https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110939
--- Comment #9 from Stefan Schulze Frielinghaus <stefansf at linux dot ibm.com>
---
Thanks for the reproducer and sorry for the hassle.
The normal form of a constant for a mode with fewer bits than in HOST_WIDE_INT
is a sign extended version of the original constant. This even holds for
unsigned constants which I missed. The following should fix this:
diff --git a/gcc/combine.cc b/gcc/combine.cc
index e46d202d0a7..9e5bf96a09d 100644
--- a/gcc/combine.cc
+++ b/gcc/combine.cc
@@ -12059,7 +12059,7 @@ simplify_compare_const (enum rtx_code code,
machine_mode mode,
: (GET_MODE_SIZE (int_mode)
- GET_MODE_SIZE (narrow_mode_iter)));
*pop0 = adjust_address_nv (op0, narrow_mode_iter, offset);
- *pop1 = GEN_INT (n);
+ *pop1 = gen_int_mode (n, narrow_mode_iter);
return adjusted_code;
}
}
Can you give this a try?
