I wrote:
> So the early returns from the buildfarm aren't very good:
> * tern/sungazer isn't getting exactly 0.5 from sind(30).
> The tern/sungazer result implies that this:
> return (sin(x * (M_PI / 180.0)) / sin(30.0 * (M_PI / 180.0))) / 2.0;
> is not producing exactly 0.5, which means that the two sin() calls aren't
> producing identical results, which I suspect is best explained by the
> theory that the compiler is rearranging 30.0 * (M_PI / 180.0) into
> (30.0 * M_PI) / 180.0, and getting a slightly different number that way.
> I think we could fix that by replacing (M_PI / 180.0) by a hard-wired
> constant (computed to say 20 digits or so).
So I pushed that, and tern/sungazer are still failing. Noah, could you
trace through that and see exactly where it's going off the rails?
regards, tom lane