mod R/M byte
| REX.R=1 | |||||||||||||||||||
| r8(/r) without REX r8(/r) with REX r16(/r) r32(/r) r64(/r) mm(/r) xmm(/r) ymm(/r) sreg eee eee /digit (opcode) reg= |
AL AL AX EAX RAX MM0 XMM0 YMM0 ES CR0 DR0 0 000 |
CL CL CX ECX RCX MM1 XMM1 YMM1 CS CR1 DR1 1 001 |
DL DL DX EDX RDX MM2 XMM2 YMM2 SS CR2 DR2 2 010 |
BL BL BX EBX RBX MM3 XMM3 YMM3 DS CR3 DR3 3 011 |
AH SPL SP ESP RSP MM4 XMM4 YMM4 FS CR4 DR4 4 100 |
CH BPL BP EBP RBP MM5 XMM5 YMM5 GS CR5 DR5 5 101 |
DH SIL SI ESI RSI MM6 XMM6 YMM6 res. CR6 DR6 6 110 |
BH DIL DI EDI RDI MM7 XMM7 YMM7 res. CR7 DR7 7 111 |
R8B R8W R8D R8 MM0 XMM8 YMM8 ES CR8 DR8 0 000 |
R9B R9W R9D R9 MM1 XMM9 YMM9 CS CR9 DR9 1 001 |
R10B R10W R10D R10 MM2 XMM10 YMM10 SS CR10 DR10 2 010 |
R11B R11W R11D R11 MM3 XMM11 YMM11 DS CR11 DR11 3 011 |
R12B R12W R12D R12 MM4 XMM12 YMM12 FS CR12 DR12 4 100 |
R13B R13W R13D R13 MM5 XMM13 YMM13 GS CR13 DR13 5 101 |
R14B R14W R14D R14 MM6 XMM14 YMM14 res. CR14 DR14 6 110 |
R15B R15W R15D R15 MM7 XMM15 YMM15 res. CR15 DR15 7 111 |
|||
| effective address | effective address REX.B=1 |
mod | R/M | value of mod R/M byte (hex) | value of mod R/M byte (hex) | ||||||||||||||
| [rAX] [rCX] [rDX] [rBX] [sib] [*] #1 [rSI] [rDI] |
[r8] [r9] [r10] [r11] [sib] [*] #1 [r14] [r15] |
00 |
000 001 010 011 100 101 110 111 |
00 01 02 03 04 05 06 07 |
08 09 0A 0B 0C 0D 0E 0F |
10 11 12 13 14 15 16 17 |
18 19 1A 1B 1C 1D 1E 1F |
20 21 22 23 24 25 26 27 |
28 29 2A 2B 2C 2D 2E 2F |
30 31 32 33 34 35 36 37 |
38 39 3A 3B 3C 3D 3E 3F |
00 01 02 03 04 05 06 07 |
08 09 0A 0B 0C 0D 0E 0F |
10 11 12 13 14 15 16 17 |
18 19 1A 1B 1C 1D 1E 1F |
20 21 22 23 24 25 26 27 |
28 29 2A 2B 2C 2D 2E 2F |
30 31 32 33 34 35 36 37 |
38 39 3A 3B 3C 3D 3E 3F |
| [rAX+sbyte] [rCX+sbyte] [rDX+sbyte] [rBX+sbyte] [sib+sbyte] [rBP+sbyte] (defaults to SS) [rSI+sbyte] [rDI+sbyte] |
[r8+sbyte] [r9+sbyte] [r10+sbyte] [r11+sbyte] [sib+sbyte] [r13+sbyte] [r14+sbyte] [r15+sbyte] |
01 |
000 001 010 011 100 101 110 111 |
40 41 42 43 44 45 46 47 |
48 49 4A 4B 4C 4D 4E 4F |
50 51 52 53 54 55 56 57 |
58 59 5A 5B 5C 5D 5E 5F |
60 61 62 63 64 65 66 67 |
