From: "H.J. Lu" <hjl.tools@gmail.com>
To: Noah Goldstein <goldstein.w.n@gmail.com>
Cc: libc-alpha@sourceware.org, carlos@systemhalted.org
Subject: Re: x86: Prepare `strrchr-evex` and `strrchr-evex512` for AVX10
Date: Thu, 21 Sep 2023 08:16:24 -0700 [thread overview]
Message-ID: <CAMe9rOoQyQfj8ifi0jeVEaYgcoJ8KY8O8d25sJxTeW+mU2mRCA@mail.gmail.com> (raw)
In-Reply-To: <CAFUsyfJEqx4Zd+A94aXG8-R8CtLMr8pNCEf+0K6hosogx=CdFg@mail.gmail.com>
On Thu, Sep 21, 2023 at 7:39 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
>
> On Thu, Sep 21, 2023 at 9:38 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
> >
> > This commit refactors `strrchr-evex` and `strrchr-evex512` to use a
> > common implementation: `strrchr-evex-base.S`.
> >
> > The motivation is `strrchr-evex` needed to be refactored to not use
> > 64-bit masked registers in preperation for AVX10.
> >
> > Once vec-width masked register combining was removed, the EVEX and
> > EVEX512 implementations can easily be implemented in the same file
> > without any major overhead.
> >
> > The net result is performance improvements (measured on TGL) for both
> > `strrchr-evex` and `strrchr-evex512`. Although, note there are some
> > regressions in the test suite and it may be many of the cases that
> > make the total-geomean of improvement/regression across bench-strrchr
> > are cold. The point of the performance measurement is to show there
> > are no major regressions, but the primary motivation is preperation
> > for AVX10.
> >
> > Benchmarks where taken on TGL:
> > https://www.intel.com/content/www/us/en/products/sku/213799/intel-core-i711850h-processor-24m-cache-up-to-4-80-ghz/specifications.html
> >
> > EVEX geometric_mean(N=5) of all benchmarks New / Original : 0.74
> > EVEX512 geometric_mean(N=5) of all benchmarks New / Original: 0.87
> Full summary of attached here.
The results look good to me. I believe that this is the only 256-bit
EVEX function
with 64-bit mask instructions.
> >
> > Full check passes on x86.
> > ---
> > sysdeps/x86_64/multiarch/strrchr-evex-base.S | 466 ++++++++++++-------
> > sysdeps/x86_64/multiarch/strrchr-evex.S | 392 +---------------
> > sysdeps/x86_64/multiarch/wcsrchr-evex.S | 1 +
> > 3 files changed, 294 insertions(+), 565 deletions(-)
> >
> > diff --git a/sysdeps/x86_64/multiarch/strrchr-evex-base.S b/sysdeps/x86_64/multiarch/strrchr-evex-base.S
> > index 58b2853ab6..2c98f07fca 100644
> > --- a/sysdeps/x86_64/multiarch/strrchr-evex-base.S
> > +++ b/sysdeps/x86_64/multiarch/strrchr-evex-base.S
> > @@ -25,240 +25,354 @@
> > # include <sysdep.h>
> >
> > # ifdef USE_AS_WCSRCHR
> > +# if VEC_SIZE == 64
> > +# define RCX_M cx
> > +# define kortestM kortestw
> > +# else
> > +# define RCX_M cl
> > +# define kortestM kortestb
> > +# endif
> > +
> > +# define SHIFT_REG VRCX
> > +# define VPCOMPRESS vpcompressd
> > # define CHAR_SIZE 4
> > -# define VPBROADCAST vpbroadcastd
> > -# define VPCMPEQ vpcmpeqd
> > -# define VPMINU vpminud
> > +# define VPMIN vpminud
> > # define VPTESTN vptestnmd
> > +# define VPTEST vptestmd
> > +# define VPBROADCAST vpbroadcastd
> > +# define VPCMPEQ vpcmpeqd
> > +# define VPCMP vpcmpd
> > # else
> > +# define SHIFT_REG VRDI
> > +# define VPCOMPRESS vpcompressb
> > # define CHAR_SIZE 1
> > -# define VPBROADCAST vpbroadcastb
> > -# define VPCMPEQ vpcmpeqb
> > -# define VPMINU vpminub
> > +# define VPMIN vpminub
> > # define VPTESTN vptestnmb
> > +# define VPTEST vptestmb
> > +# define VPBROADCAST vpbroadcastb
> > +# define VPCMPEQ vpcmpeqb
> > +# define VPCMP vpcmpb
> > +
> > +# define RCX_M VRCX
> > +# define kortestM KORTEST
> > # endif
> >
> > -# define PAGE_SIZE 4096
> > +# define VMATCH VMM(0)
> > # define CHAR_PER_VEC (VEC_SIZE / CHAR_SIZE)
> > +# define PAGE_SIZE 4096
> >
