[cfe-dev] Why no NSW/NUW with SHL instruction?

[Ryan Taylor]

I'm curious why there is not always a nsw/nuw flag with shl instruction?
For example, I have a signed int I'm shifting left (want to generate an
arithmetic left shift in backend for signed int shift lefts and logical for
unsigned, at the moment).... but shl on a signed int does not always have
nsw/nuw flag present, why is this?

Thank you.
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