b6cbf7203b
This patch imports the unmodified current version of NetBSD libc. The NetBSD includes are in /nbsd_include, while the libc code itself is split between lib/nbsd_libc and common/lib/libc.
125 lines
2.2 KiB
ArmAsm
125 lines
2.2 KiB
ArmAsm
/*
|
|
* Written by J.T. Conklin <jtc@acorntoolworks.com>
|
|
* Public domain.
|
|
*/
|
|
|
|
#include <machine/asm.h>
|
|
|
|
#if defined(LIBC_SCCS)
|
|
RCSID("$NetBSD: strrchr.S,v 1.2 2009/07/17 19:37:57 dsl Exp $")
|
|
#endif
|
|
|
|
ENTRY(strrchr)
|
|
movzbq %sil,%rcx
|
|
|
|
/* zero return value */
|
|
xorq %rax,%rax
|
|
|
|
/*
|
|
* Align to word boundary.
|
|
* Consider unrolling loop?
|
|
*/
|
|
.Lalign:
|
|
testb $7,%dil
|
|
je .Lword_aligned
|
|
movb (%rdi),%dl
|
|
cmpb %cl,%dl
|
|
cmoveq %rdi,%rax
|
|
incq %rdi
|
|
testb %dl,%dl
|
|
jne .Lalign
|
|
jmp .Ldone
|
|
|
|
.Lword_aligned:
|
|
/* copy char to all bytes in word */
|
|
movb %cl,%ch
|
|
movq %rcx,%rdx
|
|
salq $16,%rcx
|
|
orq %rdx,%rcx
|
|
movq %rcx,%rdx
|
|
salq $32,%rcx
|
|
orq %rdx,%rcx
|
|
|
|
movabsq $0x0101010101010101,%r8
|
|
movabsq $0x8080808080808080,%r9
|
|
|
|
/* Check whether any byte in the word is equal to ch or 0. */
|
|
_ALIGN_TEXT
|
|
.Lloop:
|
|
movq (%rdi),%rdx
|
|
addq $8,%rdi
|
|
movq %rdx,%rsi
|
|
subq %r8,%rdx
|
|
xorq %rcx,%rsi
|
|
subq %r8,%rsi
|
|
orq %rsi,%rdx
|
|
testq %r9,%rdx
|
|
je .Lloop
|
|
|
|
/*
|
|
* In rare cases, the above loop may exit prematurely. We must
|
|
* return to the loop if none of the bytes in the word match
|
|
* ch or are equal to 0.
|
|
*/
|
|
|
|
movb -8(%rdi),%dl
|
|
cmpb %cl,%dl /* 1st byte == ch? */
|
|
jne 1f
|
|
leaq -8(%rdi),%rax
|
|
1: testb %dl,%dl /* 1st byte == 0? */
|
|
je .Ldone
|
|
|
|
movb -7(%rdi),%dl
|
|
cmpb %cl,%dl /* 2nd byte == ch? */
|
|
jne 1f
|
|
leaq -7(%rdi),%rax
|
|
1: testb %dl,%dl /* 2nd byte == 0? */
|
|
je .Ldone
|
|
|
|
movb -6(%rdi),%dl
|
|
cmpb %cl,%dl /* 3rd byte == ch? */
|
|
jne 1f
|
|
leaq -6(%rdi),%rax
|
|
1: testb %dl,%dl /* 3rd byte == 0? */
|
|
je .Ldone
|
|
|
|
movb -5(%rdi),%dl
|
|
cmpb %cl,%dl /* 4th byte == ch? */
|
|
jne 1f
|
|
leaq -5(%rdi),%rax
|
|
1: testb %dl,%dl /* 4th byte == 0? */
|
|
je .Ldone
|
|
|
|
movb -4(%rdi),%dl
|
|
cmpb %cl,%dl /* 5th byte == ch? */
|
|
jne 1f
|
|
leaq -4(%rdi),%rax
|
|
1: testb %dl,%dl /* 5th byte == 0? */
|
|
je .Ldone
|
|
|
|
movb -3(%rdi),%dl
|
|
cmpb %cl,%dl /* 6th byte == ch? */
|
|
jne 1f
|
|
leaq -3(%rdi),%rax
|
|
1: testb %dl,%dl /* 6th byte == 0? */
|
|
je .Ldone
|
|
|
|
movb -2(%rdi),%dl
|
|
cmpb %cl,%dl /* 7th byte == ch? */
|
|
jne 1f
|
|
leaq -2(%rdi),%rax
|
|
1: testb %dl,%dl /* 7th byte == 0? */
|
|
je .Ldone
|
|
|
|
movb -1(%rdi),%dl
|
|
cmpb %cl,%dl /* 8th byte == ch? */
|
|
jne 1f
|
|
leaq -1(%rdi),%rax
|
|
1: testb %dl,%dl /* 8th byte == 0? */
|
|
jne .Lloop
|
|
|
|
.Ldone:
|
|
ret
|
|
|
|
STRONG_ALIAS(rindex,strrchr)
|