[Bug middle-end/57073] __builtin_powif (-1.0, k) should be optimized to "1.0 - 2.0 * (K%2)"

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57073



Tobias Burnus <burnus at gcc dot gnu.org> changed:



           What    |Removed                     |Added

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                 CC|                            |burnus at gcc dot gnu.org



--- Comment #2 from Tobias Burnus <burnus at gcc dot gnu.org> 2013-04-26 
07:09:54 UTC ---

As James pointed out at c.l.f, the algorithm fails if k < 0 - and suggests:



   1.0 - (float) ((k & 1) << 1)