FNCLEX

REG0=XED_REG_X87STATUS:w:SUPP

x86_64 X86_LEGACY X87_ALU X87 source: xed

XED_FNCLEX_X86_LEGACY_ONEBYTE_DB_219025

Encoding

encoding_kindX86_LEGACY
opcode_bytesDB
opcode_mapONEBYTE
mandatory_prefix-
has_modrmTrue
modrm.reg = /4/4
attributesX87_NOWAIT X87_CONTROL NOTSX
cpl3
raw_encoding0xDB MOD[0b11] MOD=3 REG[0b100] RM[0b010]

Operands (1)

# Role Kind Class / Reg Width Access Visibility Encoded in
0 REG0 REG w W SUPPRESSED MODRM_REG

Micro-ops sequence (0)

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