https://gcc.gnu.org/g:33a0437ba5984e230488daf67207354172bed3ae
commit r15-10730-g33a0437ba5984e230488daf67207354172bed3ae Author: Jakub Jelinek <[email protected]> Date: Fri Jan 23 10:37:46 2026 +0100 builtins: Only fold abs/absu if it is sane [PR123703] To my surprise the C FE marks as builtin even a declaration which has incorrect return type. Normally gimple_builtin_call_types_compatible_p etc. will just punt in cases where the return type is wrong, but builtins.cc doesn't use that. For e.g. the mathfn builtins like sqrt and many others, it will punt on weird return types, but for fold_builtin_abs it doesn't and happily tests TYPE_UNSIGNED on it and fold_convert the integral operand to it etc., which ICEs if the return type is aggregate. The following patch fixes it by punting if type is not integral. 2026-01-23 Jakub Jelinek <[email protected]> PR middle-end/123703 * builtins.cc (fold_builtin_abs): Return NULL_TREE if type is not integral. * gcc.c-torture/compile/pr123703.c: New test. (cherry picked from commit 0ba37a153fc86ca1ea9a243d6ea8c60e8de70e08) Diff: --- gcc/builtins.cc | 2 +- gcc/testsuite/gcc.c-torture/compile/pr123703.c | 10 ++++++++++ 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/gcc/builtins.cc b/gcc/builtins.cc index a387863558bc..50a59755be1a 100644 --- a/gcc/builtins.cc +++ b/gcc/builtins.cc @@ -9522,7 +9522,7 @@ fold_builtin_fabs (location_t loc, tree arg, tree type) static tree fold_builtin_abs (location_t loc, tree arg, tree type) { - if (!validate_arg (arg, INTEGER_TYPE)) + if (!validate_arg (arg, INTEGER_TYPE) || !INTEGRAL_TYPE_P (type)) return NULL_TREE; if (TYPE_UNSIGNED (type)) diff --git a/gcc/testsuite/gcc.c-torture/compile/pr123703.c b/gcc/testsuite/gcc.c-torture/compile/pr123703.c new file mode 100644 index 000000000000..a7f68a6147bc --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/compile/pr123703.c @@ -0,0 +1,10 @@ +/* PR middle-end/123703 */ + +struct S { int a; }; +struct S abs (int); + +struct S +bar (int j) +{ + return abs (j); +}
