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ioef/code/qcommon/vm_x86.c

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/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.
This file is part of Quake III Arena source code.
Quake III Arena source code 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.
Quake III Arena source code 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 Quake III Arena source code; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
===========================================================================
*/
// vm_x86.c -- load time compiler and execution environment for x86
#include "vm_local.h"
#ifdef _WIN32
#include <windows.h>
#endif
#ifdef __FreeBSD__
#include <sys/types.h>
#endif
#ifndef _WIN32
#include <sys/mman.h> // for PROT_ stuff
#endif
/* need this on NX enabled systems (i386 with PAE kernel or
* noexec32=on x86_64) */
#if defined(__linux__) || defined(__FreeBSD__)
#define VM_X86_MMAP
#endif
static void VM_Destroy_Compiled(vm_t* self);
/*
eax scratch
ebx scratch
ecx scratch (required for shifts)
edx scratch (required for divisions)
esi program stack
edi opstack
*/
#define VMFREE_BUFFERS() do {Z_Free(buf); Z_Free(jused);} while(0)
static byte *buf = NULL;
static byte *jused = NULL;
static int jusedSize = 0;
static int compiledOfs = 0;
static byte *code = NULL;
static int pc = 0;
#define FTOL_PTR
#ifdef _MSC_VER
#if defined( FTOL_PTR )
int _ftol( float );
static int ftolPtr = (int)_ftol;
#endif
#else // _MSC_VER
#if defined( FTOL_PTR )
int qftol( void );
int qftol027F( void );
int qftol037F( void );
int qftol0E7F( void );
int qftol0F7F( void );
static int ftolPtr = (int)qftol0F7F;
#endif // FTOL_PTR
#endif
static int instruction, pass;
static int lastConst = 0;
static int oc0, oc1, pop0, pop1;
static int jlabel;
typedef enum
{
LAST_COMMAND_NONE = 0,
LAST_COMMAND_MOV_EDI_EAX,
LAST_COMMAND_SUB_DI_4,
LAST_COMMAND_SUB_DI_8,
} ELastCommand;
static ELastCommand LastCommand;
static void ErrJump( void )
{
Com_Error( ERR_DROP, "program tried to execute code outside VM\n" );
exit(1);
}
static void (*const errJumpPtr)(void) = ErrJump;
static int NextConstant4(void)
{
return (code[pc] | (code[pc+1]<<8) | (code[pc+2]<<16) | (code[pc+3]<<24));
}
static int Constant4( void ) {
int v;
v = NextConstant4();
pc += 4;
return v;
}
static int Constant1( void ) {
int v;
v = code[pc];
pc += 1;
return v;
}
static void Emit1( int v )
{
buf[ compiledOfs ] = v;
compiledOfs++;
LastCommand = LAST_COMMAND_NONE;
}
#if 0
static void Emit2( int v ) {
Emit1( v & 255 );
Emit1( ( v >> 8 ) & 255 );
}
#endif
static void Emit4( int v ) {
Emit1( v & 255 );
Emit1( ( v >> 8 ) & 255 );
Emit1( ( v >> 16 ) & 255 );
Emit1( ( v >> 24 ) & 255 );
}
static int Hex( int c ) {
if ( c >= 'a' && c <= 'f' ) {
return 10 + c - 'a';
}
if ( c >= 'A' && c <= 'F' ) {
return 10 + c - 'A';
}
if ( c >= '0' && c <= '9' ) {
return c - '0';
}
VMFREE_BUFFERS();
Com_Error( ERR_DROP, "Hex: bad char '%c'", c );
return 0;
}
static void EmitString( const char *string ) {
int c1, c2;
int v;
while ( 1 ) {
c1 = string[0];
c2 = string[1];
v = ( Hex( c1 ) << 4 ) | Hex( c2 );
Emit1( v );
if ( !string[2] ) {
break;
}
string += 3;
}
}
static void EmitCommand(ELastCommand command)
{
switch(command)
{
case LAST_COMMAND_MOV_EDI_EAX:
EmitString( "89 07" ); // mov dword ptr [edi], eax
break;
case LAST_COMMAND_SUB_DI_4:
EmitString( "83 EF 04" ); // sub edi, 4
break;
case LAST_COMMAND_SUB_DI_8:
EmitString( "83 EF 08" ); // sub edi, 8
break;
default:
break;
}
LastCommand = command;
}
static void EmitAddEDI4( vm_t *vm ) {
if ( jlabel ) {
EmitString( "83 C7 04" ); // add edi,4
return;
}
if ( LastCommand == LAST_COMMAND_SUB_DI_4 )
{ // sub edi, 4
compiledOfs -= 3;
vm->instructionPointers[ instruction-1 ] = compiledOfs;
return;
}
if ( LastCommand == LAST_COMMAND_SUB_DI_8 )
{ // sub edi, 8
compiledOfs -= 3;
vm->instructionPointers[ instruction-1 ] = compiledOfs;
EmitString( "83 EF 04" ); // sub edi,4
return;
}
EmitString( "83 C7 04" ); // add edi,4
}
static void EmitMovEAXEDI(vm_t *vm) {
if ( jlabel ) {
EmitString( "8B 07" ); // mov eax, dword ptr [edi]
return;
}
if (LastCommand == LAST_COMMAND_MOV_EDI_EAX)
{ // mov [edi], eax
compiledOfs -= 2;
vm->instructionPointers[ instruction-1 ] = compiledOfs;
return;
}
if (pop1 == OP_DIVI || pop1 == OP_DIVU || pop1 == OP_MULI || pop1 == OP_MULU ||
pop1 == OP_STORE4 || pop1 == OP_STORE2 || pop1 == OP_STORE1 )
{
return;
}
if (pop1 == OP_CONST && buf[compiledOfs-6] == 0xC7 && buf[compiledOfs-5] == 0x07 )
{ // mov edi, 0x123456
compiledOfs -= 6;
vm->instructionPointers[ instruction-1 ] = compiledOfs;
EmitString( "B8" ); // mov eax, 0x12345678
Emit4( lastConst );
return;
}
EmitString( "8B 07" ); // mov eax, dword ptr [edi]
}
void EmitMovECXEDI( vm_t *vm ) {
if ( jlabel ) {
EmitString( "8B 0F" ); // mov ecx, dword ptr [edi]
return;
}
