forked from Minki/linux
1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
134 lines
1.8 KiB
ArmAsm
134 lines
1.8 KiB
ArmAsm
/* $Id: memscan.S,v 1.4 1996/09/08 02:01:20 davem Exp $
|
|
* memscan.S: Optimized memscan for the Sparc.
|
|
*
|
|
* Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
|
|
*/
|
|
|
|
/* In essence, this is just a fancy strlen. */
|
|
|
|
#define LO_MAGIC 0x01010101
|
|
#define HI_MAGIC 0x80808080
|
|
|
|
.text
|
|
.align 4
|
|
.globl __memscan_zero, __memscan_generic
|
|
.globl memscan
|
|
__memscan_zero:
|
|
/* %o0 = addr, %o1 = size */
|
|
cmp %o1, 0
|
|
bne,a 1f
|
|
andcc %o0, 3, %g0
|
|
|
|
retl
|
|
nop
|
|
|
|
1:
|
|
be mzero_scan_word
|
|
sethi %hi(HI_MAGIC), %g2
|
|
|
|
ldsb [%o0], %g3
|
|
mzero_still_not_word_aligned:
|
|
cmp %g3, 0
|
|
bne 1f
|
|
add %o0, 1, %o0
|
|
|
|
retl
|
|
sub %o0, 1, %o0
|
|
|
|
1:
|
|
subcc %o1, 1, %o1
|
|
bne,a 1f
|
|
andcc %o0, 3, %g0
|
|
|
|
retl
|
|
nop
|
|
|
|
1:
|
|
bne,a mzero_still_not_word_aligned
|
|
ldsb [%o0], %g3
|
|
|
|
sethi %hi(HI_MAGIC), %g2
|
|
mzero_scan_word:
|
|
or %g2, %lo(HI_MAGIC), %o3
|
|
sethi %hi(LO_MAGIC), %g3
|
|
or %g3, %lo(LO_MAGIC), %o2
|
|
mzero_next_word:
|
|
ld [%o0], %g2
|
|
mzero_next_word_preloaded:
|
|
sub %g2, %o2, %g2
|
|
mzero_next_word_preloaded_next:
|
|
andcc %g2, %o3, %g0
|
|
bne mzero_byte_zero
|
|
add %o0, 4, %o0
|
|
|
|
mzero_check_out_of_fuel:
|
|
subcc %o1, 4, %o1
|
|
bg,a 1f
|
|
ld [%o0], %g2
|
|
|
|
retl
|
|
nop
|
|
|
|
1:
|
|
b mzero_next_word_preloaded_next
|
|
sub %g2, %o2, %g2
|
|
|
|
/* Check every byte. */
|
|
mzero_byte_zero:
|
|
ldsb [%o0 - 4], %g2
|
|
cmp %g2, 0
|
|
bne mzero_byte_one
|
|
sub %o0, 4, %g3
|
|
|
|
retl
|
|
mov %g3, %o0
|
|
|
|
mzero_byte_one:
|
|
ldsb [%o0 - 3], %g2
|
|
cmp %g2, 0
|
|
bne,a mzero_byte_two_and_three
|
|
ldsb [%o0 - 2], %g2
|
|
|
|
retl
|
|
sub %o0, 3, %o0
|
|
|
|
mzero_byte_two_and_three:
|
|
cmp %g2, 0
|
|
bne,a 1f
|
|
ldsb [%o0 - 1], %g2
|
|
|
|
retl
|
|
sub %o0, 2, %o0
|
|
|
|
1:
|
|
cmp %g2, 0
|
|
bne,a mzero_next_word_preloaded
|
|
ld [%o0], %g2
|
|
|
|
retl
|
|
sub %o0, 1, %o0
|
|
|
|
mzero_found_it:
|
|
retl
|
|
sub %o0, 2, %o0
|
|
|
|
memscan:
|
|
__memscan_generic:
|
|
/* %o0 = addr, %o1 = c, %o2 = size */
|
|
cmp %o2, 0
|
|
bne,a 0f
|
|
ldub [%o0], %g2
|
|
|
|
b,a 2f
|
|
1:
|
|
ldub [%o0], %g2
|
|
0:
|
|
cmp %g2, %o1
|
|
be 2f
|
|
addcc %o2, -1, %o2
|
|
bne 1b
|
|
add %o0, 1, %o0
|
|
2:
|
|
retl
|
|
nop
|