462 lines
12 KiB
ArmAsm
462 lines
12 KiB
ArmAsm
/*
|
|
* Copyright (C) 2013 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.
|
|
*/
|
|
/*
|
|
* Copyright (c) 2013 ARM Ltd
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. 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.
|
|
* 3. The name of the company may not be used to endorse or promote
|
|
* products derived from this software without specific prior written
|
|
* permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY ARM LTD ``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 ARM LTD 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>
|
|
|
|
.syntax unified
|
|
|
|
.thumb
|
|
.thumb_func
|
|
|
|
.macro m_push
|
|
push {r0, r4, r5, lr}
|
|
.cfi_def_cfa_offset 16
|
|
.cfi_rel_offset r0, 0
|
|
.cfi_rel_offset r4, 4
|
|
.cfi_rel_offset r5, 8
|
|
.cfi_rel_offset lr, 12
|
|
.endm // m_push
|
|
|
|
.macro m_ret inst
|
|
\inst {r0, r4, r5, pc}
|
|
.endm // m_ret
|
|
|
|
.macro m_copy_byte reg, cmd, label
|
|
ldrb \reg, [r1], #1
|
|
strb \reg, [r0], #1
|
|
\cmd \reg, \label
|
|
.endm // m_copy_byte
|
|
|
|
ENTRY(strcpy)
|
|
// Unroll the first 8 bytes that will be copied.
|
|
m_push
|
|
m_copy_byte reg=r2, cmd=cbz, label=.Lstrcpy_finish
|
|
m_copy_byte reg=r3, cmd=cbz, label=.Lstrcpy_finish
|
|
m_copy_byte reg=r4, cmd=cbz, label=.Lstrcpy_finish
|
|
m_copy_byte reg=r5, cmd=cbz, label=.Lstrcpy_finish
|
|
m_copy_byte reg=r2, cmd=cbz, label=.Lstrcpy_finish
|
|
m_copy_byte reg=r3, cmd=cbz, label=.Lstrcpy_finish
|
|
m_copy_byte reg=r4, cmd=cbz, label=.Lstrcpy_finish
|
|
m_copy_byte reg=r5, cmd=cbnz, label=.Lstrcpy_continue
|
|
|
|
.Lstrcpy_finish:
|
|
m_ret inst=pop
|
|
|
|
.Lstrcpy_continue:
|
|
pld [r1, #0]
|
|
ands r3, r0, #7
|
|
bne .Lstrcpy_align_dst
|
|
|
|
.Lstrcpy_check_src_align:
|
|
// At this point dst is aligned to a double word, check if src
|
|
// is also aligned to a double word.
|
|
ands r3, r1, #7
|
|
bne .Lstrcpy_unaligned_copy
|
|
|
|
.p2align 2
|
|
.Lstrcpy_mainloop:
|
|
ldmia r1!, {r2, r3}
|
|
|
|
pld [r1, #64]
|
|
|
|
sub ip, r2, #0x01010101
|
|
bic ip, ip, r2
|
|
ands ip, ip, #0x80808080
|
|
bne .Lstrcpy_zero_in_first_register
|
|
|
|
sub ip, r3, #0x01010101
|
|
bic ip, ip, r3
|
|
ands ip, ip, #0x80808080
|
|
bne .Lstrcpy_zero_in_second_register
|
|
|
|
stmia r0!, {r2, r3}
|
|
b .Lstrcpy_mainloop
|
|
|
|
.Lstrcpy_zero_in_first_register:
|
|
lsls lr, ip, #17
|
|
itt ne
|
|
strbne r2, [r0]
|
|
m_ret inst=popne
|
|
itt cs
|
|
strhcs r2, [r0]
|
|
m_ret inst=popcs
|
|
lsls ip, ip, #1
|
|
itt eq
|
|
streq r2, [r0]
|
|
m_ret inst=popeq
|
|
strh r2, [r0], #2
|
|
lsr r3, r2, #16
|
|
strb r3, [r0]
|
|
m_ret inst=pop
|
|
|
|
.Lstrcpy_zero_in_second_register:
|
|
lsls lr, ip, #17
|
|
ittt ne
|
|
stmiane r0!, {r2}
|
|
strbne r3, [r0]
|
|
m_ret inst=popne
|
|
ittt cs
|
|
strcs r2, [r0], #4
|
|
strhcs r3, [r0]
|
|
m_ret inst=popcs
|
|
lsls ip, ip, #1
|
|
itt eq
|
|
stmiaeq r0, {r2, r3}
|
|
m_ret inst=popeq
|
|
stmia r0!, {r2}
|
|
strh r3, [r0], #2
|
|
lsr r4, r3, #16
|
|
strb r4, [r0]
|
|
m_ret inst=pop
|
|
|
|
.Lstrcpy_align_dst:
|
|
// Align to a double word (64 bits).