> > .section SECTION(.text), "ax", @progbits
> > -/* Aligning entry point to 64 byte, provides better performance for
> > - one vector length string. */
> > -ENTRY_P2ALIGN (STRRCHR, 6)
> > -
> > - /* Broadcast CHAR to VMM(0). */
> > - VPBROADCAST %esi, %VMM(0)
> > + /* Aligning entry point to 64 byte, provides better performance for
> > + one vector length string. */
> > +ENTRY_P2ALIGN(STRRCHR, 6)
> > movl %edi, %eax
> > - sall $20, %eax
> > - cmpl $((PAGE_SIZE - VEC_SIZE) << 20), %eax
> > - ja L(page_cross)
> > + /* Broadcast CHAR to VMATCH. */
> > + VPBROADCAST %esi, %VMATCH
> >
> > -L(page_cross_continue):
> > - /* Compare [w]char for null, mask bit will be set for match. */
> > - VMOVU (%rdi), %VMM(1)
> > + andl $(PAGE_SIZE - 1), %eax
> > + cmpl $(PAGE_SIZE - VEC_SIZE), %eax
> > + jg L(cross_page_boundary)
> >
> > - VPTESTN %VMM(1), %VMM(1), %k1
> > - KMOV %k1, %VRCX
> > - test %VRCX, %VRCX
> > - jz L(align_more)
> > -
> > - VPCMPEQ %VMM(1), %VMM(0), %k0
> > - KMOV %k0, %VRAX
> > - BLSMSK %VRCX, %VRCX
> > - and %VRCX, %VRAX
> > - jz L(ret)
> > -
> > - BSR %VRAX, %VRAX
> > + VMOVU (%rdi), %VMM(1)
> > + /* k0 has a 1 for each zero CHAR in YMM1. */
> > + VPTESTN %VMM(1), %VMM(1), %k0
> > + KMOV %k0, %VGPR(rsi)
> > + test %VGPR(rsi), %VGPR(rsi)
> > + jz L(aligned_more)
> > + /* fallthrough: zero CHAR in first VEC. */
> > +L(page_cross_return):
> > + /* K1 has a 1 for each search CHAR match in VEC(1). */
> > + VPCMPEQ %VMATCH, %VMM(1), %k1
> > + KMOV %k1, %VGPR(rax)
> > + /* Build mask up until first zero CHAR (used to mask of
> > + potential search CHAR matches past the end of the string). */
> > + blsmsk %VGPR(rsi), %VGPR(rsi)
> > + and %VGPR(rsi), %VGPR(rax)
> > + jz L(ret0)
> > + /* Get last match (the `and` removed any out of bounds matches). */
> > + bsr %VGPR(rax), %VGPR(rax)
> > # ifdef USE_AS_WCSRCHR
> > leaq (%rdi, %rax, CHAR_SIZE), %rax
> > # else
> > - add %rdi, %rax
> > + addq %rdi, %rax
> > # endif
> > -L(ret):
> > +L(ret0):
> > ret
> >
> > -L(vector_x2_end):
> > - VPCMPEQ %VMM(2), %VMM(0), %k2
> > - KMOV %k2, %VRAX
> > - BLSMSK %VRCX, %VRCX
> > - and %VRCX, %VRAX
> > - jz L(vector_x1_ret)
> > -
> > - BSR %VRAX, %VRAX
> > - leaq (VEC_SIZE)(%rdi, %rax, CHAR_SIZE), %rax
> > - ret
> > -
> > - /* Check the first vector at very last to look for match. */
> > -L(vector_x1_ret):
> > - VPCMPEQ %VMM(1), %VMM(0), %k2
> > - KMOV %k2, %VRAX
> > - test %VRAX, %VRAX
> > - jz L(ret)
> > -
> > - BSR %VRAX, %VRAX
> > + /* Returns for first vec x1/x2/x3 have hard coded backward
> > + search path for earlier matches. */
> > + .p2align 4,, 6
> > +L(first_vec_x1):
> > + VPCMPEQ %VMATCH, %VMM(2), %k1
> > + KMOV %k1, %VGPR(rax)
> > + blsmsk %VGPR(rcx), %VGPR(rcx)
> > + /* eax non-zero if search CHAR in range. */
> > + and %VGPR(rcx), %VGPR(rax)
> > + jnz L(first_vec_x1_return)
> > +
> > + /* fallthrough: no match in YMM2 then need to check for earlier
> > + matches (in YMM1). */
> > + .p2align 4,, 4
> > +L(first_vec_x0_test):
> > + VPCMPEQ %VMATCH, %VMM(1), %k1
> > + KMOV %k1, %VGPR(rax)
> > + test %VGPR(rax), %VGPR(rax)
> > + jz L(ret1)
> > + bsr %VGPR(rax), %VGPR(rax)
> > # ifdef USE_AS_WCSRCHR
> > leaq (%rsi, %rax, CHAR_SIZE), %rax
> > # else
> > - add %rsi, %rax
> > +
> > + addq %rsi, %rax
> > # endif
> > +L(ret1):
> > + ret
> > +
> > + .p2align 4,, 10
> > +L(first_vec_x3):
> > + VPCMPEQ %VMATCH, %VMM(4), %k1
> > + KMOV %k1, %VGPR(rax)
> > + blsmsk %VGPR(rcx), %VGPR(rcx)
> > + /* If no search CHAR match in range check YMM1/YMM2/YMM3. */
> > + and %VGPR(rcx), %VGPR(rax)
> > + jz L(first_vec_x1_or_x2)
> > + bsr %VGPR(rax), %VGPR(rax)
> > + leaq (VEC_SIZE * 3)(%rdi, %rax, CHAR_SIZE), %rax
> > + ret
> > + .p2align 4,, 4
> > +
> > +L(first_vec_x2):
> > + VPCMPEQ %VMATCH, %VMM(3), %k1
> > + KMOV %k1, %VGPR(rax)
