[PATCH] x86-64: Optimize load of all bits set into ZMM register [BZ #28252]
Noah Goldstein
goldstein.w.n@gmail.com
Sat Aug 21 17:49:09 GMT 2021
On Sat, Aug 21, 2021 at 12:36 PM H.J. Lu via Libc-alpha <
libc-alpha@sourceware.org> wrote:
> Optimize loads of all bits set into ZMM register in AVX512 SVML codes
> by replacing
>
> vpbroadcastq .L_2il0floatpacket.16(%rip), %zmmX
>
> and
>
> vmovups .L_2il0floatpacket.13(%rip), %zmmX
>
> with
> vpternlogd $0xff, %zmmX, %zmmX, %zmmX
>
> This fixes BZ #28252.
> ---
> .../x86_64/fpu/multiarch/svml_d_cos8_core_avx512.S | 7 +------
> .../x86_64/fpu/multiarch/svml_d_log8_core_avx512.S | 7 +------
> .../x86_64/fpu/multiarch/svml_d_sin8_core_avx512.S | 7 +------
> .../fpu/multiarch/svml_d_sincos8_core_avx512.S | 7 +------
> .../x86_64/fpu/multiarch/svml_s_cosf16_core_avx512.S | 7 +------
> .../x86_64/fpu/multiarch/svml_s_expf16_core_avx512.S | 7 +------
> .../x86_64/fpu/multiarch/svml_s_logf16_core_avx512.S | 7 +------
> .../x86_64/fpu/multiarch/svml_s_powf16_core_avx512.S | 12 ++----------
> .../fpu/multiarch/svml_s_sincosf16_core_avx512.S | 7 +------
> .../x86_64/fpu/multiarch/svml_s_sinf16_core_avx512.S | 7 +------
> 10 files changed, 11 insertions(+), 64 deletions(-)
>
> diff --git a/sysdeps/x86_64/fpu/multiarch/svml_d_cos8_core_avx512.S
> b/sysdeps/x86_64/fpu/multiarch/svml_d_cos8_core_avx512.S
> index c2cf007904..0fcb912557 100644
> --- a/sysdeps/x86_64/fpu/multiarch/svml_d_cos8_core_avx512.S
> +++ b/sysdeps/x86_64/fpu/multiarch/svml_d_cos8_core_avx512.S
> @@ -258,7 +258,7 @@ ENTRY (_ZGVeN8v_cos_skx)
> vmovaps %zmm0, %zmm8
>
> /* Check for large arguments path */
> - vpbroadcastq .L_2il0floatpacket.16(%rip), %zmm2
> + vpternlogd $0xff, %zmm2, %zmm2, %zmm2
>
Looking at the code it seems like this is used later by
vpandnq %zmm1, %zmm1, %zmm2{%k1}
AFAICT you can make the vpternlogd down there and just use
vpternlogq $0xff, %zmm1, %zmm1, %zmm2{%k1}{z}
>
> /*
> ARGUMENT RANGE REDUCTION:
> @@ -448,8 +448,3 @@ ENTRY (_ZGVeN8v_cos_skx)
> vmovsd %xmm0, 1216(%rsp,%r15)
> jmp .LBL_2_7
> END (_ZGVeN8v_cos_skx)
> -
> - .section .rodata, "a"
> -.L_2il0floatpacket.16:
> - .long 0xffffffff,0xffffffff
> - .type .L_2il0floatpacket.16,@object
> diff --git a/sysdeps/x86_64/fpu/multiarch/svml_d_log8_core_avx512.S
> b/sysdeps/x86_64/fpu/multiarch/svml_d_log8_core_avx512.S
> index e9a5d00992..5596c950ce 100644
> --- a/sysdeps/x86_64/fpu/multiarch/svml_d_log8_core_avx512.S
> +++ b/sysdeps/x86_64/fpu/multiarch/svml_d_log8_core_avx512.S
> @@ -267,7 +267,7 @@ ENTRY (_ZGVeN8v_log_skx)
>
> /* preserve mantissa, set input exponent to 2^(-10) */
> vpternlogq $248, _ExpMask(%rax), %zmm3, %zmm2
> - vpbroadcastq .L_2il0floatpacket.12(%rip), %zmm1
> + vpternlogd $0xff, %zmm1, %zmm1, %zmm1
>
Earlier in the function there is a dependency breaking
kxnorw %k3, %k3, %k3
so I think you can accomplish the same thing but breaking
