From edeb5b8258382a58e1ce8e1e79e61386250d42b2 Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Tue, 2 Sep 2025 10:16:28 +0200 Subject: tree-optimization/121753 - ICE with pattern breaking reduction constraints The recent change to vect_synth_mult_by_constant missed to handle the synth_shift_p case for alg_shift, so we still changed c * 4 to c + c + c + c. The following also amends alg_add_t2_m, alg_sub_t2_m, alg_add_factor and alg_sub_factor appropriately. PR tree-optimization/121753 * tree-vect-patterns.cc (vect_synth_mult_by_constant): Properly bail when synth_shift_p and an alg_shift use. Handle other problematic cases. --- gcc/tree-vect-patterns.cc | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'gcc') diff --git a/gcc/tree-vect-patterns.cc b/gcc/tree-vect-patterns.cc index 64a49cc..d0bf2f9 100644 --- a/gcc/tree-vect-patterns.cc +++ b/gcc/tree-vect-patterns.cc @@ -4329,7 +4329,14 @@ vect_synth_mult_by_constant (vec_info *vinfo, tree op, tree val, case alg_add_t2_m: case alg_sub_t2_m: op_uses++; + /* Fallthru. */ + case alg_shift: + if (synth_shift_p && alg.log[i]) + return NULL; break; + case alg_add_factor: + case alg_sub_factor: + return NULL; default: break; } -- cgit v1.1