> > + blsmsk %VGPR(rcx), %VGPR(rcx)
> > + /* Check YMM3 for last match first. If no match try YMM2/YMM1. */
> > + and %VGPR(rcx), %VGPR(rax)
> > + jz L(first_vec_x0_x1_test)
> > + bsr %VGPR(rax), %VGPR(rax)
> > + leaq (VEC_SIZE * 2)(%r8, %rax, CHAR_SIZE), %rax
> > ret
> >
> > -L(align_more):
> > - /* Zero r8 to store match result. */
> > - xorl %r8d, %r8d
> > - /* Save pointer of first vector, in case if no match found. */
> > + .p2align 4,, 6
> > +L(first_vec_x0_x1_test):
> > + VPCMPEQ %VMATCH, %VMM(2), %k1
> > + KMOV %k1, %VGPR(rax)
> > + /* Check YMM2 for last match first. If no match try YMM1. */
> > + test %VGPR(rax), %VGPR(rax)
> > + jz L(first_vec_x0_test)
> > + .p2align 4,, 4
> > +L(first_vec_x1_return):
> > + bsr %VGPR(rax), %VGPR(rax)
> > + leaq (VEC_SIZE)(%r8, %rax, CHAR_SIZE), %rax
> > + ret
> > +
> > + .p2align 4,, 12
> > +L(aligned_more):
> > +L(page_cross_continue):
> > + /* Need to keep original pointer incase VEC(1) has last match. */
> > movq %rdi, %rsi
> > - /* Align pointer to vector size. */
> > andq $-VEC_SIZE, %rdi
> > - /* Loop unroll for 2 vector loop. */
> > - VMOVA (VEC_SIZE)(%rdi), %VMM(2)
> > +
> > + VMOVU VEC_SIZE(%rdi), %VMM(2)
> > VPTESTN %VMM(2), %VMM(2), %k0
> > KMOV %k0, %VRCX
> > + movq %rdi, %r8
> > test %VRCX, %VRCX
> > - jnz L(vector_x2_end)
> > + jnz L(first_vec_x1)
> > +
> > + VMOVU (VEC_SIZE * 2)(%rdi), %VMM(3)
> > + VPTESTN %VMM(3), %VMM(3), %k0
> > + KMOV %k0, %VRCX
> > +
> > + test %VRCX, %VRCX
> > + jnz L(first_vec_x2)
> > +
> > + VMOVU (VEC_SIZE * 3)(%rdi), %VMM(4)
> > + VPTESTN %VMM(4), %VMM(4), %k0
> > + KMOV %k0, %VRCX
> > +
> > + /* Intentionally use 64-bit here. EVEX256 version needs 1-byte
> > + padding for efficient nop before loop alignment. */
> > + test %rcx, %rcx
> > + jnz L(first_vec_x3)
> >
> > - /* Save pointer of second vector, in case if no match
> > - found. */
> > - movq %rdi, %r9
> > - /* Align address to VEC_SIZE * 2 for loop. */
> > andq $-(VEC_SIZE * 2), %rdi
> > + .p2align 4
> > +L(first_aligned_loop):
> > + /* Preserve VEC(1), VEC(2), VEC(3), and VEC(4) until we can
> > + gurantee they don't store a match. */
> > + VMOVA (VEC_SIZE * 4)(%rdi), %VMM(5)
> > + VMOVA (VEC_SIZE * 5)(%rdi), %VMM(6)
> >
> > - .p2align 4,,11
> > -L(loop):
> > - /* 2 vector loop, as it provide better performance as compared
> > - to 4 vector loop. */
> > - VMOVA (VEC_SIZE * 2)(%rdi), %VMM(3)
> > - VMOVA (VEC_SIZE * 3)(%rdi), %VMM(4)
> > - VPCMPEQ %VMM(3), %VMM(0), %k1
> > - VPCMPEQ %VMM(4), %VMM(0), %k2
> > - VPMINU %VMM(3), %VMM(4), %VMM(5)
> > - VPTESTN %VMM(5), %VMM(5), %k0
> > - KOR %k1, %k2, %k3
> > - subq $-(VEC_SIZE * 2), %rdi
> > - /* If k0 and k3 zero, match and end of string not found. */
> > - KORTEST %k0, %k3
> > - jz L(loop)
> > -
> > - /* If k0 is non zero, end of string found. */
> > - KORTEST %k0, %k0
> > - jnz L(endloop)
> > -
> > - lea VEC_SIZE(%rdi), %r8
> > - /* A match found, it need to be stored in r8 before loop
> > - continue. */
> > - /* Check second vector first. */
> > - KMOV %k2, %VRDX
> > - test %VRDX, %VRDX
> > - jnz L(loop_vec_x2_match)
> > + VPCMP $4, %VMM(5), %VMATCH, %k2
> > + VPCMP $4, %VMM(6), %VMATCH, %k3{%k2}
> > +
> > + VPMIN %VMM(5), %VMM(6), %VMM(7)
> > +
> > + VPTEST %VMM(7), %VMM(7), %k1{%k3}
> > + subq $(VEC_SIZE * -2), %rdi
> > + kortestM %k1, %k1
> > + jc L(first_aligned_loop)
> >
> > + VPTESTN %VMM(7), %VMM(7), %k1
> > KMOV %k1, %VRDX
> > - /* Match is in first vector, rdi offset need to be subtracted
> > - by VEC_SIZE. */
> > - sub $VEC_SIZE, %r8
> > -
> > - /* If second vector doesn't have match, first vector must
> > - have match. */
> > -L(loop_vec_x2_match):
> > - BSR %VRDX, %VRDX
> > -# ifdef USE_AS_WCSRCHR
> > - sal $2, %rdx
> > -# endif
> > - add %rdx, %r8
> > - jmp L(loop)
> > + test %VRDX, %VRDX