some unlucky dep chain with:
vpmovm2d %k3, %zmm2
vpsrlq $32, %zmm4, %zmm6
>
> /* reciprocal approximation good to at least 11 bits */
> @@ -453,8 +453,3 @@ ENTRY (_ZGVeN8v_log_skx)
> vmovsd %xmm0, 1216(%rsp,%r15)
> jmp .LBL_2_7
> END (_ZGVeN8v_log_skx)
> -
> - .section .rodata, "a"
> -.L_2il0floatpacket.12:
> - .long 0xffffffff,0xffffffff
> - .type .L_2il0floatpacket.12,@object
> diff --git a/sysdeps/x86_64/fpu/multiarch/svml_d_sin8_core_avx512.S
> b/sysdeps/x86_64/fpu/multiarch/svml_d_sin8_core_avx512.S
> index 508da563fe..2981f1582e 100644
> --- a/sysdeps/x86_64/fpu/multiarch/svml_d_sin8_core_avx512.S
> +++ b/sysdeps/x86_64/fpu/multiarch/svml_d_sin8_core_avx512.S
> @@ -254,7 +254,7 @@ ENTRY (_ZGVeN8v_sin_skx)
> andq $-64, %rsp
> subq $1280, %rsp
> movq __svml_d_trig_data@GOTPCREL(%rip), %rax
> - vpbroadcastq .L_2il0floatpacket.14(%rip), %zmm14
> + vpternlogd $0xff, %zmm1, %zmm1, %zmm14
>
This one also seems to just be used by an vpandn later on:
vpandnq %zmm13, %zmm13, %zmm14{%k1}
so maybe:
vpternlogq $0xff, %zmm13, %zmm13, %zmm14{%k1}{z}
instead of the vpandn.
vmovups __dAbsMask(%rax), %zmm7
> vmovups __dInvPI(%rax), %zmm2
> vmovups __dRShifter(%rax), %zmm1
> @@ -450,8 +450,3 @@ ENTRY (_ZGVeN8v_sin_skx)
> vmovsd %xmm0, 1216(%rsp,%r15)
> jmp .LBL_2_7
> END (_ZGVeN8v_sin_skx)
> -
> - .section .rodata, "a"
> -.L_2il0floatpacket.14:
> - .long 0xffffffff,0xffffffff
> - .type .L_2il0floatpacket.14,@object
> diff --git a/sysdeps/x86_64/fpu/multiarch/svml_d_sincos8_core_avx512.S
> b/sysdeps/x86_64/fpu/multiarch/svml_d_sincos8_core_avx512.S
> index 965415f2bd..4ad366373b 100644
> --- a/sysdeps/x86_64/fpu/multiarch/svml_d_sincos8_core_avx512.S
> +++ b/sysdeps/x86_64/fpu/multiarch/svml_d_sincos8_core_avx512.S
> @@ -423,7 +423,7 @@ ENTRY (_ZGVeN8vl8l8_sincos_skx)
>
> /* SinPoly = SinR*SinPoly */
> vfmadd213pd %zmm5, %zmm5, %zmm4
> - vpbroadcastq .L_2il0floatpacket.15(%rip), %zmm3
> + vpternlogd $0xff, %zmm3, %zmm3, %zmm3
>
Also vpandn below:
vpandnq %zmm7, %zmm7, %zmm3{%k1}
> /* Update Cos result's sign */
> vxorpd %zmm2, %zmm1, %zmm1
> @@ -733,8 +733,3 @@ END (_ZGVeN8vvv_sincos_knl)
> ENTRY (_ZGVeN8vvv_sincos_skx)
> WRAPPER_AVX512_vvv_vl8l8 _ZGVeN8vl8l8_sincos_skx
> END (_ZGVeN8vvv_sincos_skx)
> -
> - .section .rodata, "a"
> -.L_2il0floatpacket.15:
> - .long 0xffffffff,0xffffffff
> - .type .L_2il0floatpacket.15,@object
> diff --git a/sysdeps/x86_64/fpu/multiarch/svml_s_cosf16_core_avx512.S
> b/sysdeps/x86_64/fpu/multiarch/svml_s_cosf16_core_avx512.S
> index cdcb16087d..b7d79efb54 100644
> --- a/sysdeps/x86_64/fpu/multiarch/svml_s_cosf16_core_avx512.S
> +++ b/sysdeps/x86_64/fpu/multiarch/svml_s_cosf16_core_avx512.S
> @@ -271,7 +271,7 @@ ENTRY (_ZGVeN16v_cosf_skx)
> X = X - Y*PI1 - Y*PI2 - Y*PI3
> */
> vmovaps %zmm0, %zmm6
> - vmovups .L_2il0floatpacket.13(%rip), %zmm12
> + vpternlogd $0xff, %zmm12, %zmm12, %zmm12
