From: "H.J. Lu" <hjl.tools@gmail.com>
To: Noah Goldstein <goldstein.w.n@gmail.com>
Cc: GNU C Library <libc-alpha@sourceware.org>
Subject: Re: [PATCH] x86-64: Optimize load of all bits set into ZMM register [BZ #28252]
Date: Sat, 21 Aug 2021 11:08:50 -0700 [thread overview]
Message-ID: <CAMe9rOohOarCLkDAg=ve-DuzEoj=kSnw+ooO+3vz02oDRQhwyw@mail.gmail.com> (raw)
In-Reply-To: <CAFUsyfLJJnffSFUSDs8OwesMrAB0W-Wi56=34t_6+_cLG6o6jw@mail.gmail.com>
On Sat, Aug 21, 2021 at 10:49 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
>
>
>
> 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
The SVM codes can use some improvements. Can you
open a separate glibc bug? I'd like to address only all 1s
load here to avoid more complexity.
Thanks.
>> 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
>>
--
H.J.
next prev parent reply other threads:[~2021-08-21 18:09 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-21 16:36 H.J. Lu
2021-08-21 17:49 ` Noah Goldstein
2021-08-21 18:08 ` H.J. Lu [this message]
2021-08-21 23:30 ` Noah Goldstein
2022-04-22 21:39 ` Sunil Pandey
2022-04-22 21:42 ` Noah Goldstein
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