|
|
rsb r3, r3, #8
|
|
lsls ip, r3, #31
|
|
beq .Lstrcpy_align_to_32
|
|
|
|
ldrb r2, [r1], #1
|
|
strb r2, [r0], #1
|
|
cbz r2, .Lstrcpy_complete
|
|
|
|
.Lstrcpy_align_to_32:
|
|
bcc .Lstrcpy_align_to_64
|
|
|
|
ldrb r4, [r1], #1
|
|
strb r4, [r0], #1
|
|
cmp r4, #0
|
|
it eq
|
|
m_ret inst=popeq
|
|
ldrb r5, [r1], #1
|
|
strb r5, [r0], #1
|
|
cmp r5, #0
|
|
it eq
|
|
m_ret inst=popeq
|
|
|
|
.Lstrcpy_align_to_64:
|
|
tst r3, #4
|
|
beq .Lstrcpy_check_src_align
|
|
ldr r2, [r1], #4
|
|
|
|
sub ip, r2, #0x01010101
|
|
bic ip, ip, r2
|
|
ands ip, ip, #0x80808080
|
|
bne .Lstrcpy_zero_in_first_register
|
|
stmia r0!, {r2}
|
|
b .Lstrcpy_check_src_align
|
|
|
|
.Lstrcpy_complete:
|
|
m_ret inst=pop
|
|
|
|
.Lstrcpy_unaligned_copy:
|
|
// Dst is aligned to a double word, while src is at an unknown alignment.
|
|
// There are 7 different versions of the unaligned copy code
|
|
// to prevent overreading the src. The mainloop of every single version
|
|
// will store 64 bits per loop. The difference is how much of src can
|
|
// be read without potentially crossing a page boundary.
|
|
tbb [pc, r3]
|
|
.Lstrcpy_unaligned_branchtable:
|
|
.byte 0
|
|
.byte ((.Lstrcpy_unalign7 - .Lstrcpy_unaligned_branchtable)/2)
|
|
.byte ((.Lstrcpy_unalign6 - .Lstrcpy_unaligned_branchtable)/2)
|
|
.byte ((.Lstrcpy_unalign5 - .Lstrcpy_unaligned_branchtable)/2)
|
|
.byte ((.Lstrcpy_unalign4 - .Lstrcpy_unaligned_branchtable)/2)
|
|
.byte ((.Lstrcpy_unalign3 - .Lstrcpy_unaligned_branchtable)/2)
|
|
.byte ((.Lstrcpy_unalign2 - .Lstrcpy_unaligned_branchtable)/2)
|
|
.byte ((.Lstrcpy_unalign1 - .Lstrcpy_unaligned_branchtable)/2)
|
|
|
|
.p2align 2
|
|
// Can read 7 bytes before possibly crossing a page.
|
|
.Lstrcpy_unalign7:
|
|
ldr r2, [r1], #4
|
|
|
|
sub ip, r2, #0x01010101
|
|
bic ip, ip, r2
|
|
ands ip, ip, #0x80808080
|
|
bne .Lstrcpy_zero_in_first_register
|
|
|
|
ldrb r3, [r1]
|
|
cbz r3, .Lstrcpy_unalign7_copy5bytes
|
|
ldrb r4, [r1, #1]
|
|
cbz r4, .Lstrcpy_unalign7_copy6bytes
|
|
ldrb r5, [r1, #2]
|
|
cbz r5, .Lstrcpy_unalign7_copy7bytes
|
|
|
|
ldr r3, [r1], #4
|
|
pld [r1, #64]
|
|
|
|
lsrs ip, r3, #24
|
|
stmia r0!, {r2, r3}
|
|
beq .Lstrcpy_unalign_return
|
|
b .Lstrcpy_unalign7
|
|
|
|
.Lstrcpy_unalign7_copy5bytes:
|
|
stmia r0!, {r2}
|
|
strb r3, [r0]
|
|
.Lstrcpy_unalign_return:
|
|
m_ret inst=pop
|
|
|
|
.Lstrcpy_unalign7_copy6bytes:
|
|
stmia r0!, {r2}
|
|
strb r3, [r0], #1
|
|
strb r4, [r0], #1
|
|
m_ret inst=pop
|
|
|
|
.Lstrcpy_unalign7_copy7bytes:
|
|
stmia r0!, {r2}
|
|
strb r3, [r0], #1
|
|
strb r4, [r0], #1
|
|
strb r5, [r0], #1
|
|
m_ret inst=pop
|
|
|
|
.p2align 2
|
|
// Can read 6 bytes before possibly crossing a page.
