[LLVMdev] Optimization of sqrt() with invalid argument

[Reid Kleckner]

On Fri, Sep 26, 2014 at 3:14 PM, Joerg Sonnenberger <joerg at britannica.bec.de
> wrote:

> On Fri, Sep 26, 2014 at 01:52:19PM -0500, Bill Schmidt wrote:
> > At the least, we should constant-fold to NaN for the non fast-math sqrt
> > calls...there's no point in going through the libcall overhead when we
> > know the answer in advance.  I can prepare a patch for that if everyone
> > agrees.
>
> The crux is that sqrt(-1) can set errno, can't it?
>

I'm pretty sure -ffast-math means you don't care about that.
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