diff options
Diffstat (limited to 'sysdeps/x86_64/multiarch/strncat-evex.S')
| -rw-r--r-- | sysdeps/x86_64/multiarch/strncat-evex.S | 525 |
1 files changed, 519 insertions, 6 deletions
diff --git a/sysdeps/x86_64/multiarch/strncat-evex.S b/sysdeps/x86_64/multiarch/strncat-evex.S index 203a19b..bced4e8 100644 --- a/sysdeps/x86_64/multiarch/strncat-evex.S +++ b/sysdeps/x86_64/multiarch/strncat-evex.S @@ -1,7 +1,520 @@ -#ifndef STRNCAT -# define STRNCAT __strncat_evex -#endif +/* {wcs|str}ncat with 256/512-bit EVEX. + Copyright (C) 2022 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) + + /* Use evex-masked stores for small sizes. Turned off at the + moment. */ +# define USE_EVEX_MASKED_STORE 0 + +# include <sysdep.h> + +# ifndef VEC_SIZE +# include "x86-evex256-vecs.h" +# endif + +# ifndef STRNCAT +# define STRNCAT __strncat_evex +# endif + + +# ifdef USE_AS_WCSCPY +# define MOVCHAR movl +# define VMOVU_MASK vmovdqu32 +# define VPMIN vpminud +# define VPTESTN vptestnmd +# define VPTEST vptestmd +# define VPCMPEQ vpcmpeqd +# define CHAR_SIZE 4 + +# define REP_MOVS rep movsd + +# define VMASK_REG VR10 +# define FIND_FIRST_ONE(src, dst) movl $CHAR_PER_VEC, %dst; bsf %src, %dst + +# define USE_WIDE_CHAR +# else +# define MOVCHAR movb +# define VMOVU_MASK vmovdqu8 +# define VPMIN vpminub +# define VPTESTN vptestnmb +# define VPTEST vptestmb +# define VPCMPEQ vpcmpeqb +# define CHAR_SIZE 1 + +# define REP_MOVS rep movsb + +# define VMASK_REG VRCX +# define FIND_FIRST_ONE(src, dst) tzcnt %src, %dst + +# endif + +# include "strncpy-or-cat-overflow-def.h" + +# include "reg-macros.h" + + +# define VZERO VMM(7) +# define VZERO_128 VMM_128(7) + +# define PAGE_SIZE 4096 +# define CHAR_PER_VEC (VEC_SIZE / CHAR_SIZE) + + .section SECTION(.text), "ax", @progbits +ENTRY(STRNCAT) + movq %rdi, %rax + + /* NB: It's safe to filter out zero-length strings WITHOUT + setting null-term. Destination MUST be a null-terminated + string so essentially the work is already done. */ +# ifdef USE_AS_WCSCPY + leaq -1(%rdx), %rcx + shrq $56, %rcx + jnz L(zero_len) +# else + test %rdx, %rdx + jle L(zero_len) +# endif + +# include "strcat-strlen-evex.h.S" + + movl %esi, %ecx + andl $(PAGE_SIZE - 1), %ecx + cmpl $(PAGE_SIZE - VEC_SIZE), %ecx + ja L(page_cross) +L(page_cross_continue): + VMOVU (%rsi), %VMM(0) + VPTESTN %VMM(0), %VMM(0), %k0 + + /* If USE_EVEX_MASK_STORE is enabled then we just handle length + <= CHAR_PER_VEC with masked instructions (which