>
Also vpandn below:
vpandnd %zmm1, %zmm1, %zmm12{%k1}
> vmovups __sRShifter(%rax), %zmm3
> vmovups __sPI1_FMA(%rax), %zmm5
> vmovups __sA9_FMA(%rax), %zmm9
> @@ -445,8 +445,3 @@ ENTRY (_ZGVeN16v_cosf_skx)
> vmovss %xmm0, 1216(%rsp,%r15,8)
> jmp .LBL_2_7
> END (_ZGVeN16v_cosf_skx)
> -
> - .section .rodata, "a"
> -.L_2il0floatpacket.13:
> - .long
> 0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff
> - .type .L_2il0floatpacket.13,@object
> diff --git a/sysdeps/x86_64/fpu/multiarch/svml_s_expf16_core_avx512.S
> b/sysdeps/x86_64/fpu/multiarch/svml_s_expf16_core_avx512.S
> index 1b09909344..9f03b9b780 100644
> --- a/sysdeps/x86_64/fpu/multiarch/svml_s_expf16_core_avx512.S
> +++ b/sysdeps/x86_64/fpu/multiarch/svml_s_expf16_core_avx512.S
> @@ -257,7 +257,7 @@ ENTRY (_ZGVeN16v_expf_skx)
> vmovaps %zmm0, %zmm7
>
> /* compare against threshold */
> - vmovups .L_2il0floatpacket.13(%rip), %zmm3
> + vpternlogd $0xff, %zmm3, %zmm3, %zmm3
>
Also below:
vpandnd %zmm2, %zmm2, %zmm3{%k1}
> vmovups __sInvLn2(%rax), %zmm4
> vmovups __sShifter(%rax), %zmm1
> vmovups __sLn2hi(%rax), %zmm6
> @@ -432,8 +432,3 @@ ENTRY (_ZGVeN16v_expf_skx)
> jmp .LBL_2_7
>
> END (_ZGVeN16v_expf_skx)
> -
> - .section .rodata, "a"
> -.L_2il0floatpacket.13:
> - .long
> 0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff
> - .type .L_2il0floatpacket.13,@object
> diff --git a/sysdeps/x86_64/fpu/multiarch/svml_s_logf16_core_avx512.S
> b/sysdeps/x86_64/fpu/multiarch/svml_s_logf16_core_avx512.S
> index 4a7b2adbbf..2ba38b0f33 100644
> --- a/sysdeps/x86_64/fpu/multiarch/svml_s_logf16_core_avx512.S
> +++ b/sysdeps/x86_64/fpu/multiarch/svml_s_logf16_core_avx512.S
> @@ -228,7 +228,7 @@ ENTRY (_ZGVeN16v_logf_skx)
> andq $-64, %rsp
> subq $1280, %rsp
> movq __svml_slog_data@GOTPCREL(%rip), %rax
> - vmovups .L_2il0floatpacket.7(%rip), %zmm6
> + vpternlogd $0xff, %zmm6, %zmm6, %zmm6
>
Also below:
vpandnd %zmm1, %zmm1, %zmm6{%k1}
> vmovups _iBrkValue(%rax), %zmm4
> vmovups _sPoly_7(%rax), %zmm8
>
> @@ -401,8 +401,3 @@ ENTRY (_ZGVeN16v_logf_skx)
> jmp .LBL_2_7
>
> END (_ZGVeN16v_logf_skx)
> -
> - .section .rodata, "a"
> -.L_2il0floatpacket.7:
> - .long
> 0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff
> - .type .L_2il0floatpacket.7,@object
> diff --git a/sysdeps/x86_64/fpu/multiarch/svml_s_powf16_core_avx512.S
> b/sysdeps/x86_64/fpu/multiarch/svml_s_powf16_core_avx512.S
> index 7f906622a5..7f0272c809 100644
> --- a/sysdeps/x86_64/fpu/multiarch/svml_s_powf16_core_avx512.S
> +++ b/sysdeps/x86_64/fpu/multiarch/svml_s_powf16_core_avx512.S
> @@ -378,7 +378,7 @@ ENTRY (_ZGVeN16vv_powf_skx)
> vpsrlq $32, %zmm3, %zmm2
> vpmovqd %zmm2, %ymm11
> vcvtps2pd %ymm14, %zmm13
> - vmovups .L_2il0floatpacket.23(%rip), %zmm14
> + vpternlogd $0xff, %zmm14, %zmm14, %zmm14
>
earlier
kxnorw %k3, %k3, %k3
can be used to get a dependency break with this:
