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Set ADDSS cost to 3 for znver5

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Znver5 has latency of addss 2 in typical case while all earlier versions has latency 3.
Unforunately addss cost is used to cost many other SSE instructions than just addss and
setting the cost to 2 makes us to vectorize 4 64bit stores into one 256bit store which
in turn regesses imagemagick.

This patch sets the cost back to 3.  Next stage1 we can untie addss from the other operatoins
and set it correctly.

bootstrapped/regtested x86_64-linux and also benchmarked on SPEC2k17

gcc/ChangeLog:

	PR target/119298
	* config/i386/x86-tune-costs.h (znver5_cost): Set ADDSS cost to 3.
This commit is contained in:
Jan Hubicka 2025-04-15 19:04:15 +02:00
parent 25775e73ea
commit e2011ab13d
1 changed files with 1 additions and 1 deletions
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gcc/config/i386/x86-tune-costs.h
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@ -2120,7 +2120,7 @@ struct processor_costs znver5_cost = {
COSTS_N_INSNS (1), /* cost of cheap SSE instruction. */
/* ADDSS has throughput 2 and latency 2
(in some cases when source is another addition). */
COSTS_N_INSNS (2), /* cost of ADDSS/SD SUBSS/SD insns. */
COSTS_N_INSNS (3), /* cost of ADDSS/SD SUBSS/SD insns. */
/* MULSS has throughput 2 and latency 3. */
COSTS_N_INSNS (3), /* cost of MULSS instruction. */
COSTS_N_INSNS (3), /* cost of MULSD instruction. */