FUCOMP

X87_ALU X87 x86_64

3 encoding forms.

X86_FUCOMP_X86_LEGACY_ONEBYTE_DD_0
(no syntax)
X86_LEGACY DD FPU
X86_FUCOMP_X86_LEGACY_ONEBYTE_DD_10310
st(i)
X86_LEGACY DD FPU
XED_FUCOMP_X86_LEGACY_ONEBYTE_DD_394625
REG0=XED_REG_ST0:r:IMPL:f80 REG1=X87():r:f80 REG2=XED_REG_X87POP:r:SUPP REG3=XED_REG_X87STATUS:rw:SUPP
X86_LEGACY DD /5 X87