cosmopolitan/libc/nexgen32e/strcspn.S
2021-01-10 13:36:31 -08:00

73 lines
2.7 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.h"
/ Returns prefix length, consisting of chars not in reject.
/ a.k.a. Return index of first byte that's in charset.
/
/ @param rdi is string
/ @param rsi is reject nul-terminated character set
/ @see strspn(), strtok_r()
/ @asyncsignalsafe
strcspn:
push %rbp
mov %rsp,%rbp
sub $16,%rsp
push %rdi
mov %rsi,%rdi
call strlen
pop %rdi
cmp $15,%rax
ja 4f
push %rdi
mov %rax,%rdx
pxor %xmm0,%xmm0
lea -16(%rbp),%rdi
movdqa %xmm0,(%rdi)
call MemCpy
movdqa (%rdi),%xmm1
pop %rdi
or $-1,%rax
0: inc %rax
movzbl (%rdi,%rax),%ecx
movd %ecx,%xmm0
punpcklbw %xmm0,%xmm0
punpcklwd %xmm0,%xmm0
pshufd $0,%xmm0,%xmm0
pcmpeqb %xmm1,%xmm0
pmovmskb %xmm0,%ecx
test %ecx,%ecx
jz 0b
9: leave
ret
1: cmp %ch,%cl
je 9b
inc %edx
2: mov (%rsi,%rdx),%ch
test %ch,%ch
jne 1b
inc %rax
3: mov (%rdi,%rax),%cl
test %cl,%cl
je 9b
xor %edx,%edx
jmp 2b
4: xor %eax,%eax
jmp 3b
.endfn strcspn,globl