https://gcc.gnu.org/g:a55a425bde33b90f215abf079197771e2ba6f276
commit r16-9097-ga55a425bde33b90f215abf079197771e2ba6f276 Author: Richard Biener <[email protected]> Date: Tue Jun 2 14:03:24 2026 +0200 tree-optimization/125553 - ICE with VN trick The following avoids re-doing an earlier CSE when trying to handle a BIT_FIELD_REF as memory reference by combining it with a defining load. This might (as in this case) result in double-insertion to the VN hashtables which rightfully ICEs. PR tree-optimization/125553 * tree-ssa-sccvn.cc (visit_nary_op): Valueize the BIT_FIELD_REF operand before looking at its definition. * gcc.dg/torture/pr125553.c: New testcase. (cherry picked from commit a62132ff21b6cec68bbf27fc5802b4e0e381920e) Diff: --- gcc/testsuite/gcc.dg/torture/pr125553.c | 22 ++++++++++++++++++++++ gcc/tree-ssa-sccvn.cc | 7 ++++--- 2 files changed, 26 insertions(+), 3 deletions(-) diff --git a/gcc/testsuite/gcc.dg/torture/pr125553.c b/gcc/testsuite/gcc.dg/torture/pr125553.c new file mode 100644 index 000000000000..6908b85f92f0 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr125553.c @@ -0,0 +1,22 @@ +/* { dg-do compile } */ + +#include <stdint.h> + +typedef int64_t v8i64 __attribute__((vector_size(64))); +int64_t g2, g17; +void *g24; +static v8i64 g25; + +void hash() +{ + v8i64 vec6; +lbl_b3: + *(v8i64 *)g24 = g25; + uint64_t __ov_tmp_g17 = __builtin_sub_overflow(g2, g2, &__ov_tmp_g17); + g17 = __ov_tmp_g17; + g25 = vec6; + vec6 = *(v8i64 *)g24; + g2 = vec6[0]; + goto lbl_b3; + g25[7]; +} diff --git a/gcc/tree-ssa-sccvn.cc b/gcc/tree-ssa-sccvn.cc index e19beb439d20..ca3ce8546236 100644 --- a/gcc/tree-ssa-sccvn.cc +++ b/gcc/tree-ssa-sccvn.cc @@ -5779,9 +5779,10 @@ visit_nary_op (tree lhs, gassign *stmt) case BIT_FIELD_REF: if (TREE_CODE (TREE_OPERAND (rhs1, 0)) == SSA_NAME) { - tree op0 = TREE_OPERAND (rhs1, 0); - gassign *ass = dyn_cast <gassign *> (SSA_NAME_DEF_STMT (op0)); - if (ass + tree op0 = vn_valueize (TREE_OPERAND (rhs1, 0)); + gassign *ass; + if (TREE_CODE (op0) == SSA_NAME + && (ass = dyn_cast <gassign *> (SSA_NAME_DEF_STMT (op0))) && !gimple_has_volatile_ops (ass) && vn_get_stmt_kind (ass) == VN_REFERENCE) {
