https://gcc.gnu.org/g:187bccedfc454304f7e35697baa5337c59fa2a58
commit r16-4650-g187bccedfc454304f7e35697baa5337c59fa2a58 Author: Richard Biener <[email protected]> Date: Mon Oct 27 11:31:32 2025 +0100 tree-optimization/122419 - reduction chain with conversion as op The following deals with reduction detection handling a non-noop conversion as reduction operation and makes the reduction chain chain re-discovery handle this situation the same. PR tree-optimization/122419 * tree-vect-slp.cc (vect_analyze_slp_reduc_chain): Only skip noop conversions. * gcc.dg/vect/pr122419.c: New testcase. Diff: --- gcc/testsuite/gcc.dg/vect/pr122419.c | 9 +++++++++ gcc/tree-vect-slp.cc | 1 + 2 files changed, 10 insertions(+) diff --git a/gcc/testsuite/gcc.dg/vect/pr122419.c b/gcc/testsuite/gcc.dg/vect/pr122419.c new file mode 100644 index 000000000000..b428cfb18129 --- /dev/null +++ b/gcc/testsuite/gcc.dg/vect/pr122419.c @@ -0,0 +1,9 @@ +/* { dg-do compile } */ + +int a; +long b; +void c() +{ + for (; b; b--) + a = (char)a; +} diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc index 31d84857d493..e02b3379bb46 100644 --- a/gcc/tree-vect-slp.cc +++ b/gcc/tree-vect-slp.cc @@ -4217,6 +4217,7 @@ vect_analyze_slp_reduc_chain (loop_vec_info vinfo, if (!gimple_extract_op (STMT_VINFO_STMT (vect_orig_stmt (stmt)), &op)) gcc_unreachable (); if (CONVERT_EXPR_CODE_P (op.code) + && tree_nop_conversion_p (op.type, TREE_TYPE (op.ops[0])) && (first || is_a <gphi *> (STMT_VINFO_STMT (next_stmt)))) ;