if ( LastCommand == LAST_COMMAND_MOV_EDI_EAX ) // mov [edi], eax
{
compiledOfs -= 2;
vm->instructionPointers[ instruction-1 ] = compiledOfs;
EmitString( "89 C1" ); // mov ecx, eax
return;
}
if (pop1 == OP_DIVI || pop1 == OP_DIVU || pop1 == OP_MULI || pop1 == OP_MULU ||
pop1 == OP_STORE4 || pop1 == OP_STORE2 || pop1 == OP_STORE1 )
{
EmitString( "89 C1" ); // mov ecx, eax
return;
}
EmitString( "8B 0F" ); // mov ecx, dword ptr [edi]
}
qboolean EmitMovEBXEDI(vm_t *vm, int andit) {
if ( jlabel ) {
EmitString( "8B 1F" ); // mov ebx, dword ptr [edi]
return qfalse;
}
if ( LastCommand == LAST_COMMAND_MOV_EDI_EAX )
{ // mov dword ptr [edi], eax
compiledOfs -= 2;
vm->instructionPointers[ instruction-1 ] = compiledOfs;
EmitString( "8B D8"); // mov bx, eax
return qfalse;
}
if ( pop1 == OP_DIVI || pop1 == OP_DIVU || pop1 == OP_MULI || pop1 == OP_MULU ||
pop1 == OP_STORE4 || pop1 == OP_STORE2 || pop1 == OP_STORE1 )
{
EmitString( "8B D8"); // mov bx, eax
return qfalse;
}
if ( pop1 == OP_CONST && buf[compiledOfs-6] == 0xC7 && buf[compiledOfs-5] == 0x07 )
{ // mov dword ptr [edi], 0x12345678
compiledOfs -= 6;
vm->instructionPointers[ instruction-1 ] = compiledOfs;
EmitString( "BB" ); // mov ebx, 0x12345678
if (andit) {
Emit4( lastConst & andit );
} else {
Emit4( lastConst );
}
return qtrue;
}
EmitString( "8B 1F" ); // mov ebx, dword ptr [edi]
return qfalse;
}
#define JUSED(x) \
do { \
if (x < 0 || x >= jusedSize) { \
VMFREE_BUFFERS(); \
Com_Error( ERR_DROP, \
"VM_CompileX86: jump target out of range at offset %d", pc ); \
} \
jused[x] = 1; \
} while(0)
#define SET_JMPOFS(x) do { buf[(x)] = compiledOfs - ((x) + 1); } while(0)
/*
=================
DoSyscall
Uses asm to retrieve arguments from registers to work around different calling conventions
=================
*/
static void DoSyscall(void)
{
vm_t *savedVM;
int *data;
int syscallNum;
int programStack;
int *opStack;
#ifdef _MSC_VER
__asm
{
mov dword ptr syscallNum, eax
mov dword ptr programStack, esi
mov dword ptr opStack, edi
}
#else
__asm__ volatile(
""
: "=a" (syscallNum), "=S" (programStack), "=D" (opStack)
:
: "memory"
);
#endif
// save currentVM so as to allow for recursive VM entry
savedVM = currentVM;
data = (int *) (savedVM->dataBase + programStack + 4);
// modify VM stack pointer for recursive VM entry
savedVM->programStack = programStack - 4;
*data = syscallNum;
opStack[1] = savedVM->systemCall(data);
currentVM = savedVM;
}
/*
=================
EmitCallProcedure
=================
*/
int EmitCallProcedure(vm_t *vm)
{
int jmpSystemCall, jmpBadAddr;
int retval;
EmitString("8B 07"); // mov eax, dword ptr [edi]
EmitString("83 EF 04"); // sub edi, 4
EmitString("85 C0"); // test eax, eax
// Jump to syscall code
EmitString("7C"); // jl systemCall
jmpSystemCall = compiledOfs++;
/************ Call inside VM ************/
EmitString("81 F8"); // cmp eax, vm->instructionCount
Emit4(vm->instructionCount);
// Error jump if invalid jump target
EmitString("73"); // jae badAddr
jmpBadAddr = compiledOfs++;
EmitString("FF 14 85"); // call dword ptr [vm->instructionPointers + eax * 4]
Emit4((intptr_t) vm->instructionPointers);
EmitString("8B 07"); // mov eax, dword ptr [edi]
EmitString("C3"); // ret
// badAddr:
SET_JMPOFS(jmpBadAddr);
EmitString("B8"); // mov eax, ErrJump
Emit4((intptr_t) ErrJump);
EmitString("FF D0"); // call eax
/************ System Call ************/
// systemCall:
SET_JMPOFS(jmpSystemCall);
retval = compiledOfs;
EmitString("F7 D0"); // not eax
// use edx register to store DoSyscall address
EmitString("BA"); // mov edx, DoSyscall
Emit4((intptr_t) DoSyscall);
// align the stack pointer to a 16-byte-boundary
EmitString("55"); // push ebp
EmitString("89 E5"); // mov ebp, esp
EmitString("83 E4 F0"); // and esp, 0xFFFFFFF0
// call the syscall wrapper function
EmitString("FF D2"); // call edx
// reset the stack pointer to its previous value
EmitString("89 EC"); // mov esp, ebp
EmitString("5D"); // pop ebp
// have opStack reg point at return value
EmitString("83 C7 04"); // add edi, 4
EmitString("C3"); // ret
return retval;
}
void EmitCall(vm_t *vm, int sysCallOfs)
{
EmitString("8B 15"); // mov edx, [dword ptr vm->codeBase]
Emit4((intptr_t) &vm->codeBase);
if(sysCallOfs)
{
if(sysCallOfs < 0x80 || sysCallOfs > 0x7f)
{
EmitString("83 C2"); // add edx, sysCallOfs
Emit1(sysCallOfs);
}
else
{
EmitString("81 C2"); // add edx, sysCallOfs
Emit4(sysCallOfs);
}
}
EmitString("FF D2"); // call edx
}
/*
=================
EmitCallConst
=================
*/
void EmitCallConst(vm_t *vm, int cdest, int sysCallOfs)
{
if(cdest < 0)
{
EmitString("B8"); // mov eax, cdest
Emit4(cdest);
EmitCall(vm, sysCallOfs);
}
else
{
JUSED(cdest);
EmitString("FF 15"); // call dword ptr [vm->instructionPointers + cdest]
Emit4((intptr_t) &vm->instructionPointers[cdest]);
}
}
/*
=================
ConstOptimize
=================
*/
qboolean ConstOptimize(vm_t *vm, int sysCallOfs)
{
int v, opt;
int op1;
