[v2,2/2] x86: Improve memmove-vec-unaligned-erms.S

Message ID 20210524031502.1975741-2-goldstein.w.n@gmail.com
State New
Headers show
Series
  • [v2,1/2] Bench: Add support for choose direction of memcpy in benchtests
Related show

Commit Message

Florian Weimer via Libc-alpha May 24, 2021, 3:15 a.m.
This patch changes the condition for copy 4x VEC so that if length is
exactly equal to 4 * VEC_SIZE it will use the 4x VEC case instead of
8x VEC case.

Results For Skylake memcpy-avx2-erms
size, al1 , al2 , Cur T   , New T   , Win , New / Cur
128 , 0   , 0   , 9.137   , 6.873   , New , 75.22
128 , 7   , 0   , 12.933  , 7.732   , New , 59.79
128 , 0   , 7   , 11.852  , 6.76    , New , 57.04
128 , 7   , 7   , 12.587  , 6.808   , New , 54.09

Results For Icelake memcpy-evex-erms
size, al1 , al2 , Cur T   , New T   , Win , New / Cur
128 , 0   , 0   , 9.963   , 5.416   , New , 54.36
128 , 7   , 0   , 16.467  , 8.061   , New , 48.95
128 , 0   , 7   , 14.388  , 7.644   , New , 53.13
128 , 7   , 7   , 14.546  , 7.642   , New , 52.54

Results For Tigerlake memcpy-evex-erms
size, al1 , al2 , Cur T   , New T   , Win , New / Cur
128 , 0   , 0   , 8.979   , 4.95    , New , 55.13
128 , 7   , 0   , 14.245  , 7.122   , New , 50.0
128 , 0   , 7   , 12.668  , 6.675   , New , 52.69
128 , 7   , 7   , 13.042  , 6.802   , New , 52.15

Results For Skylake memmove-avx2-erms
size, al1 , al2 , Cur T   , New T   , Win , New / Cur
128 , 0   , 32  , 6.181   , 5.691   , New , 92.07
128 , 32  , 0   , 6.165   , 5.752   , New , 93.3
128 , 0   , 7   , 13.923  , 9.37    , New , 67.3
128 , 7   , 0   , 12.049  , 10.182  , New , 84.5

Results For Icelake memmove-evex-erms
size, al1 , al2 , Cur T   , New T   , Win , New / Cur
128 , 0   , 32  , 5.479   , 4.889   , New , 89.23
128 , 32  , 0   , 5.127   , 4.911   , New , 95.79
128 , 0   , 7   , 18.885  , 13.547  , New , 71.73
128 , 7   , 0   , 15.565  , 14.436  , New , 92.75

Results For Tigerlake memmove-evex-erms
size, al1 , al2 , Cur T   , New T   , Win , New / Cur
128 , 0   , 32  , 5.275   , 4.815   , New , 91.28
128 , 32  , 0   , 5.376   , 4.565   , New , 84.91
128 , 0   , 7   , 19.426  , 14.273  , New , 73.47
128 , 7   , 0   , 15.924  , 14.951  , New , 93.89

Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>

---
 sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

-- 
2.25.1

Comments

Florian Weimer via Libc-alpha May 24, 2021, 3:21 a.m. | #1
On Sun, May 23, 2021 at 8:15 PM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
>

> This patch changes the condition for copy 4x VEC so that if length is

> exactly equal to 4 * VEC_SIZE it will use the 4x VEC case instead of

> 8x VEC case.