vpmovm2d %k3, %zmm14
> vmovaps %zmm14, %zmm26
> vpandd _ABSMASK(%rax), %zmm1, %zmm8
> vpcmpd $1, _INF(%rax), %zmm8, %k2
> @@ -420,7 +420,7 @@ ENTRY (_ZGVeN16vv_powf_skx)
> vpmovqd %zmm11, %ymm5
> vpxord %zmm10, %zmm10, %zmm10
> vgatherdpd _Log2Rcp_lookup(%rax,%ymm4), %zmm10{%k3}
> - vpbroadcastq .L_2il0floatpacket.24(%rip), %zmm4
> + vpternlogd $0xff, %zmm4, %zmm4, %zmm4
> vpxord %zmm11, %zmm11, %zmm11
> vcvtdq2pd %ymm7, %zmm7
> vgatherdpd _Log2Rcp_lookup(%rax,%ymm5), %zmm11{%k1}
> @@ -635,11 +635,3 @@ ENTRY (_ZGVeN16vv_powf_skx)
> vmovss %xmm0, 1216(%rsp,%r15,8)
> jmp .LBL_2_7
> END (_ZGVeN16vv_powf_skx)
> -
> - .section .rodata, "a"
> -.L_2il0floatpacket.23:
> - .long
> 0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff
> - .type .L_2il0floatpacket.23,@object
> -.L_2il0floatpacket.24:
> - .long 0xffffffff,0xffffffff
> - .type .L_2il0floatpacket.24,@object
> diff --git a/sysdeps/x86_64/fpu/multiarch/svml_s_sincosf16_core_avx512.S
> b/sysdeps/x86_64/fpu/multiarch/svml_s_sincosf16_core_avx512.S
> index 54cee3a537..e1d0154441 100644
> --- a/sysdeps/x86_64/fpu/multiarch/svml_s_sincosf16_core_avx512.S
> +++ b/sysdeps/x86_64/fpu/multiarch/svml_s_sincosf16_core_avx512.S
> @@ -310,7 +310,7 @@ ENTRY (_ZGVeN16vl4l4_sincosf_skx)
>
> /* Result sign calculations */
> vpternlogd $150, %zmm0, %zmm14, %zmm1
> - vmovups .L_2il0floatpacket.13(%rip), %zmm14
> + vpternlogd $0xff, %zmm14, %zmm14, %zmm14
>
> /* Add correction term 0.5 for cos() part */
> vaddps %zmm8, %zmm5, %zmm15
> @@ -740,8 +740,3 @@ END (_ZGVeN16vvv_sincosf_knl)
> ENTRY (_ZGVeN16vvv_sincosf_skx)
> WRAPPER_AVX512_vvv_vl4l4 _ZGVeN16vl4l4_sincosf_skx
> END (_ZGVeN16vvv_sincosf_skx)
> -
> - .section .rodata, "a"
> -.L_2il0floatpacket.13:
> - .long
> 0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff
> - .type .L_2il0floatpacket.13,@object
> diff --git a/sysdeps/x86_64/fpu/multiarch/svml_s_sinf16_core_avx512.S
> b/sysdeps/x86_64/fpu/multiarch/svml_s_sinf16_core_avx512.S
> index ec65ffdce5..bcb76ff756 100644
> --- a/sysdeps/x86_64/fpu/multiarch/svml_s_sinf16_core_avx512.S
> +++ b/sysdeps/x86_64/fpu/multiarch/svml_s_sinf16_core_avx512.S
> @@ -273,7 +273,7 @@ ENTRY (_ZGVeN16v_sinf_skx)
> movq __svml_s_trig_data@GOTPCREL(%rip), %rax
>
> /* Check for large and special values */
> - vmovups .L_2il0floatpacket.11(%rip), %zmm14
> + vpternlogd $0xff, %zmm14, %zmm14, %zmm14
>
Also below:
vpandnd %zmm2, %zmm2, %zmm14{%k1}
> vmovups __sAbsMask(%rax), %zmm5
> vmovups __sInvPI(%rax), %zmm1
> vmovups __sRShifter(%rax), %zmm2
> @@ -464,8 +464,3 @@ ENTRY (_ZGVeN16v_sinf_skx)
> vmovss %xmm0, 1216(%rsp,%r15,8)
> jmp .LBL_2_7
> END (_ZGVeN16v_sinf_skx)
> -
> - .section .rodata, "a"
> -.L_2il0floatpacket.11:
> - .long
> 0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff
> - .type .L_2il0floatpacket.11,@object
> --
> 2.31.1
>
>
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