|
|
.Lstrcpy_unalign6:
|
|
ldr r2, [r1], #4
|
|
|
|
sub ip, r2, #0x01010101
|
|
bic ip, ip, r2
|
|
ands ip, ip, #0x80808080
|
|
bne .Lstrcpy_zero_in_first_register
|
|
|
|
ldrb r4, [r1]
|
|
cbz r4, .Lstrcpy_unalign_copy5bytes
|
|
ldrb r5, [r1, #1]
|
|
cbz r5, .Lstrcpy_unalign_copy6bytes
|
|
|
|
ldr r3, [r1], #4
|
|
pld [r1, #64]
|
|
|
|
tst r3, #0xff0000
|
|
beq .Lstrcpy_unalign6_copy7bytes
|
|
lsrs ip, r3, #24
|
|
stmia r0!, {r2, r3}
|
|
beq .Lstrcpy_unalign_return
|
|
b .Lstrcpy_unalign6
|
|
|
|
.Lstrcpy_unalign6_copy7bytes:
|
|
stmia r0!, {r2}
|
|
strh r3, [r0], #2
|
|
lsr r3, #16
|
|
strb r3, [r0]
|
|
m_ret inst=pop
|
|
|
|
.p2align 2
|
|
// Can read 5 bytes before possibly crossing a page.
|
|
.Lstrcpy_unalign5:
|
|
ldr r2, [r1], #4
|
|
|
|
sub ip, r2, #0x01010101
|
|
bic ip, ip, r2
|
|
ands ip, ip, #0x80808080
|
|
bne .Lstrcpy_zero_in_first_register
|
|
|
|
ldrb r4, [r1]
|
|
cbz r4, .Lstrcpy_unalign_copy5bytes
|
|
|
|
ldr r3, [r1], #4
|
|
|
|
pld [r1, #64]
|
|
|
|
sub ip, r3, #0x01010101
|
|
bic ip, ip, r3
|
|
ands ip, ip, #0x80808080
|
|
bne .Lstrcpy_zero_in_second_register
|
|
|
|
stmia r0!, {r2, r3}
|
|
b .Lstrcpy_unalign5
|
|
|
|
.Lstrcpy_unalign_copy5bytes:
|
|
stmia r0!, {r2}
|
|
strb r4, [r0]
|
|
m_ret inst=pop
|
|
|
|
.Lstrcpy_unalign_copy6bytes:
|
|
stmia r0!, {r2}
|
|
strb r4, [r0], #1
|
|
strb r5, [r0]
|
|
m_ret inst=pop
|
|
|
|
.p2align 2
|
|
// Can read 4 bytes before possibly crossing a page.
|
|
.Lstrcpy_unalign4:
|
|
ldmia r1!, {r2}
|
|
|
|
sub ip, r2, #0x01010101
|
|
bic ip, ip, r2
|
|
ands ip, ip, #0x80808080
|
|
bne .Lstrcpy_zero_in_first_register
|
|
|
|
ldmia r1!, {r3}
|
|
pld [r1, #64]
|
|
|
|
sub ip, r3, #0x01010101
|
|
bic ip, ip, r3
|
|
ands ip, ip, #0x80808080
|
|
bne .Lstrcpy_zero_in_second_register
|
|
|
|
stmia r0!, {r2, r3}
|
|
b .Lstrcpy_unalign4
|
|
|
|
.p2align 2
|
|
// Can read 3 bytes before possibly crossing a page.