// we can safely perform optimizations only in case if
// we are 100% sure that next instruction is not a jump label
if (vm->jumpTableTargets && !jused[instruction])
op1 = code[pc+4];
else
return qfalse;
switch ( op1 ) {
case OP_LOAD4:
EmitAddEDI4(vm);
EmitString( "BB" ); // mov ebx, 0x12345678
Emit4( (Constant4()&vm->dataMask) + (int)vm->dataBase);
EmitString( "8B 03" ); // mov eax, dword ptr [ebx]
EmitCommand(LAST_COMMAND_MOV_EDI_EAX); // mov dword ptr [edi], eax
pc++; // OP_LOAD4
instruction += 1;
return qtrue;
case OP_LOAD2:
EmitAddEDI4(vm);
EmitString( "BB" ); // mov ebx, 0x12345678
Emit4( (Constant4()&vm->dataMask) + (int)vm->dataBase);
EmitString( "0F B7 03" ); // movzx eax, word ptr [ebx]
EmitCommand(LAST_COMMAND_MOV_EDI_EAX); // mov dword ptr [edi], eax
pc++; // OP_LOAD2
instruction += 1;
return qtrue;
case OP_LOAD1:
EmitAddEDI4(vm);
EmitString( "BB" ); // mov ebx, 0x12345678
Emit4( (Constant4()&vm->dataMask) + (int)vm->dataBase);
EmitString( "0F B6 03" ); // movzx eax, byte ptr [ebx]
EmitCommand(LAST_COMMAND_MOV_EDI_EAX); // mov dword ptr [edi], eax
pc++; // OP_LOAD1
instruction += 1;
return qtrue;
case OP_STORE4:
opt = EmitMovEBXEDI(vm, (vm->dataMask & ~3));
EmitString( "B8" ); // mov eax, 0x12345678
Emit4( Constant4() );
// if (!opt) {
// EmitString( "81 E3" ); // and ebx, 0x12345678
// Emit4( vm->dataMask & ~3 );
// }
EmitString( "89 83" ); // mov dword ptr [ebx+0x12345678], eax
Emit4( (int)vm->dataBase );
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
pc++; // OP_STORE4
instruction += 1;
return qtrue;
case OP_STORE2:
opt = EmitMovEBXEDI(vm, (vm->dataMask & ~1));
EmitString( "B8" ); // mov eax, 0x12345678
Emit4( Constant4() );
// if (!opt) {
// EmitString( "81 E3" ); // and ebx, 0x12345678
// Emit4( vm->dataMask & ~1 );
// }
EmitString( "66 89 83" ); // mov word ptr [ebx+0x12345678], eax
Emit4( (int)vm->dataBase );
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
pc++; // OP_STORE2
instruction += 1;
return qtrue;
case OP_STORE1:
opt = EmitMovEBXEDI(vm, vm->dataMask);
EmitString( "B8" ); // mov eax, 0x12345678
Emit4( Constant4() );
// if (!opt) {
// EmitString( "81 E3" ); // and ebx, 0x12345678
// Emit4( vm->dataMask );
// }
EmitString( "88 83" ); // mov byte ptr [ebx+0x12345678], eax
Emit4( (int)vm->dataBase );
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
pc++; // OP_STORE4
instruction += 1;
return qtrue;
case OP_ADD:
v = Constant4();
EmitMovEAXEDI( vm );
if ( v >= 0 && v <= 127 ) {
EmitString( "83 C0" ); // add eax, 0x7F
Emit1( v );
} else {
EmitString( "05" ); // add eax, 0x12345678
Emit4( v );
}
EmitCommand( LAST_COMMAND_MOV_EDI_EAX );
pc++; // OP_ADD
instruction += 1;
return qtrue;
case OP_SUB:
v = Constant4();
EmitMovEAXEDI( vm );
if ( v >= 0 && v <= 127 ) {
EmitString( "83 E8" ); // sub eax, 0x7F
Emit1( v );
} else {
EmitString( "2D" ); // sub eax, 0x12345678
Emit4( v );
}
EmitCommand( LAST_COMMAND_MOV_EDI_EAX );
pc++; // OP_SUB
instruction += 1;
return qtrue;
case OP_MULI:
v = Constant4();
EmitMovEAXEDI( vm );
if ( v >= 0 && v <= 127 ) {
EmitString( "6B C0" ); // imul eax, 0x7F
Emit1( v );
} else {
EmitString( "69 C0" ); // imul eax, 0x12345678
Emit4( v );
}
EmitCommand( LAST_COMMAND_MOV_EDI_EAX );
pc++; // OP_MULI
instruction += 1;
return qtrue;
case OP_LSH:
v = NextConstant4();
if ( v < 0 || v > 31 )
break;
EmitMovEAXEDI( vm );
EmitString( "C1 E0" ); // shl dword ptr [edi], 0x12
Emit1( v );
EmitCommand( LAST_COMMAND_MOV_EDI_EAX );
pc += 5; // CONST + OP_LSH
instruction += 1;
return qtrue;
case OP_RSHI:
v = NextConstant4();
if ( v < 0 || v > 31 )
break;
EmitMovEAXEDI( vm );
EmitString( "C1 F8" ); // sar eax, 0x12
Emit1( v );
EmitCommand( LAST_COMMAND_MOV_EDI_EAX );
pc += 5; // CONST + OP_RSHI
instruction += 1;
return qtrue;
case OP_RSHU:
v = NextConstant4();
if ( v < 0 || v > 31 )
break;
EmitMovEAXEDI( vm );
EmitString( "C1 E8" ); // shr eax, 0x12
Emit1( v );
EmitCommand( LAST_COMMAND_MOV_EDI_EAX );
pc += 5; // CONST + OP_RSHU
instruction += 1;
return qtrue;
case OP_BAND:
v = Constant4();
EmitMovEAXEDI( vm );
if ( v >= 0 && v <= 127 ) {
EmitString( "83 E0" ); // and eax, 0x7F
Emit1( v );
} else {
EmitString( "25" ); // and eax, 0x12345678
Emit4( v );
}
EmitCommand( LAST_COMMAND_MOV_EDI_EAX );
pc += 1; // OP_BAND
instruction += 1;
return qtrue;
case OP_BOR:
v = Constant4();
EmitMovEAXEDI( vm );
if ( v >= 0 && v <= 127 ) {
EmitString( "83 C8" ); // or eax, 0x7F
Emit1( v );
} else {
EmitString( "0D" ); // or eax, 0x12345678
Emit4( v );
}
EmitCommand( LAST_COMMAND_MOV_EDI_EAX );
pc += 1; // OP_BOR
instruction += 1;
return qtrue;
case OP_BXOR:
v = Constant4();
EmitMovEAXEDI( vm );
if ( v >= 0 && v <= 127 ) {
EmitString( "83 F0" ); // xor eax, 0x7F
Emit1( v );
} else {
EmitString( "35" ); // xor eax, 0x12345678
Emit4( v );
}
EmitCommand( LAST_COMMAND_MOV_EDI_EAX );
pc += 1; // OP_BXOR
instruction += 1;
return qtrue;
case OP_EQF:
