Hi!
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.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for
trunk/15.2/14.4?
2025-07-17 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.
--- gcc/gimple-fold.cc.jj 2025-06-30 10:59:37.553460624 +0200
+++ gcc/gimple-fold.cc 2025-07-17 16:09:34.993333798 +0200
@@ -9916,10 +9916,17 @@ fold_nonarray_ctor_reference (tree type,
{
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,
--- gcc/testsuite/gcc.dg/bitint-124.c.jj 2025-07-17 16:17:52.412798465
+0200
+++ gcc/testsuite/gcc.dg/bitint-124.c 2025-07-17 16:21:03.803284269 +0200
@@ -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
+}
Jakub
