https://gcc.gnu.org/g:d51d503af7db6e4d8ca40e29d9250850f25aee1a
commit r14-11898-gd51d503af7db6e4d8ca40e29d9250850f25aee1a
Author: Jakub Jelinek <ja...@redhat.com>
Date: Fri Jul 18 09:20:30 2025 +0200
gimple-fold: Fix up big endian _BitInt adjustment [PR121131]
The following testcase ICEs because SCALAR_INT_TYPE_MODE of course
doesn't work for large BITINT_TYPE types which have BLKmode.
native_encode* as well as e.g. r14-8276 use in cases like these
GET_MODE_SIZE (SCALAR_INT_TYPE_MODE ()) and TREE_INT_CST_LOW (TYPE_SIZE_UNIT
()) for the BLKmode ones.
In this case, it wants bits rather than bytes, so I've used
GET_MODE_BITSIZE like before and TYPE_SIZE otherwise.
Furthermore, the patch only computes encoding_size for big endian
targets, for little endian we don't really adjust anything, so there
is no point computing it.
2025-07-18 Jakub Jelinek <ja...@redhat.com>
PR tree-optimization/121131
* gimple-fold.cc (fold_nonarray_ctor_reference): Use
TREE_INT_CST_LOW (TYPE_SIZE ()) instead of
GET_MODE_BITSIZE (SCALAR_INT_TYPE_MODE ()) for BLKmode BITINT_TYPEs.
Don't compute encoding_size at all for little endian targets.
* gcc.dg/bitint-124.c: New test.
(cherry picked from commit 90955b2f61f787ebc446f0a105b5f49672388d89)
Diff:
---
gcc/gimple-fold.cc | 13 ++++++++++---
gcc/testsuite/gcc.dg/bitint-124.c | 30 ++++++++++++++++++++++++++++++
2 files changed, 40 insertions(+), 3 deletions(-)
diff --git a/gcc/gimple-fold.cc b/gcc/gimple-fold.cc
index 026dac45deda..cc84d392a83c 100644
--- a/gcc/gimple-fold.cc
+++ b/gcc/gimple-fold.cc
@@ -8243,10 +8243,17 @@ fold_nonarray_ctor_reference (tree type, tree ctor,
{
if (BYTES_BIG_ENDIAN != WORDS_BIG_ENDIAN)
return NULL_TREE;
- const unsigned int encoding_size
- = GET_MODE_BITSIZE (SCALAR_INT_TYPE_MODE (TREE_TYPE (cfield)));
if (BYTES_BIG_ENDIAN)
- inner_offset += encoding_size - wi::to_offset (field_size);
+ {
+ tree ctype = TREE_TYPE (cfield);
+ unsigned int encoding_size;
+ if (TYPE_MODE (ctype) != BLKmode)
+ encoding_size
+ = GET_MODE_BITSIZE (SCALAR_INT_TYPE_MODE (ctype));
+ else
+ encoding_size = TREE_INT_CST_LOW (TYPE_SIZE (ctype));
+ inner_offset += encoding_size - wi::to_offset (field_size);
+ }
}
return fold_ctor_reference (type, cval,
diff --git a/gcc/testsuite/gcc.dg/bitint-124.c
b/gcc/testsuite/gcc.dg/bitint-124.c
new file mode 100644
index 000000000000..160a1e3394ab
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/bitint-124.c
@@ -0,0 +1,30 @@
+/* PR tree-optimization/121131 */
+/* { dg-do run { target bitint } } */
+/* { dg-options "-O2" } */
+
+#if __BITINT_MAXWIDTH__ >= 156
+struct A { _BitInt(156) b : 135; };
+
+static inline _BitInt(156)
+foo (struct A *x)
+{
+ return x[1].b;
+}
+
+__attribute__((noipa)) _BitInt(156)
+bar (void)
+{
+ struct A a[] = { 1, 1, -13055525270329736316393717310914023773847wb,
+ 1, 1, 1, 1, 1, 1, 1, 1, 1 };
+ return foo (&a[1]);
+}
+#endif
+
+int
+main ()
+{
+#if __BITINT_MAXWIDTH__ >= 156
+ if (bar () != -13055525270329736316393717310914023773847wb)
+ __builtin_abort ();
+#endif
+}