> > + jz L(second_aligned_loop_prep)
> >
> > -L(endloop):
> > - /* Check if string end in first loop vector. */
> > - VPTESTN %VMM(3), %VMM(3), %k0
> > - KMOV %k0, %VRCX
> > - test %VRCX, %VRCX
> > - jnz L(loop_vector_x1_end)
> > + kortestM %k3, %k3
> > + jnc L(return_first_aligned_loop)
> >
> > - /* Check if it has match in first loop vector. */
> > - KMOV %k1, %VRAX
> > + .p2align 4,, 6
> > +L(first_vec_x1_or_x2_or_x3):
> > + VPCMPEQ %VMM(4), %VMATCH, %k4
> > + KMOV %k4, %VRAX
> > test %VRAX, %VRAX
> > - jz L(loop_vector_x2_end)
> > + jz L(first_vec_x1_or_x2)
> > + bsr %VRAX, %VRAX
> > + leaq (VEC_SIZE * 3)(%r8, %rax, CHAR_SIZE), %rax
> > + ret
> >
> > - BSR %VRAX, %VRAX
> > - leaq (%rdi, %rax, CHAR_SIZE), %r8
> >
> > - /* String must end in second loop vector. */
> > -L(loop_vector_x2_end):
> > - VPTESTN %VMM(4), %VMM(4), %k0
> > + .p2align 4,, 8
> > +L(return_first_aligned_loop):
> > + VPTESTN %VMM(5), %VMM(5), %k0
> > KMOV %k0, %VRCX
> > + blsmsk %VRCX, %VRCX
> > + jnc L(return_first_new_match_first)
> > + blsmsk %VRDX, %VRDX
> > + VPCMPEQ %VMM(6), %VMATCH, %k0
> > + KMOV %k0, %VRAX
> > + addq $VEC_SIZE, %rdi
> > + and %VRDX, %VRAX
> > + jnz L(return_first_new_match_ret)
> > + subq $VEC_SIZE, %rdi
> > +L(return_first_new_match_first):
> > KMOV %k2, %VRAX
> > - BLSMSK %VRCX, %VRCX
> > - /* Check if it has match in second loop vector. */
> > +# ifdef USE_AS_WCSRCHR
> > + xorl $((1 << CHAR_PER_VEC)- 1), %VRAX
> > and %VRCX, %VRAX
> > - jz L(check_last_match)
> > +# else
> > + andn %VRCX, %VRAX, %VRAX
> > +# endif
> > + jz L(first_vec_x1_or_x2_or_x3)
> > +L(return_first_new_match_ret):
> > + bsr %VRAX, %VRAX
> > + leaq (VEC_SIZE * 2)(%rdi, %rax, CHAR_SIZE), %rax
> > + ret
> >
> > - BSR %VRAX, %VRAX
> > - leaq (VEC_SIZE)(%rdi, %rax, CHAR_SIZE), %rax
> > + .p2align 4,, 10
> > +L(first_vec_x1_or_x2):
> > + VPCMPEQ %VMM(3), %VMATCH, %k3
> > + KMOV %k3, %VRAX
> > + test %VRAX, %VRAX
> > + jz L(first_vec_x0_x1_test)
> > + bsr %VRAX, %VRAX
> > + leaq (VEC_SIZE * 2)(%r8, %rax, CHAR_SIZE), %rax
> > ret
> >
> > - /* String end in first loop vector. */
> > -L(loop_vector_x1_end):
> > - KMOV %k1, %VRAX
> > - BLSMSK %VRCX, %VRCX
> > - /* Check if it has match in second loop vector. */
> > - and %VRCX, %VRAX
> > - jz L(check_last_match)
> >
> > - BSR %VRAX, %VRAX
> > - leaq (%rdi, %rax, CHAR_SIZE), %rax
> > - ret
> > + .p2align 4
> > + /* We can throw away the work done for the first 4x checks here
> > + as we have a later match. This is the 'fast' path persay. */
> > +L(second_aligned_loop_prep):
> > +L(second_aligned_loop_set_furthest_match):
> > + movq %rdi, %rsi
> > + VMOVA %VMM(5), %VMM(7)
> > + VMOVA %VMM(6), %VMM(8)
> > + .p2align 4
> > +L(second_aligned_loop):
> > + VMOVU (VEC_SIZE * 4)(%rdi), %VMM(5)
> > + VMOVU (VEC_SIZE * 5)(%rdi), %VMM(6)
> > + VPCMP $4, %VMM(5), %VMATCH, %k2
> > + VPCMP $4, %VMM(6), %VMATCH, %k3{%k2}
> > +
> > + VPMIN %VMM(5), %VMM(6), %VMM(4)
> > +
> > + VPTEST %VMM(4), %VMM(4), %k1{%k3}
> > + subq $(VEC_SIZE * -2), %rdi
> > + KMOV %k1, %VRCX
> > + inc %RCX_M
> > + jz L(second_aligned_loop)
> > + VPTESTN %VMM(4), %VMM(4), %k1
> > + KMOV %k1, %VRDX
> > + test %VRDX, %VRDX
> > + jz L(second_aligned_loop_set_furthest_match)
> >
> > - /* No match in first and second loop vector. */
> > -L(check_last_match):
> > - /* Check if any match recorded in r8. */
> > - test %r8, %r8
> > - jz L(vector_x2_ret)
> > - movq %r8, %rax
> > + kortestM %k3, %k3
> > + jnc L(return_new_match)
> > + /* branch here because there is a significant advantage interms
> > + of output dependency chance in using edx. */
> > +
> > +
> > +L(return_old_match):
> > + VPCMPEQ %VMM(8), %VMATCH, %k0
> > + KMOV %k0, %VRCX
> > + bsr %VRCX, %VRCX
> > + jnz L(return_old_match_ret)
> > +