>

> Results For Skylake memcpy-avx2-erms

> size, al1 , al2 , Cur T   , New T   , Win , New / Cur

> 128 , 0   , 0   , 9.137   , 6.873   , New , 75.22

> 128 , 7   , 0   , 12.933  , 7.732   , New , 59.79

> 128 , 0   , 7   , 11.852  , 6.76    , New , 57.04

> 128 , 7   , 7   , 12.587  , 6.808   , New , 54.09

>

> Results For Icelake memcpy-evex-erms

> size, al1 , al2 , Cur T   , New T   , Win , New / Cur

> 128 , 0   , 0   , 9.963   , 5.416   , New , 54.36

> 128 , 7   , 0   , 16.467  , 8.061   , New , 48.95

> 128 , 0   , 7   , 14.388  , 7.644   , New , 53.13

> 128 , 7   , 7   , 14.546  , 7.642   , New , 52.54

>

> Results For Tigerlake memcpy-evex-erms

> size, al1 , al2 , Cur T   , New T   , Win , New / Cur

> 128 , 0   , 0   , 8.979   , 4.95    , New , 55.13

> 128 , 7   , 0   , 14.245  , 7.122   , New , 50.0

> 128 , 0   , 7   , 12.668  , 6.675   , New , 52.69

> 128 , 7   , 7   , 13.042  , 6.802   , New , 52.15

>

> Results For Skylake memmove-avx2-erms

> size, al1 , al2 , Cur T   , New T   , Win , New / Cur

> 128 , 0   , 32  , 6.181   , 5.691   , New , 92.07

> 128 , 32  , 0   , 6.165   , 5.752   , New , 93.3

> 128 , 0   , 7   , 13.923  , 9.37    , New , 67.3

> 128 , 7   , 0   , 12.049  , 10.182  , New , 84.5

>

> Results For Icelake memmove-evex-erms

> size, al1 , al2 , Cur T   , New T   , Win , New / Cur

> 128 , 0   , 32  , 5.479   , 4.889   , New , 89.23

> 128 , 32  , 0   , 5.127   , 4.911   , New , 95.79

> 128 , 0   , 7   , 18.885  , 13.547  , New , 71.73

> 128 , 7   , 0   , 15.565  , 14.436  , New , 92.75

>

> Results For Tigerlake memmove-evex-erms

> size, al1 , al2 , Cur T   , New T   , Win , New / Cur

> 128 , 0   , 32  , 5.275   , 4.815   , New , 91.28

> 128 , 32  , 0   , 5.376   , 4.565   , New , 84.91

> 128 , 0   , 7   , 19.426  , 14.273  , New , 73.47

> 128 , 7   , 0   , 15.924  , 14.951  , New , 93.89

>

> Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>

> ---

>  sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S | 6 +++---

>  1 file changed, 3 insertions(+), 3 deletions(-)

>

> diff --git a/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S b/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S

> index 5e4a071f16..a783da5de2 100644

> --- a/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S

> +++ b/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S

> @@ -420,8 +420,8 @@ L(more_2x_vec):

>         cmpq    $(VEC_SIZE * 8), %rdx

>         ja      L(more_8x_vec)

>         cmpq    $(VEC_SIZE * 4), %rdx

> -       jb      L(last_4x_vec)

> -       /* Copy from 4 * VEC to 8 * VEC, inclusively. */

> +       jbe     L(last_4x_vec)

> +       /* Copy from 4 * VEC + 1 to 8 * VEC, inclusively. */

>         VMOVU   (%rsi), %VEC(0)

>         VMOVU   VEC_SIZE(%rsi), %VEC(1)

>         VMOVU   (VEC_SIZE * 2)(%rsi), %VEC(2)

> @@ -440,7 +440,7 @@ L(more_2x_vec):

>         VMOVU   %VEC(7), -(VEC_SIZE * 4)(%rdi,%rdx)

>         VZEROUPPER_RETURN

>  L(last_4x_vec):

> -       /* Copy from 2 * VEC to 4 * VEC. */

> +       /* Copy from 2 * VEC + 1 to 4 * VEC, inclusively. */

>         VMOVU   (%rsi), %VEC(0)

>         VMOVU   VEC_SIZE(%rsi), %VEC(1)

>         VMOVU   -VEC_SIZE(%rsi,%rdx), %VEC(2)

> --

> 2.25.1

>


LGTM.

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>


Thanks.

-- 
H.J.

Patch

diff --git a/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S b/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S
index 5e4a071f16..a783da5de2 100644
--- a/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S
+++ b/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S
@@ -420,8 +420,8 @@  L(more_2x_vec):
 	cmpq	$(VEC_SIZE * 8), %rdx
 	ja	L(more_8x_vec)
 	cmpq	$(VEC_SIZE * 4), %rdx
-	jb	L(last_4x_vec)
-	/* Copy from 4 * VEC to 8 * VEC, inclusively. */
+	jbe	L(last_4x_vec)
+	/* Copy from 4 * VEC + 1 to 8 * VEC, inclusively. */
 	VMOVU	(%rsi), %VEC(0)
 	VMOVU	VEC_SIZE(%rsi), %VEC(1)
 	VMOVU	(VEC_SIZE * 2)(%rsi), %VEC(2)
@@ -440,7 +440,7 @@  L(more_2x_vec):
 	VMOVU	%VEC(7), -(VEC_SIZE * 4)(%rdi,%rdx)
 	VZEROUPPER_RETURN
 L(last_4x_vec):
-	/* Copy from 2 * VEC to 4 * VEC. */
+	/* Copy from 2 * VEC + 1 to 4 * VEC, inclusively. */
 	VMOVU	(%rsi), %VEC(0)
 	VMOVU	VEC_SIZE(%rsi), %VEC(1)
 	VMOVU	-VEC_SIZE(%rsi,%rdx), %VEC(2)