From 50374fdacbd121bc4a61b073e559208ff61bee06 Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Wed, 23 Jun 2021 12:43:03 +0200 Subject: [PATCH] tree-optimization/101105 - fix runtime alias test optimization We were ignoring DR_STEP for VF == 1 which is OK only in case the scalar order is preserved or both DR steps are the same. 2021-06-23 Richard Biener PR tree-optimization/101105 * tree-vect-data-refs.c (vect_prune_runtime_alias_test_list): Only ignore steps when they are equal or scalar order is preserved. * gcc.dg/torture/pr101105.c: New testcase. --- gcc/testsuite/gcc.dg/torture/pr101105.c | 19 +++++++++++++++++++ gcc/tree-vect-data-refs.c | 9 +++++++-- 2 files changed, 26 insertions(+), 2 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/torture/pr101105.c diff --git a/gcc/testsuite/gcc.dg/torture/pr101105.c b/gcc/testsuite/gcc.dg/torture/pr101105.c new file mode 100644 index 00000000000..9222351683d --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr101105.c @@ -0,0 +1,19 @@ +/* { dg-do run } */ + +short a; +int b[5][4] = {2, 2}; +int d; +short e(int f) { return f == 0 || a && f == 1 ? 0 : a; } +int main() { + int g, h; + g = 3; + for (; g >= 0; g--) { + h = 3; + for (; h >= 0; h--) + b[g][h] = b[0][1] && e(1); + } + d = b[0][1]; + if (d != 0) + __builtin_abort (); + return 0; +} diff --git a/gcc/tree-vect-data-refs.c b/gcc/tree-vect-data-refs.c index be067c8923b..579149dfd61 100644 --- a/gcc/tree-vect-data-refs.c +++ b/gcc/tree-vect-data-refs.c @@ -3479,9 +3479,9 @@ vect_prune_runtime_alias_test_list (loop_vec_info loop_vinfo) /* Step values are irrelevant for aliasing if the number of vector iterations is equal to the number of scalar iterations (which can happen for fully-SLP loops). */ - bool ignore_step_p = known_eq (LOOP_VINFO_VECT_FACTOR (loop_vinfo), 1U); + bool vf_one_p = known_eq (LOOP_VINFO_VECT_FACTOR (loop_vinfo), 1U); - if (!ignore_step_p) + if (!vf_one_p) { /* Convert the checks for nonzero steps into bound tests. */ tree value; @@ -3534,6 +3534,11 @@ vect_prune_runtime_alias_test_list (loop_vec_info loop_vinfo) bool preserves_scalar_order_p = vect_preserves_scalar_order_p (dr_info_a, dr_info_b); + bool ignore_step_p + = (vf_one_p + && (preserves_scalar_order_p + || operand_equal_p (DR_STEP (dr_info_a->dr), + DR_STEP (dr_info_b->dr)))); /* Skip the pair if inter-iteration dependencies are irrelevant and intra-iteration dependencies are guaranteed to be honored. */ -- 2.34.1