have + potential for dramatically bad perf if dst splits a page and + is not in the TLB). */ +# if USE_EVEX_MASKED_STORE + KMOV %k0, %VRCX + FIND_FIRST_ONE (VRCX, VR8) + cmpq %r8, %rdx + jbe L(less_1x_vec) + + test %VRCX, %VRCX + jz L(more_1x_vec) + + blsmsk %VRCX, %VRCX + KMOV %VRCX, %k1 + VMOVU_MASK %VMM(0), (%rdi){%k1} + ret + +L(less_1x_vec): + mov $-1, %VRCX + bzhi %VRDX, %VRCX, %VRCX + KMOV %VRCX, %k1 + MOVCHAR $0, (%rdi, %rdx, CHAR_SIZE) + VMOVU_MASK %VMM(0), (%rdi){%k1} + + ret +# else + KMOV %k0, %VMASK_REG + /* tzcnt for strncat and `movl $CHAR_PER_VEC, %VRCX; bsf + %VMASK_REG, %VRCX` for wcsncat. */ + FIND_FIRST_ONE (VMASK_REG, VRCX) + cmpq %rcx, %rdx + jbe L(less_1x_vec) + + /* If there were no zero-CHARs (rcx was zero before + FIND_FIRST_ONE), then ecx will be $CHAR_PER_VEC. */ + cmpl $CHAR_PER_VEC, %ecx + je L(more_1x_vec) + + movl %ecx, %edx + +L(less_1x_vec): +# if VEC_SIZE == 64 + cmpl $(32 / CHAR_SIZE), %edx + jae L(copy_32_63) +# endif + + cmpl $(16 / CHAR_SIZE), %edx + jae L(copy_16_31) + + + cmpl $(8 / CHAR_SIZE), %edx + jae L(copy_8_15) + +# ifdef USE_AS_WCSCPY + vmovd %VMM_128(0), (%rdi) + MOVCHAR $0, (%rdi, %rdx, CHAR_SIZE) + ret +# else + + cmpl $4, %edx + jae L(copy_4_7) + + movzbl (%rsi), %ecx + cmpl $1, %edx + jbe L(set_null_term) + + movzwl 1(%rsi), %esi + movw %si, 1(%rdi) + + .p2align 4,, 1 +L(set_null_term): + movb %cl, (%rdi) + MOVCHAR $0, (%rdi, %rdx) + ret +# endif + +# if VEC_SIZE == 64 + .p2align 4,, 6 +L(copy_32_63): + VMOVU -(32)(%rsi, %rdx, CHAR_SIZE), %VMM_256(1) + VMOVU %VMM_256(0), (%rdi) + VMOVU %VMM_256(1), -(32)(%rdi, %rdx, CHAR_SIZE) + MOVCHAR $0, (%rdi, %rdx, CHAR_SIZE) + ret +# endif + .p2align 4,, 6 +L(copy_16_31): + /* Use xmm1 explicitly here as it won't require a `vzeroupper` + and will save code size. */ + vmovdqu -(16)(%rsi, %rdx, CHAR_SIZE), %xmm1 + VMOVU %VMM_128(0), (%rdi) + vmovdqu %xmm1, -(16)(%rdi, %rdx, CHAR_SIZE) + MOVCHAR $0, (%rdi, %rdx, CHAR_SIZE) + ret + + .p2align 4,, 2 +L(copy_8_15): + movq -(8)(%rsi, %rdx, CHAR_SIZE), %rcx + vmovq %VMM_128(0), (%rdi) + movq %rcx, -(8)(%rdi, %rdx, CHAR_SIZE) + MOVCHAR $0, (%rdi, %rdx, CHAR_SIZE) + ret + +# ifndef USE_AS_WCSCPY + .p2align 4,, 12 +L(copy_4_7): + movl -(4)(%rsi, %rdx, CHAR_SIZE), %ecx + vmovd %VMM_128(0), (%rdi) + movl %ecx, -(4)(%rdi, %rdx, CHAR_SIZE) + MOVCHAR $0, (%rdi, %rdx, CHAR_SIZE) + ret +# endif + +# endif + .p2align 4,, 4 +L(zero_len): +# ifdef USE_AS_WCSCPY + test %rdx, %rdx +# endif + jne