On Thu, Sep 5, 2019 at 10:53 AM Uros Bizjak <ubiz...@gmail.com> wrote:
>
> On Thu, Sep 5, 2019 at 7:47 AM Hongtao Liu <crazy...@gmail.com> wrote:
> >
> > Change cost from 2->6 got
> > -------------
> > 531.deepsjeng_r 9.64%
> > 548.exchange_r 10.24%
> > 557.xc_r 7.99%
> > 508.namd_r 1.08%
> > 527.cam4_r 6.91%
> > 553.nab_r 3.06%
> > ------------
> >
> > for 531,548,557,527, even better comparing to version before regression.
> > for 508,533, still little regressions comparing to version before
> > regression.
>
> Good, that brings us into "noise" region.
>
> Based on these results and other findings, I propose the following solution:
>
> - The inter-regset move costs of architectures, that have been defined
> before r125951 remain the same. These are: size, i386, i486, pentium,
> pentiumpro, geode, k6, athlon, k8, amdfam10, pentium4 and nocona.
> - bdver, btver1 and btver2 have costs higher than 8, so they are not affected.
> - lakemont, znver1, znver2, atom, slm, intel and generic costs have
> inter-regset costs above intra-regset and below or equal memory
> load/store cost, should remain as they are. Additionally, intel and
> generic costs are regularly re-tuned.
> - only skylake and core costs remain problematic
>
> So, I propose to raise XMM<->intreg costs of skylake and core
> architectures to 6 to solve the regression. These can be fine-tuned
> later, we are now able to change the cost for RA independently of RTX
> costs. Also, the RA cost can be asymmetrical.
>
> Attached patch implements the proposal. If there are no other
> proposals or discussions, I plan to commit it on Friday.
2019-09-06 Uroš Bizjak <ubiz...@gmail.com>
PR target/91654
* config/i386/x86-tune-costs.h (skylake_cost): Raise the
cost of SSE->integer and integer->SSE moves from 2 to 6.
(core_cost): Ditto.
Bootstrapped and regression tested on x86_64-linux-gnu {,-m32}.
Committed to mainline SVN.
Uros.
diff --git a/gcc/config/i386/x86-tune-costs.h b/gcc/config/i386/x86-tune-costs.h
index 3381b8bf143c..00edece3eb68 100644
--- a/gcc/config/i386/x86-tune-costs.h
+++ b/gcc/config/i386/x86-tune-costs.h
@@ -1610,7 +1610,7 @@ struct processor_costs skylake_cost = {
in 32,64,128,256 and 512-bit */
{8, 8, 8, 12, 24}, /* cost of storing SSE registers
in 32,64,128,256 and 512-bit */
- 2, 2, /* SSE->integer and
integer->SSE moves */
+ 6, 6, /* SSE->integer and
integer->SSE moves */
/* End of register allocator costs. */
},
@@ -2555,7 +2555,7 @@ struct processor_costs core_cost = {
in 32,64,128,256 and 512-bit */
{6, 6, 6, 6, 12}, /* cost of storing SSE registers
in 32,64,128,256 and 512-bit */
- 2, 2, /* SSE->integer and
integer->SSE moves */
+ 6, 6, /* SSE->integer and
integer->SSE moves */
/* End of register allocator costs. */
},
