From 22736f3d0d4fb8ce4afb3230023f8accdb03a623 Mon Sep 17 00:00:00 2001 From: Michael Meissner Date: Thu, 14 Jul 2022 11:16:08 -0400 Subject: [PATCH] [BACKPORT] Disable generating load/store vector pairs for block copies. Testing has found that using load and store vector pair for block copies can result in a slow down on power10. This patch disables using the vector pair instructions for block copies if we are tuning for power10. 2022-06-11 Michael Meissner gcc/ * config/rs6000/rs6000.cc (rs6000_option_override_internal): Do not generate block copies with vector pair instructions if we are tuning for power10. Back port from master branch. --- gcc/config/rs6000/rs6000.cc | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc index 4030864aa1a..040487bd277 100644 --- a/gcc/config/rs6000/rs6000.cc +++ b/gcc/config/rs6000/rs6000.cc @@ -4151,7 +4151,10 @@ rs6000_option_override_internal (bool global_init_p) if (!(rs6000_isa_flags_explicit & OPTION_MASK_BLOCK_OPS_VECTOR_PAIR)) { - if (TARGET_MMA && TARGET_EFFICIENT_UNALIGNED_VSX) + /* Do not generate lxvp and stxvp on power10 since there are some + performance issues. */ + if (TARGET_MMA && TARGET_EFFICIENT_UNALIGNED_VSX + && rs6000_tune != PROCESSOR_POWER10) rs6000_isa_flags |= OPTION_MASK_BLOCK_OPS_VECTOR_PAIR; else rs6000_isa_flags &= ~OPTION_MASK_BLOCK_OPS_VECTOR_PAIR;