case OP_NEF:
if ( NextConstant4() != 0 )
break;
pc += 5; // CONST + OP_EQF|OP_NEF
EmitMovEAXEDI( vm );
EmitCommand(LAST_COMMAND_SUB_DI_4);
// floating point hack :)
EmitString( "25" ); // and eax, 0x7FFFFFFF
Emit4( 0x7FFFFFFF );
if ( op1 == OP_EQF )
EmitString( "75 06" ); // jnz +6
else
EmitString( "74 06" ); // jz +6
EmitString( "FF 25" ); // jmp [0x12345678]
v = Constant4();
JUSED(v);
Emit4( (int)vm->instructionPointers + v*4 );
instruction += 1;
return qtrue;
case OP_EQ:
case OP_NE:
v = Constant4();
EmitMovEAXEDI( vm );
EmitCommand(LAST_COMMAND_SUB_DI_4);
if ( v == 0 ) {
EmitString( "85 C0" ); // test eax, eax
} else {
EmitString( "3D" ); // cmp eax, 0x12345678
Emit4( v );
}
pc += 1; // OP_EQ/OP_NE
if ( op1 == OP_EQ )
EmitString( "75 06" ); // jne +6
else
EmitString( "74 06" ); // je +6
EmitString( "FF 25" ); // jmp [0x12345678]
v = Constant4();
JUSED(v);
Emit4( (int)vm->instructionPointers + v*4 );
instruction += 1;
return qtrue;
case OP_GEI:
case OP_GTI:
v = Constant4();
EmitMovEAXEDI( vm );
EmitCommand( LAST_COMMAND_SUB_DI_4 );
EmitString( "3D" ); // cmp eax, 0x12345678
Emit4( v );
pc += 1; // OP_GEI|OP_GTI
if ( op1 == OP_GEI )
EmitString( "7C 06" ); // jl +6
else
EmitString( "7E 06" ); // jle +6
EmitString( "FF 25" ); // jmp [0x12345678]
v = Constant4();
JUSED(v);
Emit4( (int)vm->instructionPointers + v*4 );
instruction += 1;
return qtrue;
case OP_LEI:
case OP_LTI:
v = Constant4();
EmitMovEAXEDI( vm );
EmitCommand( LAST_COMMAND_SUB_DI_4 );
EmitString( "3D" ); // cmp eax, 0x12345678
Emit4( v );
pc += 1; // OP_GEI|OP_GTI
if ( op1 == OP_LEI )
EmitString( "7F 06" ); // jg +6
else
EmitString( "7D 06" ); // jge +6
EmitString( "FF 25" ); // jmp [0x12345678]
v = Constant4();
JUSED(v);
Emit4( (int)vm->instructionPointers + v*4 );
instruction += 1;
return qtrue;
case OP_JUMP:
v = Constant4();
JUSED(v);
EmitString( "FF 25" ); // jmp dword ptr [instructionPointers + 0x12345678]
Emit4( (int)vm->instructionPointers + v*4 );
pc += 1; // OP_JUMP
instruction += 1;
return qtrue;
case OP_CALL:
if ( NextConstant4() < 0 )
break;
v = Constant4();
EmitCallConst(vm, v, sysCallOfs);
pc += 1; // OP_CALL
instruction += 1;
return qtrue;
default:
break;
}
return qfalse;
}
/*
=================
VM_Compile
=================
*/
void VM_Compile( vm_t *vm, vmHeader_t *header ) {
int op;
int maxLength;
int v;
int i;
int sysCallOfs;
jusedSize = header->instructionCount + 2;
// allocate a very large temp buffer, we will shrink it later
maxLength = header->codeLength * 8;
buf = Z_Malloc(maxLength);
jused = Z_Malloc(jusedSize);
code = Z_Malloc(header->codeLength+32);
Com_Memset(jused, 0, jusedSize);
Com_Memset(buf, 0, maxLength);
// copy code in larger buffer and put some zeros at the end
// so we can safely look ahead for a few instructions in it
// without a chance to get false-positive because of some garbage bytes
Com_Memset(code, 0, header->codeLength+32);
Com_Memcpy(code, (byte *)header + header->codeOffset, header->codeLength );
// ensure that the optimisation pass knows about all the jump
// table targets
for( i = 0; i < vm->numJumpTableTargets; i++ ) {
jused[ *(int *)(vm->jumpTableTargets + ( i * sizeof( int ) ) ) ] = 1;
}
// Start buffer with x86-VM specific procedures
compiledOfs = 0;
sysCallOfs = EmitCallProcedure(vm);
vm->entryOfs = compiledOfs;
for(pass=0;pass<2;pass++) {
oc0 = -23423;
oc1 = -234354;
pop0 = -43435;
pop1 = -545455;
// translate all instructions
pc = 0;
instruction = 0;
//code = (byte *)header + header->codeOffset;
compiledOfs = vm->entryOfs;
LastCommand = LAST_COMMAND_NONE;
while(instruction < header->instructionCount)
{
if(compiledOfs > maxLength - 16)
{
VMFREE_BUFFERS();
Com_Error(ERR_DROP, "VM_CompileX86: maxLength exceeded");
}
vm->instructionPointers[ instruction ] = compiledOfs;
if ( !vm->jumpTableTargets )
jlabel = 1;
else
jlabel = jused[ instruction ];
instruction++;
if(pc > header->codeLength)
{
VMFREE_BUFFERS();
Com_Error(ERR_DROP, "VM_CompileX86: pc > header->codeLength");
}
op = code[ pc ];
pc++;
switch ( op ) {
case 0:
break;
case OP_BREAK:
EmitString( "CC" ); // int 3
break;
case OP_ENTER:
EmitString( "81 EE" ); // sub esi, 0x12345678
Emit4( Constant4() );
break;
case OP_CONST:
if(ConstOptimize(vm, sysCallOfs))
break;
EmitAddEDI4(vm);
EmitString( "C7 07" ); // mov dword ptr [edi], 0x12345678
lastConst = Constant4();
Emit4( lastConst );
if (code[pc] == OP_JUMP) {
JUSED(lastConst);
}
break;
case OP_LOCAL:
EmitAddEDI4(vm);
EmitString( "8D 86" ); // lea eax, [0x12345678 + esi]
oc0 = oc1;
oc1 = Constant4();
Emit4( oc1 );
EmitCommand(LAST_COMMAND_MOV_EDI_EAX); // mov dword ptr [edi], eax
break;
case OP_ARG:
EmitMovEAXEDI(vm); // mov eax,dword ptr [edi]
EmitString( "89 86" ); // mov dword ptr [esi+database],eax
Emit4((Constant1() & vm->dataMask & 0xFF) + (int) vm->dataBase);
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
break;
case OP_CALL:
EmitCall(vm, 0);
