Displaying 2 results from an estimated 2 matches for "fneg_constrained".
2018 Oct 01
6
[FPEnv] FNEG instruction
...e any controversy for the preliminary requirement of
removing BinaryOperator::isFNeg()
and friends, so start with that?
That work may reveal other potential regressions that we can patch in
advance too.
Other than that, I think there's really only a question of do we want 1 or
both of fneg and fneg_constrained (and if we choose both, then I assume
we'd also add fabs_constrained and copysign_constrained).
I don't see why we want those redundancies. As discussed here, we already
can't canonicalize to the FP bitops in IR because of non-IEEE targets
(D19391). In IR and the backend, you don't...
2018 Sep 27
2
[FPEnv] FNEG instruction
Regarding non-IEEE targets: yes, we definitely support those, so we do have
to be careful about not breaking them. I know because I have broken them. :)
See the discussion and related links here: https://reviews.llvm.org/D19391
But having an exactly specified fneg op makes that easier, not harder, as I
see it. Unfortunately, if a target doesn't support this op (always toggle
the sign bit and