mirrors/cosmopolitan
1
0
Fork 0
mirror of https://github.com/jart/cosmopolitan.git synced 2025-07-05 10:48:29 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

Make a few fixups

Browse source
This commit is contained in:
Justine Tunney 2022-06-12 07:32:14 -07:00
parent a5849f8549
commit 6070a53e89
8 changed files with 176 additions and 88 deletions
Download patch file Download diff file Expand all files Collapse all files

62
libc/nexgen32e/memrchr.S
View file

@ -1,62 +0,0 @@
/*-*- 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/nexgen32e/x86feature.h"
#include "libc/dce.h"
#include "libc/macros.internal.h"
// Searches for last instance of byte in memory region.
//
// @param rdi points to data to search
// @param esi is treated as unsigned char
// @param rdx is byte length of rdi
// @return rax is address of last %sil in %rdi, or NULL
// @note AVX2 requires Haswell (2014+) or Excavator (2015+)
// @asyncsignalsafe
memrchr:
.leafprologue
.profilable
#if !IsTiny()
cmp $32,%rdx
jb 5f
testb X86_HAVE(AVX2)+kCpuids(%rip)
jz 5f
vmovd %esi,%xmm0
vpbroadcastb %xmm0,%ymm0
3: vmovdqu -32(%rdi,%rdx),%ymm1
vpcmpeqb %ymm1,%ymm0,%ymm1
vpmovmskb %ymm1,%eax
lzcnt %eax,%eax
mov %eax,%ecx
sub %rcx,%rdx
cmp $32,%eax
jne 5f
cmp $31,%rdx
ja 3b
vzeroupper
#endif
5: xor %eax,%eax
mov %rdx,%rcx
6: sub $1,%rcx
jb 9f
cmp %sil,-1(%rdi,%rdx)
mov %rcx,%rdx
jne 6b
lea (%rdi,%rcx),%rax
9: .leafepilogue
.endfn memrchr,globl