break;
case OP_PUSH:
EmitAddEDI4(vm);
break;
case OP_POP:
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
break;
case OP_LEAVE:
v = Constant4();
EmitString( "81 C6" ); // add esi, 0x12345678
Emit4( v );
EmitString( "C3" ); // ret
break;
case OP_LOAD4:
if (code[pc] == OP_CONST && code[pc+5] == OP_ADD && code[pc+6] == OP_STORE4) {
if (oc0 == oc1 && pop0 == OP_LOCAL && pop1 == OP_LOCAL) {
compiledOfs -= 11;
vm->instructionPointers[ instruction-1 ] = compiledOfs;
}
pc++; // OP_CONST
v = Constant4();
EmitMovEBXEDI(vm, vm->dataMask);
if (v == 1 && oc0 == oc1 && pop0 == OP_LOCAL && pop1 == OP_LOCAL) {
EmitString( "FF 83"); // inc dword ptr [ebx + 0x12345678]
Emit4( (int)vm->dataBase );
} else {
EmitString( "8B 83" ); // mov eax, dword ptr [ebx + 0x12345678]
Emit4( (int)vm->dataBase );
EmitString( "05" ); // add eax, const
Emit4( v );
if (oc0 == oc1 && pop0 == OP_LOCAL && pop1 == OP_LOCAL) {
EmitString( "89 83" ); // mov dword ptr [ebx+0x12345678], eax
Emit4( (int)vm->dataBase );
} else {
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
EmitString( "8B 1F" ); // mov ebx, dword ptr [edi]
EmitString( "89 83" ); // mov dword ptr [ebx+0x12345678], eax
Emit4( (int)vm->dataBase );
}
}
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
pc++; // OP_ADD
pc++; // OP_STORE
instruction += 3;
break;
}
if (code[pc] == OP_CONST && code[pc+5] == OP_SUB && code[pc+6] == OP_STORE4) {
if (oc0 == oc1 && pop0 == OP_LOCAL && pop1 == OP_LOCAL) {
compiledOfs -= 11;
vm->instructionPointers[ instruction-1 ] = compiledOfs;
}
EmitMovEBXEDI(vm, vm->dataMask);
EmitString( "8B 83" ); // mov eax, dword ptr [ebx + 0x12345678]
Emit4( (int)vm->dataBase );
pc++; // OP_CONST
v = Constant4();
if (v == 1 && oc0 == oc1 && pop0 == OP_LOCAL && pop1 == OP_LOCAL) {
EmitString( "FF 8B"); // dec dword ptr [ebx + 0x12345678]
Emit4( (int)vm->dataBase );
} else {
EmitString( "2D" ); // sub eax, const
Emit4( v );
if (oc0 == oc1 && pop0 == OP_LOCAL && pop1 == OP_LOCAL) {
EmitString( "89 83" ); // mov dword ptr [ebx+0x12345678], eax
Emit4( (int)vm->dataBase );
} else {
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
EmitString( "8B 1F" ); // mov ebx, dword ptr [edi]
EmitString( "89 83" ); // mov dword ptr [ebx+0x12345678], eax
Emit4( (int)vm->dataBase );
}
}
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
pc++; // OP_SUB
pc++; // OP_STORE
instruction += 3;
break;
}
if (buf[compiledOfs-2] == 0x89 && buf[compiledOfs-1] == 0x07) {
compiledOfs -= 2;
vm->instructionPointers[ instruction-1 ] = compiledOfs;
EmitString( "8B 80"); // mov eax, dword ptr [eax + 0x1234567]
Emit4( (int)vm->dataBase );
EmitCommand(LAST_COMMAND_MOV_EDI_EAX); // mov dword ptr [edi], eax
break;
}
EmitMovEBXEDI(vm, vm->dataMask);
EmitString( "8B 83" ); // mov eax, dword ptr [ebx + 0x12345678]
Emit4( (int)vm->dataBase );
EmitCommand(LAST_COMMAND_MOV_EDI_EAX); // mov dword ptr [edi], eax
break;
case OP_LOAD2:
EmitMovEBXEDI(vm, vm->dataMask);
EmitString( "0F B7 83" ); // movzx eax, word ptr [ebx + 0x12345678]
Emit4( (int)vm->dataBase );
EmitCommand(LAST_COMMAND_MOV_EDI_EAX); // mov dword ptr [edi], eax
break;
case OP_LOAD1:
EmitMovEBXEDI(vm, vm->dataMask);
EmitString( "0F B6 83" ); // movzx eax, byte ptr [ebx + 0x12345678]
Emit4( (int)vm->dataBase );
EmitCommand(LAST_COMMAND_MOV_EDI_EAX); // mov dword ptr [edi], eax
break;
case OP_STORE4:
EmitMovEAXEDI(vm);
EmitString( "8B 5F FC" ); // mov ebx, dword ptr [edi-4]
// if (pop1 != OP_CALL) {
// EmitString( "81 E3" ); // and ebx, 0x12345678
// Emit4( vm->dataMask & ~3 );
// }
EmitString( "89 83" ); // mov dword ptr [ebx+0x12345678], eax
Emit4( (int)vm->dataBase );
EmitCommand(LAST_COMMAND_SUB_DI_8); // sub edi, 8
break;
case OP_STORE2:
EmitMovEAXEDI(vm);
EmitString( "8B 5F FC" ); // mov ebx, dword ptr [edi-4]
// EmitString( "81 E3" ); // and ebx, 0x12345678
// Emit4( vm->dataMask & ~1 );
EmitString( "66 89 83" ); // mov word ptr [ebx+0x12345678], eax
Emit4( (int)vm->dataBase );
EmitCommand(LAST_COMMAND_SUB_DI_8); // sub edi, 8
break;
case OP_STORE1:
EmitMovEAXEDI(vm);
EmitString( "8B 5F FC" ); // mov ebx, dword ptr [edi-4]
// EmitString( "81 E3" ); // and ebx, 0x12345678
// Emit4( vm->dataMask );
EmitString( "88 83" ); // mov byte ptr [ebx+0x12345678], eax
Emit4( (int)vm->dataBase );
EmitCommand(LAST_COMMAND_SUB_DI_8); // sub edi, 8
break;
case OP_EQ:
EmitMovEAXEDI( vm );
EmitCommand( LAST_COMMAND_SUB_DI_8 ); // sub edi, 8
EmitString( "3B 47 04" ); // cmp eax, dword ptr [edi+4]
EmitString( "75 06" ); // jne +6
EmitString( "FF 25" ); // jmp [0x12345678]
v = Constant4();
JUSED(v);
Emit4( (int)vm->instructionPointers + v*4 );
break;
case OP_NE:
EmitMovEAXEDI( vm );
EmitCommand( LAST_COMMAND_SUB_DI_8 ); // sub edi, 8
EmitString( "3B 47 04" ); // cmp eax, dword ptr [edi+4]
EmitString( "74 06" ); // je +6
EmitString( "FF 25" ); // jmp [0x12345678]
v = Constant4();
JUSED(v);
Emit4( (int)vm->instructionPointers + v*4 );