> > + VPCMPEQ %VMM(7), %VMATCH, %k0
> > + KMOV %k0, %VRCX
> > + bsr %VRCX, %VRCX
> > + subq $VEC_SIZE, %rsi
> > +L(return_old_match_ret):
> > + leaq (VEC_SIZE * 3)(%rsi, %rcx, CHAR_SIZE), %rax
> > ret
> >
> > - /* No match recorded in r8. Check the second saved vector
> > - in beginning. */
> > -L(vector_x2_ret):
> > - VPCMPEQ %VMM(2), %VMM(0), %k2
> > - KMOV %k2, %VRAX
> > - test %VRAX, %VRAX
> > - jz L(vector_x1_ret)
> >
> > - /* Match found in the second saved vector. */
> > - BSR %VRAX, %VRAX
> > - leaq (VEC_SIZE)(%r9, %rax, CHAR_SIZE), %rax
> > +L(return_new_match):
> > + VPTESTN %VMM(5), %VMM(5), %k0
> > + KMOV %k0, %VRCX
> > + blsmsk %VRCX, %VRCX
> > + jnc L(return_new_match_first)
> > + dec %VRDX
> > + VPCMPEQ %VMM(6), %VMATCH, %k0
> > + KMOV %k0, %VRAX
> > + addq $VEC_SIZE, %rdi
> > + and %VRDX, %VRAX
> > + jnz L(return_new_match_ret)
> > + subq $VEC_SIZE, %rdi
> > +L(return_new_match_first):
> > + KMOV %k2, %VRAX
> > +# ifdef USE_AS_WCSRCHR
> > + xorl $((1 << CHAR_PER_VEC)- 1), %VRAX
> > + and %VRCX, %VRAX
> > +# else
> > + andn %VRCX, %VRAX, %VRAX
> > +# endif
> > + jz L(return_old_match)
> > +L(return_new_match_ret):
> > + bsr %VRAX, %VRAX
> > + leaq (VEC_SIZE * 2)(%rdi, %rax, CHAR_SIZE), %rax
> > ret
> >
> > -L(page_cross):
> > - mov %rdi, %rax
> > - movl %edi, %ecx
> > + .p2align 4,, 4
> > +L(cross_page_boundary):
> > + xorq %rdi, %rax
> > + mov $-1, %VRDX
> > + VMOVU (PAGE_SIZE - VEC_SIZE)(%rax), %VMM(6)
> > + VPTESTN %VMM(6), %VMM(6), %k0
> > + KMOV %k0, %VRSI
> >
> > # ifdef USE_AS_WCSRCHR
> > - /* Calculate number of compare result bits to be skipped for
> > - wide string alignment adjustment. */
> > - andl $(VEC_SIZE - 1), %ecx
> > - sarl $2, %ecx
> > + movl %edi, %ecx
> > + and $(VEC_SIZE - 1), %ecx
> > + shrl $2, %ecx
> > # endif
> > - /* ecx contains number of w[char] to be skipped as a result
> > - of address alignment. */
> > - andq $-VEC_SIZE, %rax
> > - VMOVA (%rax), %VMM(1)
> > - VPTESTN %VMM(1), %VMM(1), %k1
> > - KMOV %k1, %VRAX
> > - SHR %cl, %VRAX
> > - jz L(page_cross_continue)
> > - VPCMPEQ %VMM(1), %VMM(0), %k0
> > - KMOV %k0, %VRDX
> > - SHR %cl, %VRDX
> > - BLSMSK %VRAX, %VRAX
> > - and %VRDX, %VRAX
> > - jz L(ret)
> > - BSR %VRAX, %VRAX
> > + shlx %SHIFT_REG, %VRDX, %VRDX
> > +
> > # ifdef USE_AS_WCSRCHR
> > - leaq (%rdi, %rax, CHAR_SIZE), %rax
> > + kmovw %edx, %k1
> > # else
> > - add %rdi, %rax
> > + KMOV %VRDX, %k1
> > # endif
> >
> > - ret
> > -END (STRRCHR)
> > + VPCOMPRESS %VMM(6), %VMM(1){%k1}{z}
> > + /* We could technically just jmp back after the vpcompress but
> > + it doesn't save any 16-byte blocks. */
> > +
> > + shrx %SHIFT_REG, %VRSI, %VRSI
> > + test %VRSI, %VRSI
> > + jnz L(page_cross_return)
> > + jmp L(page_cross_continue)
> > + /* 1-byte from cache line. */
> > +END(STRRCHR)
> > #endif
> > diff --git a/sysdeps/x86_64/multiarch/strrchr-evex.S b/sysdeps/x86_64/multiarch/strrchr-evex.S
> > index 85e3b0119f..b606e6f69c 100644
> > --- a/sysdeps/x86_64/multiarch/strrchr-evex.S
> > +++ b/sysdeps/x86_64/multiarch/strrchr-evex.S
> > @@ -1,394 +1,8 @@
> > -/* strrchr/wcsrchr optimized with 256-bit EVEX instructions.
> > - Copyright (C) 2021-2023 Free Software Foundation, Inc.
> > - This file is part of the GNU C Library.
> > -
> > - The GNU C Library is free software; you can redistribute it and/or
> > - modify it under the terms of the GNU Lesser General Public
> > - License as published by the Free Software Foundation; either
> > - version 2.1 of the License, or (at your option) any later version.
> > -
> > - The GNU C Library is distributed in the hope that it will be useful,
> > - but WITHOUT ANY WARRANTY; without even the implied warranty of
> > - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> > - Lesser General Public License for more details.
