checkasm.asm

;*****************************************************************************
;* Assembly testing and benchmarking tool
;* Copyright (c) 2008 Loren Merritt
;* Copyright (c) 2012 Henrik Gramner
;*
;* This file is part of Libav.
;*
;* Libav 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.
;*
;* Libav 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.
;*****************************************************************************

%define private_prefix checkasm
%include "libavutil/x86/x86inc.asm"

SECTION_RODATA

error_message: db "failed to preserve register", 0

%if ARCH_X86_64
; just random numbers to reduce the chance of incidental match
ALIGN 16
x6:  dq 0x1a1b2550a612b48c,0x79445c159ce79064
x7:  dq 0x2eed899d5a28ddcd,0x86b2536fcd8cf636
x8:  dq 0xb0856806085e7943,0x3f2bf84fc0fcca4e
x9:  dq 0xacbd382dcf5b8de2,0xd229e1f5b281303f
x10: dq 0x71aeaff20b095fd9,0xab63e2e11fa38ed9
x11: dq 0x89b0c0765892729a,0x77d410d5c42c882d
x12: dq 0xc45ea11a955d8dd5,0x24b3c1d2a024048b
x13: dq 0x2e8ec680de14b47c,0xdd7b8919edd42786
x14: dq 0x135ce6888fa02cbf,0x11e53e2b2ac655ef
x15: dq 0x011ff554472a7a10,0x6de8f4c914c334d5
n7:  dq 0x21f86d66c8ca00ce
n8:  dq 0x75b6ba21077c48ad
n9:  dq 0xed56bb2dcb3c7736
n10: dq 0x8bda43d3fd1a7e06
n11: dq 0xb64a9c9e5d318408
n12: dq 0xdf9a54b303f1d3a3
n13: dq 0x4a75479abd64e097
n14: dq 0x249214109d5d1c88
%endif

SECTION .text

cextern fail_func

; max number of args used by any asm function.
; (max_args % 4) must equal 3 for stack alignment
%define max_args 15

%if ARCH_X86_64

;-----------------------------------------------------------------------------
; int checkasm_stack_clobber(uint64_t clobber, ...)
;-----------------------------------------------------------------------------
cglobal stack_clobber, 1,2
    ; Clobber the stack with junk below the stack pointer
    %define size (max_args+6)*8
    SUB  rsp, size
    mov   r1, size-8
.loop:
    mov [rsp+r1], r0
    sub   r1, 8
    jge .loop
    ADD  rsp, size
    RET

%if WIN64
    %assign free_regs 7
%else
    %assign free_regs 9
%endif

;-----------------------------------------------------------------------------
; intptr_t checkasm_checked_call(intptr_t (*func)(), ...)
;-----------------------------------------------------------------------------
INIT_XMM
cglobal checked_call, 2,15,16,max_args*8+8
    mov  r6, r0

    ; All arguments have been pushed on the stack instead of registers in order to
    ; test for incorrect assumptions that 32-bit ints are zero-extended to 64-bit.
    mov  r0, r6mp
    mov  r1, r7mp
    mov  r2, r8mp
    mov  r3, r9mp
%if UNIX64
    mov  r4, r10mp
    mov  r5, r11mp
    %assign i 6
    %rep max_args-6
        mov  r9, [rsp+stack_offset+(i+1)*8]
        mov  [rsp+(i-6)*8], r9
        %assign i i+1
    %endrep
%else
    %assign i 4
    %rep max_args-4
        mov  r9, [rsp+stack_offset+(i+7)*8]
        mov  [rsp+i*8], r9
        %assign i i+1
    %endrep
%endif

%if WIN64
    %assign i 6
    %rep 16-6
        mova m %+ i, [x %+ i]
        %assign i i+1
    %endrep
%endif

%assign i 14
%rep 15-free_regs
    mov r %+ i, [n %+ i]
    %assign i i-1
%endrep
    call r6
%assign i 14
%rep 15-free_regs
    xor r %+ i, [n %+ i]
    or  r14, r %+ i
    %assign i i-1
%endrep

%if WIN64
    %assign i 6
    %rep 16-6
        pxor m %+ i, [x %+ i]
        por  m6, m %+ i
        %assign i i+1
    %endrep
    packsswb m6, m6
    movq r5, m6
    or  r14, r5
%endif

    jz .ok
    mov  r9, rax
    lea  r0, [error_message]
    call fail_func
    mov rax, r9
.ok:
    RET

%else

; just random numbers to reduce the chance of incidental match
%define n3 dword 0x6549315c
%define n4 dword 0xe02f3e23
%define n5 dword 0xb78d0d1d
%define n6 dword 0x33627ba7

;-----------------------------------------------------------------------------
; intptr_t checkasm_checked_call(intptr_t (*func)(), ...)
;-----------------------------------------------------------------------------
cglobal checked_call, 1,7
    mov  r3, n3
    mov  r4, n4
    mov  r5, n5
    mov  r6, n6
%rep max_args
    PUSH dword [esp+20+max_args*4]
%endrep
    call r0
    xor  r3, n3
    xor  r4, n4
    xor  r5, n5
    xor  r6, n6
    or   r3, r4
    or   r5, r6
    or   r3, r5
    jz .ok
    mov  r3, eax
    lea  r0, [error_message]
    mov [esp], r0
    call fail_func
    mov  eax, r3
.ok:
    add  esp, max_args*4
    REP_RET

%endif ; ARCH_X86_64