|
|
.Lstrcpy_unalign3:
|
|
ldrb r2, [r1]
|
|
cbz r2, .Lstrcpy_unalign3_copy1byte
|
|
ldrb r3, [r1, #1]
|
|
cbz r3, .Lstrcpy_unalign3_copy2bytes
|
|
ldrb r4, [r1, #2]
|
|
cbz r4, .Lstrcpy_unalign3_copy3bytes
|
|
|
|
ldr r2, [r1], #4
|
|
ldr r3, [r1], #4
|
|
|
|
pld [r1, #64]
|
|
|
|
lsrs lr, r2, #24
|
|
beq .Lstrcpy_unalign_copy4bytes
|
|
|
|
sub ip, r3, #0x01010101
|
|
bic ip, ip, r3
|
|
ands ip, ip, #0x80808080
|
|
bne .Lstrcpy_zero_in_second_register
|
|
|
|
stmia r0!, {r2, r3}
|
|
b .Lstrcpy_unalign3
|
|
|
|
.Lstrcpy_unalign3_copy1byte:
|
|
strb r2, [r0]
|
|
m_ret inst=pop
|
|
|
|
.Lstrcpy_unalign3_copy2bytes:
|
|
strb r2, [r0], #1
|
|
strb r3, [r0]
|
|
m_ret inst=pop
|
|
|
|
.Lstrcpy_unalign3_copy3bytes:
|
|
strb r2, [r0], #1
|
|
strb r3, [r0], #1
|
|
strb r4, [r0]
|
|
m_ret inst=pop
|
|
|
|
.p2align 2
|
|
// Can read 2 bytes before possibly crossing a page.
|
|
.Lstrcpy_unalign2:
|
|
ldrb r2, [r1]
|
|
cbz r2, .Lstrcpy_unalign_copy1byte
|
|
ldrb r3, [r1, #1]
|
|
cbz r3, .Lstrcpy_unalign_copy2bytes
|
|
|
|
ldr r2, [r1], #4
|
|
ldr r3, [r1], #4
|
|
pld [r1, #64]
|
|
|
|
tst r2, #0xff0000
|
|
beq .Lstrcpy_unalign_copy3bytes
|
|
lsrs ip, r2, #24
|
|
beq .Lstrcpy_unalign_copy4bytes
|
|
|
|
sub ip, r3, #0x01010101
|
|
bic ip, ip, r3
|
|
ands ip, ip, #0x80808080
|
|
bne .Lstrcpy_zero_in_second_register
|
|
|
|
stmia r0!, {r2, r3}
|
|
b .Lstrcpy_unalign2
|
|
|
|
.p2align 2
|
|
// Can read 1 byte before possibly crossing a page.
|
|
.Lstrcpy_unalign1:
|
|
ldrb r2, [r1]
|
|
cbz r2, .Lstrcpy_unalign_copy1byte
|
|
|
|
ldr r2, [r1], #4
|
|
ldr r3, [r1], #4
|
|
|
|
pld [r1, #64]
|
|
|
|
sub ip, r2, #0x01010101
|
|
bic ip, ip, r2
|
|
ands ip, ip, #0x80808080
|
|
bne .Lstrcpy_zero_in_first_register
|
|
|
|
sub ip, r3, #0x01010101
|
|
bic ip, ip, r3
|
|
ands ip, ip, #0x80808080
|
|
bne .Lstrcpy_zero_in_second_register
|
|
|
|
stmia r0!, {r2, r3}
|
|
b .Lstrcpy_unalign1
|
|
|
|
.Lstrcpy_unalign_copy1byte:
|
|
strb r2, [r0]
|
|
m_ret inst=pop
|
|
|
|
.Lstrcpy_unalign_copy2bytes:
|
|
strb r2, [r0], #1
|
|
strb r3, [r0]
|
|
m_ret inst=pop
|
|
|
|
.Lstrcpy_unalign_copy3bytes:
|
|
strh r2, [r0], #2
|
|
lsr r2, #16
|
|
strb r2, [r0]
|
|
m_ret inst=pop
|
|
|
|
.Lstrcpy_unalign_copy4bytes:
|
|
stmia r0, {r2}
|
|
m_ret inst=pop
|
|
END(strcpy)
|