> > -
> > - You should have received a copy of the GNU Lesser General Public
> > - License along with the GNU C Library; if not, see
> > - <https://www.gnu.org/licenses/>. */
> > -
> > -#include <isa-level.h>
> > -
> > -#if ISA_SHOULD_BUILD (4)
> > -
> > -# include <sysdep.h>
> > -
> > # ifndef STRRCHR
> > # define STRRCHR __strrchr_evex
> > # endif
> >
> > -# include "x86-evex256-vecs.h"
> > -
> > -# ifdef USE_AS_WCSRCHR
> > -# define SHIFT_REG rsi
> > -# define kunpck_2x kunpckbw
> > -# define kmov_2x kmovd
> > -# define maskz_2x ecx
> > -# define maskm_2x eax
> > -# define CHAR_SIZE 4
> > -# define VPMIN vpminud
> > -# define VPTESTN vptestnmd
> > -# define VPTEST vptestmd
> > -# define VPBROADCAST vpbroadcastd
> > -# define VPCMPEQ vpcmpeqd
> > -# define VPCMP vpcmpd
> > -
> > -# define USE_WIDE_CHAR
> > -# else
> > -# define SHIFT_REG rdi
> > -# define kunpck_2x kunpckdq
> > -# define kmov_2x kmovq
> > -# define maskz_2x rcx
> > -# define maskm_2x rax
> > -
> > -# define CHAR_SIZE 1
> > -# define VPMIN vpminub
> > -# define VPTESTN vptestnmb
> > -# define VPTEST vptestmb
> > -# define VPBROADCAST vpbroadcastb
> > -# define VPCMPEQ vpcmpeqb
> > -# define VPCMP vpcmpb
> > -# endif
> > -
> > -# include "reg-macros.h"
> > -
> > -# define VMATCH VMM(0)
> > -# define CHAR_PER_VEC (VEC_SIZE / CHAR_SIZE)
> > -# define PAGE_SIZE 4096
> > -
> > - .section SECTION(.text), "ax", @progbits
> > -ENTRY_P2ALIGN(STRRCHR, 6)
> > - movl %edi, %eax
> > - /* Broadcast CHAR to VMATCH. */
> > - VPBROADCAST %esi, %VMATCH
> > -
> > - andl $(PAGE_SIZE - 1), %eax
> > - cmpl $(PAGE_SIZE - VEC_SIZE), %eax
> > - jg L(cross_page_boundary)
> > -L(page_cross_continue):
> > - VMOVU (%rdi), %VMM(1)
> > - /* k0 has a 1 for each zero CHAR in VEC(1). */
> > - VPTESTN %VMM(1), %VMM(1), %k0
> > - KMOV %k0, %VRSI
> > - test %VRSI, %VRSI
> > - jz L(aligned_more)
> > - /* fallthrough: zero CHAR in first VEC. */
> > - /* K1 has a 1 for each search CHAR match in VEC(1). */
> > - VPCMPEQ %VMATCH, %VMM(1), %k1
> > - KMOV %k1, %VRAX
> > - /* Build mask up until first zero CHAR (used to mask of
> > - potential search CHAR matches past the end of the string).
> > - */
> > - blsmsk %VRSI, %VRSI
> > - and %VRSI, %VRAX
> > - jz L(ret0)
> > - /* Get last match (the `and` removed any out of bounds matches).
> > - */
> > - bsr %VRAX, %VRAX
> > -# ifdef USE_AS_WCSRCHR
> > - leaq (%rdi, %rax, CHAR_SIZE), %rax
> > -# else
> > - addq %rdi, %rax
> > -# endif
> > -L(ret0):
> > - ret
> > -
> > - /* Returns for first vec x1/x2/x3 have hard coded backward
> > - search path for earlier matches. */
> > - .p2align 4,, 6
> > -L(first_vec_x1):
> > - VPCMPEQ %VMATCH, %VMM(2), %k1
> > - KMOV %k1, %VRAX
> > - blsmsk %VRCX, %VRCX
> > - /* eax non-zero if search CHAR in range. */
> > - and %VRCX, %VRAX
> > - jnz L(first_vec_x1_return)
> > -
> > - /* fallthrough: no match in VEC(2) then need to check for
> > - earlier matches (in VEC(1)). */
> > - .p2align 4,, 4
> > -L(first_vec_x0_test):
> > - VPCMPEQ %VMATCH, %VMM(1), %k1
> > - KMOV %k1, %VRAX
> > - test %VRAX, %VRAX
> > - jz L(ret1)
> > - bsr %VRAX, %VRAX
> > -# ifdef USE_AS_WCSRCHR
> > - leaq (%rsi, %rax, CHAR_SIZE), %rax
> > -# else
> > - addq %rsi, %rax
> > -# endif
> > -L(ret1):
> > - ret
> > -
> > - .p2align 4,, 10
> > -L(first_vec_x1_or_x2):
> > - VPCMPEQ %VMM(3), %VMATCH, %k3
> > - VPCMPEQ %VMM(2), %VMATCH, %k2
> > - /* K2 and K3 have 1 for any search CHAR match. Test if any
> > - matches between either of them. Otherwise check VEC(1). */
> > - KORTEST %k2, %k3
> > - jz L(first_vec_x0_test)
> > -
> > - /* Guaranteed that VEC(2) and VEC(3) are within range so merge
> > - the two bitmasks then get last result. */
> > - kunpck_2x %k2, %k3, %k3
> > - kmov_2x %k3, %maskm_2x
> > - bsr %maskm_2x, %maskm_2x
> > - leaq (VEC_SIZE * 1)(%r8, %rax, CHAR_SIZE), %rax
> > - ret
> > -
> > - .p2align 4,, 7
> > -L(first_vec_x3):
> > - VPCMPEQ %VMATCH, %VMM(4), %k1
> > - KMOV %k1, %VRAX
> > - blsmsk %VRCX, %VRCX
> > - /* If no search CHAR match in range check VEC(1)/VEC(2)/VEC(3).
> > - */
> > - and %VRCX, %VRAX
> > - jz L(first_vec_x1_or_x2)
> > - bsr %VRAX, %VRAX
> > - leaq (VEC_SIZE * 3)(%rdi, %rax, CHAR_SIZE), %rax
> > - ret
> > -
> > -
> > - .p2align 4,, 6
> > -L(first_vec_x0_x1_test):
> > - VPCMPEQ %VMATCH, %VMM(2), %k1
> > - KMOV %k1, %VRAX
> > - /* Check VEC(2) for last match first. If no match try VEC(1).
