Shouldn't unsafe-math-optimizations (re-)enable fp-contract=fast?

[Ian Bolton]

Hi there,

I see in common.opt that fp-contract=fast is the default for GCC.

But then it gets disabled in c-family/c-opts.c if you are using ISO C
(e.g. with -std=c99).

But surely if you have also specified -funsafe-math-optimizations then
it should flip it back onto fast?

I see in gcc/opts.c that a few other flags are triggered based on
-funsafe-math-optimizations but not -ffp-contract=fast.

I think this is a bug and could lead to less optimal code than people
would like if they want c99 compliance for reason A but also unsafe
math for reason B.

What do you think?

Cheers,
Ian