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/****************************************************************************
* Assembly testing and benchmarking tool
* Copyright (c) 2015 Martin Storsjo
* Copyright (c) 2015 Janne Grunau
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111, USA.
*****************************************************************************/
#include "libavutil/arm/asm.S"
/* override fpu so that NEON instructions are rejected */
#if HAVE_VFP
FPU .fpu vfp
ELF .eabi_attribute 10, 0 @ suppress Tag_FP_arch
#endif
const register_init, align=3
.quad 0x21f86d66c8ca00ce
.quad 0x75b6ba21077c48ad
.quad 0xed56bb2dcb3c7736
.quad 0x8bda43d3fd1a7e06
.quad 0xb64a9c9e5d318408
.quad 0xdf9a54b303f1d3a3
.quad 0x4a75479abd64e097
.quad 0x249214109d5d1c88
endconst
const error_message_fpscr
.asciz "failed to preserve register FPSCR, changed bits: %x"
error_message_gpr:
.asciz "failed to preserve register r%d"
error_message_vfp:
.asciz "failed to preserve register d%d"
error_message_stack:
.asciz "failed to preserve stack"
endconst
@ max number of args used by any asm function.
#define MAX_ARGS 15
#define ARG_STACK 4*(MAX_ARGS - 4)
@ Align the used stack space to 8 to preserve the stack alignment.
@ +8 for stack canary reference.
#define ARG_STACK_A (((ARG_STACK + pushed + 7) & ~7) - pushed + 8)
.macro clobbercheck variant
.equ pushed, 4*9
function checkasm_checked_call_\variant, export=1
push {r4-r11, lr}
.ifc \variant, vfp
vpush {d8-d15}
fmrx r4, FPSCR
push {r4}
.equ pushed, pushed + 16*4 + 4
.endif
movrel r12, register_init
.ifc \variant, vfp
vldm r12, {d8-d15}
.endif
ldm r12, {r4-r11}
sub sp, sp, #ARG_STACK_A
.equ pos, 0
.rept MAX_ARGS-4
ldr r12, [sp, #ARG_STACK_A + pushed + 8 + pos]
str r12, [sp, #pos]
.equ pos, pos + 4
.endr
@ For stack overflows, the callee is free to overwrite the parameters
@ that were passed on the stack (if any), so we can only check after
@ that point. First figure out how many parameters the function
@ really took on the stack:
ldr r12, [sp, #ARG_STACK_A + pushed + 8 + 4*(MAX_ARGS-4)]
@ Load the first non-parameter value from the stack, that should be
@ left untouched by the function. Store a copy of it inverted, so that
@ e.g. overwriting everything with zero would be noticed.
ldr r12, [sp, r12, lsl #2]
mvn r12, r12
str r12, [sp, #ARG_STACK_A - 4]
mov r12, r0
mov r0, r2
mov r1, r3
ldrd r2, r3, [sp, #ARG_STACK_A + pushed]
@ Call the target function
blx r12
@ Load the number of stack parameters, stack canary and its reference
ldr r12, [sp, #ARG_STACK_A + pushed + 8 + 4*(MAX_ARGS-4)]
ldr r2, [sp, r12, lsl #2]
ldr r3, [sp, #ARG_STACK_A - 4]
add sp, sp, #ARG_STACK_A
push {r0, r1}
mvn r3, r3
cmp r2, r3
bne 5f
movrel r12, register_init
.ifc \variant, vfp
.macro check_reg_vfp, dreg, offset
ldrd r2, r3, [r12, #8 * (\offset)]
vmov r0, lr, \dreg
eor r2, r2, r0
eor r3, r3, lr
orrs r2, r2, r3
bne 4f
.endm
.irp n, 8, 9, 10, 11, 12, 13, 14, 15
@ keep track of the checked double/SIMD register
mov r1, #\n
check_reg_vfp d\n, \n-8
.endr
.purgem check_reg_vfp
fmrx r1, FPSCR
ldr r3, [sp, #8]
eor r1, r1, r3
@ Ignore changes in bits 0-4 and 7
bic r1, r1, #0x9f
@ Ignore changes in the topmost 5 bits
bics r1, r1, #0xf8000000
bne 3f
.endif
@ keep track of the checked GPR
mov r1, #4
.macro check_reg reg1, reg2=
ldrd r2, r3, [r12], #8
eors r2, r2, \reg1
bne 2f
add r1, r1, #1
.ifnb \reg2
eors r3, r3, \reg2
bne 2f
.endif
add r1, r1, #1
.endm
check_reg r4, r5
check_reg r6, r7
@ r9 is a volatile register in the ios ABI
#ifdef __APPLE__
check_reg r8
#else
check_reg r8, r9
#endif
check_reg r10, r11
.purgem check_reg
b 0f
5:
movrel r0, error_message_stack
b 1f
4:
movrel r0, error_message_vfp
b 1f
3:
movrel r0, error_message_fpscr
b 1f
2:
movrel r0, error_message_gpr
1:
bl X(checkasm_fail_func)
0:
pop {r0, r1}
.ifc \variant, vfp
pop {r2}
fmxr FPSCR, r2
vpop {d8-d15}
.endif
pop {r4-r11, pc}
endfunc
.endm
#if HAVE_VFP || HAVE_NEON
clobbercheck vfp
#endif
clobbercheck novfp
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