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e5672763c4
On x32, the size_t parameter may be passed in the lower 32 bits of a 64-bit register with the non-zero upper 32 bits. The string/memory functions written in assembly can only use the lower 32 bits of a 64-bit register as length or must clear the upper 32 bits before using the full 64-bit register for length. This pach fixes strncpy for x32. Tested on x86-64 and x32. On x86-64, libc.so is the same with and without the fix. Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
995 lines
22 KiB
ArmAsm
995 lines
22 KiB
ArmAsm
/* {wcs|wcp|str|stp}ncpy with 256/512-bit EVEX instructions.
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Copyright (C) 2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <isa-level.h>
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#if ISA_SHOULD_BUILD (4)
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/* Use evex-masked stores for small sizes. Turned off at the
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moment. */
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# define USE_EVEX_MASKED_STORE 0
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# include <sysdep.h>
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# ifndef VEC_SIZE
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# include "x86-evex256-vecs.h"
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# endif
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# ifndef STRNCPY
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# define STRNCPY __strncpy_evex
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# endif
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# ifdef USE_AS_WCSCPY
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# define VMOVU_MASK vmovdqu32
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# define VPCMPEQ vpcmpeqd
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# define VPMIN vpminud
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# define VPTESTN vptestnmd
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# define VPTEST vptestmd
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# define CHAR_SIZE 4
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# define REP_MOVS rep movsd
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# define REP_STOS rep stosl
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# define USE_WIDE_CHAR
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# else
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# define VMOVU_MASK vmovdqu8
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# define VPCMPEQ vpcmpeqb
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# define VPMIN vpminub
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# define VPTESTN vptestnmb
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# define VPTEST vptestmb
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# define CHAR_SIZE 1
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# define REP_MOVS rep movsb
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# define REP_STOS rep stosb
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# endif
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# include "strncpy-or-cat-overflow-def.h"
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# define PAGE_SIZE 4096
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# define CHAR_PER_VEC (VEC_SIZE / CHAR_SIZE)
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# include "reg-macros.h"
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# define VZERO VMM(7)
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# define VZERO_256 VMM_256(7)
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# define VZERO_128 VMM_128(7)
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# if VEC_SIZE == 64
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# define VZERO_HALF VZERO_256
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# else
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# define VZERO_HALF VZERO_128
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# endif
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.section SECTION(.text), "ax", @progbits
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ENTRY(STRNCPY)
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# ifdef __ILP32__
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/* Clear the upper 32 bits. */
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movl %edx, %edx
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# endif
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/* Filter zero length strings and very long strings. Zero
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length strings just return, very long strings are handled by
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just running rep stos{b|l} to zero set (which will almost
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certainly segfault), if that succeeds then just calling
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OVERFLOW_STRCPY (strcpy, stpcpy, wcscpy, wcpcpy). */
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# ifdef USE_AS_WCSCPY
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decq %rdx
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movq %rdx, %rax
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/* 56 is end of max supported address space. */
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shr $56, %rax
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jnz L(zero_len)
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# else
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decq %rdx
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/* If the flag needs to become `jb` replace `dec` with `sub`.
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*/
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jl L(zero_len)
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# endif
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vpxorq %VZERO_128, %VZERO_128, %VZERO_128
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movl %esi, %eax
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andl $(PAGE_SIZE - 1), %eax
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cmpl $(PAGE_SIZE - VEC_SIZE), %eax
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ja L(page_cross)
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L(page_cross_continue):
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VMOVU (%rsi), %VMM(0)
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VPTESTN %VMM(0), %VMM(0), %k0
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KMOV %k0, %VRCX
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/* If no STPCPY just save end ahead of time. */
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# ifndef USE_AS_STPCPY
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movq %rdi, %rax
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# endif
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cmpq $(CHAR_PER_VEC), %rdx
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/* If USE_EVEX_MASK_STORE is enabled then we just handle length
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<= CHAR_PER_VEC with masked instructions (which have
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potential for dramatically bad perf if dst splits a page and
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is not in the TLB). */
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# if USE_EVEX_MASKED_STORE
