https://gcc.gnu.org/g:4a04110ec8388b6540380cfedbe50af1b29e3e36
commit r14-10435-g4a04110ec8388b6540380cfedbe50af1b29e3e36
Author: Richard Biener <rguent...@suse.de>
Date: Tue Jul 16 10:45:27 2024 +0200
Fixup unaligned load/store cost for znver5
Currently unaligned YMM and ZMM load and store costs are cheaper than
aligned which causes the vectorizer to purposely mis-align accesses
by adding an alignment prologue. It looks like the unaligned costs
were simply copied from the bogus znver4 costs. The following makes
the unaligned costs equal to the aligned costs like in the fixed znver4
version.
* config/i386/x86-tune-costs.h (znver5_cost): Update unaligned
load and store cost from the aligned costs.
(cherry picked from commit 896393791ee34ffc176c87d232dfee735db3aaab)
Diff:
---
gcc/config/i386/x86-tune-costs.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/gcc/config/i386/x86-tune-costs.h b/gcc/config/i386/x86-tune-costs.h
index d0168eebdc15..8348ab8230ad 100644
--- a/gcc/config/i386/x86-tune-costs.h
+++ b/gcc/config/i386/x86-tune-costs.h
@@ -2060,8 +2060,8 @@ struct processor_costs znver5_cost = {
in 32bit, 64bit, 128bit, 256bit and
512bit */
{8, 8, 8, 12, 12}, /* cost of storing SSE register
in 32bit, 64bit, 128bit, 256bit and
512bit */
- {6, 6, 6, 6, 6}, /* cost of unaligned loads. */
- {8, 8, 8, 8, 8}, /* cost of unaligned stores. */
+ {6, 6, 10, 10, 12}, /* cost of unaligned loads. */
+ {8, 8, 8, 12, 12}, /* cost of unaligned stores. */
2, 2, 2, /* cost of moving XMM,YMM,ZMM
register. */
6, /* cost of moving SSE register to
integer. */
