Merge "Add optimized version of memset for Cortex A9"

This commit is contained in:
Elliott Hughes 2012-11-09 15:06:50 -08:00 committed by Gerrit Code Review
commit b62e2770e7

View File

@ -26,23 +26,113 @@
* SUCH DAMAGE.
*/
#include <machine/cpu-features.h>
#include <machine/asm.h>
/*
* Optimized memset() for ARM.
*
* memset() returns its first argument.
*/
#if defined(__ARM_NEON__)
.fpu neon
#endif
ENTRY(bzero)
mov r2, r1
mov r1, #0
END(bzero)
ENTRY(memset)
#if defined(__ARM_NEON__)
#ifdef NEON_MEMSET_DIVIDER
cmp r2, #NEON_MEMSET_DIVIDER
bhi 11f
#endif
.save {r0}
stmfd sp!, {r0}
vdup.8 q0, r1
#ifndef NEON_UNALIGNED_ACCESS
/* do we have at least 16-bytes to write (needed for alignment below) */
cmp r2, #16
blo 3f
/* align destination to 16 bytes for the write-buffer */
rsb r3, r0, #0
ands r3, r3, #0xF
beq 2f
/* write up to 15-bytes (count in r3) */
sub r2, r2, r3
movs ip, r3, lsl #31
strmib r1, [r0], #1
strcsb r1, [r0], #1
strcsb r1, [r0], #1
movs ip, r3, lsl #29
bge 1f
// writes 4 bytes, 32-bits aligned
vst1.32 {d0[0]}, [r0, :32]!
1: bcc 2f
// writes 8 bytes, 64-bits aligned
vst1.8 {d0}, [r0, :64]!
2:
#endif
/* make sure we have at least 32 bytes to write */
subs r2, r2, #32
blo 2f
vmov q1, q0
1: /* The main loop writes 32 bytes at a time */
subs r2, r2, #32
#ifndef NEON_UNALIGNED_ACCESS
vst1.8 {d0 - d3}, [r0, :128]!
#else
vst1.8 {d0 - d3}, [r0]!
#endif
bhs 1b
2: /* less than 32 left */
add r2, r2, #32
tst r2, #0x10
beq 3f
// writes 16 bytes, 128-bits aligned
#ifndef NEON_UNALIGNED_ACCESS
vst1.8 {d0, d1}, [r0, :128]!
#else
vst1.8 {d0, d1}, [r0]!
#endif
3: /* write up to 15-bytes (count in r2) */
movs ip, r2, lsl #29
bcc 1f
vst1.8 {d0}, [r0]!
1: bge 2f
vst1.32 {d0[0]}, [r0]!
2: movs ip, r2, lsl #31
strmib r1, [r0], #1
strcsb r1, [r0], #1
strcsb r1, [r0], #1
ldmfd sp!, {r0}
bx lr
11:
#endif
/*
* Optimized memset() for ARM.
*
* memset() returns its first argument.
*/
/* compute the offset to align the destination
* offset = (4-(src&3))&3 = -src & 3
*/
.save {r0, r4-r7, lr}
stmfd sp!, {r0, r4-r7, lr}
rsb r3, r0, #0
@ -70,7 +160,7 @@ ENTRY(memset)
mov r5, r1
mov r6, r1
mov r7, r1
rsb r3, r0, #0
ands r3, r3, #0x1C
beq 3f
@ -78,7 +168,7 @@ ENTRY(memset)
andhi r3, r2, #0x1C
sub r2, r2, r3
/* conditionnaly writes 0 to 7 words (length in r3) */
/* conditionally writes 0 to 7 words (length in r3) */
movs r3, r3, lsl #28
stmcsia r0!, {r1, lr}
stmcsia r0!, {r1, lr}
@ -95,7 +185,7 @@ ENTRY(memset)
bhs 1b
2: add r2, r2, #32
/* conditionnaly stores 0 to 31 bytes */
/* conditionally stores 0 to 31 bytes */
movs r2, r2, lsl #28
stmcsia r0!, {r1,r3,r12,lr}
stmmiia r0!, {r1, lr}