[v1] x86: Improve vec generation in memset-vec-unaligned-erms.S

Message ID 20220205224201.1166468-1-goldstein.w.n@gmail.com
State Committed
Headers
Series [v1] x86: Improve vec generation in memset-vec-unaligned-erms.S |

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Context Check Description
dj/TryBot-apply_patch success Patch applied to master at the time it was sent
dj/TryBot-32bit success Build for i686

Commit Message

Noah Goldstein Feb. 5, 2022, 10:42 p.m. UTC
  No bug.

Split vec generation into multiple steps. This allows the
broadcast in AVX2 to use 'xmm' registers for the L(less_vec)
case. This saves an expensive lane-cross instruction and removes
the need for 'vzeroupper'.

For SSE2 replace 2x 'punpck' instructions with zero-idiom 'pxor' for
byte broadcast.

Results for memset-avx2 small (geomean of N = 20 benchset runs).

size, New Time, Old Time, New / Old
   1,    5.074,    4.399,     0.867
   2,    4.433,    4.411,     0.995
   4,    4.487,    4.415,     0.984
   8,    4.454,    4.396,     0.987
  16,    4.502,    4.443,     0.987

All relevant string/wcsmbs tests are passing.
---
 sysdeps/x86_64/memset.S                       |  21 ++-
 .../multiarch/memset-avx2-unaligned-erms.S    |  18 +-
 .../multiarch/memset-avx512-unaligned-erms.S  |  18 +-
 .../multiarch/memset-evex-unaligned-erms.S    |  18 +-
 .../multiarch/memset-vec-unaligned-erms.S     | 163 +++++++++++-------
 5 files changed, 151 insertions(+), 87 deletions(-)
  

Comments

H.J. Lu Feb. 5, 2022, 10:50 p.m. UTC | #1
On Sat, Feb 5, 2022 at 2:42 PM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
>
> No bug.
>
> Split vec generation into multiple steps. This allows the
> broadcast in AVX2 to use 'xmm' registers for the L(less_vec)
> case. This saves an expensive lane-cross instruction and removes
> the need for 'vzeroupper'.
>
> For SSE2 replace 2x 'punpck' instructions with zero-idiom 'pxor' for
> byte broadcast.

I am working on the same codes.  Please give me a few hours.

