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.
127 lines
2.1 KiB
ArmAsm
127 lines
2.1 KiB
ArmAsm
/*
|
|
* Written by J.T. Conklin <jtc@acorntoolworks.com>
|
|
* Public domain.
|
|
*/
|
|
|
|
#include <machine/asm.h>
|
|
|
|
#if defined(LIBC_SCCS)
|
|
RCSID("$NetBSD: strcat.S,v 1.1 2005/12/20 19:28:49 christos Exp $")
|
|
#endif
|
|
|
|
ENTRY(strcat)
|
|
pushl %ebx
|
|
movl 8(%esp),%ecx
|
|
movl 12(%esp),%eax
|
|
|
|
/*
|
|
* Align destination to word boundary.
|
|
* Consider unrolling loop?
|
|
*/
|
|
.Lscan:
|
|
.Lscan_align:
|
|
testb $3,%cl
|
|
je .Lscan_aligned
|
|
cmpb $0,(%ecx)
|
|
je .Lcopy
|
|
incl %ecx
|
|
jmp .Lscan_align
|
|
|
|
_ALIGN_TEXT
|
|
.Lscan_aligned:
|
|
.Lscan_loop:
|
|
movl (%ecx),%ebx
|
|
addl $4,%ecx
|
|
leal -0x01010101(%ebx),%edx
|
|
testl $0x80808080,%edx
|
|
je .Lscan_loop
|
|
|
|
/*
|
|
* In rare cases, the above loop may exit prematurely. We must
|
|
* return to the loop if none of the bytes in the word equal 0.
|
|
*/
|
|
|
|
/*
|
|
* The optimal code for determining whether each byte is zero
|
|
* differs by processor. This space-optimized code should be
|
|
* acceptable on all, especially since we don't expect it to
|
|
* be run frequently,
|
|
*/
|
|
|
|
testb %bl,%bl /* 1st byte == 0? */
|
|
jne 1f
|
|
subl $4,%ecx
|
|
jmp .Lcopy
|
|
|
|
1: testb %bh,%bh /* 2nd byte == 0? */
|
|
jne 1f
|
|
subl $3,%ecx
|
|
jmp .Lcopy
|
|
|
|
1: shrl $16,%ebx
|
|
testb %bl,%bl /* 3rd byte == 0? */
|
|
jne 1f
|
|
subl $2,%ecx
|
|
jmp .Lcopy
|
|
|
|
1: testb %bh,%bh /* 4th byte == 0? */
|
|
jne .Lscan_loop
|
|
subl $1,%ecx
|
|
|
|
/*
|
|
* Align source to a word boundary.
|
|
* Consider unrolling loop?
|
|
*/
|
|
.Lcopy:
|
|
.Lcopy_align:
|
|
testl $3,%eax
|
|
je .Lcopy_aligned
|
|
movb (%eax),%bl
|
|
incl %eax
|
|
movb %bl,(%ecx)
|
|
incl %ecx
|
|
testb %bl,%bl
|
|
jne .Lcopy_align
|
|
jmp .Ldone
|
|
|
|
_ALIGN_TEXT
|
|
.Lcopy_loop:
|
|
movl %ebx,(%ecx)
|
|
addl $4,%ecx
|
|
.Lcopy_aligned:
|
|
movl (%eax),%ebx
|
|
addl $4,%eax
|
|
leal -0x01010101(%ebx),%edx
|
|
testl $0x80808080,%edx
|
|
je .Lcopy_loop
|
|
|
|
/*
|
|
* In rare cases, the above loop may exit prematurely. We must
|
|
* return to the loop if none of the bytes in the word equal 0.
|
|
*/
|
|
|
|
movb %bl,(%ecx)
|
|
incl %ecx
|
|
testb %bl,%bl
|
|
je .Ldone
|
|
|
|
movb %bh,(%ecx)
|
|
incl %ecx
|
|
testb %bh,%bh
|
|
je .Ldone
|
|
|
|
shrl $16,%ebx
|
|
movb %bl,(%ecx)
|
|
incl %ecx
|
|
testb %bl,%bl
|
|
je .Ldone
|
|
|
|
movb %bh,(%ecx)
|
|
incl %ecx
|
|
testb %bh,%bh
|
|
jne .Lcopy_aligned
|
|
|
|
.Ldone:
|
|
movl 8(%esp),%eax
|
|
popl %ebx
|
|
ret
|