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.
Undo the combination if *cc_use_loc is not COMPARISON_P.
Also remove buggy and now redundant check for (const 0) RTX as part of
the comparison.
PR rtl-optimization/112560
gcc/ChangeLog:
* combine.cc (try_combine): Reject the combination
if *cc_use_loc is not COMPARISON_P.
Bootstrapped and regression tested on x86_64-pc-linux-gnu {,-m32}.
OK for trunk?
Uros.
diff --git a/gcc/combine.cc b/gcc/combine.cc
index a4479f8d836..6dac9ffca85 100644
--- a/gcc/combine.cc
+++ b/gcc/combine.cc
@@ -3184,11 +3184,21 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1,
rtx_insn *i0,
&& (cc_use_loc = find_single_use (SET_DEST (newpat), i3,
&cc_use_insn)))
{
- compare_code = orig_compare_code = GET_CODE (*cc_use_loc);
- if (is_a <scalar_int_mode> (GET_MODE (i2dest), &mode))
- compare_code = simplify_compare_const (compare_code, mode,
- &op0, &op1);
- target_canonicalize_comparison (&compare_code, &op0, &op1, 1);
+ if (COMPARISON_P (*cc_use_loc))
+ {
+ compare_code = orig_compare_code = GET_CODE (*cc_use_loc);
+ if (is_a <scalar_int_mode> (GET_MODE (i2dest), &mode))
+ compare_code = simplify_compare_const (compare_code, mode,
+ &op0, &op1);
+ target_canonicalize_comparison (&compare_code, &op0, &op1, 1);
+ }
+ else
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "CC register not used in comparison.\n");
+ undo_all ();
+ return 0;
+ }
}
/* Do the rest only if op1 is const0_rtx, which may be the
@@ -3221,9 +3231,7 @@ 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)
+ if (compare_code != orig_compare_code)
{
/* Replace cc_use_loc with entire new RTX. */
SUBST (*cc_use_loc,
