* [PATCH/AARCH64] Improve ThunderX2 T99 address cost model
@ 2017-01-23 23:39 Andrew Pinski
2017-01-23 23:59 ` Richard Earnshaw
0 siblings, 1 reply; 2+ messages in thread
From: Andrew Pinski @ 2017-01-23 23:39 UTC (permalink / raw)
To: GCC Patches
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Hi,
On ThunderX 2, the logical shifts that are part of the address cause
a 1 cycle extra and this is not modeled correctly. For induction
variables we don't want to do the shift. When I change the cost for
the shift of the addresses, I get a 12% improvement on HMMER; all over
benchmarks in SPEC CPU 2006 were neutral.
OK? Bootstrapped and tested on aarch64-linux-gnu with no regressions.
Thanks,
Andrew Pinski
ChangeLog:
* config/aarch64/aarch64.c (thunderx2t99_addrcost_table): Improve cost table.
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Index: gcc/config/aarch64/aarch64.c
===================================================================
--- gcc/config/aarch64/aarch64.c (revision 244839)
+++ gcc/config/aarch64/aarch64.c (working copy)
@@ -273,9 +273,9 @@ static const struct cpu_addrcost_table q
static const struct cpu_addrcost_table thunderx2t99_addrcost_table =
{
{
- 0, /* hi */
- 0, /* si */
- 0, /* di */
+ 1, /* hi */
+ 1, /* si */
+ 1, /* di */
2, /* ti */
},
0, /* pre_modify */
^ permalink raw reply [flat|nested] 2+ messages in thread* Re: [PATCH/AARCH64] Improve ThunderX2 T99 address cost model
2017-01-23 23:39 [PATCH/AARCH64] Improve ThunderX2 T99 address cost model Andrew Pinski
@ 2017-01-23 23:59 ` Richard Earnshaw
0 siblings, 0 replies; 2+ messages in thread
From: Richard Earnshaw @ 2017-01-23 23:59 UTC (permalink / raw)
To: Andrew Pinski, GCC Patches
On 23/01/17 23:35, Andrew Pinski wrote:
> Hi,
> On ThunderX 2, the logical shifts that are part of the address cause
> a 1 cycle extra and this is not modeled correctly. For induction
> variables we don't want to do the shift. When I change the cost for
> the shift of the addresses, I get a 12% improvement on HMMER; all over
> benchmarks in SPEC CPU 2006 were neutral.
>
> OK? Bootstrapped and tested on aarch64-linux-gnu with no regressions.
>
> Thanks,
> Andrew Pinski
>
> ChangeLog:
> * config/aarch64/aarch64.c (thunderx2t99_addrcost_table): Improve cost table.
>
OK.
R.
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