OVERFLOW_STRCAT + ret -#define USE_AS_STRNCAT -#define STRCAT STRNCAT -#include "strcat-evex.S" + .p2align 4,, 8 +L(more_1x_vec): + VMOVU %VMM(0), (%rdi) + + /* We are going to align rsi here so will need to be able to re- + adjust rdi/rdx afterwords. NB: We filtered out huge lengths + so rsi + rdx * CHAR_SIZE cannot overflow. */ + + leaq (VEC_SIZE * -1)(%rsi, %rdx, CHAR_SIZE), %rdx + subq %rsi, %rdi + andq $-(VEC_SIZE), %rsi +L(loop_last_4x_vec): + addq %rsi, %rdi + subq %rsi, %rdx +# ifdef USE_AS_WCSCPY + shrq $2, %rdx +# endif + + /* Will need this regardless. */ + VMOVA (VEC_SIZE * 1)(%rsi), %VMM(1) + VPTESTN %VMM(1), %VMM(1), %k0 + KMOV %k0, %VMASK_REG + + cmpq $(CHAR_PER_VEC * 2), %rdx + ja L(more_2x_vec) + +L(last_2x_vec): + FIND_FIRST_ONE (VMASK_REG, VRCX) + cmpl %ecx, %edx + jbe L(ret_vec_x1_len) + + /* If there were no zero-CHARs (rcx was zero before + FIND_FIRST_ONE), then ecx will be $CHAR_PER_VEC. */ + cmpl $CHAR_PER_VEC, %ecx + jne L(ret_vec_x1) + + VMOVA (VEC_SIZE * 2)(%rsi), %VMM(2) + VMOVU %VMM(1), (VEC_SIZE * 1)(%rdi) + VPTESTN %VMM(2), %VMM(2), %k0 + KMOV %k0, %VRCX + addl $-CHAR_PER_VEC, %edx + bzhi %VRDX, %VRCX, %VR8 + jz L(ret_vec_x2_len) +L(ret_vec_x2): + bsf %VRCX, %VRDX +L(ret_vec_x2_len): + VMOVU (VEC_SIZE * 2 -(VEC_SIZE))(%rsi, %rdx, CHAR_SIZE), %VMM(0) + MOVCHAR $0, (VEC_SIZE * 2)(%rdi, %rdx, CHAR_SIZE) + VMOVU %VMM(0), (VEC_SIZE * 2 -(VEC_SIZE))(%rdi, %rdx, CHAR_SIZE) + ret + + .p2align 4,, 4 +L(ret_vec_x1_len): + movl %edx, %ecx +L(ret_vec_x1): + VMOVU (VEC_SIZE -(VEC_SIZE))(%rsi, %rcx, CHAR_SIZE), %VMM(0) + MOVCHAR $0, (VEC_SIZE)(%rdi, %rcx, CHAR_SIZE) + VMOVU %VMM(0), (VEC_SIZE-(VEC_SIZE))(%rdi, %rcx, CHAR_SIZE) + VZEROUPPER_RETURN + + + .p2align 4,, 8 +L(last_4x_vec): + addl $-(CHAR_PER_VEC * 4), %edx + VMOVA (VEC_SIZE * 5)(%rsi), %VMM(1) + VPTESTN %VMM(1), %VMM(1), %k0 + KMOV %k0, %VMASK_REG + subq $-(VEC_SIZE * 4), %rsi + subq $-(VEC_SIZE * 4), %rdi + cmpl $(CHAR_PER_VEC * 2), %edx + jbe L(last_2x_vec) + .p2align 4,, 8 +L(more_2x_vec): +# ifdef USE_AS_WCSCPY + xorl %ecx, %ecx +# endif + bsf %VMASK_REG, %VRCX + jnz L(ret_vec_x1) + + VMOVA (VEC_SIZE * 2)(%rsi), %VMM(2) + VMOVU %VMM(1), (VEC_SIZE * 1)(%rdi) + VPTESTN %VMM(2), %VMM(2), %k0 + KMOV %k0, %VRCX + test %VRCX, %VRCX + jnz L(ret_vec_x2) + + VMOVA (VEC_SIZE * 3)(%rsi), %VMM(3) + VMOVU %VMM(2), (VEC_SIZE * 2)(%rdi) + VPTESTN %VMM(3), %VMM(3), %k0 + KMOV %k0, %VMASK_REG + + cmpq $(CHAR_PER_VEC * 4), %rdx + ja L(more_4x_vec) + + /* Adjust