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/* `jae` because length rdx is now length - 1. */
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jae L(more_1x_vec)
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/* If there where multiple zero-CHAR matches in the first VEC,
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VRCX will be overset but thats fine since any oversets where
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at zero-positions anyways. */
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# ifdef USE_AS_STPCPY
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tzcnt %VRCX, %VRAX
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cmpl %eax, %edx
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cmovb %edx, %eax
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# ifdef USE_AS_WCSCPY
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adcl $0, %eax
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leaq (%rdi, %rax, CHAR_SIZE), %rax
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# else
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adcq %rdi, %rax
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# endif
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# endif
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dec %VRCX
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/* Zero out all non-zero CHAR's after the first zero match. */
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KMOV %VRCX, %k1
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/* Use VZERO as destination so this can be reused for
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L(zfill_less_vec) (which if jumped to by subsequent logic
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will have zerod out VZERO. */
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VMOVU_MASK %VMM(0), %VZERO{%k1}{z}
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L(zfill_less_vec):
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/* Get mask for what we need to set. */
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incl %edx
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mov $-1, %VRCX
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bzhi %VRDX, %VRCX, %VRCX
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KMOV %VRCX, %k1
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VMOVU_MASK %VZERO, (%rdi){%k1}
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ret
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.p2align 4,, 4
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L(zero_len):
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cmpq $-1, %rdx
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jne L(best_effort_strncpy)
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movq %rdi, %rax
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ret
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.p2align 4,, 8
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L(more_1x_vec):
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# else
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/* `jb` because length rdx is now length - 1. */
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jb L(less_1x_vec)
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# endif
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/* This may overset but thats fine because we still need to zero
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fill. */
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VMOVU %VMM(0), (%rdi)
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/* Length must be >= CHAR_PER_VEC so match here means we must
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zero-fill. */
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test %VRCX, %VRCX
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jnz L(zfill)
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/* We are going to align rsi here so will need to be able to re-
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adjust rdi/rdx afterwords. NB: We filtered out huge lengths
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so rsi + rdx * CHAR_SIZE cannot overflow. */
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leaq (VEC_SIZE * -1)(%rsi, %rdx, CHAR_SIZE), %rdx
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subq %rsi, %rdi
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andq $-(VEC_SIZE), %rsi
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L(loop_last_4x_vec):
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addq %rsi, %rdi
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subq %rsi, %rdx
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# ifdef USE_AS_WCSCPY
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shrq $2, %rdx
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# endif
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VMOVA (VEC_SIZE * 1)(%rsi), %VMM(1)
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VPTESTN %VMM(1), %VMM(1), %k0
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KMOV %k0, %VRCX
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/* -1 because of the `dec %rdx` earlier. */
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cmpq $(CHAR_PER_VEC * 2 - 1), %rdx
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ja L(more_2x_vec)
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L(last_2x_vec):
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/* This will be need to be computed no matter what. We do it
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ahead of time for CHAR_PER_VEC == 64 because we can't adjust
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the value of `tzcnt` with a shift. */
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# if CHAR_PER_VEC == 64
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tzcntq %rcx, %rcx
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# endif
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cmpl $(CHAR_PER_VEC), %edx
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jb L(ret_vec_x1_len)
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/* Seperate logic for CHAR_PER_VEC == 64 because we already did
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`tzcnt` on VRCX. */
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# if CHAR_PER_VEC == 64
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/* cl == CHAR_PER_VEC iff it was zero before the `tzcnt`. */
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cmpb $CHAR_PER_VEC, %cl
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jnz L(ret_vec_x1_no_bsf)
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# else
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test %VRCX, %VRCX
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jnz L(ret_vec_x1)
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# endif
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VPCMPEQ (VEC_SIZE * 2)(%rsi), %VZERO, %k0
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VMOVU %VMM(1), (VEC_SIZE * 1)(%rdi)
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KMOV %k0, %VRCX
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# if CHAR_PER_VEC < 64
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/* This essentiallys adds CHAR_PER_VEC to computed result. */
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shlq $CHAR_PER_VEC, %rcx
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# else