> Results for memset-avx2 small (geomean of N = 20 benchset runs).
>
> size, New Time, Old Time, New / Old
>    1,    5.074,    4.399,     0.867
>    2,    4.433,    4.411,     0.995
>    4,    4.487,    4.415,     0.984
>    8,    4.454,    4.396,     0.987
>   16,    4.502,    4.443,     0.987
>
> All relevant string/wcsmbs tests are passing.
> ---
>  sysdeps/x86_64/memset.S                       |  21 ++-
>  .../multiarch/memset-avx2-unaligned-erms.S    |  18 +-
>  .../multiarch/memset-avx512-unaligned-erms.S  |  18 +-
>  .../multiarch/memset-evex-unaligned-erms.S    |  18 +-
>  .../multiarch/memset-vec-unaligned-erms.S     | 163 +++++++++++-------
>  5 files changed, 151 insertions(+), 87 deletions(-)
>
> diff --git a/sysdeps/x86_64/memset.S b/sysdeps/x86_64/memset.S
> index 65c09bd0ac..ccf036be53 100644
> --- a/sysdeps/x86_64/memset.S
> +++ b/sysdeps/x86_64/memset.S
> @@ -28,17 +28,22 @@
>  #define VMOVU     movups
>  #define VMOVA     movaps
>
> -#define MEMSET_VDUP_TO_VEC0_AND_SET_RETURN(d, r) \
> +# define MEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
>    movd d, %xmm0; \
> -  movq r, %rax; \
> -  punpcklbw %xmm0, %xmm0; \
> -  punpcklwd %xmm0, %xmm0; \
> -  pshufd $0, %xmm0, %xmm0
> +  pxor %xmm1, %xmm1; \
> +  pshufb %xmm1, %xmm0; \
> +  movq r, %rax
>
> -#define WMEMSET_VDUP_TO_VEC0_AND_SET_RETURN(d, r) \
> +# define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
>    movd d, %xmm0; \
> -  movq r, %rax; \
> -  pshufd $0, %xmm0, %xmm0
> +  pshufd $0, %xmm0, %xmm0; \
> +  movq r, %rax
> +
> +# define MEMSET_VDUP_TO_VEC0_HIGH()
> +# define MEMSET_VDUP_TO_VEC0_LOW()
> +
> +# define WMEMSET_VDUP_TO_VEC0_HIGH()
> +# define WMEMSET_VDUP_TO_VEC0_LOW()
>
>  #define SECTION(p)             p
>
> diff --git a/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S
> index 1af668af0a..c0bf2875d0 100644
> --- a/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S
> +++ b/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S
> @@ -10,15 +10,18 @@
>  # define VMOVU     vmovdqu
>  # define VMOVA     vmovdqa
>
> -# define MEMSET_VDUP_TO_VEC0_AND_SET_RETURN(d, r) \
> +# define MEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
>    vmovd d, %xmm0; \
> -  movq r, %rax; \
> -  vpbroadcastb %xmm0, %ymm0
> +  movq r, %rax;
>
> -# define WMEMSET_VDUP_TO_VEC0_AND_SET_RETURN(d, r) \
> -  vmovd d, %xmm0; \
> -  movq r, %rax; \
> -  vpbroadcastd %xmm0, %ymm0
> +# define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
> +  MEMSET_SET_VEC0_AND_SET_RETURN(d, r)
> +
> +# define MEMSET_VDUP_TO_VEC0_HIGH() vpbroadcastb %xmm0, %ymm0
> +# define MEMSET_VDUP_TO_VEC0_LOW() vpbroadcastb %xmm0, %xmm0
> +
> +# define WMEMSET_VDUP_TO_VEC0_HIGH() vpbroadcastd %xmm0, %ymm0
> +# define WMEMSET_VDUP_TO_VEC0_LOW() vpbroadcastd %xmm0, %xmm0
>
>  # ifndef SECTION
>  #  define SECTION(p)           p##.avx
> @@ -30,5 +33,6 @@
>  #  define WMEMSET_SYMBOL(p,s)  p##_avx2_##s
>  # endif
>
> +# define USE_XMM_LESS_VEC
>  # include "memset-vec-unaligned-erms.S"
>  #endif
> diff --git a/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S
> index f14d6f8493..5241216a77 100644
> --- a/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S
> +++ b/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S
> @@ -15,13 +15,19 @@
>
>  # define VZEROUPPER
>
> -# define MEMSET_VDUP_TO_VEC0_AND_SET_RETURN(d, r) \
> -  movq r, %rax; \
> -  vpbroadcastb d, %VEC0
> +# define MEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
> +  vpbroadcastb d, %VEC0; \
> +  movq r, %rax
>
> -# define WMEMSET_VDUP_TO_VEC0_AND_SET_RETURN(d, r) \
> -  movq r, %rax; \
> -  vpbroadcastd d, %VEC0
> +# define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
> +  vpbroadcastd d, %VEC0; \
> +  movq r, %rax
> +
> +# define MEMSET_VDUP_TO_VEC0_HIGH()
> +# define MEMSET_VDUP_TO_VEC0_LOW()
> +
> +# define WMEMSET_VDUP_TO_VEC0_HIGH()
> +# define WMEMSET_VDUP_TO_VEC0_LOW()
>
>  # define SECTION(p)            p##.evex512
>  # define MEMSET_SYMBOL(p,s)    p##_avx512_##s
> diff --git a/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S
> index 64b09e77cc..6370021506 100644
> --- a/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S
> +++ b/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S
> @@ -15,13 +15,19 @@
>
>  # define VZEROUPPER
>
> -# define MEMSET_VDUP_TO_VEC0_AND_SET_RETURN(d, r) \
> -  movq r, %rax; \
> -  vpbroadcastb d, %VEC0
> +# define MEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
> +  vpbroadcastb d, %VEC0; \
> +  movq r, %rax
>
> -# define WMEMSET_VDUP_TO_VEC0_AND_SET_RETURN(d, r) \
> -  movq r, %rax; \
> -  vpbroadcastd d, %VEC0
> +# define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
> +  vpbroadcastd d, %VEC0; \
> +  movq r, %rax
> +
> +# define MEMSET_VDUP_TO_VEC0_HIGH()
> +# define MEMSET_VDUP_TO_VEC0_LOW()
> +
> +# define WMEMSET_VDUP_TO_VEC0_HIGH()
> +# define WMEMSET_VDUP_TO_VEC0_LOW()
>
>  # define SECTION(p)            p##.evex
>  # define MEMSET_SYMBOL(p,s)    p##_evex_##s
> diff --git a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
> index 1e0511c79a..fb9053f4d6 100644
> --- a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