> > - */
> > - test %VRAX, %VRAX
> > - jz L(first_vec_x0_test)
> > - .p2align 4,, 4
> > -L(first_vec_x1_return):
> > - bsr %VRAX, %VRAX
> > - leaq (VEC_SIZE)(%rdi, %rax, CHAR_SIZE), %rax
> > - ret
> > -
> > -
> > - .p2align 4,, 10
> > -L(first_vec_x2):
> > - VPCMPEQ %VMATCH, %VMM(3), %k1
> > - KMOV %k1, %VRAX
> > - blsmsk %VRCX, %VRCX
> > - /* Check VEC(3) for last match first. If no match try
> > - VEC(2)/VEC(1). */
> > - and %VRCX, %VRAX
> > - jz L(first_vec_x0_x1_test)
> > - bsr %VRAX, %VRAX
> > - leaq (VEC_SIZE * 2)(%rdi, %rax, CHAR_SIZE), %rax
> > - ret
> > -
> > -
> > - .p2align 4,, 12
> > -L(aligned_more):
> > - /* Need to keep original pointer in case VEC(1) has last match.
> > - */
> > - movq %rdi, %rsi
> > - andq $-VEC_SIZE, %rdi
> > -
> > - VMOVU VEC_SIZE(%rdi), %VMM(2)
> > - VPTESTN %VMM(2), %VMM(2), %k0
> > - KMOV %k0, %VRCX
> > -
> > - test %VRCX, %VRCX
> > - jnz L(first_vec_x1)
> > -
> > - VMOVU (VEC_SIZE * 2)(%rdi), %VMM(3)
> > - VPTESTN %VMM(3), %VMM(3), %k0
> > - KMOV %k0, %VRCX
> > -
> > - test %VRCX, %VRCX
> > - jnz L(first_vec_x2)
> > -
> > - VMOVU (VEC_SIZE * 3)(%rdi), %VMM(4)
> > - VPTESTN %VMM(4), %VMM(4), %k0
> > - KMOV %k0, %VRCX
> > - movq %rdi, %r8
> > - test %VRCX, %VRCX
> > - jnz L(first_vec_x3)
> > -
> > - andq $-(VEC_SIZE * 2), %rdi
> > - .p2align 4,, 10
> > -L(first_aligned_loop):
> > - /* Preserve VEC(1), VEC(2), VEC(3), and VEC(4) until we can
> > - guarantee they don't store a match. */
> > - VMOVA (VEC_SIZE * 4)(%rdi), %VMM(5)
> > - VMOVA (VEC_SIZE * 5)(%rdi), %VMM(6)
> > -
> > - VPCMPEQ %VMM(5), %VMATCH, %k2
> > - vpxord %VMM(6), %VMATCH, %VMM(7)
> > -
> > - VPMIN %VMM(5), %VMM(6), %VMM(8)
> > - VPMIN %VMM(8), %VMM(7), %VMM(7)
> > -
> > - VPTESTN %VMM(7), %VMM(7), %k1
> > - subq $(VEC_SIZE * -2), %rdi
> > - KORTEST %k1, %k2
> > - jz L(first_aligned_loop)
> > -
> > - VPCMPEQ %VMM(6), %VMATCH, %k3
> > - VPTESTN %VMM(8), %VMM(8), %k1
> > -
> > - /* If k1 is zero, then we found a CHAR match but no null-term.
> > - We can now safely throw out VEC1-4. */
> > - KTEST %k1, %k1
> > - jz L(second_aligned_loop_prep)
> > -
> > - KORTEST %k2, %k3
> > - jnz L(return_first_aligned_loop)
> > -
> > -
> > - .p2align 4,, 6
> > -L(first_vec_x1_or_x2_or_x3):
> > - VPCMPEQ %VMM(4), %VMATCH, %k4
> > - KMOV %k4, %VRAX
> > - bsr %VRAX, %VRAX
> > - jz L(first_vec_x1_or_x2)
> > - leaq (VEC_SIZE * 3)(%r8, %rax, CHAR_SIZE), %rax
> > - ret
> > -
> > -
> > - .p2align 4,, 8
> > -L(return_first_aligned_loop):
> > - VPTESTN %VMM(5), %VMM(5), %k0
> > -
> > - /* Combined results from VEC5/6. */
> > - kunpck_2x %k0, %k1, %k0
> > - kmov_2x %k0, %maskz_2x
> > -
> > - blsmsk %maskz_2x, %maskz_2x
> > - kunpck_2x %k2, %k3, %k3
> > - kmov_2x %k3, %maskm_2x
> > - and %maskz_2x, %maskm_2x
> > - jz L(first_vec_x1_or_x2_or_x3)
> > -
> > - bsr %maskm_2x, %maskm_2x
> > - leaq (VEC_SIZE * 2)(%rdi, %rax, CHAR_SIZE), %rax
> > - ret
> > -
> > - .p2align 4
> > - /* We can throw away the work done for the first 4x checks here
> > - as we have a later match. This is the 'fast' path persay.