break;
case OP_LTI:
EmitMovEAXEDI( vm );
EmitCommand(LAST_COMMAND_SUB_DI_8); // sub edi, 8
EmitString( "39 47 04" ); // cmp dword ptr [edi+4], eax
EmitString( "7D 06" ); // jnl +6
EmitString( "FF 25" ); // jmp [0x12345678]
v = Constant4();
JUSED(v);
Emit4( (int)vm->instructionPointers + v*4 );
break;
case OP_LEI:
EmitMovEAXEDI( vm );
EmitCommand(LAST_COMMAND_SUB_DI_8); // sub edi, 8
EmitString( "39 47 04" ); // cmp dword ptr [edi+4], eax
EmitString( "7F 06" ); // jnle +6
EmitString( "FF 25" ); // jmp [0x12345678]
v = Constant4();
JUSED(v);
Emit4( (int)vm->instructionPointers + v*4 );
break;
case OP_GTI:
EmitMovEAXEDI( vm );
EmitCommand(LAST_COMMAND_SUB_DI_8); // sub edi, 8
EmitString( "39 47 04" ); // cmp eax, dword ptr [edi+4]
EmitString( "7E 06" ); // jng +6
EmitString( "FF 25" ); // jmp [0x12345678]
v = Constant4();
JUSED(v);
Emit4( (int)vm->instructionPointers + v*4 );
break;
case OP_GEI:
EmitMovEAXEDI( vm );
EmitCommand(LAST_COMMAND_SUB_DI_8); // sub edi, 8
EmitString( "39 47 04" ); // cmp eax, dword ptr [edi+4]
EmitString( "7C 06" ); // jnge +6
EmitString( "FF 25" ); // jmp [0x12345678]
v = Constant4();
JUSED(v);
Emit4( (int)vm->instructionPointers + v*4 );
break;
case OP_LTU:
EmitMovEAXEDI( vm );
EmitCommand(LAST_COMMAND_SUB_DI_8); // sub edi, 8
EmitString( "39 47 04" ); // cmp eax, dword ptr [edi+4]
EmitString( "73 06" ); // jnb +6
EmitString( "FF 25" ); // jmp [0x12345678]
v = Constant4();
JUSED(v);
Emit4( (int)vm->instructionPointers + v*4 );
break;
case OP_LEU:
EmitMovEAXEDI( vm );
EmitCommand(LAST_COMMAND_SUB_DI_8); // sub edi, 8
EmitString( "39 47 04" ); // cmp eax, dword ptr [edi+4]
EmitString( "77 06" ); // jnbe +6
EmitString( "FF 25" ); // jmp [0x12345678]
v = Constant4();
JUSED(v);
Emit4( (int)vm->instructionPointers + v*4 );
break;
case OP_GTU:
EmitMovEAXEDI( vm );
EmitCommand(LAST_COMMAND_SUB_DI_8); // sub edi, 8
EmitString( "39 47 04" ); // cmp eax, dword ptr [edi+4]
EmitString( "76 06" ); // jna +6
EmitString( "FF 25" ); // jmp [0x12345678]
v = Constant4();
JUSED(v);
Emit4( (int)vm->instructionPointers + v*4 );
break;
case OP_GEU:
EmitMovEAXEDI( vm );
EmitCommand(LAST_COMMAND_SUB_DI_8); // sub edi, 8
EmitString( "39 47 04" ); // cmp eax, dword ptr [edi+4]
EmitString( "72 06" ); // jnae +6
EmitString( "FF 25" ); // jmp [0x12345678]
v = Constant4();
JUSED(v);
Emit4( (int)vm->instructionPointers + v*4 );
break;
case OP_EQF:
EmitCommand(LAST_COMMAND_SUB_DI_8); // sub edi, 8
EmitString( "D9 47 04" ); // fld dword ptr [edi+4]
EmitString( "D8 5F 08" ); // fcomp dword ptr [edi+8]
EmitString( "DF E0" ); // fnstsw ax
EmitString( "F6 C4 40" ); // test ah,0x40
EmitString( "74 06" ); // je +6
EmitString( "FF 25" ); // jmp [0x12345678]
v = Constant4();
JUSED(v);
Emit4( (int)vm->instructionPointers + v*4 );
break;
case OP_NEF:
EmitCommand(LAST_COMMAND_SUB_DI_8); // sub edi, 8
EmitString( "D9 47 04" ); // fld dword ptr [edi+4]
EmitString( "D8 5F 08" ); // fcomp dword ptr [edi+8]
EmitString( "DF E0" ); // fnstsw ax
EmitString( "F6 C4 40" ); // test ah,0x40
EmitString( "75 06" ); // jne +6
EmitString( "FF 25" ); // jmp [0x12345678]
v = Constant4();
JUSED(v);
Emit4( (int)vm->instructionPointers + v*4 );
break;
case OP_LTF:
EmitCommand(LAST_COMMAND_SUB_DI_8); // sub edi, 8
EmitString( "D9 47 04" ); // fld dword ptr [edi+4]
EmitString( "D8 5F 08" ); // fcomp dword ptr [edi+8]
EmitString( "DF E0" ); // fnstsw ax
EmitString( "F6 C4 01" ); // test ah,0x01
EmitString( "74 06" ); // je +6
EmitString( "FF 25" ); // jmp [0x12345678]
v = Constant4();
JUSED(v);
Emit4( (int)vm->instructionPointers + v*4 );
break;
case OP_LEF:
EmitCommand(LAST_COMMAND_SUB_DI_8); // sub edi, 8
EmitString( "D9 47 04" ); // fld dword ptr [edi+4]
EmitString( "D8 5F 08" ); // fcomp dword ptr [edi+8]
EmitString( "DF E0" ); // fnstsw ax
EmitString( "F6 C4 41" ); // test ah,0x41
EmitString( "74 06" ); // je +6
EmitString( "FF 25" ); // jmp [0x12345678]
v = Constant4();
JUSED(v);
Emit4( (int)vm->instructionPointers + v*4 );
break;
case OP_GTF:
EmitCommand(LAST_COMMAND_SUB_DI_8); // sub edi, 8
EmitString( "D9 47 04" ); // fld dword ptr [edi+4]
EmitString( "D8 5F 08" ); // fcomp dword ptr [edi+8]
EmitString( "DF E0" ); // fnstsw ax
EmitString( "F6 C4 41" ); // test ah,0x41
EmitString( "75 06" ); // jne +6
EmitString( "FF 25" ); // jmp [0x12345678]
v = Constant4();
JUSED(v);
Emit4( (int)vm->instructionPointers + v*4 );
break;
case OP_GEF:
EmitCommand(LAST_COMMAND_SUB_DI_8); // sub edi, 8
EmitString( "D9 47 04" ); // fld dword ptr [edi+4]
EmitString( "D8 5F 08" ); // fcomp dword ptr [edi+8]
EmitString( "DF E0" ); // fnstsw ax
EmitString( "F6 C4 01" ); // test ah,0x01
EmitString( "75 06" ); // jne +6
EmitString( "FF 25" ); // jmp [0x12345678]
v = Constant4();
JUSED(v);
Emit4( (int)vm->instructionPointers + v*4 );
break;
case OP_NEGI:
EmitMovEAXEDI( vm );
EmitString( "F7 D8" ); // neg eax