> +++ b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
> @@ -58,8 +58,10 @@
>  #ifndef MOVQ
>  # if VEC_SIZE > 16
>  #  define MOVQ                         vmovq
> +#  define MOVD                         vmovd
>  # else
>  #  define MOVQ                         movq
> +#  define MOVD                         movd
>  # endif
>  #endif
>
> @@ -72,9 +74,17 @@
>  #if defined USE_WITH_EVEX || defined USE_WITH_AVX512
>  # define END_REG       rcx
>  # define LOOP_REG      rdi
> +# define LESS_VEC_REG  rax
>  #else
>  # define END_REG       rdi
>  # define LOOP_REG      rdx
> +# define LESS_VEC_REG  rdi
> +#endif
> +
> +#ifdef USE_XMM_LESS_VEC
> +# define XMM_SMALL     1
> +#else
> +# define XMM_SMALL     0
>  #endif
>
>  #define PAGE_SIZE 4096
> @@ -110,8 +120,12 @@ END_CHK (WMEMSET_CHK_SYMBOL (__wmemset_chk, unaligned))
>
>  ENTRY (WMEMSET_SYMBOL (__wmemset, unaligned))
>         shl     $2, %RDX_LP
> -       WMEMSET_VDUP_TO_VEC0_AND_SET_RETURN (%esi, %rdi)
> -       jmp     L(entry_from_bzero)
> +       WMEMSET_SET_VEC0_AND_SET_RETURN (%esi, %rdi)
> +       WMEMSET_VDUP_TO_VEC0_LOW()
> +       cmpq    $VEC_SIZE, %rdx
> +       jb      L(less_vec_no_vdup)
> +       WMEMSET_VDUP_TO_VEC0_HIGH()
> +       jmp     L(entry_from_wmemset)
>  END (WMEMSET_SYMBOL (__wmemset, unaligned))
>  #endif
>
> @@ -123,7 +137,7 @@ END_CHK (MEMSET_CHK_SYMBOL (__memset_chk, unaligned))
>  #endif
>
>  ENTRY (MEMSET_SYMBOL (__memset, unaligned))
> -       MEMSET_VDUP_TO_VEC0_AND_SET_RETURN (%esi, %rdi)
> +       MEMSET_SET_VEC0_AND_SET_RETURN (%esi, %rdi)
>  # ifdef __ILP32__
>         /* Clear the upper 32 bits.  */
>         mov     %edx, %edx
> @@ -131,6 +145,8 @@ ENTRY (MEMSET_SYMBOL (__memset, unaligned))
>  L(entry_from_bzero):
>         cmpq    $VEC_SIZE, %rdx
>         jb      L(less_vec)
> +       MEMSET_VDUP_TO_VEC0_HIGH()
> +L(entry_from_wmemset):
>         cmpq    $(VEC_SIZE * 2), %rdx
>         ja      L(more_2x_vec)
>         /* From VEC and to 2 * VEC.  No branch when size == VEC_SIZE.  */
> @@ -179,27 +195,27 @@ END_CHK (MEMSET_CHK_SYMBOL (__memset_chk, unaligned_erms))
>  # endif
>
>  ENTRY_P2ALIGN (MEMSET_SYMBOL (__memset, unaligned_erms), 6)
> -       MEMSET_VDUP_TO_VEC0_AND_SET_RETURN (%esi, %rdi)
> +       MEMSET_SET_VEC0_AND_SET_RETURN (%esi, %rdi)
>  # ifdef __ILP32__
>         /* Clear the upper 32 bits.  */
>         mov     %edx, %edx
>  # endif
>         cmp     $VEC_SIZE, %RDX_LP
>         jb      L(less_vec)
> +       MEMSET_VDUP_TO_VEC0_HIGH ()
>         cmp     $(VEC_SIZE * 2), %RDX_LP
>         ja      L(stosb_more_2x_vec)
> -       /* From VEC and to 2 * VEC.  No branch when size == VEC_SIZE.
> -        */
> -       VMOVU   %VEC(0), (%rax)
> -       VMOVU   %VEC(0), -VEC_SIZE(%rax, %rdx)
> +       /* From VEC and to 2 * VEC.  No branch when size == VEC_SIZE.  */
> +       VMOVU   %VEC(0), (%rdi)
> +       VMOVU   %VEC(0), (VEC_SIZE * -1)(%rdi, %rdx)
>         VZEROUPPER_RETURN
>  #endif
>
> -       .p2align 4,, 10
> +       .p2align 4,, 4
>  L(last_2x_vec):
>  #ifdef USE_LESS_VEC_MASK_STORE
> -       VMOVU   %VEC(0), (VEC_SIZE * 2 + LOOP_4X_OFFSET)(%rcx)
> -       VMOVU   %VEC(0), (VEC_SIZE * 3 + LOOP_4X_OFFSET)(%rcx)
> +       VMOVU   %VEC(0), (VEC_SIZE * -2)(%rdi, %rdx)
> +       VMOVU   %VEC(0), (VEC_SIZE * -1)(%rdi, %rdx)
>  #else
>         VMOVU   %VEC(0), (VEC_SIZE * -2)(%rdi)
>         VMOVU   %VEC(0), (VEC_SIZE * -1)(%rdi)
> @@ -212,6 +228,7 @@ L(last_2x_vec):
>  #ifdef USE_LESS_VEC_MASK_STORE
>         .p2align 4,, 10
>  L(less_vec):
> +L(less_vec_no_vdup):
>         /* Less than 1 VEC.  */
>  # if VEC_SIZE != 16 && VEC_SIZE != 32 && VEC_SIZE != 64
>  #  error Unsupported VEC_SIZE!
> @@ -262,28 +279,18 @@ L(stosb_more_2x_vec):
>         /* Fallthrough goes to L(loop_4x_vec). Tests for memset (2x, 4x]
>            and (4x, 8x] jump to target.  */
>  L(more_2x_vec):
> -
> -       /* Two different methods of setting up pointers / compare. The
> -          two methods are based on the fact that EVEX/AVX512 mov
> -          instructions take more bytes then AVX2/SSE2 mov instructions. As
> -          well that EVEX/AVX512 machines also have fast LEA_BID. Both
> -          setup and END_REG to avoid complex address mode. For EVEX/AVX512
> -          this saves code size and keeps a few targets in one fetch block.
> -          For AVX2/SSE2 this helps prevent AGU bottlenecks.  */
> -#if defined USE_WITH_EVEX || defined USE_WITH_AVX512
> -       /* If EVEX/AVX512 compute END_REG - (VEC_SIZE * 4 +
> -          LOOP_4X_OFFSET) with LEA_BID.  */
> -
> -       /* END_REG is rcx for EVEX/AVX512.  */
> -       leaq    -(VEC_SIZE * 4 + LOOP_4X_OFFSET)(%rdi, %rdx), %END_REG
> -#endif
> -
> -       /* Stores to first 2x VEC before cmp as any path forward will
> -          require it.  */
> -       VMOVU   %VEC(0), (%rax)
> -       VMOVU   %VEC(0), VEC_SIZE(%rax)
> +       /* Store next 2x vec regardless.  */
> +       VMOVU   %VEC(0), (%rdi)
> +       VMOVU   %VEC(0), (VEC_SIZE * 1)(%rdi)
>
>
> +       /* Two different methods of setting up pointers / compare. The two
> +          methods are based on the fact that EVEX/AVX512 mov instructions take
