FNCLEX

X87_ALU X87 x86_64

2 encoding forms.

X86_FNCLEX_X86_LEGACY_ONEBYTE_DB_0
(no syntax)
X86_LEGACY DB FPU
XED_FNCLEX_X86_LEGACY_ONEBYTE_DB_219025
REG0=XED_REG_X87STATUS:w:SUPP
X86_LEGACY DB /4 X87