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Add remaining possible uses of MOVBE

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Also fixes a missing 'break' statement in DisassembleMov().
This commit is contained in:
Tillmann Karras
2014-04-23 15:05:40 +02:00
parent 13b1ff5160
commit acfd9ee76c
6 changed files with 161 additions and 144 deletions
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222
Source/Core/Common/x64Analyzer.cpp
View File

@ -8,8 +8,8 @@ bool DisassembleMov(const unsigned char *codePtr, InstructionInfo *info)
{
unsigned const char *startCodePtr = codePtr;
u8 rex = 0;
u8 codeByte = 0;
u8 codeByte2 = 0;
u32 opcode;
int opcode_length;
//Check for regular prefix
info->operandSize = 4;
@ -17,6 +17,7 @@ bool DisassembleMov(const unsigned char *codePtr, InstructionInfo *info)
info->signExtend = false;
info->hasImmediate = false;
info->isMemoryWrite = false;
info->byteSwap = false;
u8 modRMbyte = 0;
u8 sibByte = 0;
@ -45,41 +46,53 @@ bool DisassembleMov(const unsigned char *codePtr, InstructionInfo *info)
codePtr++;
}
codeByte = *codePtr++;
// Skip two-byte opcode byte
bool twoByte = false;
if (codeByte == 0x0F)
opcode = *codePtr++;
opcode_length = 1;
if (opcode == 0x0F)
{
twoByte = true;
codeByte2 = *codePtr++;
}
if (!twoByte)
{
if ((codeByte & 0xF0) == 0x80 ||
((codeByte & 0xF8) == 0xC0 && (codeByte & 0x0E) != 0x02))
opcode = (opcode << 8) | *codePtr++;
opcode_length = 2;
if ((opcode & 0xFB) == 0x38)
{
modRMbyte = *codePtr++;
hasModRM = true;
opcode = (opcode << 8) | *codePtr++;
opcode_length = 3;
}
}
else
switch (opcode_length)
{
if (((codeByte2 & 0xF0) == 0x00 && (codeByte2 & 0x0F) >= 0x04 && (codeByte2 & 0x0D) != 0x0D) ||
(codeByte2 & 0xF0) == 0x30 ||
codeByte2 == 0x77 ||
(codeByte2 & 0xF0) == 0x80 ||
((codeByte2 & 0xF0) == 0xA0 && (codeByte2 & 0x07) <= 0x02) ||
(codeByte2 & 0xF8) == 0xC8)
{
// No mod R/M byte
}
else
{
modRMbyte = *codePtr++;
hasModRM = true;
}
case 1:
if ((opcode & 0xF0) == 0x80 ||
((opcode & 0xF8) == 0xC0 && (opcode & 0x0E) != 0x02))
{
modRMbyte = *codePtr++;
hasModRM = true;
}
break;
case 2:
if (((opcode & 0xF0) == 0x00 && (opcode & 0x0F) >= 0x04 && (opcode & 0x0D) != 0x0D) ||
((opcode & 0xF0) == 0xA0 && (opcode & 0x07) <= 0x02) ||
(opcode & 0xF0) == 0x30 ||
(opcode & 0xFF) == 0x77 ||
(opcode & 0xF0) == 0x80 ||
(opcode & 0xF8) == 0xC8)
{
// No mod R/M byte
}
else
{
modRMbyte = *codePtr++;
hasModRM = true;
}
break;
case 3:
// TODO: support more 3-byte opcode instructions
if ((opcode & 0xFE) == 0xF0)
{
modRMbyte = *codePtr++;
hasModRM = true;
}
break;
}
if (hasModRM)
@ -114,109 +127,92 @@ bool DisassembleMov(const unsigned char *codePtr, InstructionInfo *info)
if (displacementSize == 1)
info->displacement = (s32)(s8)*codePtr;
else
info->displacement = *((s32 *)codePtr);
info->displacement = *((s32*)codePtr);
codePtr += displacementSize;
switch (codeByte)
switch (opcode)
{
// writes
case 0xC6: // mem <- imm8
{
info->isMemoryWrite = true;
info->hasImmediate = true;
info->immediate = *codePtr;
codePtr++; //move past immediate
}
info->isMemoryWrite = true;
info->hasImmediate = true;
info->immediate = *codePtr;
codePtr++;
break;
case 0xC7: // mem <- imm16/32
info->isMemoryWrite = true;
switch (info->operandSize)
{
info->isMemoryWrite = true;
if (info->operandSize == 2)
{
info->hasImmediate = true;
info->immediate = *(u16*)codePtr;
codePtr += 2;
}
else if (info->operandSize == 4)
{
info->hasImmediate = true;
info->immediate = *(u32*)codePtr;
codePtr += 4;
}
else if (info->operandSize == 8)
{
info->zeroExtend = true;
info->immediate = *(u32*)codePtr;
codePtr += 4;
}
case 2:
info->hasImmediate = true;
info->immediate = *(u16*)codePtr;
codePtr += 2;
break;
case 4:
info->hasImmediate = true;
info->immediate = *(u32*)codePtr;
codePtr += 4;
break;
case 8:
info->zeroExtend = true;
info->immediate = *(u32*)codePtr;
codePtr += 4;
break;
}
break;
case 0x88: // mem <- r8
info->isMemoryWrite = true;
if (info->operandSize != 4)
{
info->isMemoryWrite = true;
if (info->operandSize == 4)
{
info->operandSize = 1;
break;
}
else
return false;
break;
return false;
}
info->operandSize = 1;
break;
case 0x89: // mem <- r16/32/64
{
info->isMemoryWrite = true;
break;
}
case 0x0F: // two-byte escape
{
info->isMemoryWrite = false;
switch (codeByte2)
{
case 0xB6: // movzx on byte
info->zeroExtend = true;
info->operandSize = 1;
break;
case 0xB7: // movzx on short
info->zeroExtend = true;
info->operandSize = 2;
break;
case 0xBE: // movsx on byte
info->signExtend = true;
info->operandSize = 1;
break;
case 0xBF: // movsx on short
info->signExtend = true;
info->operandSize = 2;
break;
default:
return false;
}
break;
}
info->isMemoryWrite = true;
break;
case 0x8A: // r8 <- mem
if (info->operandSize != 4)
{
info->isMemoryWrite = false;
if (info->operandSize == 4)
{
info->operandSize = 1;
break;
}
else
return false;
return false;
}
info->operandSize = 1;
break;
case 0x8B: // r16/32/64 <- mem
{
info->isMemoryWrite = false;
break;
}
break;
case 0x0FB6: // movzx on byte
info->zeroExtend = true;
info->operandSize = 1;
break;
case 0x0FB7: // movzx on short
info->zeroExtend = true;
info->operandSize = 2;
break;
case 0x0FBE: // movsx on byte
info->signExtend = true;
info->operandSize = 1;
break;
case 0x0FBF: // movsx on short
info->signExtend = true;
info->operandSize = 2;
break;
case 0x0F38F0: // movbe read
info->byteSwap = true;
break;
case 0x0F38F1: // movbe write
info->byteSwap = true;
info->isMemoryWrite = true;
break;
default:

1
Source/Core/Common/x64Analyzer.h
View File

@ -17,6 +17,7 @@ struct InstructionInfo
bool signExtend;
bool hasImmediate;
bool isMemoryWrite;
bool byteSwap;
u64 immediate;
s32 displacement;
};