https://gcc.gnu.org/g:87e35da16df74cd1c4729a55d94e7bc592487f48
commit r15-124-g87e35da16df74cd1c4729a55d94e7bc592487f48 Author: Richard Biener <rguent...@suse.de> Date: Thu May 2 13:55:15 2024 +0200 tree-optimization/114921 - _Float16 -> __bf16 isn't noop The vectorizer handles a _Float16 to __bf16 conversion through vectorizable_assignment, thinking it's a noop. The following fixes this by requiring the same vector component mode when checking for CONVERT_EXPR_CODE_P, being stricter than for VIEW_CONVERT_EXPR. PR tree-optimization/114921 * tree-vect-stmts.cc (vectorizable_assignment): Require same vector component modes for input and output for CONVERT_EXPR_CODE_P. Diff: --- gcc/tree-vect-stmts.cc | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc index f8d8636b139..7e571968a59 100644 --- a/gcc/tree-vect-stmts.cc +++ b/gcc/tree-vect-stmts.cc @@ -5955,14 +5955,17 @@ vectorizable_assignment (vec_info *vinfo, if (!vectype_in) vectype_in = get_vectype_for_scalar_type (vinfo, TREE_TYPE (op), slp_node); - /* We can handle NOP_EXPR conversions that do not change the number - of elements or the vector size. */ - if ((CONVERT_EXPR_CODE_P (code) - || code == VIEW_CONVERT_EXPR) - && (!vectype_in - || maybe_ne (TYPE_VECTOR_SUBPARTS (vectype_in), nunits) - || maybe_ne (GET_MODE_SIZE (TYPE_MODE (vectype)), - GET_MODE_SIZE (TYPE_MODE (vectype_in))))) + /* We can handle VIEW_CONVERT conversions that do not change the number + of elements or the vector size or other conversions when the component + mode keeps the same. */ + if (!vectype_in + || maybe_ne (TYPE_VECTOR_SUBPARTS (vectype_in), nunits) + || (code == VIEW_CONVERT_EXPR + && maybe_ne (GET_MODE_SIZE (TYPE_MODE (vectype)), + GET_MODE_SIZE (TYPE_MODE (vectype_in)))) + || (CONVERT_EXPR_CODE_P (code) + && (TYPE_MODE (TREE_TYPE (vectype)) + != TYPE_MODE (TREE_TYPE (vectype_in))))) return false; if (VECTOR_BOOLEAN_TYPE_P (vectype) != VECTOR_BOOLEAN_TYPE_P (vectype_in))