From: Kito Cheng <kito.cheng@sifive.com>
Date: Mon, 29 Dec 2025 06:14:25 +0000 (+0800)
Subject: VN: Fix VN ICE for large _BitInt types
X-Git-Tag: basepoints/gcc-17~2072
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=cbb9d3815201cfb8869140fc80f0cee19f004a3f;p=thirdparty%2Fgcc.git

VN: Fix VN ICE for large _BitInt types

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.

For BITINT_TYPE with maxsizei > MAX_FIXED_MODE_SIZE, use build_bitint_type
instead of build_nonstandard_integer_type, similar to what tree-sra.cc does.

gcc/ChangeLog:

	* tree-ssa-sccvn.cc (vn_walk_cb_data::push_partial_def): Use
	build_bitint_type for BITINT_TYPE when maxsizei exceeds
	MAX_FIXED_MODE_SIZE.
---

diff --git a/gcc/tree-ssa-sccvn.cc b/gcc/tree-ssa-sccvn.cc
index b152dcb5943..13deccb6c6b 100644
--- a/gcc/tree-ssa-sccvn.cc
+++ b/gcc/tree-ssa-sccvn.cc
@@ -2316,7 +2316,13 @@ 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)
+	type = build_bitint_type (maxsizei, TYPE_UNSIGNED (type));
+      else
+	type = build_nonstandard_integer_type (maxsizei, TYPE_UNSIGNED (type));
+    }
   tree val;
   if (BYTES_BIG_ENDIAN)
     {