266 lines
8.4 KiB
C++
266 lines
8.4 KiB
C++
// disasm.cc
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// 1/27/2013 jichi
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// Original source: http://hack-expo.void.ru/groups/blt/text/disasm.txt
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//
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// 7/19/2014 jichi: Need to add SSE instruction support for PCSX2
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// Sample problematic input from Fate/Stay night PS2:
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// 3024b80c -0f88 ae58dbd2 js pcsx2.030010c0
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// 3024b812 0f1201 movlps xmm0,qword ptr ds:[ecx] ; jichi: hook here
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// 3024b815 0f1302 movlps qword ptr ds:[edx],xmm0
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#include "disasm.h"
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#include <windows.h>
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// disasm_flag values:
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enum : unsigned {
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C_66 = 0x00000001 // 66-prefix
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, C_67 = 0x00000002 // 67-prefix
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, C_LOCK = 0x00000004 // lock
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, C_REP = 0x00000008 // repz/repnz
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, C_SEG = 0x00000010 // seg-prefix
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, C_OPCODE2 = 0x00000020 // 2nd opcode present (1st==0f)
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, C_MODRM = 0x00000040 // modrm present
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, C_SIB = 0x00000080 // sib present
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, C_ANYPREFIX = (C_66|C_67|C_LOCK|C_REP|C_SEG)
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};
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DISASM_BEGIN_NAMESPACE
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// These values are served as the output of disasm
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// But the are currently unused and could make disasm thread-unsafe
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namespace { // unnamed
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BYTE disasm_seg // CS DS ES SS FS GS
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, disasm_rep // REPZ/REPNZ
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, disasm_opcode // opcode
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, disasm_opcode2 // used when opcode==0f
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, disasm_modrm // modxxxrm
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, disasm_sib // scale-index-base
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, disasm_mem[8] // mem addr value
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, disasm_data[8] // data value
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;
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} // unnamed namespace
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// return: length if success, 0 if error
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size_t disasm(const void *opcode0)
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{
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const BYTE *opcode = (const BYTE *)opcode0;
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DWORD disasm_len = 0, // 0 if error
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disasm_flag = 0, // C_xxx
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disasm_memsize = 0, // value = disasm_mem
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disasm_datasize = 0, // value = disasm_data
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disasm_defdata = 4, // == C_66 ? 2 : 4
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disasm_defmem = 4; // == C_67 ? 2 : 4
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retry:
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disasm_opcode = *opcode++;
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switch (disasm_opcode) {
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case 0x99: // 7/20/2014 jichi: CDQ, size = 1
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break;
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case 0x00: case 0x01: case 0x02: case 0x03:
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case 0x08: case 0x09: case 0x0a: case 0x0b:
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case 0x10: case 0x11: case 0x12: case 0x13:
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case 0x18: case 0x19: case 0x1a: case 0x1b:
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case 0x20: case 0x21: case 0x22: case 0x23:
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case 0x28: case 0x29: case 0x2a: case 0x2b:
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case 0x30: case 0x31: case 0x32: case 0x33:
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case 0x38: case 0x39: case 0x3a: case 0x3b:
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case 0x62: case 0x63:
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case 0x84: case 0x85: case 0x86: case 0x87:
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case 0x88: case 0x89: case 0x8a: case 0x8b:
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case 0x8c: case 0x8d: case 0x8e: case 0x8f:
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case 0xc4: case 0xc5:
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case 0xd0: case 0xd1: case 0xd2: case 0xd3:
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case 0xd8: case 0xd9: case 0xda: case 0xdb:
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case 0xdc: case 0xdd: case 0xde: case 0xdf:
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case 0xfe: case 0xff:
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disasm_flag |= C_MODRM;
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break;
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case 0xcd: disasm_datasize += *opcode==0x20 ? 1+4 : 1;
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break;
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case 0xf6:
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case 0xf7: disasm_flag |= C_MODRM;
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if (*opcode & 0x38) break;
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// continue if <test ..., xx>
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case 0x04: case 0x05: case 0x0c: case 0x0d:
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case 0x14: case 0x15: case 0x1c: case 0x1d:
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case 0x24: case 0x25: case 0x2c: case 0x2d:
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case 0x34: case 0x35: case 0x3c: case 0x3d:
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if (disasm_opcode & 1)
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disasm_datasize += disasm_defdata;
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else
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disasm_datasize++;
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break;
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case 0x6a:
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case 0xa8:
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case 0xb0: case 0xb1: case 0xb2: case 0xb3:
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case 0xb4: case 0xb5: case 0xb6: case 0xb7:
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case 0xd4: case 0xd5:
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case 0xe4: case 0xe5: case 0xe6: case 0xe7:
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case 0x70: case 0x71: case 0x72: case 0x73:
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case 0x74: case 0x75: case 0x76: case 0x77:
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case 0x78: case 0x79: case 0x7a: case 0x7b:
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case 0x7c: case 0x7d: case 0x7e: case 0x7f:
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case 0xeb:
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case 0xe0: case 0xe1: case 0xe2: case 0xe3:
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disasm_datasize++;
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break;
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case 0x26: case 0x2e: case 0x36: case 0x3e:
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case 0x64: case 0x65:
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if (disasm_flag & C_SEG) return 0;
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disasm_flag |= C_SEG;
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disasm_seg = disasm_opcode;
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goto retry;
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case 0xf0:
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if (disasm_flag & C_LOCK) return 0;
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disasm_flag |= C_LOCK;
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goto retry;
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case 0xf2: case 0xf3:
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if (disasm_flag & C_REP) return 0;
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disasm_flag |= C_REP;
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disasm_rep = disasm_opcode;
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goto retry;
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case 0x66:
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if (disasm_flag & C_66) return 0;