> +          more bytes then AVX2/SSE2 mov instructions. As well that EVEX/AVX512
> +          machines also have fast LEA_BID. Both setup and END_REG to avoid complex
> +          address mode. For EVEX/AVX512 this saves code size and keeps a few
> +          targets in one fetch block. For AVX2/SSE2 this helps prevent AGU
> +          bottlenecks.  */
>  #if !(defined USE_WITH_EVEX || defined USE_WITH_AVX512)
>         /* If AVX2/SSE2 compute END_REG (rdi) with ALU.  */
>         addq    %rdx, %END_REG
> @@ -292,6 +299,15 @@ L(more_2x_vec):
>         cmpq    $(VEC_SIZE * 4), %rdx
>         jbe     L(last_2x_vec)
>
> +
> +#if defined USE_WITH_EVEX || defined USE_WITH_AVX512
> +       /* If EVEX/AVX512 compute END_REG - (VEC_SIZE * 4 + LOOP_4X_OFFSET) with
> +          LEA_BID.  */
> +
> +       /* END_REG is rcx for EVEX/AVX512.  */
> +       leaq    -(VEC_SIZE * 4 + LOOP_4X_OFFSET)(%rdi, %rdx), %END_REG
> +#endif
> +
>         /* Store next 2x vec regardless.  */
>         VMOVU   %VEC(0), (VEC_SIZE * 2)(%rax)
>         VMOVU   %VEC(0), (VEC_SIZE * 3)(%rax)
> @@ -355,65 +371,92 @@ L(stosb_local):
>         /* Define L(less_vec) only if not otherwise defined.  */
>         .p2align 4
>  L(less_vec):
> +       /* Broadcast esi to partial register (i.e VEC_SIZE == 32 broadcast to
> +          xmm). This is only does anything for AVX2.  */
> +       MEMSET_VDUP_TO_VEC0_LOW ()
> +L(less_vec_no_vdup):
>  #endif
>  L(cross_page):
>  #if VEC_SIZE > 32
>         cmpl    $32, %edx
> -       jae     L(between_32_63)
> +       jge     L(between_32_63)
>  #endif
>  #if VEC_SIZE > 16
>         cmpl    $16, %edx
> -       jae     L(between_16_31)
> +       jge     L(between_16_31)
> +#endif
> +#ifndef USE_XMM_LESS_VEC
> +       MOVQ    %XMM0, %rcx
>  #endif
> -       MOVQ    %XMM0, %rdi
>         cmpl    $8, %edx
> -       jae     L(between_8_15)
> +       jge     L(between_8_15)
>         cmpl    $4, %edx
> -       jae     L(between_4_7)
> +       jge     L(between_4_7)
>         cmpl    $1, %edx
> -       ja      L(between_2_3)
> -       jb      L(return)
> -       movb    %sil, (%rax)
> -       VZEROUPPER_RETURN
> +       jg      L(between_2_3)
> +       jl      L(return)
> +       movb    %sil, (%LESS_VEC_REG)
> +       ret
>
> -       /* Align small targets only if not doing so would cross a fetch
> -          line.  */
> +       /* Align small targets only if not doing so would cross a fetch line.
> +        */
>  #if VEC_SIZE > 32
>         .p2align 4,, SMALL_MEMSET_ALIGN(MOV_SIZE, RET_SIZE)
>         /* From 32 to 63.  No branch when size == 32.  */
>  L(between_32_63):
> -       VMOVU   %YMM0, (%rax)
> -       VMOVU   %YMM0, -32(%rax, %rdx)
> +       VMOVU   %YMM0, (%LESS_VEC_REG)
> +       VMOVU   %YMM0, -32(%LESS_VEC_REG, %rdx)
>         VZEROUPPER_RETURN
>  #endif
>
>  #if VEC_SIZE >= 32
> -       .p2align 4,, SMALL_MEMSET_ALIGN(MOV_SIZE, RET_SIZE)
> +       .p2align 4,, SMALL_MEMSET_ALIGN(MOV_SIZE, 1)
>  L(between_16_31):
>         /* From 16 to 31.  No branch when size == 16.  */
> -       VMOVU   %XMM0, (%rax)
> -       VMOVU   %XMM0, -16(%rax, %rdx)
> -       VZEROUPPER_RETURN
> +       VMOVU   %XMM0, (%LESS_VEC_REG)
> +       VMOVU   %XMM0, -16(%LESS_VEC_REG, %rdx)
> +       ret
>  #endif
>
> -       .p2align 4,, SMALL_MEMSET_ALIGN(3, RET_SIZE)
> +       /* Move size is 3 for SSE2, EVEX, and AVX512. Move size is 4 for AVX2.
> +        */
> +       .p2align 4,, SMALL_MEMSET_ALIGN(3 + XMM_SMALL, 1)
>  L(between_8_15):
>         /* From 8 to 15.  No branch when size == 8.  */
> -       movq    %rdi, (%rax)
> -       movq    %rdi, -8(%rax, %rdx)
> -       VZEROUPPER_RETURN
> +#ifdef USE_XMM_LESS_VEC
> +       MOVQ    %XMM0, (%rdi)
> +       MOVQ    %XMM0, -8(%rdi, %rdx)
> +#else
> +       movq    %rcx, (%LESS_VEC_REG)
> +       movq    %rcx, -8(%LESS_VEC_REG, %rdx)
> +#endif
> +       ret
>
> -       .p2align 4,, SMALL_MEMSET_ALIGN(2, RET_SIZE)
> +       /* Move size is 2 for SSE2, EVEX, and AVX512. Move size is 4 for AVX2.
> +        */
> +       .p2align 4,, SMALL_MEMSET_ALIGN(2 << XMM_SMALL, 1)
>  L(between_4_7):
>         /* From 4 to 7.  No branch when size == 4.  */
> -       movl    %edi, (%rax)
> -       movl    %edi, -4(%rax, %rdx)
> -       VZEROUPPER_RETURN
> +#ifdef USE_XMM_LESS_VEC
> +       MOVD    %XMM0, (%rdi)
> +       MOVD    %XMM0, -4(%rdi, %rdx)
> +#else
> +       movl    %ecx, (%LESS_VEC_REG)
> +       movl    %ecx, -4(%LESS_VEC_REG, %rdx)
> +#endif
> +       ret
>
> -       .p2align 4,, SMALL_MEMSET_ALIGN(3, RET_SIZE)
> +       /* 4 * XMM_SMALL for the third mov for AVX2.  */
> +       .p2align 4,, 4 * XMM_SMALL + SMALL_MEMSET_ALIGN(3, 1)
>  L(between_2_3):
>         /* From 2 to 3.  No branch when size == 2.  */
> -       movw    %di, (%rax)
> -       movb    %dil, -1(%rax, %rdx)
> -       VZEROUPPER_RETURN
> +#ifdef USE_XMM_LESS_VEC
> +       movb    %sil, (%rdi)
> +       movb    %sil, 1(%rdi)
> +       movb    %sil, -1(%rdi, %rdx)
> +#else
> +       movw    %cx, (%LESS_VEC_REG)
> +       movb    %sil, -1(%LESS_VEC_REG, %rdx)
> +#endif
> +       ret
>  END (MEMSET_SYMBOL (__memset, unaligned_erms))
> --
> 2.25.1
>
  

