Hi All,
The comment of UNDEF in ISDOpcodes.h [1] is pretty simple,
/// UNDEF - An undefined node.
UNDEF,
The name make me think of C undefined behavior, which is … scary. But I also see there are
APIs like isBuildVectorAllOnes, isBuildVectorAllZeros, … etc, seems UNDEF just can be any
value and we don’t care about what it is. The most case I see UNDEF is in BUULD_VECTOR,
VECTOR_SHUFFLE, … etc. I would like to know usually how we deal with those UNDEF nodes?
Thanks.
[1] http://llvm.org/doxygen/ISDOpcodes_8h_source.html
Regards,
chenwj