Eric Blake wrote: > should we raise this as a gcc bug, that when it > does constant-folding optimization of signbit at compile-time > (signbit(-0.0) => 1), it results in a different value than when the macro > is used on a runtime value (signbit(result) => mask off all but the sign bit)?
I don't think it's a bug. The spec http://www.opengroup.org/susv3/functions/signbit.html does not specify which non-zero return value is used. You don't even have the guarantee that two different invocations of signbit(x) with the same x will yield the same results. Things would be different if the return value was 'bool'. But it's 'int'. Bruno
