On 19/10/17 14:07, Wilco Dijkstra wrote:
> Vladimir wrote:
>
> +# Disable floating-point expression contraction
> +LIBGCC2_FFP_CONTRAST_CFLAGS = -ffp-contract=off
> +
>
> It looks like this disables fp-contract in all of libgcc...
> What is the the number of FMAs in libgcc before/after?
>
> If it disables anything other than the ones in complex division, it
> would have an unintended performance impact. It's best to do
> this just for complex division.
>
> Wilco
>
It's probably better to do this with an attribute
__attribute__((optimize("fp-contract=off")))
on the affected functions.
R.
