LZCNT
REG0=GPRv_R():w:v MEM0:r:v REG0=GPRv_R():w:v REG1=GPRv_B():r:v
x86_64 X86_LEGACY LZCNT LZCNT source: xed
XED_LZCNT_X86_LEGACY_0F_BD_123234
Encoding
| encoding_kind | X86_LEGACY |
| opcode_bytes | BD 0F BD |
| opcode_map | 0F |
| mandatory_prefix | - |
| has_modrm | True |
| cpl | 3 |
| raw_encoding | 0x0F 0xBD f3_refining_prefix LZCNT=1 MOD[mm] MOD!=3 REG[rrr] RM[nnn] MODRM() 0x0F 0xBD f3_refining_prefix LZCNT=1 MOD[0b11] MOD=3 REG[rrr] RM[nnn] |
Operands (4)
| # | Role | Kind | Class / Reg | Width | Access | Visibility | Encoded in |
|---|---|---|---|---|---|---|---|
| 0 | REG0 | REG | w | W | EXPLICIT | MODRM_REG | |
| 1 | MEM0 | MEM | v | R | EXPLICIT | MODRM_RM | |
| 2 | REG1 | REG | w | W | EXPLICIT | MODRM_REG | |
| 3 | REG2 | REG | v | R | EXPLICIT | MODRM_REG |
Flag effects (6)
CF = WRITE
PF = UNDEFINED
AF = UNDEFINED
ZF = WRITE
SF = UNDEFINED
OF = UNDEFINED
Micro-ops sequence (0)
No micro-ops authored for this encoding. Emulator semantics not yet defined — decoder still works.