length before going to L(ret_vec_x3_len) or + L(ret_vec_x3). */ + addl $(CHAR_PER_VEC * -2), %edx + + FIND_FIRST_ONE (VMASK_REG, VRCX) + cmpl %ecx, %edx + jbe L(ret_vec_x3_len) + + /* If there were no zero-CHARs (rcx was zero before + FIND_FIRST_ONE), then ecx will be $CHAR_PER_VEC. */ + cmpl $CHAR_PER_VEC, %ecx + jne L(ret_vec_x3) + + VMOVA (VEC_SIZE * 4)(%rsi), %VMM(4) + VMOVU %VMM(3), (VEC_SIZE * 3)(%rdi) + VPTESTN %VMM(4), %VMM(4), %k0 + KMOV %k0, %VRCX + addl $-CHAR_PER_VEC, %edx + bzhi %VRDX, %VRCX, %VR8 + jz L(ret_vec_x4_len) +L(ret_vec_x4): + bsf %VRCX, %VRDX +L(ret_vec_x4_len): + VMOVU (VEC_SIZE * 4 -(VEC_SIZE))(%rsi, %rdx, CHAR_SIZE), %VMM(0) + MOVCHAR $0, (VEC_SIZE * 4)(%rdi, %rdx, CHAR_SIZE) + VMOVU %VMM(0), (VEC_SIZE * 4 -(VEC_SIZE))(%rdi, %rdx, CHAR_SIZE) + ret + + .p2align 4,, 4 +L(ret_vec_x3_len): + movl %edx, %ecx +L(ret_vec_x3): + VMOVU (VEC_SIZE * 3 -(VEC_SIZE))(%rsi, %rcx, CHAR_SIZE), %VMM(0) + MOVCHAR $0, (VEC_SIZE * 3)(%rdi, %rcx, CHAR_SIZE) + VMOVU %VMM(0), (VEC_SIZE * 3-(VEC_SIZE))(%rdi, %rcx, CHAR_SIZE) + ret + + .p2align 4,, 8 +L(more_4x_vec): +# ifdef USE_AS_WCSCPY + xorl %ecx, %ecx +# endif + bsf %VMASK_REG, %VRCX + jnz L(ret_vec_x3) + + VMOVA (VEC_SIZE * 4)(%rsi), %VMM(4) + VMOVU %VMM(3), (VEC_SIZE * 3)(%rdi) + VPTESTN %VMM(4), %VMM(4), %k0 + KMOV %k0, %VRCX + test %VRCX, %VRCX + jnz L(ret_vec_x4) + + VMOVU %VMM(4), (VEC_SIZE * 4)(%rdi) + + /* Check if we are near the end before aligning. */ + cmpq $(CHAR_PER_VEC * 8), %rdx + jbe L(last_4x_vec) + + + /* Add rsi to rdx (length) before aligning rsi. NB: Since we + filtered out huge lengths this cannot overflow. */ +# ifdef USE_AS_WCSCPY + leaq (%rsi, %rdx, CHAR_SIZE), %rdx +# else + addq %rsi, %rdx +# endif + + /* Subtract rsi from rdi before aligning (add back will have + correct rdi for aligned rsi). */ + subq %rsi, %rdi + subq $-(VEC_SIZE * 5), %rsi + andq $(VEC_SIZE * -4), %rsi + + /* Load first half of the loop before entry. */ + VMOVA (VEC_SIZE * 0 + 0)(%rsi), %VMM(0) + VMOVA (VEC_SIZE * 1 + 0)(%rsi), %VMM(1) + VMOVA (VEC_SIZE * 2 + 0)(%rsi), %VMM(2) + VMOVA (VEC_SIZE * 3 + 0)(%rsi), %VMM(3) + + VPMIN %VMM(0), %VMM(1), %VMM(4) + VPMIN %VMM(2), %VMM(3), %VMM(6) + VPTESTN %VMM(4), %VMM(4), %k2 + VPTESTN %VMM(6), %VMM(6), %k4 + + /* Offset rsi by VEC_SIZE so that we can jump to + L(loop_last_4x_vec). */ + addq $-(VEC_SIZE), %rsi + KORTEST %k2, %k4 + jnz L(loop_4x_done) + + /* Store loop end in r9. */ + leaq -(VEC_SIZE * 5)(%rdx), %r9 + + .p2align 4,, 11 +L(loop_4x_vec): + VMOVU %VMM(0), (VEC_SIZE * 1 + 0)(%rdi, %rsi) + VMOVU %VMM(1), (VEC_SIZE * 2 + 0)(%rdi, %rsi) + VMOVU %VMM(2), (VEC_SIZE * 3 + 0)(%rdi, %rsi) + VMOVU %VMM(3), (VEC_SIZE * 4 + 0)(%rdi, %rsi) + + subq $(VEC_SIZE * -4), %rsi + cmpq %rsi, %r9 + jbe L(loop_last_4x_vec) + + VMOVA (VEC_SIZE * 1 + 0)(%rsi), %VMM(0) + VMOVA (VEC_SIZE * 2 + 0)(%rsi), %VMM(1) + VMOVA (VEC_SIZE * 3 + 0)(%rsi), %VMM(2) + VMOVA (VEC_SIZE * 4 + 0)(%rsi), %VMM(3) + + VPMIN %VMM(0), %VMM(1), %VMM(4) + VPMIN %VMM(2), %VMM(3), %VMM(6) + VPTESTN %VMM(4), %VMM(4), %k2 + VPTESTN %VMM(6), %VMM(6), %k4 + KORTEST %k2, %k4 + jz L(loop_4x_vec) + +L(loop_4x_done): + VPTESTN %VMM(0), %VMM(0), %k0 + KMOV %k0, %VRCX + /* Restore rdi (dst). */ + addq %rsi, %rdi + + /* L(ret_vec_x1) expects rcx to have position of zero-CHAR so + test with bsf. */ + bsf %VRCX, %VRCX + jnz L(ret_vec_x1) + VMOVU %VMM(0), (VEC_SIZE * 1 + 0)(%rdi) + + KMOV %k2, %VRCX + test %VRCX, %VRCX + jnz L(ret_vec_x2) + VMOVU %VMM(1), (VEC_SIZE * 2 + 0)(%rdi) + + VPTESTN %VMM(2), %VMM(2), %k0 + KMOV %k0, %VRCX + bsf %VRCX, %VRCX + jnz L(ret_vec_x3) + VMOVU %VMM(2), (VEC_SIZE * 3 + 0)(%rdi) + + KMOV %k4, %VRCX + bsf %VRCX, %VRCX + VMOVU ((VEC_SIZE * 4)-(VEC_SIZE - CHAR_SIZE))(%rsi, %rcx, CHAR_SIZE), %VMM(0) + VMOVU %VMM(0), ((VEC_SIZE * 4 + 0)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rcx, CHAR_SIZE) + ret + + + .p2align 4,, 4 +L(page_cross): + movq %rsi, %r8 + andq $(VEC_SIZE * -1), %r8 + VPCMPEQ (%r8), %VZERO, %k0 + +# ifdef USE_AS_WCSCPY + KMOV %k0, %VR9 + shrl $2, %ecx + andl $(CHAR_PER_VEC - 1), %ecx + shrx %VRCX, %VR9, %VRCX +# else + KMOV %k0, %VRCX + shrx %VRSI, %VRCX, %VRCX +# endif + + subl %esi, %r8d + andl $(VEC_SIZE - 1), %r8d +# ifdef USE_AS_WCSCPY + shrl $2, %r8d +# endif + cmpq %r8, %rdx + jbe L(page_cross_small) + /* Optimizing more for space as this is very cold code. This + saves 2x cache lines. */ + + /* This adds once to the later result which will get correct + copy bounds. NB: this can never zero-out a non-zero RCX as + to be in the page cross case rsi cannot be aligned and we + already right-shift rcx by the misalignment. */ + shl %VRCX + jz L(page_cross_continue) + bsf %VRCX, %VRCX + REP_MOVS + ret + +L(page_cross_small): + tzcnt %VRCX, %VRCX + jz L(page_cross_setz) + cmpl %edx, %ecx + cmova %edx, %ecx + +# ifdef USE_AS_WCSCPY + rep movsd +# else + rep movsb +# endif +L(page_cross_setz): + MOVCHAR $0, (%rdi) + ret +END(STRNCAT) +#endif |