diff options
Diffstat (limited to 'sysdeps/x86_64/multiarch/strncpy-evex.S')
| -rw-r--r-- | sysdeps/x86_64/multiarch/strncpy-evex.S | 995 |
1 files changed, 989 insertions, 6 deletions
diff --git a/sysdeps/x86_64/multiarch/strncpy-evex.S b/sysdeps/x86_64/multiarch/strncpy-evex.S index 1b3426d511..49eaf4cbd9 100644 --- a/sysdeps/x86_64/multiarch/strncpy-evex.S +++ b/sysdeps/x86_64/multiarch/strncpy-evex.S @@ -1,7 +1,990 @@ -#ifndef STRNCPY -# define STRNCPY __strncpy_evex -#endif +/* {wcs|wcp|str|stp}ncpy with 256/512-bit EVEX instructions. + 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 STRNCPY +# define STRNCPY __strncpy_evex +# endif + +# ifdef USE_AS_WCSCPY +# define VMOVU_MASK vmovdqu32 +# define VPCMPEQ vpcmpeqd +# define VPMIN vpminud +# define VPTESTN vptestnmd +# define VPTEST vptestmd +# define CHAR_SIZE 4 + +# define REP_MOVS rep movsd +# define REP_STOS rep stosl + +# define USE_WIDE_CHAR + +# else +# define VMOVU_MASK vmovdqu8 +# define VPCMPEQ vpcmpeqb +# define VPMIN vpminub +# define VPTESTN vptestnmb +# define VPTEST vptestmb +# define CHAR_SIZE 1 + +# define REP_MOVS rep movsb +# define REP_STOS rep stosb +# endif + +# include "strncpy-or-cat-overflow-def.h" + +# define PAGE_SIZE 4096 +# define CHAR_PER_VEC (VEC_SIZE / CHAR_SIZE) + +# include "reg-macros.h" + + +# define VZERO VMM(7) +# define VZERO_256 VMM_256(7) +# define VZERO_128 VMM_128(7) + +# if VEC_SIZE == 64 +# define VZERO_HALF VZERO_256 +# else +# define VZERO_HALF VZERO_128 +# endif + + .section SECTION(.text), "ax", @progbits +ENTRY(STRNCPY) + /* Filter zero length strings and very long strings. Zero + length strings just return, very long strings are handled by + just running rep stos{b|l} to zero set (which will almost + certainly segfault), if that succeeds then just calling + OVERFLOW_STRCPY (strcpy, stpcpy, wcscpy, wcpcpy). */ +# ifdef USE_AS_WCSCPY + decq %rdx + movq %rdx, %rax + /* 56 is end of max supported address space. */ + shr $56, %rax + jnz L(zero_len) +# else + decq %rdx + /* If the flag needs to become `jb` replace `dec` with `sub`. + */ + jl L(zero_len) +# endif + + vpxorq %VZERO_128, %VZERO_128, %VZERO_128 + movl %esi, %eax + andl $(PAGE_SIZE - 1), %eax + cmpl $(PAGE_SIZE - VEC_SIZE), %eax + ja L(page_cross) + +L(page_cross_continue): + VMOVU (%rsi), %VMM(0) + VPTESTN %VMM(0), %VMM(0), %k0 + KMOV %k0, %VRCX + + /* If no STPCPY just save end ahead of time. */ +# ifndef USE_AS_STPCPY + movq %rdi, %rax +# endif + + + cmpq $(CHAR_PER_VEC), %rdx + + /* 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 + /* `jae` because length rdx is now length - 