68 69 6A 6B 6C 6D 6E 6F |
70 71 72 73 74 75 76 77 |
78 79 7A 7B 7C 7D 7E 7F |
40 41 42 43 44 45 46 47 |
48 49 4A 4B 4C 4D 4E 4F |
50 51 52 53 54 55 56 57 |
58 59 5A 5B 5C 5D 5E 5F |
60 61 62 63 64 65 66 67 |
68 69 6A 6B 6C 6D 6E 6F |
70 71 72 73 74 75 76 77 |
78 79 7A 7B 7C 7D 7E 7F |
| [rAX+sdword] [rCX+sdword] [rDX+sdword] [rBX+sdword] [sib+sdword] [rBP+sdword] (defaults to SS) [rSI+sdword] [rDI+sdword] |
[r8+sdword] [r9+sdword] [r10+sdword] [r11+sdword] [sib+sdword] [r13+sdword] [r14+sdword] [r15+sdword] |
10 |
000 001 010 011 100 101 110 111 |
80 81 82 83 84 85 86 87 |
88 89 8A 8B 8C 8D 8E 8F |
90 91 92 93 94 95 96 97 |
98 99 9A 9B 9C 9D 9E 9F |
A0 A1 A2 A3 A4 A5 A6 A7 |
A8 A9 AA AB AC AD AE AF |
B0 B1 B2 B3 B4 B5 B6 B7 |
B8 B9 BA BB BC BD BE BF |
80 81 82 83 84 85 86 87 |
88 89 8A 8B 8C 8D 8E 8F |
90 91 92 93 94 95 96 97 |
98 99 9A 9B 9C 9D 9E 9F |
A0 A1 A2 A3 A4 A5 A6 A7 |
A8 A9 AA AB AC AD AE AF |
B0 B1 B2 B3 B4 B5 B6 B7 |
B8 B9 BA BB BC BD BE BF |
| AL/rAX/MM0/XMM0/YMM0 CL/rCX/MM1/XMM1/YMM1 DL/rDX/MM2/XMM2/YMM2 BL/rBX/MM3/XMM3/YMM3 AH/SPL/rSP/MM4/XMM4/YMM4 CH/BPL/rBP/MM5/XMM5/YMM5 DH/SIL/rSI/MM6/XMM6/YMM6 BH/DIL/rDI/MM7/XMM7/YMM7 |
R8(B/W/D/Q)/MM0/XMM8/YMM8 R9(B/W/D/Q)/MM1/XMM9/YMM9 R10(B/W/D/Q)/MM2/XMM10/YMM10 R11(B/W/D/Q)/MM3/XMM11/YMM11 R12(B/W/D/Q)/MM4/XMM12/YMM12 R13(B/W/D/Q)/MM5/XMM13/YMM13 R14(B/W/D/Q)/MM6/XMM14/YMM14 R15(B/W/D/Q)/MM7/XMM15/YMM15 |
11 |
000 001 010 011 100 101 110 111 |
C0 C1 C2 C3 C4 C5 C6 C7 |
C8 C9 CA CB CC CD CE CF |
D0 D1 D2 D3 D4 D5 D6 D7 |
D8 D9 DA DB DC DD DE DF |
E0 E1 E2 E3 E4 E5 E6 E7 |
E8 E9 EA EB EC ED EE EF |
F0 F1 F2 F3 F4 F5 F6 F7 |
F8 F9 FA FB FC FD FE FF |
C0 C1 C2 C3 C4 C5 C6 C7 |
C8 C9 CA CB CC CD CE CF |
D0 D1 D2 D3 D4 D5 D6 D7 |
D8 D9 DA DB DC DD DE DF |
E0 E1 E2 E3 E4 E5 E6 E7 |
E8 E9 EA EB EC ED EE EF |
F0 F1 F2 F3 F4 F5 F6 F7 |
F8 F9 FA FB FC FD FE FF |
| note | description | ||||||||||||||||||
| #1 |
if PM64 and adsize=64, then effective address = [RIP+sdword] if PM64 and adsize=32, then effective address = [EIP+sdword] else effective address = [sdword] |
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