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tzcntq %rcx, %rcx
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addl $CHAR_PER_VEC, %ecx
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# endif
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.p2align 4,, 4
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L(ret_vec_x1_len):
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/* If CHAR_PER_VEC < 64 we still need to tzcnt, otherwise it has
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already been done. */
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# if CHAR_PER_VEC < 64
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tzcntq %rcx, %rcx
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# endif
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cmpl %ecx, %edx
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jbe L(ret_vec_x1_len_no_zfill)
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/* Fall through (expectation) is copy len < buffer len. */
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VMOVU %VZERO, ((VEC_SIZE)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rdx, CHAR_SIZE)
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L(ret_vec_x1_len_no_zfill_mov):
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movl %ecx, %edx
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# ifdef USE_AS_STPCPY
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/* clear flags. */
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xorl %ecx, %ecx
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# endif
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L(ret_vec_x1_len_no_zfill):
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VMOVU ((VEC_SIZE)-(VEC_SIZE - CHAR_SIZE))(%rsi, %rdx, CHAR_SIZE), %VMM(0)
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VMOVU %VMM(0), ((VEC_SIZE)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rdx, CHAR_SIZE)
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# ifdef USE_AS_STPCPY
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# ifdef USE_AS_WCSCPY
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adcq $0, %rdx
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leaq (VEC_SIZE * 1)(%rdi, %rdx, CHAR_SIZE), %rax
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# else
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leal (VEC_SIZE)(%rdx), %eax
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adcq %rdi, %rax
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# endif
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# endif
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ret
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.p2align 4,, 10
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L(ret_vec_x1):
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bsf %VRCX, %VRCX
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L(ret_vec_x1_no_bsf):
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VMOVU %VZERO, ((VEC_SIZE)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rdx, CHAR_SIZE)
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subl %ecx, %edx
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cmpl $CHAR_PER_VEC, %edx
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jb L(ret_vec_x1_len_no_zfill_mov)
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/* Fall through (expectation) is copy len < buffer len. */
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VMOVU %VMM(1), (VEC_SIZE * 1)(%rdi)
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VMOVU %VZERO, (VEC_SIZE * 1)(%rdi, %rcx, CHAR_SIZE)
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# ifdef USE_AS_STPCPY
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leaq (VEC_SIZE * 1)(%rdi, %rcx, CHAR_SIZE), %rax
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# endif
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ret
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.p2align 4,, 8
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L(last_4x_vec):
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/* Seperate logic for CHAR_PER_VEC == 64 because we can do `andl
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$(CHAR_PER_VEC * 4 - 1), %edx` with less code size just
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using `movzbl`. */
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# if CHAR_PER_VEC == 64
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movzbl %dl, %edx
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# else
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andl $(CHAR_PER_VEC * 4 - 1), %edx
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# endif
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VMOVA (VEC_SIZE * 5)(%rsi), %VMM(1)
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VPTESTN %VMM(1), %VMM(1), %k0
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KMOV %k0, %VRCX
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subq $-(VEC_SIZE * 4), %rsi
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subq $-(VEC_SIZE * 4), %rdi
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cmpl $(CHAR_PER_VEC * 2 - 1), %edx
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jbe L(last_2x_vec)
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.p2align 4,, 8
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L(more_2x_vec):
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VMOVU %VMM(1), (VEC_SIZE * 1)(%rdi)
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test %VRCX, %VRCX
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/* Must fill at least 2x VEC. */
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jnz L(zfill_vec1)
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VMOVA (VEC_SIZE * 2)(%rsi), %VMM(2)
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VMOVU %VMM(2), (VEC_SIZE * 2)(%rdi)
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VPTESTN %VMM(2), %VMM(2), %k0
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KMOV %k0, %VRCX
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test %VRCX, %VRCX
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/* Must fill at least 1x VEC. */
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jnz L(zfill_vec2)
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VMOVA (VEC_SIZE * 3)(%rsi), %VMM(3)
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VPTESTN %VMM(3), %VMM(3), %k0
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KMOV %k0, %VRCX
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/* Check if len is more 4x VEC. -1 because rdx is len - 1. */
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cmpq $(CHAR_PER_VEC * 4 - 1), %rdx
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ja L(more_4x_vec)
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subl $(CHAR_PER_VEC * 3), %edx
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jb L(ret_vec_x3_len)
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test %VRCX, %VRCX
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jnz L(ret_vec_x3)
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VPCMPEQ (VEC_SIZE * 4)(%rsi), %VZERO, %k0
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VMOVU %VMM(3), (VEC_SIZE * 3)(%rdi)
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KMOV %k0, %VRCX
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tzcnt %VRCX, %VRCX
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cmpl %ecx, %edx
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jbe L(ret_vec_x4_len_no_zfill)