EmitCommand( LAST_COMMAND_MOV_EDI_EAX );
break;
case OP_ADD:
EmitMovEAXEDI(vm); // mov eax, dword ptr [edi]
EmitString( "01 47 FC" ); // add dword ptr [edi-4],eax
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
break;
case OP_SUB:
EmitMovEAXEDI(vm); // mov eax, dword ptr [edi]
EmitString( "29 47 FC" ); // sub dword ptr [edi-4],eax
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
break;
case OP_DIVI:
EmitString( "8B 47 FC" ); // mov eax,dword ptr [edi-4]
EmitString( "99" ); // cdq
EmitString( "F7 3F" ); // idiv dword ptr [edi]
EmitString( "89 47 FC" ); // mov dword ptr [edi-4],eax
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
break;
case OP_DIVU:
EmitString( "8B 47 FC" ); // mov eax,dword ptr [edi-4]
EmitString( "33 D2" ); // xor edx, edx
EmitString( "F7 37" ); // div dword ptr [edi]
EmitString( "89 47 FC" ); // mov dword ptr [edi-4],eax
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
break;
case OP_MODI:
EmitString( "8B 47 FC" ); // mov eax,dword ptr [edi-4]
EmitString( "99" ); // cdq
EmitString( "F7 3F" ); // idiv dword ptr [edi]
EmitString( "89 57 FC" ); // mov dword ptr [edi-4],edx
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
break;
case OP_MODU:
EmitString( "8B 47 FC" ); // mov eax,dword ptr [edi-4]
EmitString( "33 D2" ); // xor edx, edx
EmitString( "F7 37" ); // div dword ptr [edi]
EmitString( "89 57 FC" ); // mov dword ptr [edi-4],edx
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
break;
case OP_MULI:
EmitString( "8B 47 FC" ); // mov eax,dword ptr [edi-4]
EmitString( "F7 2F" ); // imul dword ptr [edi]
EmitString( "89 47 FC" ); // mov dword ptr [edi-4],eax
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
break;
case OP_MULU:
EmitString( "8B 47 FC" ); // mov eax,dword ptr [edi-4]
EmitString( "F7 27" ); // mul dword ptr [edi]
EmitString( "89 47 FC" ); // mov dword ptr [edi-4],eax
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
break;
case OP_BAND:
EmitMovEAXEDI(vm); // mov eax, dword ptr [edi]
EmitString( "21 47 FC" ); // and dword ptr [edi-4],eax
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
break;
case OP_BOR:
EmitMovEAXEDI(vm); // mov eax, dword ptr [edi]
EmitString( "09 47 FC" ); // or dword ptr [edi-4],eax
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
break;
case OP_BXOR:
EmitMovEAXEDI(vm); // mov eax, dword ptr [edi]
EmitString( "31 47 FC" ); // xor dword ptr [edi-4],eax
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
break;
case OP_BCOM:
EmitString( "F7 17" ); // not dword ptr [edi]
break;
case OP_LSH:
//EmitString( "8B 0F" ); // mov ecx, dword ptr [edi]
EmitMovECXEDI( vm );
EmitString( "D3 67 FC" ); // shl dword ptr [edi-4], cl
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
break;
case OP_RSHI:
//EmitString( "8B 0F" ); // mov ecx, dword ptr [edi]
EmitMovECXEDI( vm );
EmitString( "D3 7F FC" ); // sar dword ptr [edi-4], cl
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
break;
case OP_RSHU:
//EmitString( "8B 0F" ); // mov ecx, dword ptr [edi]
EmitMovECXEDI( vm );
EmitString( "D3 6F FC" ); // shr dword ptr [edi-4], cl
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
break;
case OP_NEGF:
EmitString( "D9 07" ); // fld dword ptr [edi]
EmitString( "D9 E0" ); // fchs
EmitString( "D9 1F" ); // fstp dword ptr [edi]
break;
case OP_ADDF:
EmitString( "D9 47 FC" ); // fld dword ptr [edi-4]
EmitString( "D8 07" ); // fadd dword ptr [edi]
EmitString( "D9 5F FC" ); // fstp dword ptr [edi-4]
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
break;
case OP_SUBF:
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
EmitString( "D9 07" ); // fld dword ptr [edi]
EmitString( "D8 67 04" ); // fsub dword ptr [edi+4]
EmitString( "D9 1F" ); // fstp dword ptr [edi]
break;
case OP_DIVF:
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
EmitString( "D9 07" ); // fld dword ptr [edi]
EmitString( "D8 77 04" ); // fdiv dword ptr [edi+4]
EmitString( "D9 1F" ); // fstp dword ptr [edi]
break;
case OP_MULF:
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
EmitString( "D9 07" ); // fld dword ptr [edi]
EmitString( "D8 4f 04" ); // fmul dword ptr [edi+4]
EmitString( "D9 1F" ); // fstp dword ptr [edi]
break;
case OP_CVIF:
EmitString( "DB 07" ); // fild dword ptr [edi]
EmitString( "D9 1F" ); // fstp dword ptr [edi]
break;
case OP_CVFI:
#ifndef FTOL_PTR // WHENHELLISFROZENOVER
// not IEEE complient, but simple and fast
EmitString( "D9 07" ); // fld dword ptr [edi]
EmitString( "DB 1F" ); // fistp dword ptr [edi]
#else // FTOL_PTR
// call the library conversion function
EmitString( "D9 07" ); // fld dword ptr [edi]
EmitString( "FF 15" ); // call ftolPtr
Emit4( (int)&ftolPtr );
EmitCommand(LAST_COMMAND_MOV_EDI_EAX); // mov dword ptr [edi], eax
#endif
break;
case OP_SEX8:
EmitString( "0F BE 07" ); // movsx eax, byte ptr [edi]
EmitCommand(LAST_COMMAND_MOV_EDI_EAX); // mov dword ptr [edi], eax
break;
