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/*
* 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.
*/
#include <private/bionic_asm.h>
#include <private/libc_events.h>
/*
* This code assumes it is running on a processor that supports all arm v7
* instructions and that supports neon instructions.
*/
.fpu neon
.syntax unified
ENTRY(__memset_chk)
cmp r2, r3
bls .L_done
// Preserve lr for backtrace.
push {lr}
.cfi_def_cfa_offset 4
.cfi_rel_offset lr, 0
ldr r0, error_message
ldr r1, error_code
1:
add r0, pc
bl __fortify_chk_fail
error_code:
.word BIONIC_EVENT_MEMSET_BUFFER_OVERFLOW
error_message:
.word error_string-(1b+8)
END(__memset_chk)
ENTRY(bzero)
mov r2, r1
mov r1, #0
.L_done:
// Fall through to memset...
END(bzero)
/* memset() returns its first argument. */
ENTRY(memset)
// The neon memset only wins for less than 132.
cmp r2, #132
bhi __memset_large_copy
stmfd sp!, {r0}
.cfi_def_cfa_offset 4
.cfi_rel_offset r0, 0
vdup.8 q0, r1
/* 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
vst1.8 {d0 - d3}, [r0]!
bhs 1b
2: /* less than 32 left */
add r2, r2, #32
tst r2, #0x10
beq 3f
// writes 16 bytes, 128-bits aligned
vst1.8 {d0, d1}, [r0]!
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
strbmi r1, [r0], #1
strbcs r1, [r0], #1
strbcs r1, [r0], #1
ldmfd sp!, {r0}
bx lr
END(memset)
ENTRY_PRIVATE(__memset_large_copy)
/* compute the offset to align the destination
* offset = (4-(src&3))&3 = -src & 3
*/
stmfd sp!, {r0, r4-r7, lr}
.cfi_def_cfa_offset 24
.cfi_rel_offset r0, 0
.cfi_rel_offset r4, 4
.cfi_rel_offset r5, 8
.cfi_rel_offset r6, 12
.cfi_rel_offset r7, 16
.cfi_rel_offset lr, 20
rsb r3, r0, #0
ands r3, r3, #3
cmp r3, r2
movhi r3, r2
/* splat r1 */
mov r1, r1, lsl #24
orr r1, r1, r1, lsr #8
orr r1, r1, r1, lsr #16
movs r12, r3, lsl #31
strbcs r1, [r0], #1 /* can't use strh (alignment unknown) */
strbcs r1, [r0], #1
strbmi r1, [r0], #1
subs r2, r2, r3
popls {r0, r4-r7, pc} /* return */
/* align the destination to a cache-line */
mov r12, r1
mov lr, r1
mov r4, r1
mov r5, r1
mov r6, r1
mov r7, r1
rsb r3, r0, #0
ands r3, r3, #0x1C
beq 3f
cmp r3, r2
andhi r3, r2, #0x1C
sub r2, r2, r3
/* conditionally writes 0 to 7 words (length in r3) */
movs r3, r3, lsl #28
stmcs r0!, {r1, lr}
stmcs r0!, {r1, lr}
stmmi r0!, {r1, lr}
movs r3, r3, lsl #2
strcs r1, [r0], #4
3:
subs r2, r2, #32
mov r3, r1
bmi 2f
1: subs r2, r2, #32
stmia r0!, {r1,r3,r4,r5,r6,r7,r12,lr}
bhs 1b
2: add r2, r2, #32
/* conditionally stores 0 to 31 bytes */
movs r2, r2, lsl #28
stmcs r0!, {r1,r3,r12,lr}
stmmi r0!, {r1, lr}
movs r2, r2, lsl #2
strcs r1, [r0], #4
strhmi r1, [r0], #2
movs r2, r2, lsl #2
strbcs r1, [r0]
ldmfd sp!, {r0, r4-r7, pc}
END(__memset_large_copy)
.data
error_string:
.string "memset: prevented write past end of buffer"
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