mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 19:43:32 +00:00
49 lines
2.5 KiB
ArmAsm
49 lines
2.5 KiB
ArmAsm
/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8 -*-│
|
|
│vi: set et ft=asm ts=8 tw=8 fenc=utf-8 :vi│
|
|
╞══════════════════════════════════════════════════════════════════════════════╡
|
|
│ Copyright 2020 Justine Alexandra Roberts Tunney │
|
|
│ │
|
|
│ Permission to use, copy, modify, and/or distribute this software for │
|
|
│ any purpose with or without fee is hereby granted, provided that the │
|
|
│ above copyright notice and this permission notice appear in all copies. │
|
|
│ │
|
|
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
|
|
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
|
|
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
|
|
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
|
|
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
|
|
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
|
|
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
|
|
│ PERFORMANCE OF THIS SOFTWARE. │
|
|
╚─────────────────────────────────────────────────────────────────────────────*/
|
|
#include "libc/macros.internal.h"
|
|
|
|
// Creates bit mask of which bytes are the same.
|
|
//
|
|
// @param %rdi points to bit mask (write-only)
|
|
// @param %rsi points to first buffer (read-only)
|
|
// @param %rdx points to second buffer (read-only)
|
|
// @param %rcx is byte length of both %rsi and %rdx
|
|
// @return %rax is set to %rdi
|
|
// @note buffers should be 128-byte aligned
|
|
memeqmask:
|
|
.leafprologue
|
|
xor %eax,%eax
|
|
test %ecx,%ecx
|
|
jz 1f
|
|
shr $3,%ecx
|
|
0: movdqa (%rsi,%rax,8),%xmm0
|
|
movdqa 16(%rsi,%rax,8),%xmm1
|
|
pcmpeqb (%rdx,%rax,8),%xmm0
|
|
pcmpeqb 16(%rdx,%rax,8),%xmm1
|
|
pmovmskb %xmm0,%r8d
|
|
pmovmskb %xmm1,%r9d
|
|
mov %r8w,(%rdi,%rax)
|
|
mov %r9w,2(%rdi,%rax)
|
|
add $4,%eax
|
|
cmp %ecx,%eax
|
|
jb 0b
|
|
1: mov %rdi,%rax
|
|
.leafepilogue
|
|
.endfn memeqmask,globl
|
|
.source __FILE__
|