;*****************************************************************************
;* checkasm-a.asm: assembly check tool
;*****************************************************************************
;* Copyright (C) 2008-2014 x264 project
;*
;* Authors: Loren Merritt <lorenm@u.washington.edu>
;*          Henrik Gramner <henrik@gramner.com>
;*
;* This program 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.
;*
;* This program 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.
;*
;* This program is also available under a commercial proprietary license.
;* For more information, contact us at licensing@x264.com.
;*****************************************************************************

%include "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:  ddq 0x79445c159ce790641a1b2550a612b48c
x7:  ddq 0x86b2536fcd8cf6362eed899d5a28ddcd
x8:  ddq 0x3f2bf84fc0fcca4eb0856806085e7943
x9:  ddq 0xd229e1f5b281303facbd382dcf5b8de2
x10: ddq 0xab63e2e11fa38ed971aeaff20b095fd9
x11: ddq 0x77d410d5c42c882d89b0c0765892729a
x12: ddq 0x24b3c1d2a024048bc45ea11a955d8dd5
x13: ddq 0xdd7b8919edd427862e8ec680de14b47c
x14: ddq 0x11e53e2b2ac655ef135ce6888fa02cbf
x15: ddq 0x6de8f4c914c334d5011ff554472a7a10
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_naked puts

; max number of args used by any x264 asm function.
; (max_args % 4) must equal 3 for stack alignment
%define max_args 15

%if ARCH_X86_64

;-----------------------------------------------------------------------------
; void x264_checkasm_stack_clobber( uint64_t clobber, ... )
;-----------------------------------------------------------------------------
cglobal checkasm_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 x264_checkasm_call( intptr_t (*func)(), int *ok, ... )
;-----------------------------------------------------------------------------
INIT_XMM
cglobal checkasm_call, 2,15,16,max_args*8+8
    mov  r6, r0
    mov  [rsp+max_args*8], r1

    ; 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 puts
    mov  r1, [rsp+max_args*8]
    mov  dword [r1], 0
    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 x264_checkasm_call( intptr_t (*func)(), int *ok, ... )
;-----------------------------------------------------------------------------
cglobal checkasm_call, 1,7
    mov  r3, n3
    mov  r4, n4
    mov  r5, n5
    mov  r6, n6
%rep max_args
    push dword [esp+24+max_args*4]
%endrep
    call r0
    add  esp, max_args*4
    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  r1, [error_message]
    push r1
    call puts
    add  esp, 4
    mov  r1, r1m
    mov  dword [r1], 0
    mov  eax, r3
.ok:
    REP_RET

%endif ; ARCH_X86_64

;-----------------------------------------------------------------------------
; int x264_stack_pagealign( int (*func)(), int align )
;-----------------------------------------------------------------------------
cglobal stack_pagealign, 2,2
    movsxdifnidn r1, r1d
    push rbp
    mov  rbp, rsp
%if WIN64
    sub  rsp, 32 ; shadow space
%endif
    and  rsp, ~0xfff
    sub  rsp, r1
    call r0
    leave
    RET