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disasm_flag |= C_66;
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disasm_defdata = 2;
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goto retry;
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case 0x67:
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if (disasm_flag & C_67) return 0;
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disasm_flag |= C_67;
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disasm_defmem = 2;
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goto retry;
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case 0x6b:
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case 0x80:
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case 0x82:
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case 0x83:
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case 0xc0:
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case 0xc1:
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case 0xc6: disasm_datasize++;
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disasm_flag |= C_MODRM;
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break;
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case 0x69:
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case 0x81:
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case 0xc7:
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disasm_datasize += disasm_defdata;
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disasm_flag |= C_MODRM;
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break;
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case 0x9a:
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case 0xea: disasm_datasize += 2 + disasm_defdata;
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break;
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case 0xa0:
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case 0xa1:
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case 0xa2:
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case 0xa3: disasm_memsize += disasm_defmem;
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break;
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case 0x68:
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case 0xa9:
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case 0xb8: case 0xb9: case 0xba: case 0xbb:
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case 0xbc: case 0xbd: case 0xbe: case 0xbf:
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case 0xe8:
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case 0xe9:
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disasm_datasize += disasm_defdata;
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break;
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case 0xc2:
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case 0xca: disasm_datasize += 2;
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break;
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case 0xc8:
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disasm_datasize += 3;
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break;
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case 0xf1:
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return 0;
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case 0x0f:
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// 7/19/2014 jichi: 0x0f1201 = movlps xmm0,qword ptr ds:[ecx]
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// Given 0x0f1201, 0x0f will be strip off here and left 0x1201
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disasm_flag |= C_OPCODE2;
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disasm_opcode2 = *opcode++;
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switch (disasm_opcode2) {
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case 0x00: case 0x01: case 0x02: case 0x03:
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case 0x90: case 0x91: case 0x92: case 0x93:
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case 0x94: case 0x95: case 0x96: case 0x97:
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case 0x98: case 0x99: case 0x9a: case 0x9b:
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case 0x9c: case 0x9d: case 0x9e: case 0x9f:
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case 0xa3:
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case 0xa5:
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case 0xab:
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case 0xad:
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case 0xaf:
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case 0xb0: case 0xb1: case 0xb2: case 0xb3:
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case 0xb4: case 0xb5: case 0xb6: case 0xb7:
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case 0xbb:
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case 0xbc: case 0xbd: case 0xbe: case 0xbf:
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case 0xc0:
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case 0xc1:
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// 7/19/2014 jichi: Add more cases for SSE instructions
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// Sample instructions I need to consider
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// 0f1201 movlps xmm0,qword ptr ds:[ecx] ; jichi: hook here
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// 0f1302 movlps qword ptr ds:[edx],xmm0
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case 0x12:
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case 0x13:
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disasm_flag |= C_MODRM;
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break;
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case 0x06:
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case 0x08: case 0x09: case 0x0a: case 0x0b:
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case 0xa0: case 0xa1: case 0xa2: case 0xa8:
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case 0xa9:
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case 0xaa:
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case 0xc8: case 0xc9: case 0xca: case 0xcb:
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case 0xcc: case 0xcd: case 0xce: case 0xcf:
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break;
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case 0x80: case 0x81: case 0x82: case 0x83:
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case 0x84: case 0x85: case 0x86: case 0x87:
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case 0x88: case 0x89: case 0x8a: case 0x8b:
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case 0x8c: case 0x8d: case 0x8e: case 0x8f:
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disasm_datasize += disasm_defdata;
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break;
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case 0xa4:
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case 0xac:
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case 0xba:
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default: return 0; // 7/19/2014 jichi: error
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} // 0F-switch
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break;
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} // switch
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if (disasm_flag & C_MODRM) {
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disasm_modrm = *opcode++;
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BYTE mod = disasm_modrm & 0xc0;
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BYTE rm = disasm_modrm & 0x07;
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if (mod != 0xc0) {
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if (mod == 0x40)
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disasm_memsize++;
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if (mod == 0x80)
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disasm_memsize += disasm_defmem;
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if (disasm_defmem == 2) { // modrm16
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if (mod == 0x00 && rm == 0x06)
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disasm_memsize += 2;
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} else { // modrm32
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if (rm == 0x04) {
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disasm_flag |= C_SIB;
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disasm_sib = *opcode++;
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rm = disasm_sib & 0x07;
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}
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if (rm == 0x05 && mod == 0x00)
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disasm_memsize += 4;
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}
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}
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} // C_MODRM
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for (DWORD i = 0; i < disasm_memsize; i++)
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disasm_mem[i] = *opcode++;
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for (DWORD i = 0; i < disasm_datasize; i++)
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disasm_data[i] = *opcode++;
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disasm_len = opcode - (const BYTE *)opcode0;
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return disasm_len;
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} // disasm
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DISASM_END_NAMESPACE
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// EOF
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