-ffloat-store behavior (Re: Susprising behavior of gcc on x86 (-m32))

[Manuel López-Ibáñez]

On 08/09/15 22:05, Mathieu Malaterre wrote:
>
> Ok, I think I understand now. -O0 did produce code that is compatible
> with -ffloat-store. However I am still required to use -ffloat-store
> (explicitly) for any other optimization (at least required with -O2 in
> my case).

You are not required to use -ffloat-store, neither is -ffloat-store guaranteed 
to work. Please read https://gcc.gnu.org/wiki/FAQ#PR323

(If there is something that is not explained there, it would be better to 
expand the answer rather than reply here with bits of info.)

Cheers,

Manuel.