platform_bionic/libc/arch-arm/krait/bionic/memcpy.S
Christopher Ferris 7c83a1ed81 Break bionic implementations into arch versions. DO NOT MERGE
Move arch specific code for arm, mips, x86 into separate
makefiles.
In addition, add different arm cpu versions of memcpy/memset.

Bug: 8005082

(cherry picked from commit acdde8c1cf)

Change-Id: I0108d432af9f6283ae99adfc92a3399e5ab3e31d
2013-02-28 17:45:16 -08:00

146 lines
5.2 KiB
ArmAsm

/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/* Assumes neon instructions and a cache line size of 32 bytes. */
#include <machine/cpu-features.h>
#include <machine/asm.h>
/*
* This code assumes it is running on a processor that supports all arm v7
* instructions, that supports neon instructions, and that has a 32 byte
* cache line.
*/
.text
.fpu neon
#define CACHE_LINE_SIZE 32
ENTRY(memcpy)
.save {r0, lr}
/* start preloading as early as possible */
pld [r1, #(CACHE_LINE_SIZE*0)]
stmfd sp!, {r0, lr}
pld [r1, #(CACHE_LINE_SIZE*2)]
/* do we have at least 16-bytes to copy (needed for alignment below) */
cmp r2, #16
blo 5f
/* align destination to cache-line for the write-buffer */
rsb r3, r0, #0
ands r3, r3, #0xF
beq 0f
/* copy up to 15-bytes (count in r3) */
sub r2, r2, r3
movs ip, r3, lsl #31
ldrmib lr, [r1], #1
strmib lr, [r0], #1
ldrcsb ip, [r1], #1
ldrcsb lr, [r1], #1
strcsb ip, [r0], #1
strcsb lr, [r0], #1
movs ip, r3, lsl #29
bge 1f
// copies 4 bytes, destination 32-bits aligned
vld4.8 {d0[0], d1[0], d2[0], d3[0]}, [r1]!
vst4.8 {d0[0], d1[0], d2[0], d3[0]}, [r0, :32]!
1: bcc 2f
// copies 8 bytes, destination 64-bits aligned
vld1.8 {d0}, [r1]!
vst1.8 {d0}, [r0, :64]!
2:
0: /* preload immediately the next cache line, which we may need */
pld [r1, #(CACHE_LINE_SIZE*0)]
pld [r1, #(CACHE_LINE_SIZE*2)]
/* make sure we have at least 64 bytes to copy */
subs r2, r2, #64
blo 2f
/* Preload all the cache lines we need.
* NOTE: The number of pld below depends on CACHE_LINE_SIZE,
* ideally we would increase the distance in the main loop to
* avoid the goofy code below. In practice this doesn't seem to make
* a big difference.
* NOTE: The value CACHE_LINE_SIZE * 8 was chosen through
* experimentation.
*/
pld [r1, #(CACHE_LINE_SIZE*4)]
pld [r1, #(CACHE_LINE_SIZE*6)]
pld [r1, #(CACHE_LINE_SIZE*8)]
1: /* The main loop copies 64 bytes at a time */
vld1.8 {d0 - d3}, [r1]!
vld1.8 {d4 - d7}, [r1]!
pld [r1, #(CACHE_LINE_SIZE*8)]
subs r2, r2, #64
vst1.8 {d0 - d3}, [r0, :128]!
vst1.8 {d4 - d7}, [r0, :128]!
bhs 1b
2: /* fix-up the remaining count and make sure we have >= 32 bytes left */
add r2, r2, #64
subs r2, r2, #32
blo 4f
3: /* 32 bytes at a time. These cache lines were already preloaded */
vld1.8 {d0 - d3}, [r1]!
subs r2, r2, #32
vst1.8 {d0 - d3}, [r0, :128]!
bhs 3b
4: /* less than 32 left */
add r2, r2, #32
tst r2, #0x10
beq 5f
// copies 16 bytes, 128-bits aligned
vld1.8 {d0, d1}, [r1]!
vst1.8 {d0, d1}, [r0, :128]!
5: /* copy up to 15-bytes (count in r2) */
movs ip, r2, lsl #29
bcc 1f
vld1.8 {d0}, [r1]!
vst1.8 {d0}, [r0]!
1: bge 2f
vld4.8 {d0[0], d1[0], d2[0], d3[0]}, [r1]!
vst4.8 {d0[0], d1[0], d2[0], d3[0]}, [r0]!
2: movs ip, r2, lsl #31
ldrmib r3, [r1], #1
ldrcsb ip, [r1], #1
ldrcsb lr, [r1], #1
strmib r3, [r0], #1
strcsb ip, [r0], #1
strcsb lr, [r0], #1
ldmfd sp!, {r0, lr}
bx lr
END(memcpy)