When backporting the PR109473 fix I failed to realize its testcase will run into an unrelated similar bug. With GCC 12 the code has seen substantial refactoring so the following applies a local fix to make sure we are using the correct types when building initial values for reductions.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed. PR tree-optimization/109473 * tree-vect-loop.cc (get_initial_def_for_reduction): Convert the scalar values to the vector component type before using it to build the vector for the initial value. --- gcc/tree-vect-loop.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c index bb021ccf382..ebdba65c55e 100644 --- a/gcc/tree-vect-loop.c +++ b/gcc/tree-vect-loop.c @@ -4730,10 +4730,14 @@ get_initial_def_for_reduction (loop_vec_info loop_vinfo, else def_for_init = build_int_cst (scalar_type, int_init_val); - if (adjustment_def || operand_equal_p (def_for_init, init_val, 0)) + bool same_p = operand_equal_p (def_for_init, init_val, 0); + init_val = gimple_convert (&stmts, TREE_TYPE (vectype), init_val); + def_for_init = gimple_convert (&stmts, TREE_TYPE (vectype), def_for_init); + + if (adjustment_def || same_p) { /* Option1: the first element is '0' or '1' as well. */ - if (!operand_equal_p (def_for_init, init_val, 0)) + if (!same_p) *adjustment_def = init_val; init_def = gimple_build_vector_from_val (&stmts, vectype, def_for_init); -- 2.35.3