1. */ + jae L(more_1x_vec) + + /* If there where multiple zero-CHAR matches in the first VEC, + VRCX will be overset but thats fine since any oversets where + at zero-positions anyways. */ + +# ifdef USE_AS_STPCPY + tzcnt %VRCX, %VRAX + cmpl %eax, %edx + cmovb %edx, %eax +# ifdef USE_AS_WCSCPY + adcl $0, %eax + leaq (%rdi, %rax, CHAR_SIZE), %rax +# else + adcq %rdi, %rax +# endif +# endif + dec %VRCX + + /* Zero out all non-zero CHAR's after the first zero match. */ + KMOV %VRCX, %k1 + + /* Use VZERO as destination so this can be reused for + L(zfill_less_vec) (which if jumped to by subsequent logic + will have zerod out VZERO. */ + VMOVU_MASK %VMM(0), %VZERO{%k1}{z} +L(zfill_less_vec): + /* Get mask for what we need to set. */ + incl %edx + mov $-1, %VRCX + bzhi %VRDX, %VRCX, %VRCX + KMOV %VRCX, %k1 + VMOVU_MASK %VZERO, (%rdi){%k1} + ret + + .p2align 4,, 4 +L(zero_len): + cmpq $-1, %rdx + jne L(best_effort_strncpy) + movq %rdi, %rax + ret + + .p2align 4,, 8 +L(more_1x_vec): +# else + /* `jb` because length rdx is now length - 1. */ + jb L(less_1x_vec) +# endif + + + /* This may overset but thats fine because we still need to zero + fill. */ + VMOVU %VMM(0), (%rdi) + + + /* Length must be >= CHAR_PER_VEC so match here means we must + zero-fill. */ + test %VRCX, %VRCX + jnz L(zfill) + + + /* 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 + + VMOVA (VEC_SIZE * 1)(%rsi), %VMM(1) + VPTESTN %VMM(1), %VMM(1), %k0 + KMOV %k0, %VRCX + + /* -1 because of the `dec %rdx` earlier. */ + cmpq $(CHAR_PER_VEC * 2 - 1), %rdx + ja L(more_2x_vec) + +L(last_2x_vec): + /* This will be need to be computed no matter what. We do it + ahead of time for CHAR_PER_VEC == 64 because we can't adjust + the value of `tzcnt` with a shift. */ +# if CHAR_PER_VEC == 64 + tzcntq %rcx, %rcx +# endif + + cmpl $(CHAR_PER_VEC), %edx + jb L(ret_vec_x1_len) + + /* Seperate logic for CHAR_PER_VEC == 64 because we already did + `tzcnt` on VRCX. */ +# if CHAR_PER_VEC == 64 + /* cl == CHAR_PER_VEC iff it was zero before the `tzcnt`. */ + cmpb $CHAR_PER_VEC, %cl + jnz L(ret_vec_x1_no_bsf) +# else + test %VRCX, %VRCX + jnz L(ret_vec_x1) +# endif + + + + VPCMPEQ (VEC_SIZE * 2)(%rsi), %VZERO, %k0 + VMOVU %VMM(1), (VEC_SIZE * 1)(%rdi) + KMOV %k0, %VRCX + +# if CHAR_PER_VEC < 64 + /* This essentiallys adds CHAR_PER_VEC to computed result. */ + shlq $CHAR_PER_VEC, %rcx +# else + tzcntq %rcx, %rcx + addl $CHAR_PER_VEC, %ecx +# endif + + .p2align 4,, 4 +L(ret_vec_x1_len): + /* If CHAR_PER_VEC < 64 we still need to tzcnt, otherwise it has + already been done. */ +# if CHAR_PER_VEC < 64 + tzcntq %rcx, %rcx +# endif + cmpl %ecx, %edx + jbe L(ret_vec_x1_len_no_zfill) + /* Fall through (expectation) is copy len < buffer len. */ + VMOVU %VZERO, ((VEC_SIZE)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rdx, CHAR_SIZE) +L(ret_vec_x1_len_no_zfill_mov): + movl %ecx, %edx +# ifdef USE_AS_STPCPY + /* clear flags. */ + xorl %ecx, %ecx +# endif +L(ret_vec_x1_len_no_zfill): + VMOVU ((VEC_SIZE)-(VEC_SIZE - CHAR_SIZE))(%rsi, %rdx, CHAR_SIZE), %VMM(0) + VMOVU %VMM(0), ((VEC_SIZE)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rdx, CHAR_SIZE) +# ifdef USE_AS_STPCPY +# ifdef USE_AS_WCSCPY + adcq $0, %rdx + leaq (VEC_SIZE * 1)(%rdi, %rdx, CHAR_SIZE), %rax +# else + leal (VEC_SIZE)(%rdx), %eax + adcq %rdi, %rax +# endif +# endif + ret + + + .p2align 4,, 10 +L(ret_vec_x1): + bsf %VRCX, %VRCX +L(ret_vec_x1_no_bsf): + VMOVU %VZERO, ((VEC_SIZE)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rdx, CHAR_SIZE) + subl %ecx, %edx + cmpl $CHAR_PER_VEC, %edx + jb L(ret_vec_x1_len_no_zfill_mov) + /* Fall through (expectation) is copy len < buffer len. */ + VMOVU %VMM(1), (VEC_SIZE * 1)(%rdi) + VMOVU %VZERO, (VEC_SIZE * 1)(%rdi, %rcx, CHAR_SIZE) +# ifdef USE_AS_STPCPY + leaq (VEC_SIZE * 1)(%rdi, %rcx, CHAR_SIZE), %rax +# endif + ret + + .p2align 4,, 8 +L(last_4x_vec): + /* Seperate logic for CHAR_PER_VEC == 64 because we can do `andl + $(CHAR_PER_VEC * 4 - 1), %edx` with less code size just + using `movzbl`. */ +# if CHAR_PER_VEC == 64 + movzbl %dl, %edx +# else + andl $(CHAR_PER_VEC * 4 - 1), %edx +# endif + VMOVA (VEC_SIZE * 5)(%rsi), %VMM(1) + VPTESTN %VMM(1), %VMM(1), %k0 + KMOV %k0, %VRCX + subq $-(VEC_SIZE * 4), %rsi + subq $-(VEC_SIZE * 4), %rdi + cmpl $(CHAR_PER_VEC * 2 - 1), %edx + jbe L(last_2x_vec) + .p2align 4,, 8 +L(more_2x_vec): + VMOVU %VMM(1), (VEC_SIZE * 1)(%rdi) + test %VRCX, %VRCX + /* Must fill at least 2x VEC. */ + jnz L(zfill_vec1) + + VMOVA (VEC_SIZE * 2)(%rsi), %VMM(2) + VMOVU %VMM(2), (VEC_SIZE * 2)(%rdi) + VPTESTN %VMM(2), %VMM(2), %k0 + KMOV %k0, %VRCX + test %VRCX, %VRCX + /* Must fill at least 1x VEC. */ + jnz L(zfill_vec2) + + VMOVA (VEC_SIZE * 3)(%rsi), %VMM(3) + VPTESTN %VMM(3), %VMM(3), %k0 + KMOV %k0, %VRCX + + /* Check if len is more 4x VEC. -1 because rdx is len - 1. */ + cmpq $(CHAR_PER_VEC * 4 - 1), %rdx + ja L(more_4x_vec) + + subl $(CHAR_PER_VEC * 3), %edx + jb L(ret_vec_x3_len) + + test %VRCX, %VRCX + jnz L(ret_vec_x3) + + VPCMPEQ (VEC_SIZE * 4)(%rsi), %VZERO, %k0 + VMOVU %VMM(3), (VEC_SIZE * 3)(%rdi) + KMOV %k0, %VRCX + tzcnt %VRCX, %VRCX + cmpl %ecx, %edx + jbe L(ret_vec_x4_len_no_zfill) + /* Fall through (expectation) is