case OP_SEX16:
EmitString( "0F BF 07" ); // movsx eax, word ptr [edi]
EmitCommand(LAST_COMMAND_MOV_EDI_EAX); // mov dword ptr [edi], eax
break;
case OP_BLOCK_COPY:
// FIXME: range check
EmitString( "56" ); // push esi
EmitString( "57" ); // push edi
EmitString( "8B 37" ); // mov esi,[edi]
EmitString( "8B 7F FC" ); // mov edi,[edi-4]
EmitString( "B9" ); // mov ecx,0x12345678
Emit4( Constant4() >> 2 );
EmitString( "B8" ); // mov eax, datamask
Emit4( vm->dataMask );
EmitString( "BB" ); // mov ebx, database
Emit4( (int)vm->dataBase );
EmitString( "23 F0" ); // and esi, eax
EmitString( "03 F3" ); // add esi, ebx
EmitString( "23 F8" ); // and edi, eax
EmitString( "03 FB" ); // add edi, ebx
EmitString( "F3 A5" ); // rep movsd
EmitString( "5F" ); // pop edi
EmitString( "5E" ); // pop esi
EmitCommand(LAST_COMMAND_SUB_DI_8); // sub edi, 8
break;
case OP_JUMP:
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
EmitString( "8B 47 04" ); // mov eax,dword ptr [edi+4]
EmitString("81 F8"); // cmp eax, vm->instructionCount
Emit4(vm->instructionCount);
EmitString( "73 07" ); // jae +7
EmitString( "FF 24 85" ); // jmp dword ptr [instructionPointers + eax * 4]
Emit4((intptr_t) vm->instructionPointers);
EmitString( "FF 15" ); // call errJumpPtr
Emit4((intptr_t) &errJumpPtr);
break;
default:
VMFREE_BUFFERS();
Com_Error(ERR_DROP, "VM_CompileX86: bad opcode %i at offset %i", op, pc);
}
pop0 = pop1;
pop1 = op;
}
}
// copy to an exact sized buffer with the appropriate permission bits
vm->codeLength = compiledOfs;
#ifdef VM_X86_MMAP
vm->codeBase = mmap(NULL, compiledOfs, PROT_WRITE, MAP_SHARED|MAP_ANONYMOUS, -1, 0);
if(vm->codeBase == MAP_FAILED)
Com_Error(ERR_FATAL, "VM_CompileX86: can't mmap memory");
#elif _WIN32
// allocate memory with EXECUTE permissions under windows.
vm->codeBase = VirtualAlloc(NULL, compiledOfs, MEM_COMMIT, PAGE_EXECUTE_READWRITE);
if(!vm->codeBase)
Com_Error(ERR_FATAL, "VM_CompileX86: VirtualAlloc failed");
#else
vm->codeBase = malloc(compiledOfs);
if(!vm->codeBase)
Com_Error(ERR_FATAL, "VM_CompileX86: malloc failed");
#endif
Com_Memcpy( vm->codeBase, buf, compiledOfs );
#ifdef VM_X86_MMAP
if(mprotect(vm->codeBase, compiledOfs, PROT_READ|PROT_EXEC))
Com_Error(ERR_FATAL, "VM_CompileX86: mprotect failed");
#elif _WIN32
{
DWORD oldProtect = 0;
// remove write permissions.
if(!VirtualProtect(vm->codeBase, compiledOfs, PAGE_EXECUTE_READ, &oldProtect))
Com_Error(ERR_FATAL, "VM_CompileX86: VirtualProtect failed");
}
#endif
Z_Free( code );
Z_Free( buf );
Z_Free( jused );
Com_Printf( "VM file %s compiled to %i bytes of code\n", vm->name, compiledOfs );
vm->destroy = VM_Destroy_Compiled;
// offset all the instruction pointers for the new location
for ( i = 0 ; i < header->instructionCount ; i++ ) {
vm->instructionPointers[i] += (int)vm->codeBase;
}
}
void VM_Destroy_Compiled(vm_t* self)
{
#ifdef VM_X86_MMAP
munmap(self->codeBase, self->codeLength);
#elif _WIN32
VirtualFree(self->codeBase, 0, MEM_RELEASE);
#else
free(self->codeBase);
#endif
}
/*
==============
VM_CallCompiled
This function is called directly by the generated code
==============
*/
int VM_CallCompiled( vm_t *vm, int *args ) {
int stack[1024];
void *entryPoint;
int programCounter;
int programStack;
int stackOnEntry;
byte *image;
void *opStack;
currentVM = vm;
// interpret the code
vm->currentlyInterpreting = qtrue;
// we might be called recursively, so this might not be the very top
programStack = vm->programStack;
stackOnEntry = programStack;
// set up the stack frame
image = vm->dataBase;
programCounter = 0;
programStack -= 48;
*(int *)&image[ programStack + 44] = args[9];
*(int *)&image[ programStack + 40] = args[8];
*(int *)&image[ programStack + 36] = args[7];
*(int *)&image[ programStack + 32] = args[6];
*(int *)&image[ programStack + 28] = args[5];
*(int *)&image[ programStack + 24] = args[4];
*(int *)&image[ programStack + 20] = args[3];
*(int *)&image[ programStack + 16] = args[2];
*(int *)&image[ programStack + 12] = args[1];
*(int *)&image[ programStack + 8 ] = args[0];
*(int *)&image[ programStack + 4 ] = 0; // return stack
*(int *)&image[ programStack ] = -1; // will terminate the loop on return
// off we go into generated code...
entryPoint = vm->codeBase + vm->entryOfs;
opStack = &stack;
#ifdef _MSC_VER
__asm
{
pushad
mov esi, programStack
mov edi, opStack
call entryPoint
mov programStack, esi
mov opStack, edi
popad
}
#else
__asm__ volatile(
"call *%2\r\n"
: "+S" (programStack), "+D" (opStack)
: "r" (vm->codeBase + vm->entryOfs)
: "cc", "memory", "%eax", "%ebx", "%ecx", "%edx"
);
#endif
if ( opStack != &stack[1] ) {
Com_Error( ERR_DROP, "opStack corrupted in compiled code" );
}
if ( programStack != stackOnEntry - 48 ) {
Com_Error( ERR_DROP, "programStack corrupted in compiled code" );
}
vm->programStack = stackOnEntry;
return *(int *)opStack;
}
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