Patch

diff --git a/sysdeps/x86_64/memset.S b/sysdeps/x86_64/memset.S
index 65c09bd0ac..ccf036be53 100644
--- a/sysdeps/x86_64/memset.S
+++ b/sysdeps/x86_64/memset.S
@@ -28,17 +28,22 @@ 
 #define VMOVU     movups
 #define VMOVA     movaps
 
-#define MEMSET_VDUP_TO_VEC0_AND_SET_RETURN(d, r) \
+# define MEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
   movd d, %xmm0; \
-  movq r, %rax; \
-  punpcklbw %xmm0, %xmm0; \
-  punpcklwd %xmm0, %xmm0; \
-  pshufd $0, %xmm0, %xmm0
+  pxor %xmm1, %xmm1; \
+  pshufb %xmm1, %xmm0; \
+  movq r, %rax
 
-#define WMEMSET_VDUP_TO_VEC0_AND_SET_RETURN(d, r) \
+# define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
   movd d, %xmm0; \
-  movq r, %rax; \
-  pshufd $0, %xmm0, %xmm0
+  pshufd $0, %xmm0, %xmm0; \
+  movq r, %rax
+
+# define MEMSET_VDUP_TO_VEC0_HIGH()
+# define MEMSET_VDUP_TO_VEC0_LOW()
+
+# define WMEMSET_VDUP_TO_VEC0_HIGH()
+# define WMEMSET_VDUP_TO_VEC0_LOW()
 
 #define SECTION(p)		p
 
diff --git a/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S
index 1af668af0a..c0bf2875d0 100644
--- a/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S
+++ b/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S
@@ -10,15 +10,18 @@ 
 # define VMOVU     vmovdqu
 # define VMOVA     vmovdqa
 
-# define MEMSET_VDUP_TO_VEC0_AND_SET_RETURN(d, r) \
+# define MEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
   vmovd d, %xmm0; \
-  movq r, %rax; \
-  vpbroadcastb %xmm0, %ymm0
+  movq r, %rax;
 
-# define WMEMSET_VDUP_TO_VEC0_AND_SET_RETURN(d, r) \
-  vmovd d, %xmm0; \
-  movq r, %rax; \
-  vpbroadcastd %xmm0, %ymm0
+# define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
+  MEMSET_SET_VEC0_AND_SET_RETURN(d, r)
+
+# define MEMSET_VDUP_TO_VEC0_HIGH() vpbroadcastb %xmm0, %ymm0
+# define MEMSET_VDUP_TO_VEC0_LOW() vpbroadcastb %xmm0, %xmm0
+
+# define WMEMSET_VDUP_TO_VEC0_HIGH() vpbroadcastd %xmm0, %ymm0
+# define WMEMSET_VDUP_TO_VEC0_LOW() vpbroadcastd %xmm0, %xmm0
 
 # ifndef SECTION
 #  define SECTION(p)		p##.avx
@@ -30,5 +33,6 @@ 
 #  define WMEMSET_SYMBOL(p,s)	p##_avx2_##s
 # endif
 
+# define USE_XMM_LESS_VEC
 # include "memset-vec-unaligned-erms.S"
 #endif
diff --git a/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S
index f14d6f8493..5241216a77 100644
--- a/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S
+++ b/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S
@@ -15,13 +15,19 @@ 
 
 # define VZEROUPPER
 
-# define MEMSET_VDUP_TO_VEC0_AND_SET_RETURN(d, r) \
-  movq r, %rax; \
-  vpbroadcastb d, %VEC0
+# define MEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
+  vpbroadcastb d, %VEC0; \
+  movq r, %rax
 
