Displaying 2 results from an estimated 2 matches for "size_of_type_in_bits".
2018 Sep 11
2
[FPEnv] FNEG instruction
Which exactly was the plan?
Add a new, regular instruction?
Add a new constrained math intrinsic?
Both?
Andrew Kaylor made a good point here:
* As I said, all LLVM IR FP instructions are //assumed// to have no side effects. I'm not sure we want an instruction that goes beyond this to be //defined// as having no side effects. It adds a complication to the language and introduces
2018 Sep 11
2
[FPEnv] FNEG instruction
...rules, I think emergence guarantees that we
> don't have to worry about the side effects of FNEG (please correct me if
> I've missed something).
>
> Extending on that, I suspect that we should not be canonicalizing FNEG(X)
> as FSUB(-0.0, X), but rather as XOR(X, 1 << (SIZE_OF_TYPE_IN_BITS - 1)). A
> utility function could provide us with the sign-bit constant, so it's not
> that ugly.
>
> That said, I agree that Andrew's take is compelling. And I would be okay
> with adding a constrained FNEG to solve the immediate issue, if that is the
> final decision.
&g...