copy len < buffer len. */ + VMOVU %VZERO, ((VEC_SIZE * 4)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rdx, CHAR_SIZE) + movl %ecx, %edx +L(ret_vec_x4_len_no_zfill): + VMOVU ((VEC_SIZE * 4)-(VEC_SIZE - CHAR_SIZE))(%rsi, %rdx, CHAR_SIZE), %VMM(0) + VMOVU %VMM(0), ((VEC_SIZE * 4)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rdx, CHAR_SIZE) +# ifdef USE_AS_STPCPY +# ifdef USE_AS_WCSCPY + adcq $0, %rdx + leaq (VEC_SIZE * 4)(%rdi, %rdx, CHAR_SIZE), %rax +# else + leal (VEC_SIZE * 4 + 0)(%rdx), %eax + adcq %rdi, %rax +# endif +# endif + ret + + +L(ret_vec_x3_len): + addl $(CHAR_PER_VEC * 1), %edx + tzcnt %VRCX, %VRCX + cmpl %ecx, %edx + jbe L(ret_vec_x3_len_no_zfill) + /* Fall through (expectation) is copy len < buffer len. */ + VMOVU %VZERO, ((VEC_SIZE * 3)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rdx, CHAR_SIZE) +L(ret_vec_x3_len_no_zfill_mov): + movl %ecx, %edx +# ifdef USE_AS_STPCPY + /* clear flags. */ + xorl %ecx, %ecx +# endif + .p2align 4,, 4 +L(ret_vec_x3_len_no_zfill): + VMOVU ((VEC_SIZE * 3)-(VEC_SIZE - CHAR_SIZE))(%rsi, %rdx, CHAR_SIZE), %VMM(0) + VMOVU %VMM(0), ((VEC_SIZE * 3)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rdx, CHAR_SIZE) +# ifdef USE_AS_STPCPY +# ifdef USE_AS_WCSCPY + adcq $0, %rdx + leaq (VEC_SIZE * 3)(%rdi, %rdx, CHAR_SIZE), %rax +# else + leal (VEC_SIZE * 3 + 0)(%rdx), %eax + adcq %rdi, %rax +# endif +# endif + ret + + + .p2align 4,, 8 +L(ret_vec_x3): + bsf %VRCX, %VRCX + VMOVU %VZERO, (VEC_SIZE * 4 +(-(VEC_SIZE - CHAR_SIZE)))(%rdi, %rdx, CHAR_SIZE) + subl %ecx, %edx + jl L(ret_vec_x3_len_no_zfill_mov) + VMOVU %VMM(3), (VEC_SIZE * 3)(%rdi) + VMOVU %VZERO, (VEC_SIZE * 3)(%rdi, %rcx, CHAR_SIZE) +# ifdef USE_AS_STPCPY + leaq (VEC_SIZE * 3)(%rdi, %rcx, CHAR_SIZE), %rax +# endif + ret + + .p2align 4,, 8 +L(more_4x_vec): + VMOVU %VMM(3), (VEC_SIZE * 3)(%rdi) + test %VRCX, %VRCX + jnz L(zfill_vec3) + + VMOVA (VEC_SIZE * 4)(%rsi), %VMM(4) + VMOVU %VMM(4), (VEC_SIZE * 4)(%rdi) + VPTESTN %VMM(4), %VMM(4), %k0 + KMOV %k0, %VRCX + test %VRCX, %VRCX + jnz L(zfill_vec4) -#define USE_AS_STRNCPY -#define STRCPY STRNCPY -#include "strcpy-evex.S" + /* Recheck length before aligning. */ + cmpq $(CHAR_PER_VEC * 8 - 1), %rdx + jbe L(last_4x_vec) + + /* Align rsi to VEC_SIZE * 4, need to readjust rdx / rdi. */ +# ifdef USE_AS_WCSCPY + leaq (%rsi, %rdx, CHAR_SIZE), %rdx +# else + addq %rsi, %rdx +# endif + 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 - CHAR_SIZE)(%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): + /* Restore rdx (length). */ + subq %rsi, %rdx +# ifdef USE_AS_WCSCPY + shrq $2, %rdx +# endif + VMOVU %VMM(0), (VEC_SIZE * 1 + 0)(%rdi, %rsi) + /* Restore rdi (dst). */ + addq %rsi, %rdi + VPTESTN %VMM(0), %VMM(0), %k0 + KMOV %k0, %VRCX + test %VRCX, %VRCX + jnz L(zfill_vec1) + + VMOVU %VMM(1), (VEC_SIZE * 2 + 0)(%rdi) + KMOV %k2, %VRCX + test %VRCX, %VRCX + jnz L(zfill_vec2) + + VMOVU %VMM(2), (VEC_SIZE * 3 + 0)(%rdi) + VPTESTN %VMM(2), %VMM(2), %k0 + KMOV %k0, %VRCX + test %VRCX, %VRCX + jnz L(zfill_vec3) + + VMOVU %VMM(3), (VEC_SIZE * 4 + 0)(%rdi) + KMOV %k4, %VRCX + // Zfill more.... + + .p2align 4,, 4 +L(zfill_vec4): + subq $(VEC_SIZE * -2), %rdi + addq $(CHAR_PER_VEC * -2), %rdx +L(zfill_vec2): + subq $(VEC_SIZE * -2), %rdi + addq $(CHAR_PER_VEC * -1), %rdx +L(zfill): + /* VRCX must be non-zero. */ + bsf %VRCX, %VRCX + + /* Adjust length / dst for zfill. */ + subq %rcx, %rdx +# ifdef USE_AS_WCSCPY + leaq (%rdi, %rcx, CHAR_SIZE), %rdi +# else + addq %rcx, %rdi +# endif +# ifdef USE_AS_STPCPY + movq %rdi, %rax +# endif +L(zfill_from_page_cross): + + /* From here on out its just memset(rdi, 0, rdx). */ + cmpq $CHAR_PER_VEC, %rdx + jb L(zfill_less_vec) + +L(zfill_more_1x_vec): + VMOVU %VZERO, (%rdi) + VMOVU %VZERO, (CHAR_SIZE - VEC_SIZE)(%rdi, %rdx, CHAR_SIZE) + cmpq $(CHAR_PER_VEC * 2 - 1), %rdx + ja L(zfill_more_2x_vec) +L(zfill_done0): + ret + + /* Coming from vec1/vec2 we must be able to zfill at least 2x + VEC. */ + .p2align 4,, 8 +L(zfill_vec3): + subq $(VEC_SIZE * -2), %rdi + addq $(CHAR_PER_VEC * -2), %rdx + .p2align 4,, 2 +L(zfill_vec1): + bsfq %rcx, %rcx + /* rdi is currently dst - VEC_SIZE so add back VEC_SIZE here. + */ + leaq VEC_SIZE(%rdi, %rcx, CHAR_SIZE), %rdi + subq %rcx, %rdx +# ifdef USE_AS_STPCPY + movq %rdi, %rax +# endif + + + VMOVU %VZERO, (%rdi) + VMOVU %VZERO, (CHAR_SIZE - VEC_SIZE)(%rdi, %rdx, CHAR_SIZE) + cmpq $(CHAR_PER_VEC * 2), %rdx + jb L(zfill_done0) +L(zfill_more_2x_vec): + VMOVU %VZERO, (CHAR_SIZE - VEC_SIZE * 2)(%rdi, %rdx, CHAR_SIZE) + VMOVU %VZERO, (VEC_SIZE)(%rdi) + subq $(CHAR_PER_VEC * 4 - 1), %rdx + jbe L(zfill_done) + +# ifdef USE_AS_WCSCPY + leaq (%rdi, %rdx, CHAR_SIZE), %rdx +# else + addq %rdi, %rdx +# endif + + VMOVU %VZERO, (VEC_SIZE * 2)(%rdi) + VMOVU %VZERO, (VEC_SIZE * 3)(%rdi) + + + VMOVU %VZERO, (VEC_SIZE * 0 + 0)(%rdx) + VMOVU %VZERO, (VEC_SIZE * 1 + 0)(%rdx) + + subq $-(VEC_SIZE * 4), %rdi + cmpq %rdi, %rdx + jbe L(zfill_done) + + /* Align rdi and zfill loop. */ + andq $-(VEC_SIZE), %rdi + .p2align 4,, 12 +L(zfill_loop_4x_vec): + VMOVA %VZERO, (VEC_SIZE * 0)(%rdi) + VMOVA %VZERO, (VEC_SIZE * 1)(%rdi) + VMOVA %VZERO, (VEC_SIZE * 2)(%rdi) + VMOVA %VZERO, (VEC_SIZE * 3)(%rdi) + subq $-(VEC_SIZE * 4), %rdi + cmpq %rdi, %rdx + ja L(zfill_loop_4x_vec) +L(zfill_done): + ret + + + /* Less 1x VEC case if we are not using evex masked store. */ +# if !USE_EVEX_MASKED_STORE + .p2align 4,, 8 +L(copy_1x): + /* Special case for copy 1x. It can be handled quickly and many + buffer sizes have convenient alignment. */ + VMOVU %VMM(0), (%rdi) + /* If no zeros then we are done. */ + testl %ecx, %ecx + jz L(ret_1x_1x) + + /* Need to zfill, not we know that length <= CHAR_PER_VEC so we + only handle the small case here. */ + bsf %VRCX, %VRCX +L(zfill_less_vec_no_bsf): + /* Adjust length / dst then just zfill less_vec. */ + subq %rcx, %rdx +# ifdef USE_AS_WCSCPY + leaq (%rdi, %rcx, CHAR_SIZE), %rdi +# else + addq %rcx, %rdi +# endif +# ifdef USE_AS_STPCPY + movq %rdi, %rax +# endif + +L(zfill_less_vec): + cmpl $((VEC_SIZE / 2) / CHAR_SIZE), %edx + jb L(zfill_less_half) + + VMOVU %VZERO_HALF, (%rdi) + VMOVU %VZERO_HALF, -((VEC_SIZE / 2)- CHAR_SIZE)(%rdi, %rdx, CHAR_SIZE) + ret +# ifdef USE_AS_STPCPY +L(ret_1x_1x): + leaq CHAR_SIZE(%rdi, %rdx, CHAR_SIZE), %rax + ret +# endif + + +# if VEC_SIZE == 64 + .p2align 4,, 4 +L(copy_32_63): + /* Overfill to avoid branches. */ + VMOVU -(32 - CHAR_SIZE)(%rsi, %rdx, CHAR_SIZE), %VMM_256(1) + VMOVU %VMM_256(0), (%rdi) + VMOVU %VMM_256(1), -(32 - CHAR_SIZE)(%rdi, %rdx, CHAR_SIZE) + + /* We are taking advantage of the fact that to be here we must + be writing null-term as (%rdi, %rcx) we have a byte of lee- + way for overwriting. */ + cmpl %ecx, %edx + ja L(zfill_less_vec_no_bsf) +# ifndef USE_AS_STPCPY +L(ret_1x_1x): +# else +# ifdef USE_AS_WCSCPY + adcq $0, %rdx + leaq (%rdi, %rdx, CHAR_SIZE), %rax +# else + movl %edx, %eax + adcq %rdi, %rax +# endif +# endif + ret +# endif + + .p2align 4,, 4 +L(copy_16_31): + /* Overfill to avoid branches. */ + vmovdqu -(16 - CHAR_SIZE)(%rsi, %rdx, CHAR_SIZE), %xmm1 + VMOVU %VMM_128(0), (%rdi) + vmovdqu %xmm1, -(16 - CHAR_SIZE)(%rdi, %rdx, CHAR_SIZE) + cmpl %ecx, %edx + + /* Seperate logic depending on VEC_SIZE. If VEC_SIZE == 64 then + we have a larger copy block for 32-63 so this is just falls + through to zfill 16-31. If VEC_SIZE == 32 then we check for + full zfill of less 1x VEC. */ +# if VEC_SIZE == 64 + jbe L(ret_16_31) + subl %ecx, %edx +# ifdef USE_AS_WCSCPY + leaq (%rdi, %rcx, CHAR_SIZE), %rdi +# else + addq %rcx, %rdi +# endif +# ifdef USE_AS_STPCPY + movq %rdi, %rax +# endif +L(zfill_less_half): +L(zfill_less_32): + cmpl $(16 / CHAR_SIZE), %edx + jb L(zfill_less_16) + VMOVU %VZERO_128, (%rdi) + VMOVU %VZERO_128, -(16 - CHAR_SIZE)(%rdi, %rdx, CHAR_SIZE) +# ifdef