-# define WMEMSET_VDUP_TO_VEC0_AND_SET_RETURN(d, r) \
-  movq r, %rax; \
-  vpbroadcastd d, %VEC0
+# define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
+  vpbroadcastd d, %VEC0; \
+  movq r, %rax
+
+# define MEMSET_VDUP_TO_VEC0_HIGH()
+# define MEMSET_VDUP_TO_VEC0_LOW()
+
+# define WMEMSET_VDUP_TO_VEC0_HIGH()
+# define WMEMSET_VDUP_TO_VEC0_LOW()
 
 # define SECTION(p)		p##.evex512
 # define MEMSET_SYMBOL(p,s)	p##_avx512_##s
diff --git a/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S
index 64b09e77cc..6370021506 100644
--- a/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S
+++ b/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S
@@ -15,13 +15,19 @@ 
 
 # define VZEROUPPER
 
-# define MEMSET_VDUP_TO_VEC0_AND_SET_RETURN(d, r) \
-  movq r, %rax; \
-  vpbroadcastb d, %VEC0
+# define MEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
+  vpbroadcastb d, %VEC0; \
+  movq r, %rax
 
-# define WMEMSET_VDUP_TO_VEC0_AND_SET_RETURN(d, r) \
-  movq r, %rax; \
-  vpbroadcastd d, %VEC0
+# define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
+  vpbroadcastd d, %VEC0; \
+  movq r, %rax
+
+# define MEMSET_VDUP_TO_VEC0_HIGH()
+# define MEMSET_VDUP_TO_VEC0_LOW()
+
+# define WMEMSET_VDUP_TO_VEC0_HIGH()
+# define WMEMSET_VDUP_TO_VEC0_LOW()
 
 # define SECTION(p)		p##.evex
 # define MEMSET_SYMBOL(p,s)	p##_evex_##s
diff --git a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
index 1e0511c79a..fb9053f4d6 100644
--- a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
+++ b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
@@ -58,8 +58,10 @@ 
 #ifndef MOVQ
 # if VEC_SIZE > 16
 #  define MOVQ				vmovq
+#  define MOVD				vmovd
 # else
 #  define MOVQ				movq
+#  define MOVD				movd
 # endif
 #endif
 
@@ -72,9 +74,17 @@ 
 #if defined USE_WITH_EVEX || defined USE_WITH_AVX512
 # define END_REG	rcx
 # define LOOP_REG	rdi
+# define LESS_VEC_REG	rax
 #else
 # define END_REG	rdi
 # define LOOP_REG	rdx
+# define LESS_VEC_REG	rdi
+#endif
+
+#ifdef USE_XMM_LESS_VEC
+# define XMM_SMALL	1
+#else
+# define XMM_SMALL	0
 #endif
 
 #define PAGE_SIZE 4096
@@ -110,8 +120,12 @@  END_CHK (WMEMSET_CHK_SYMBOL (__wmemset_chk, unaligned))
 
 ENTRY (WMEMSET_SYMBOL (__wmemset, unaligned))
 	shl	$2, %RDX_LP
-	WMEMSET_VDUP_TO_VEC0_AND_SET_RETURN (%esi, %rdi)
-	jmp	L(entry_from_bzero)
+	WMEMSET_SET_VEC0_AND_SET_RETURN (%esi, %rdi)
+	WMEMSET_VDUP_TO_VEC0_LOW()
+	cmpq	$VEC_SIZE, %rdx
+	jb	L(less_vec_no_vdup)
+	WMEMSET_VDUP_TO_VEC0_HIGH()
+	jmp	L(entry_from_wmemset)
 END (WMEMSET_SYMBOL (__wmemset, unaligned))
 #endif
 
@@ -123,7 +137,7 @@  END_CHK (MEMSET_CHK_SYMBOL (__memset_chk, unaligned))
 #endif
 
 ENTRY (MEMSET_SYMBOL (__memset, unaligned))
-	MEMSET_VDUP_TO_VEC0_AND_SET_RETURN (%esi, %rdi)
+	MEMSET_SET_VEC0_AND_SET_RETURN (%esi, %rdi)
 # ifdef __ILP32__
 	/* Clear the upper 32 bits.  */
 	mov	%edx, %edx
@@ -131,6 +145,8 @@  ENTRY (MEMSET_SYMBOL (__memset, unaligned))
 L(entry_from_bzero):
 	cmpq	$VEC_SIZE, %rdx
 	jb	L(less_vec)
+	MEMSET_VDUP_TO_VEC0_HIGH()
+L(entry_from_wmemset):
 	cmpq	$(VEC_SIZE * 2), %rdx
 	ja	L(more_2x_vec)
 	/* From VEC and to 2 * VEC.  No branch when size == VEC_SIZE.  */
@@ -179,27 +195,27 @@  END_CHK (MEMSET_CHK_SYMBOL (__memset_chk, unaligned_erms))
 # endif
 
