Re: graphics/py-Pillow fails to build on 7.0 unless gcc is 4.9+

[Joerg Sonnenberger <joerg%bec.de@localhost>]

On Fri, Jan 12, 2018 at 08:36:55AM +0100, Adam wrote:
> > Looking at libImaging/ImagingUtils.h:40:
> > 
> > /* This is to work around a bug in GCC prior 4.9 in 64 bit mode.
> >   GCC generates code with partial dependency which is 3 times slower.
> >   See: http://stackoverflow.com/a/26588074/253146 */
> > #if defined(__x86_64__) && defined(__SSE__) &&  ! defined(__NO_INLINE__) && \
> >    ! defined(__clang__) && defined(GCC_VERSION) && (GCC_VERSION < 40900)
> > static float __attribute__((always_inline)) inline _i2f(int v) {
> >    float x;
> >    __asm__("xorps %0, %0; cvtsi2ss %1, %0" : "=X"(x) : "r"(v) );
> >    return x;
> > }
> > #else
> > static float inline _i2f(int v) { return (float) v; }
> > #endif
> > 
> > It seems the workaround is also wrong... I'm just going to try gcc 4.9.
> > 
> > GCC_REQD+=      4.9
> > 
> > makes it build.
> 
> Or disable the hack completely. Then GCC <4.9 would supposedly produce worse code.
> 
> Which one is better? :-)

Not forcing the new GCC is better.

Joerg