URDMSR

REG0=GPR64_B():w:q:u64 REG1=GPR64_R():r:q:u64 REG2=XED_REG_MSRS:r:SUPP

x86_64 X86_LEGACY APX USER_MSR source: xed

XED_URDMSR_GPR64u64_GPR64u64

Encoding

encoding_kindX86_LEGACY
opcode_bytesF8
opcode_map0F38
mandatory_prefix-
has_modrmTrue
requires_modelong
attributesNOTSX
exception_classUSER-MSR-LEGACY
cpl3
raw_encoding0x0F 0x38 0xF8 MOD[0b11] MOD=3 REG[rrr] RM[nnn] f2_refining_prefix mode64 DF64()

Operands (3)

# Role Kind Class / Reg Width Access Visibility Encoded in
0 REG0 REG w W EXPLICIT MODRM_REG
1 REG1 REG q R EXPLICIT MODRM_REG
2 REG2 REG R SUPPRESSED MODRM_REG

Micro-ops sequence (0)

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