 ENTRY_P2ALIGN (MEMSET_SYMBOL (__memset, unaligned_erms), 6)
-	MEMSET_VDUP_TO_VEC0_AND_SET_RETURN (%esi, %rdi)
+	MEMSET_SET_VEC0_AND_SET_RETURN (%esi, %rdi)
 # ifdef __ILP32__
 	/* Clear the upper 32 bits.  */
 	mov	%edx, %edx
 # endif
 	cmp	$VEC_SIZE, %RDX_LP
 	jb	L(less_vec)
+	MEMSET_VDUP_TO_VEC0_HIGH ()
 	cmp	$(VEC_SIZE * 2), %RDX_LP
 	ja	L(stosb_more_2x_vec)
-	/* From VEC and to 2 * VEC.  No branch when size == VEC_SIZE.
-	 */
-	VMOVU	%VEC(0), (%rax)
-	VMOVU	%VEC(0), -VEC_SIZE(%rax, %rdx)
+	/* From VEC and to 2 * VEC.  No branch when size == VEC_SIZE.  */
+	VMOVU	%VEC(0), (%rdi)
+	VMOVU	%VEC(0), (VEC_SIZE * -1)(%rdi, %rdx)
 	VZEROUPPER_RETURN
 #endif
 
-	.p2align 4,, 10
+	.p2align 4,, 4
 L(last_2x_vec):
 #ifdef USE_LESS_VEC_MASK_STORE
-	VMOVU	%VEC(0), (VEC_SIZE * 2 + LOOP_4X_OFFSET)(%rcx)
-	VMOVU	%VEC(0), (VEC_SIZE * 3 + LOOP_4X_OFFSET)(%rcx)
+	VMOVU	%VEC(0), (VEC_SIZE * -2)(%rdi, %rdx)
+	VMOVU	%VEC(0), (VEC_SIZE * -1)(%rdi, %rdx)
 #else
 	VMOVU	%VEC(0), (VEC_SIZE * -2)(%rdi)
 	VMOVU	%VEC(0), (VEC_SIZE * -1)(%rdi)
@@ -212,6 +228,7 @@  L(last_2x_vec):
 #ifdef USE_LESS_VEC_MASK_STORE
 	.p2align 4,, 10
 L(less_vec):
+L(less_vec_no_vdup):
 	/* Less than 1 VEC.  */
 # if VEC_SIZE != 16 && VEC_SIZE != 32 && VEC_SIZE != 64
 #  error Unsupported VEC_SIZE!
@@ -262,28 +279,18 @@  L(stosb_more_2x_vec):
 	/* Fallthrough goes to L(loop_4x_vec). Tests for memset (2x, 4x]
 	   and (4x, 8x] jump to target.  */
 L(more_2x_vec):
-
-	/* Two different methods of setting up pointers / compare. The
-	   two methods are based on the fact that EVEX/AVX512 mov
-	   instructions take more bytes then AVX2/SSE2 mov instructions. As
-	   well that EVEX/AVX512 machines also have fast LEA_BID. Both
-	   setup and END_REG to avoid complex address mode. For EVEX/AVX512
-	   this saves code size and keeps a few targets in one fetch block.
-	   For AVX2/SSE2 this helps prevent AGU bottlenecks.  */
-#if defined USE_WITH_EVEX || defined USE_WITH_AVX512
-	/* If EVEX/AVX512 compute END_REG - (VEC_SIZE * 4 +
-	   LOOP_4X_OFFSET) with LEA_BID.  */
-
-	/* END_REG is rcx for EVEX/AVX512.  */
-	leaq	-(VEC_SIZE * 4 + LOOP_4X_OFFSET)(%rdi, %rdx), %END_REG
-#endif
-
-	/* Stores to first 2x VEC before cmp as any path forward will
-	   require it.  */
-	VMOVU	%VEC(0), (%rax)
-	VMOVU	%VEC(0), VEC_SIZE(%rax)
+	/* Store next 2x vec regardless.  */
+	VMOVU	%VEC(0), (%rdi)
+	VMOVU	%VEC(0), (VEC_SIZE * 1)(%rdi)
 
 
+	/* Two different methods of setting up pointers / compare. The two
+	   methods are based on the fact that EVEX/AVX512 mov instructions take
+	   more bytes then AVX2/SSE2 mov instructions. As well that EVEX/AVX512
+	   machines also have fast LEA_BID. Both setup and END_REG to avoid complex
+	   address mode. For EVEX/AVX512 this saves code size and keeps a few
+	   targets in one fetch block. For AVX2/SSE2 this helps prevent AGU
+	   bottlenecks.  */
 #if !(defined USE_WITH_EVEX || defined USE_WITH_AVX512)
 	/* If AVX2/SSE2 compute END_REG (rdi) with ALU.  */
 	addq	%rdx, %END_REG
@@ -292,6 +299,15 @@  L(more_2x_vec):
 	cmpq	$(VEC_SIZE * 4), %rdx
 	jbe	L(last_2x_vec)
 