USE_AS_STPCPY + ret +# endif +L(ret_16_31): +# ifdef USE_AS_STPCPY +# ifdef USE_AS_WCSCPY + adcq $0, %rdx + leaq (%rdi, %rdx, CHAR_SIZE), %rax +# else + movl %edx, %eax + adcq %rdi, %rax +# endif +# endif + ret +# else + /* VEC_SIZE == 32 begins. */ + ja L(zfill_less_vec_no_bsf) +# ifndef USE_AS_STPCPY +L(ret_1x_1x): +# else +# ifdef USE_AS_WCSCPY + adcq $0, %rdx + leaq (%rdi, %rdx, CHAR_SIZE), %rax +# else + movl %edx, %eax + adcq %rdi, %rax +# endif +# endif + ret +# endif + + + .p2align 4,, 4 +L(copy_8_15): + /* Overfill to avoid branches. */ + movq -(8 - CHAR_SIZE)(%rsi, %rdx, CHAR_SIZE), %rsi + vmovq %VMM_128(0), (%rdi) + movq %rsi, -(8 - CHAR_SIZE)(%rdi, %rdx, CHAR_SIZE) + cmpl %ecx, %edx + jbe L(ret_8_15) + subl %ecx, %edx +# ifdef USE_AS_WCSCPY + leaq (%rdi, %rcx, CHAR_SIZE), %rdi +# else + addq %rcx, %rdi +# endif +# ifdef USE_AS_STPCPY + movq %rdi, %rax +# endif + .p2align 4,, 8 +# if VEC_SIZE == 32 +L(zfill_less_half): +# endif +L(zfill_less_16): + xorl %ecx, %ecx + cmpl $(8 / CHAR_SIZE), %edx + jb L(zfill_less_8) + movq %rcx, (%rdi) + movq %rcx, -(8 - CHAR_SIZE)(%rdi, %rdx, CHAR_SIZE) +# ifndef USE_AS_STPCPY +L(ret_8_15): +# endif + ret + + .p2align 4,, 8 +L(less_1x_vec): + je L(copy_1x) + + /* We will need `tzcnt` result for all other copy sizes. */ + tzcnt %VRCX, %VRCX +# 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 + testl %ecx, %ecx + jz L(zfill_less_8_set_ret) + + movl (%rsi, %rdx, CHAR_SIZE), %esi + vmovd %VMM_128(0), (%rdi) + movl %esi, (%rdi, %rdx, CHAR_SIZE) +# ifdef USE_AS_STPCPY + cmpl %ecx, %edx +L(ret_8_15): + adcq $0, %rdx + leaq (%rdi, %rdx, CHAR_SIZE), %rax +# endif + ret +L(zfill_less_8_set_ret): + xorl %ecx, %ecx +# ifdef USE_AS_STPCPY + movq %rdi, %rax +# endif +L(zfill_less_8): + movl %ecx, (%rdi) + movl %ecx, (%rdi, %rdx, CHAR_SIZE) + ret +# else + cmpl $3, %edx + jb L(copy_0_3) + /* Overfill to avoid branches. */ + movl -3(%rsi, %rdx), %esi + vmovd %VMM_128(0), (%rdi) + movl %esi, -3(%rdi, %rdx) + cmpl %ecx, %edx + jbe L(ret_4_7) + subq %rcx, %rdx + addq %rcx, %rdi +# ifdef USE_AS_STPCPY + movq %rdi, %rax +# endif + xorl %ecx, %ecx + .p2align 4,, 8 +L(zfill_less_8): + cmpl $3, %edx + jb L(zfill_less_3) + movl %ecx, (%rdi) + movl %ecx, -3(%rdi, %rdx) +# ifdef USE_AS_STPCPY + ret +# endif + +L(ret_4_7): +# ifdef USE_AS_STPCPY +L(ret_8_15): + movl %edx, %eax + adcq %rdi, %rax +# endif + ret + + .p2align 4,, 4 +L(zfill_less_3): + testl %edx, %edx + jz L(zfill_1) + movw %cx, (%rdi) +L(zfill_1): + movb %cl, (%rdi, %rdx) + ret + + .p2align 4,, 8 +L(copy_0_3): + vmovd %VMM_128(0), %r8d + testl %edx, %edx + jz L(copy_1) + movw %r8w, (%rdi) + cmpl %ecx, %edx + ja L(zfill_from_1) + movzbl (%rsi, %rdx), %r8d +# ifdef USE_AS_STPCPY + movl %edx, %eax + adcq %rdi, %rax + movb %r8b, (%rdi, %rdx) + ret +# endif + +L(copy_1): +# ifdef USE_AS_STPCPY + movl %edx, %eax + cmpl %ecx, %edx + adcq %rdi, %rax +# endif +# ifdef USE_AS_WCSCPY + vmovd %VMM_128(0), (%rdi) +# else + movb %r8b, (%rdi, %rdx) +# endif + ret +# endif + + +# ifndef USE_AS_WCSCPY + .p2align 4,, 8 +L(zfill_from_1): +# ifdef USE_AS_STPCPY + leaq (%rdi, %rcx), %rax +# endif + movw $0, -1(%rdi, %rdx) + ret +# endif + + .p2align 4,, 4 +L(zero_len): + incq %rdx + jne L(best_effort_strncpy) + movq %rdi, %rax + ret +# endif + + + .p2align 4,, 4 + .p2align 6,, 8 +L(page_cross): + movq %rsi, %rax + andq $(VEC_SIZE * -1), %rax + VPCMPEQ (%rax), %VZERO, %k0 + KMOV %k0, %VRCX +# ifdef USE_AS_WCSCPY + movl %esi, %r8d + shrl $2, %r8d + andl $(CHAR_PER_VEC - 1), %r8d + shrx %VR8, %VRCX, %VRCX +# else + shrx %VRSI, %VRCX, %VRCX +# endif + + /* Compute amount of bytes we checked. */ + subl %esi, %eax + andl $(VEC_SIZE - 1), %eax +# ifdef USE_AS_WCSCPY + shrl $2, %eax +# endif + + /* If rax > rdx then we are finishing the copy at the end of the + page. */ + cmpq %rax, %rdx + jb L(page_cross_small) + + + /* If rcx is non-zero then continue. */ + test %VRCX, %VRCX + jz L(page_cross_continue) + + /* We found zero-CHAR so need to copy then zfill (we know we + didn't cover all of length here). */ + bsf %VRCX, %VRCX +L(movsb_and_zfill): + incl %ecx + subq %rcx, %rdx +# ifdef USE_AS_STPCPY + leaq -CHAR_SIZE(%rdi, %rcx, CHAR_SIZE), %rax +# else + movq %rdi, %rax +# endif + + REP_MOVS +# ifdef USE_AS_WCSCPY + movl $0, (%rdi) +# else + movb $0, (%rdi) +# endif + jmp L(zfill_from_page_cross) + +L(page_cross_small): + tzcnt %VRCX, %VRCX + cmpl %ecx, %edx + jbe L(page_cross_copy_only) + + /* Do a zfill of the tail before copying. */ + movq %rdi, %r9 + xorl %eax, %eax + + movl %ecx, %r8d + + subl %ecx, %edx + leaq CHAR_SIZE(%rdi, %rcx, CHAR_SIZE), %rdi + movl %edx, %ecx + REP_STOS + movq %r9, %rdi + movl %r8d, %edx +L(page_cross_copy_only): + leal 1(%rdx), %ecx +# ifdef USE_AS_STPCPY +# ifdef USE_AS_WCSCPY + adcl $0, %edx + leaq (%rdi, %rdx, CHAR_SIZE), %rax +# else + movl %edx, %eax + adcq %rdi, %rax +# endif +# else + movq %rdi, %rax +# endif + REP_MOVS + ret + + +L(best_effort_strncpy): + movq %rdx, %rcx + xorl %eax, %eax + movq %rdi, %r8 + /* The length is >= 2^63. We very much so expect to segfault at + rep stos. If that doesn't happen then just strcpy to finish. + */ + REP_STOS + movq %r8, %rdi + jmp OVERFLOW_STRCPY +END(STRNCPY) +#endif |