93 lines
1.8 KiB
ArmAsm
93 lines
1.8 KiB
ArmAsm
/*
|
|
* Copyright 2004-2009 Analog Devices Inc.
|
|
*
|
|
* Licensed under the ADI BSD license or the GPL-2 (or later)
|
|
*/
|
|
|
|
#include <linux/linkage.h>
|
|
|
|
/* int memcmp(const void *s1, const void *s2, size_t n);
|
|
* R0 = First Address (s1)
|
|
* R1 = Second Address (s2)
|
|
* R2 = count (n)
|
|
*
|
|
* Favours word aligned data.
|
|
*/
|
|
|
|
.text
|
|
|
|
.align 2
|
|
|
|
ENTRY(_memcmp)
|
|
I1 = P3;
|
|
P0 = R0; /* P0 = s1 address */
|
|
P3 = R1; /* P3 = s2 Address */
|
|
P2 = R2 ; /* P2 = count */
|
|
CC = R2 <= 7(IU);
|
|
IF CC JUMP .Ltoo_small;
|
|
I0 = R1; /* s2 */
|
|
R1 = R1 | R0; /* OR addresses together */
|
|
R1 <<= 30; /* check bottom two bits */
|
|
CC = AZ; /* AZ set if zero. */
|
|
IF !CC JUMP .Lbytes ; /* Jump if addrs not aligned. */
|
|
|
|
P1 = P2 >> 2; /* count = n/4 */
|
|
R3 = 3;
|
|
R2 = R2 & R3; /* remainder */
|
|
P2 = R2; /* set remainder */
|
|
|
|
LSETUP (.Lquad_loop_s, .Lquad_loop_e) LC0=P1;
|
|
.Lquad_loop_s:
|
|
#if ANOMALY_05000202
|
|
R0 = [P0++];
|
|
R1 = [I0++];
|
|
#else
|
|
MNOP || R0 = [P0++] || R1 = [I0++];
|
|
#endif
|
|
CC = R0 == R1;
|
|
IF !CC JUMP .Lquad_different;
|
|
.Lquad_loop_e:
|
|
NOP;
|
|
|
|
P3 = I0; /* s2 */
|
|
.Ltoo_small:
|
|
CC = P2 == 0; /* Check zero count*/
|
|
IF CC JUMP .Lfinished; /* very unlikely*/
|
|
|
|
.Lbytes:
|
|
LSETUP (.Lbyte_loop_s, .Lbyte_loop_e) LC0=P2;
|
|
.Lbyte_loop_s:
|
|
R1 = B[P3++](Z); /* *s2 */
|
|
R0 = B[P0++](Z); /* *s1 */
|
|
CC = R0 == R1;
|
|
IF !CC JUMP .Ldifferent;
|
|
.Lbyte_loop_e:
|
|
NOP;
|
|
|
|
.Ldifferent:
|
|
R0 = R0 - R1;
|
|
P3 = I1;
|
|
RTS;
|
|
|
|
.Lquad_different:
|
|
/* We've read two quads which don't match.
|
|
* Can't just compare them, because we're
|
|
* a little-endian machine, so the MSBs of
|
|
* the regs occur at later addresses in the
|
|
* string.
|
|
* Arrange to re-read those two quads again,
|
|
* byte-by-byte.
|
|
*/
|
|
P0 += -4; /* back up to the start of the */
|
|
P3 = I0; /* quads, and increase the*/
|
|
P2 += 4; /* remainder count*/
|
|
P3 += -4;
|
|
JUMP .Lbytes;
|
|
|
|
.Lfinished:
|
|
R0 = 0;
|
|
P3 = I1;
|
|
RTS;
|
|
|
|
ENDPROC(_memcmp)
|