The function gimple_expand_vec_set_expr in the isel pass, converted VIEW_CONVERT_EXPR to VEC_SET_EXPR without checking the bounds on the index, which cause ICE on targets that supported VEC_SET_EXPR like x86 and powerpc. This patch adds a bound check on the index operand and rejects the conversion if index is out of bound.
2025-11-06 Avinash Jayakar <[email protected]> gcc/ChangeLog: PR tree-optimization/122126 * gimple-isel.cc (gimple_expand_vec_set_extract_expr): Add bound check. gcc/testsuite/ChangeLog: PR tree-optimization/122126 * gcc.dg/pr122126_vextr.c: New test. * gcc.dg/pr122126_vset.c: New test. --- gcc/gimple-isel.cc | 10 ++++++++++ gcc/testsuite/gcc.dg/pr122126_vextr.c | 9 +++++++++ gcc/testsuite/gcc.dg/pr122126_vset.c | 9 +++++++++ 3 files changed, 28 insertions(+) create mode 100644 gcc/testsuite/gcc.dg/pr122126_vextr.c create mode 100644 gcc/testsuite/gcc.dg/pr122126_vset.c diff --git a/gcc/gimple-isel.cc b/gcc/gimple-isel.cc index b5dc579ff46..e745608904e 100644 --- a/gcc/gimple-isel.cc +++ b/gcc/gimple-isel.cc @@ -102,6 +102,16 @@ gimple_expand_vec_set_extract_expr (struct function *fun, tree pos = TREE_OPERAND (ref, 1); tree view_op0 = TREE_OPERAND (op0, 0); + + tree idx = TREE_OPERAND (ref, 1); + // if index is a constant, then check the bounds + poly_uint64 idx_poly; + if (poly_int_tree_p (idx, &idx_poly)) + { + poly_uint64 nelts = TYPE_VECTOR_SUBPARTS (TREE_TYPE (view_op0)); + if (known_gt (idx_poly, nelts)) + return false; + } machine_mode outermode = TYPE_MODE (TREE_TYPE (view_op0)); machine_mode extract_mode = TYPE_MODE (TREE_TYPE (ref)); diff --git a/gcc/testsuite/gcc.dg/pr122126_vextr.c b/gcc/testsuite/gcc.dg/pr122126_vextr.c new file mode 100644 index 00000000000..d25555b0aec --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr122126_vextr.c @@ -0,0 +1,9 @@ +/* { dg-do compile } */ +/* { dg-options "-O2" } */ +/* { dg-additional-options "-mavx2" { target x86_64-*-* i?86-*-* } } */ + +#define vect16 __attribute__((vector_size(16))) +void ub_set() { + volatile vect16 unsigned BS_VAR_0; + unsigned a = BS_VAR_0[12]; +} \ No newline at end of file diff --git a/gcc/testsuite/gcc.dg/pr122126_vset.c b/gcc/testsuite/gcc.dg/pr122126_vset.c new file mode 100644 index 00000000000..a398b484a36 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr122126_vset.c @@ -0,0 +1,9 @@ +/* { dg-do compile } */ +/* { dg-options "-O2" } */ +/* { dg-additional-options "-mavx2" { target x86_64-*-* i?86-*-* } } */ + +#define vect16 __attribute__((vector_size(16))) +void ub_set() { + volatile vect16 unsigned BS_VAR_0; + BS_VAR_0[12] = 4; +} \ No newline at end of file -- 2.51.0
