mirror of https://gitee.com/openkylin/linux.git
80 lines
1.5 KiB
ArmAsm
80 lines
1.5 KiB
ArmAsm
/*
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* linux/arch/arm/lib/io-readsl.S
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*
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* Copyright (C) 1995-2000 Russell King
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/linkage.h>
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#include <asm/assembler.h>
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ENTRY(__raw_readsl)
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teq r2, #0 @ do we have to check for the zero len?
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reteq lr
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ands ip, r1, #3
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bne 3f
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subs r2, r2, #4
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bmi 2f
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stmfd sp!, {r4, lr}
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1: ldr r3, [r0, #0]
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ldr r4, [r0, #0]
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ldr ip, [r0, #0]
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ldr lr, [r0, #0]
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subs r2, r2, #4
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stmia r1!, {r3, r4, ip, lr}
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bpl 1b
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ldmfd sp!, {r4, lr}
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2: movs r2, r2, lsl #31
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ldrcs r3, [r0, #0]
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ldrcs ip, [r0, #0]
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stmcsia r1!, {r3, ip}
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ldrne r3, [r0, #0]
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strne r3, [r1, #0]
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ret lr
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3: ldr r3, [r0]
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cmp ip, #2
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mov ip, r3, get_byte_0
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strb ip, [r1], #1
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bgt 6f
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mov ip, r3, get_byte_1
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strb ip, [r1], #1
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beq 5f
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mov ip, r3, get_byte_2
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strb ip, [r1], #1
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4: subs r2, r2, #1
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mov ip, r3, lspull #24
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ldrne r3, [r0]
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orrne ip, ip, r3, lspush #8
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strne ip, [r1], #4
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bne 4b
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b 8f
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5: subs r2, r2, #1
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mov ip, r3, lspull #16
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ldrne r3, [r0]
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orrne ip, ip, r3, lspush #16
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strne ip, [r1], #4
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bne 5b
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b 7f
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6: subs r2, r2, #1
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mov ip, r3, lspull #8
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ldrne r3, [r0]
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orrne ip, ip, r3, lspush #24
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strne ip, [r1], #4
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bne 6b
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mov r3, ip, get_byte_2
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strb r3, [r1, #2]
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7: mov r3, ip, get_byte_1
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strb r3, [r1, #1]
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8: mov r3, ip, get_byte_0
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strb r3, [r1, #0]
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ret lr
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ENDPROC(__raw_readsl)
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