> > - */
> > -L(second_aligned_loop_prep):
> > -L(second_aligned_loop_set_furthest_match):
> > - movq %rdi, %rsi
> > - /* Ideally we would safe k2/k3 but `kmov/kunpck` take uops on
> > - port0 and have noticeable overhead in the loop. */
> > - VMOVA %VMM(5), %VMM(7)
> > - VMOVA %VMM(6), %VMM(8)
> > - .p2align 4
> > -L(second_aligned_loop):
> > - VMOVU (VEC_SIZE * 4)(%rdi), %VMM(5)
> > - VMOVU (VEC_SIZE * 5)(%rdi), %VMM(6)
> > - VPCMPEQ %VMM(5), %VMATCH, %k2
> > - vpxord %VMM(6), %VMATCH, %VMM(3)
> > -
> > - VPMIN %VMM(5), %VMM(6), %VMM(4)
> > - VPMIN %VMM(3), %VMM(4), %VMM(3)
> > -
> > - VPTESTN %VMM(3), %VMM(3), %k1
> > - subq $(VEC_SIZE * -2), %rdi
> > - KORTEST %k1, %k2
> > - jz L(second_aligned_loop)
> > - VPCMPEQ %VMM(6), %VMATCH, %k3
> > - VPTESTN %VMM(4), %VMM(4), %k1
> > - KTEST %k1, %k1
> > - jz L(second_aligned_loop_set_furthest_match)
> > -
> > - /* branch here because we know we have a match in VEC7/8 but
> > - might not in VEC5/6 so the latter is expected to be less
> > - likely. */
> > - KORTEST %k2, %k3
> > - jnz L(return_new_match)
> > -
> > -L(return_old_match):
> > - VPCMPEQ %VMM(8), %VMATCH, %k0
> > - KMOV %k0, %VRCX
> > - bsr %VRCX, %VRCX
> > - jnz L(return_old_match_ret)
> > -
> > - VPCMPEQ %VMM(7), %VMATCH, %k0
> > - KMOV %k0, %VRCX
> > - bsr %VRCX, %VRCX
> > - subq $VEC_SIZE, %rsi
> > -L(return_old_match_ret):
> > - leaq (VEC_SIZE * 3)(%rsi, %rcx, CHAR_SIZE), %rax
> > - ret
> > -
> > - .p2align 4,, 10
> > -L(return_new_match):
> > - VPTESTN %VMM(5), %VMM(5), %k0
> > -
> > - /* Combined results from VEC5/6. */
> > - kunpck_2x %k0, %k1, %k0
> > - kmov_2x %k0, %maskz_2x
> > -
> > - blsmsk %maskz_2x, %maskz_2x
> > - kunpck_2x %k2, %k3, %k3
> > - kmov_2x %k3, %maskm_2x
> > -
> > - /* Match at end was out-of-bounds so use last known match. */
> > - and %maskz_2x, %maskm_2x
> > - jz L(return_old_match)
> > -
> > - bsr %maskm_2x, %maskm_2x
> > - leaq (VEC_SIZE * 2)(%rdi, %rax, CHAR_SIZE), %rax
> > - ret
> > -
> > -L(cross_page_boundary):
> > - /* eax contains all the page offset bits of src (rdi). `xor rdi,
> > - rax` sets pointer will all page offset bits cleared so
> > - offset of (PAGE_SIZE - VEC_SIZE) will get last aligned VEC
> > - before page cross (guaranteed to be safe to read). Doing this
> > - as opposed to `movq %rdi, %rax; andq $-VEC_SIZE, %rax` saves
> > - a bit of code size. */
> > - xorq %rdi, %rax
> > - VMOVU (PAGE_SIZE - VEC_SIZE)(%rax), %VMM(1)
> > - VPTESTN %VMM(1), %VMM(1), %k0
> > - KMOV %k0, %VRCX
> > -
> > - /* Shift out zero CHAR matches that are before the beginning of
> > - src (rdi). */
> > -# ifdef USE_AS_WCSRCHR
> > - movl %edi, %esi
> > - andl $(VEC_SIZE - 1), %esi
> > - shrl $2, %esi
> > -# endif
> > - shrx %VGPR(SHIFT_REG), %VRCX, %VRCX
> > -
> > - test %VRCX, %VRCX
> > - jz L(page_cross_continue)
> > +#include "x86-evex512-vecs.h"
> > +#include "reg-macros.h"
> >
> > - /* Found zero CHAR so need to test for search CHAR. */
> > - VPCMP $0, %VMATCH, %VMM(1), %k1
> > - KMOV %k1, %VRAX
> > - /* Shift out search CHAR matches that are before the beginning of
> > - src (rdi). */
> > - shrx %VGPR(SHIFT_REG), %VRAX, %VRAX
> > -
> > - /* Check if any search CHAR match in range. */
> > - blsmsk %VRCX, %VRCX
> > - and %VRCX, %VRAX
> > - jz L(ret3)
> > - bsr %VRAX, %VRAX
> > -# ifdef USE_AS_WCSRCHR
> > - leaq (%rdi, %rax, CHAR_SIZE), %rax
> > -# else
> > - addq %rdi, %rax
> > -# endif
> > -L(ret3):
> > - ret
> > -END(STRRCHR)
> > -#endif
> > +#include "strrchr-evex-base.S"
> > diff --git a/sysdeps/x86_64/multiarch/wcsrchr-evex.S b/sysdeps/x86_64/multiarch/wcsrchr-evex.S
> > index e5c5fe3bf2..a584cd3f43 100644
> > --- a/sysdeps/x86_64/multiarch/wcsrchr-evex.S
> > +++ b/sysdeps/x86_64/multiarch/wcsrchr-evex.S
> > @@ -4,4 +4,5 @@
> >
> > #define STRRCHR WCSRCHR
> > #define USE_AS_WCSRCHR 1
> > +#define USE_WIDE_CHAR 1
> > #include "strrchr-evex.S"
> > --
> > 2.34.1
> >
--
H.J.
next prev parent reply other threads:[~2023-09-21 15:17 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-21 14:38 Noah Goldstein
2023-09-21 14:39 ` Noah Goldstein
2023-09-21 15:16 ` H.J. Lu [this message]
2023-09-21 19:19 ` Noah Goldstein
2023-10-04 18:48 ` Noah Goldstein
2023-10-04 19:00 ` Sunil Pandey
2023-10-18 9:18 ` Florian Weimer
2023-11-01 21:04 ` Florian Weimer
2023-11-01 21:11 ` Noah Goldstein
2023-11-01 21:22 ` Noah Goldstein
2023-11-01 22:17 ` Noah Goldstein
2023-11-02 6:44 ` Florian Weimer
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