: Uros Bizjak <ubiz...@gmail.com>
Date: Mon Apr 8 20:54:30 2024 +0200
combine: Fix ICE in try_combine on pr112494.c [PR112560]
The compiler, configured with --enable-checking=yes,rtl,extra ICEs with:
internal compiler error: RTL check: expected elt 0 type 'e' or 'u', have
'E' (rtx unspec) in try_combine, at combine.cc:3237
This is
3236 /* Just replace the CC reg with a new mode. */
3237 SUBST (XEXP (*cc_use_loc, 0), newpat_dest);
3238 undobuf.other_insn = cc_use_insn;
in combine.cc, where *cc_use_loc is
(unspec:DI [
(reg:CC 17 flags)
] UNSPEC_PUSHFL)
combine assumes CC must be used inside of a comparison and uses XEXP (...,
0)
without checking on the RTX type of the argument.
Replace cc_use_loc with the entire new RTX only in case cc_use_loc satisfies
COMPARISON_P predicate. Otherwise scan the entire cc_use_loc RTX for CC reg
to be updated with a new mode.
PR rtl-optimization/112560
gcc/ChangeLog:
* combine.cc (try_combine): Replace cc_use_loc with the entire
new RTX only in case cc_use_loc satisfies COMPARISON_P predicate.
Otherwise scan the entire cc_use_loc RTX for CC reg to be updated
with a new mode.
* config/i386/i386.md (@pushf<mode>2): Allow all CC modes for
operand 1.
Diff:
---
gcc/combine.cc | 16 +++++++++++++---
gcc/config/i386/i386.md | 4 ++--
2 files changed, 15 insertions(+), 5 deletions(-)
diff --git a/gcc/combine.cc b/gcc/combine.cc
index 745391016d0..71c9abc145c 100644
--- a/gcc/combine.cc
+++ b/gcc/combine.cc
@@ -3222,8 +3222,7 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1,
rtx_insn *i0,
#endif
/* Cases for modifying the CC-using comparison. */
if (compare_code != orig_compare_code
- /* ??? Do we need to verify the zero rtx? */
- && XEXP (*cc_use_loc, 1) == const0_rtx)
+ && COMPARISON_P (*cc_use_loc))
{
/* Replace cc_use_loc with entire new RTX. */
SUBST (*cc_use_loc,
@@ -3233,8 +3232,19 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1,
rtx_insn *i0,
}
else if (compare_mode != orig_compare_mode)
{
+ subrtx_ptr_iterator::array_type array;
+
/* Just replace the CC reg with a new mode. */
- SUBST (XEXP (*cc_use_loc, 0), newpat_dest);
+ FOR_EACH_SUBRTX_PTR (iter, array, cc_use_loc, NONCONST)
+ {
+ rtx *loc = *iter;
+ if (REG_P (*loc)
+ && REGNO (*loc) == REGNO (newpat_dest))
+ {
+ SUBST (*loc, newpat_dest);
+ iter.skip_subrtxes ();
+ }
+ }
undobuf.other_insn = cc_use_insn;
}
}
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index bb2c72f3473..10ae3113ae8 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -2219,9 +2219,9 @@
(define_insn "@pushfl<mode>2"
[(set (match_operand:W 0 "push_operand" "=<")
- (unspec:W [(match_operand:CC 1 "flags_reg_operand")]
+ (unspec:W [(match_operand 1 "flags_reg_operand")]
UNSPEC_PUSHFL))]
- ""
+ "GET_MODE_CLASS (GET_MODE (operands[1])) == MODE_CC"
"pushf{<imodesuffix>}"
[(set_attr "type" "push")
(set_attr "mode" "<MODE>")])