+
+#if defined USE_WITH_EVEX || defined USE_WITH_AVX512
+	/* If EVEX/AVX512 compute END_REG - (VEC_SIZE * 4 + LOOP_4X_OFFSET) with
+	   LEA_BID.  */
+
+	/* END_REG is rcx for EVEX/AVX512.  */
+	leaq	-(VEC_SIZE * 4 + LOOP_4X_OFFSET)(%rdi, %rdx), %END_REG
+#endif
+
 	/* Store next 2x vec regardless.  */
 	VMOVU	%VEC(0), (VEC_SIZE * 2)(%rax)
 	VMOVU	%VEC(0), (VEC_SIZE * 3)(%rax)
@@ -355,65 +371,92 @@  L(stosb_local):
 	/* Define L(less_vec) only if not otherwise defined.  */
 	.p2align 4
 L(less_vec):
+	/* Broadcast esi to partial register (i.e VEC_SIZE == 32 broadcast to
+	   xmm). This is only does anything for AVX2.  */
+	MEMSET_VDUP_TO_VEC0_LOW ()
+L(less_vec_no_vdup):
 #endif
 L(cross_page):
 #if VEC_SIZE > 32
 	cmpl	$32, %edx
-	jae	L(between_32_63)
+	jge	L(between_32_63)
 #endif
 #if VEC_SIZE > 16
 	cmpl	$16, %edx
-	jae	L(between_16_31)
+	jge	L(between_16_31)
+#endif
+#ifndef USE_XMM_LESS_VEC
+	MOVQ	%XMM0, %rcx
 #endif
-	MOVQ	%XMM0, %rdi
 	cmpl	$8, %edx
-	jae	L(between_8_15)
+	jge	L(between_8_15)
 	cmpl	$4, %edx
-	jae	L(between_4_7)
+	jge	L(between_4_7)
 	cmpl	$1, %edx
-	ja	L(between_2_3)
-	jb	L(return)
-	movb	%sil, (%rax)
-	VZEROUPPER_RETURN
+	jg	L(between_2_3)
+	jl	L(return)
+	movb	%sil, (%LESS_VEC_REG)
+	ret
 
-	/* Align small targets only if not doing so would cross a fetch
-	   line.  */
+	/* Align small targets only if not doing so would cross a fetch line.
+	 */
 #if VEC_SIZE > 32
 	.p2align 4,, SMALL_MEMSET_ALIGN(MOV_SIZE, RET_SIZE)
 	/* From 32 to 63.  No branch when size == 32.  */
 L(between_32_63):
-	VMOVU	%YMM0, (%rax)
-	VMOVU	%YMM0, -32(%rax, %rdx)
+	VMOVU	%YMM0, (%LESS_VEC_REG)
+	VMOVU	%YMM0, -32(%LESS_VEC_REG, %rdx)
 	VZEROUPPER_RETURN
 #endif
 
 #if VEC_SIZE >= 32
-	.p2align 4,, SMALL_MEMSET_ALIGN(MOV_SIZE, RET_SIZE)
+	.p2align 4,, SMALL_MEMSET_ALIGN(MOV_SIZE, 1)
 L(between_16_31):
 	/* From 16 to 31.  No branch when size == 16.  */
-	VMOVU	%XMM0, (%rax)
-	VMOVU	%XMM0, -16(%rax, %rdx)
-	VZEROUPPER_RETURN
+	VMOVU	%XMM0, (%LESS_VEC_REG)
+	VMOVU	%XMM0, -16(%LESS_VEC_REG, %rdx)
+	ret
 #endif
 
-	.p2align 4,, SMALL_MEMSET_ALIGN(3, RET_SIZE)
+	/* Move size is 3 for SSE2, EVEX, and AVX512. Move size is 4 for AVX2.
+	 */
+	.p2align 4,, SMALL_MEMSET_ALIGN(3 + XMM_SMALL, 1)
 L(between_8_15):
 	/* From 8 to 15.  No branch when size == 8.  */
-	movq	%rdi, (%rax)
-	movq	%rdi, -8(%rax, %rdx)
-	VZEROUPPER_RETURN
+#ifdef USE_XMM_LESS_VEC
+	MOVQ	%XMM0, (%rdi)
+	MOVQ	%XMM0, -8(%rdi, %rdx)
+#else
+	movq	%rcx, (%LESS_VEC_REG)
+	movq	%rcx, -8(%LESS_VEC_REG, %rdx)
+#endif
+	ret
 
-	.p2align 4,, SMALL_MEMSET_ALIGN(2, RET_SIZE)
+	/* Move size is 2 for SSE2, EVEX, and AVX512. Move size is 4 for AVX2.
+	 */
+	.p2align 4,, SMALL_MEMSET_ALIGN(2 << XMM_SMALL, 1)
 L(between_4_7):
 	/* From 4 to 7.  No branch when size == 4.  */
-	movl	%edi, (%rax)
-	movl	%edi, -4(%rax, %rdx)
-	VZEROUPPER_RETURN
+#ifdef USE_XMM_LESS_VEC
+	MOVD	%XMM0, (%rdi)
+	MOVD	%XMM0, -4(%rdi, %rdx)
+#else
+	movl	%ecx, (%LESS_VEC_REG)
+	movl	%ecx, -4(%LESS_VEC_REG, %rdx)
+#endif
+	ret
 
-	.p2align 4,, SMALL_MEMSET_ALIGN(3, RET_SIZE)
+	/* 4 * XMM_SMALL for the third mov for AVX2.  */
+	.p2align 4,, 4 * XMM_SMALL + SMALL_MEMSET_ALIGN(3, 1)
 L(between_2_3):
 	/* From 2 to 3.  No branch when size == 2.  */
-	movw	%di, (%rax)
-	movb	%dil, -1(%rax, %rdx)
-	VZEROUPPER_RETURN
+#ifdef USE_XMM_LESS_VEC
+	movb	%sil, (%rdi)
+	movb	%sil, 1(%rdi)
+	movb	%sil, -1(%rdi, %rdx)
+#else
+	movw	%cx, (%LESS_VEC_REG)
+	movb	%sil, -1(%LESS_VEC_REG, %rdx)
+#endif
+	ret
 END (MEMSET_SYMBOL (__memset, unaligned_erms))