CMPXCHG
REG0=GPRv_B():rcw REG1=GPRv_R():r REG2=OrAX():rcw:SUPP
x86_64 X86_LEGACY SEMAPHORE I486REAL source: xed
XED_CMPXCHG_X86_LEGACY_0F_B1_258234
Encoding
| encoding_kind | X86_LEGACY |
| opcode_bytes | B1 |
| opcode_map | 0F |
| mandatory_prefix | - |
| has_modrm | True |
| cpl | 3 |
| raw_encoding | 0x0F 0xB1 MOD[0b11] MOD=3 REG[rrr] RM[nnn] |
Operands (3)
| # | Role | Kind | Class / Reg | Width | Access | Visibility | Encoded in |
|---|---|---|---|---|---|---|---|
| 0 | REG0 | REG | R | EXPLICIT | MODRM_REG | ||
| 1 | REG1 | REG | R | EXPLICIT | MODRM_REG | ||
| 2 | REG2 | REG | R | SUPPRESSED | MODRM_REG |
Flag effects (6)
CF = WRITE
PF = WRITE
AF = WRITE
ZF = WRITE
SF = WRITE
OF = WRITE
Micro-ops sequence (0)
No micro-ops authored for this encoding. Emulator semantics not yet defined — decoder still works.