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/* Fall through (expectation) is copy len < buffer len. */
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VMOVU %VZERO, ((VEC_SIZE * 4)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rdx, CHAR_SIZE)
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movl %ecx, %edx
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L(ret_vec_x4_len_no_zfill):
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VMOVU ((VEC_SIZE * 4)-(VEC_SIZE - CHAR_SIZE))(%rsi, %rdx, CHAR_SIZE), %VMM(0)
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VMOVU %VMM(0), ((VEC_SIZE * 4)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rdx, CHAR_SIZE)
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# ifdef USE_AS_STPCPY
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# ifdef USE_AS_WCSCPY
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adcq $0, %rdx
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leaq (VEC_SIZE * 4)(%rdi, %rdx, CHAR_SIZE), %rax
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# else
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leal (VEC_SIZE * 4 + 0)(%rdx), %eax
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adcq %rdi, %rax
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# endif
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# endif
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ret
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L(ret_vec_x3_len):
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addl $(CHAR_PER_VEC * 1), %edx
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tzcnt %VRCX, %VRCX
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cmpl %ecx, %edx
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jbe L(ret_vec_x3_len_no_zfill)
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/* Fall through (expectation) is copy len < buffer len. */
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VMOVU %VZERO, ((VEC_SIZE * 3)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rdx, CHAR_SIZE)
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L(ret_vec_x3_len_no_zfill_mov):
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movl %ecx, %edx
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# ifdef USE_AS_STPCPY
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/* clear flags. */
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xorl %ecx, %ecx
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# endif
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.p2align 4,, 4
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L(ret_vec_x3_len_no_zfill):
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VMOVU ((VEC_SIZE * 3)-(VEC_SIZE - CHAR_SIZE))(%rsi, %rdx, CHAR_SIZE), %VMM(0)
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VMOVU %VMM(0), ((VEC_SIZE * 3)-(VEC_SIZE - CHAR_SIZE))(%rdi, %rdx, CHAR_SIZE)
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# ifdef USE_AS_STPCPY
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# ifdef USE_AS_WCSCPY
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adcq $0, %rdx
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leaq (VEC_SIZE * 3)(%rdi, %rdx, CHAR_SIZE), %rax
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# else
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leal (VEC_SIZE * 3 + 0)(%rdx), %eax
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adcq %rdi, %rax
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# endif
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# endif
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ret
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.p2align 4,, 8
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L(ret_vec_x3):
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bsf %VRCX, %VRCX
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VMOVU %VZERO, (VEC_SIZE * 4 +(-(VEC_SIZE - CHAR_SIZE)))(%rdi, %rdx, CHAR_SIZE)
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subl %ecx, %edx
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jl L(ret_vec_x3_len_no_zfill_mov)
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VMOVU %VMM(3), (VEC_SIZE * 3)(%rdi)
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VMOVU %VZERO, (VEC_SIZE * 3)(%rdi, %rcx, CHAR_SIZE)
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# ifdef USE_AS_STPCPY
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leaq (VEC_SIZE * 3)(%rdi, %rcx, CHAR_SIZE), %rax
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# endif
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ret
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.p2align 4,, 8
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L(more_4x_vec):
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VMOVU %VMM(3), (VEC_SIZE * 3)(%rdi)
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test %VRCX, %VRCX
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jnz L(zfill_vec3)
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VMOVA (VEC_SIZE * 4)(%rsi), %VMM(4)
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VMOVU %VMM(4), (VEC_SIZE * 4)(%rdi)
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VPTESTN %VMM(4), %VMM(4), %k0
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KMOV %k0, %VRCX
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test %VRCX, %VRCX
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jnz L(zfill_vec4)
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/* Recheck length before aligning. */
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cmpq $(CHAR_PER_VEC * 8 - 1), %rdx
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jbe L(last_4x_vec)
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/* Align rsi to VEC_SIZE * 4, need to readjust rdx / rdi. */
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# ifdef USE_AS_WCSCPY
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leaq (%rsi, %rdx, CHAR_SIZE), %rdx
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# else
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addq %rsi, %rdx
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# endif
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subq %rsi, %rdi
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subq $-(VEC_SIZE * 5), %rsi
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andq $(VEC_SIZE * -4), %rsi
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/* Load first half of the loop before entry. */
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VMOVA (VEC_SIZE * 0 + 0)(%rsi), %VMM(0)
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VMOVA (VEC_SIZE * 1 + 0)(%rsi), %VMM(1)
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VMOVA (VEC_SIZE * 2 + 0)(%rsi), %VMM(2)
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VMOVA (VEC_SIZE * 3 + 0)(%rsi), %VMM(3)
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VPMIN %VMM(0), %VMM(1), %VMM(4)
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VPMIN %VMM(2), %VMM(3), %VMM(6)
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VPTESTN %VMM(4), %VMM(4), %k2
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VPTESTN %VMM(6), %VMM(6), %k4
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/* Offset rsi by VEC_SIZE so that we can jump to
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L(loop_last_4x_vec). */
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addq $-(VEC_SIZE), %rsi
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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
|