gcc.dg/torture/bitint-18.c triggers an ICE in push_partial_def when
compiling for RISC-V with -O2. The issue occurs because
build_nonstandard_integer_type cannot handle bit widths larger than
MAX_FIXED_MODE_SIZE. Bail out early for such cases.
gcc/ChangeLog:
* tree-ssa-sccvn.cc (vn_walk_cb_data::push_partial_def): Bail out
for BITINT_TYPE when maxsizei exceeds MAX_FIXED_MODE_SIZE.
---
gcc/tree-ssa-sccvn.cc | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/gcc/tree-ssa-sccvn.cc b/gcc/tree-ssa-sccvn.cc
index 0c519cf4c21..e931a227afd 100644
--- a/gcc/tree-ssa-sccvn.cc
+++ b/gcc/tree-ssa-sccvn.cc
@@ -2315,7 +2315,17 @@ vn_walk_cb_data::push_partial_def (pd_data pd,
/* Make sure to interpret in a type that has a range covering the whole
access size. */
if (INTEGRAL_TYPE_P (vr->type) && maxsizei != TYPE_PRECISION (vr->type))
- type = build_nonstandard_integer_type (maxsizei, TYPE_UNSIGNED (type));
+ {
+ if (TREE_CODE (vr->type) == BITINT_TYPE
+ && maxsizei > MAX_FIXED_MODE_SIZE)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Failed to combine %u partial definitions "
+ "(exceeds MAX_FIXED_MODE_SIZE)\n", ndefs);
+ return (void *)-1;
+ }
+ type = build_nonstandard_integer_type (maxsizei, TYPE_UNSIGNED (type));
+ }
tree val;
if (BYTES_BIG_ENDIAN)
{
--
2.52.0
