On Thu, Nov 18, 2021 at 7:17 AM liuhongt via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> Make them be equal to cost of unaligned ones to avoid odd alignment
> peeling.
>
> Impact for SPEC2017 on CLX:
> fprate:
> 503.bwaves_r BuildSame
> 507.cactuBSSN_r -0.22
> 508.namd_r -0.02
> 510.parest_r -0.28
> 511.povray_r -0.20
> 519.lbm_r BuildSame
> 521.wrf_r -0.58
> 526.blender_r -0.30
> 527.cam4_r 1.07
> 538.imagick_r 0.01
> 544.nab_r -0.09
> 549.fotonik3d_r BuildSame
> 554.roms_r BuildSame
> intrate:
> 500.perlbench_r -0.25
> 502.gcc_r -0.15
> 505.mcf_r BuildSame
> 520.omnetpp_r 1.03
> 523.xalancbmk_r -0.13
> 525.x264_r -0.05
> 531.deepsjeng_r -0.27
> 541.leela_r -0.24
> 548.exchange2_r -0.06
> 557.xz_r -0.10
> 999.specrand_ir 2.69
>
> Bootstrapped and regtested on x86_64-linux-gnu{-m32,}.
> Ready to push to trunk.
OK.
> gcc/ChangeLog:
>
> PR target/102543
> * config/i386/x86-tune-costs.h (skylake_cost): Reduce cost of
> storing 256/512-bit SSE register to be equal to cost of
> unaligned store to avoid odd alignment peeling.
> (icelake_cost): Ditto.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/i386/pr102543.c: New test.
> ---
> gcc/config/i386/x86-tune-costs.h | 4 +--
> gcc/testsuite/gcc.target/i386/pr102543.c | 35 ++++++++++++++++++++++++
> 2 files changed, 37 insertions(+), 2 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/i386/pr102543.c
>
> diff --git a/gcc/config/i386/x86-tune-costs.h
> b/gcc/config/i386/x86-tune-costs.h
> index dd5563d2e64..60d50c97fca 100644
> --- a/gcc/config/i386/x86-tune-costs.h
> +++ b/gcc/config/i386/x86-tune-costs.h
> @@ -1903,7 +1903,7 @@ struct processor_costs skylake_cost = {
> {6, 6, 6}, /* cost of storing integer registers
> */
> {6, 6, 6, 10, 20}, /* cost of loading SSE register
> in 32bit, 64bit, 128bit, 256bit
> and 512bit */
> - {8, 8, 8, 12, 24}, /* cost of storing SSE register
> + {8, 8, 8, 8, 16}, /* cost of storing SSE register
> in 32bit, 64bit, 128bit, 256bit
> and 512bit */
> {6, 6, 6, 10, 20}, /* cost of unaligned loads. */
> {8, 8, 8, 8, 16}, /* cost of unaligned stores. */
> @@ -2029,7 +2029,7 @@ struct processor_costs icelake_cost = {
> {6, 6, 6}, /* cost of storing integer registers
> */
> {6, 6, 6, 10, 20}, /* cost of loading SSE register
> in 32bit, 64bit, 128bit, 256bit
> and 512bit */
> - {8, 8, 8, 12, 24}, /* cost of storing SSE register
> + {8, 8, 8, 8, 16}, /* cost of storing SSE register
> in 32bit, 64bit, 128bit, 256bit
> and 512bit */
> {6, 6, 6, 10, 20}, /* cost of unaligned loads. */
> {8, 8, 8, 8, 16}, /* cost of unaligned stores. */
> diff --git a/gcc/testsuite/gcc.target/i386/pr102543.c
> b/gcc/testsuite/gcc.target/i386/pr102543.c
> new file mode 100644
> index 00000000000..893eb9a5902
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr102543.c
> @@ -0,0 +1,35 @@
> +/* PR target/102543 */
> +/* { dg-do compile } */
> +/* { dg-options "-Ofast -march=skylake-avx512 -fdump-tree-optimized" } */
> +/* { dg-final { scan-tree-dump-not "MEM\\\[" "optimized" } } */
> +
> +struct a
> +{
> + int a[100];
> +};
> +typedef struct a misaligned_t __attribute__ ((aligned (8)));
> +typedef struct a aligned_t __attribute__ ((aligned (32)));
> +
> +__attribute__ ((used))
> +__attribute__ ((noinline))
> +void
> +t(void *a, int misaligned, aligned_t *d)
> +{
> + int i,v;
> + for (i=0;i<100;i++)
> + {
> + if (misaligned)
> + v=((misaligned_t *)a)->a[i];
> + else
> + v=((aligned_t *)a)->a[i];
> + d->a[i]+=v;
> + }
> +}
> +struct b {int v; misaligned_t m;aligned_t aa;} b;
> +aligned_t d;
> +int
> +main()
> +{
> + t(&b.m, 1, &d);
> + return 0;
> +}
> --
> 2.18.2
>
