699c401889
Use the memset function in bionic for better performance. Signed-off-by: zhangyuan21 <zhangyuan21@xiaomi.com>
110 lines
2.8 KiB
ArmAsm
110 lines
2.8 KiB
ArmAsm
/****************************************************************************
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* libs/libc/machine/arm/armv7-m/gnu/arch_memset.S
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*
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* Copyright (C) 2008 The Android Open Source Project
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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****************************************************************************/
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#include "libc.h"
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#ifdef LIBC_BUILD_STRING
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.thumb
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.syntax unified
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.global memset
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.type memset, %function
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memset:
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stmfd sp!, {r0, r4-r7, lr}
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rsb r3, r0, #0
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ands r3, r3, #3
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cmp r3, r2
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movhi r3, r2
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/* splat r1 */
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mov r1, r1, lsl #24
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orr r1, r1, r1, lsr #8
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orr r1, r1, r1, lsr #16
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movs r12, r3, lsl #31
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strbcs r1, [r0], #1
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strbcs r1, [r0], #1
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strbmi r1, [r0], #1
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subs r2, r2, r3
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popls {r0, r4-r7, pc}
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/* align the destination to a cache-line */
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mov r12, r1
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mov lr, r1
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mov r4, r1
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mov r5, r1
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mov r6, r1
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mov r7, r1
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rsb r3, r0, #0
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ands r3, r3, #0x1C
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beq 3f
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cmp r3, r2
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andhi r3, r2, #0x1C
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sub r2, r2, r3
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/* conditionally writes 0 to 7 words (length in r3) */
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movs r3, r3, lsl #28
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stmcs r0!, {r1, lr}
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stmcs r0!, {r1, lr}
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stmmi r0!, {r1, lr}
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movs r3, r3, lsl #2
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strcs r1, [r0], #4
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3:
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subs r2, r2, #32
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mov r3, r1
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bmi 2f
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1:
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subs r2, r2, #32
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stmia r0!, {r1,r3,r4,r5,r6,r7,r12,lr}
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bhs 1b
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2:
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add r2, r2, #32
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/* conditionally stores 0 to 31 bytes */
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movs r2, r2, lsl #28
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stmcs r0!, {r1,r3,r12,lr}
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stmmi r0!, {r1, lr}
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movs r2, r2, lsl #2
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strcs r1, [r0], #4
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strhmi r1, [r0], #2
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movs r2, r2, lsl #2
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strbcs r1, [r0]
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ldmfd sp!, {r0, r4-r7, pc}
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.size memset, . - memset
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#endif
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