NOP

MEM0:r:v REG0=GPRv_R():r REG0=GPRv_B():r REG1=GPRv_R():r

x86_64 X86_LEGACY WIDENOP FAT_NOP source: xed

XED_NOP_MEMv_GPRv_0F1D NOP_GPRv_GPRv_0F1D

Encoding

encoding_kindX86_LEGACY
opcode_bytes1D 0F 1D
opcode_map0F
mandatory_prefix-
has_modrmTrue
attributesNOP
cpl3
raw_encoding0x0F 0x1D MOD[mm] MOD!=3 REG[rrr] RM[nnn] MODRM() 0x0F 0x1D MOD[0b11] MOD=3 REG[rrr] RM[nnn]

Operands (4)

# Role Kind Class / Reg Width Access Visibility Encoded in
0 MEM0 MEM v R EXPLICIT MODRM_RM
1 REG0 REG R EXPLICIT MODRM_REG
2 REG1 REG R EXPLICIT MODRM_REG
3 REG2 REG R EXPLICIT MODRM_REG

Micro-ops sequence (0)

No micro-ops authored for this encoding. Emulator semantics not yet defined — decoder still works.