Well, a GCC "bug" - IIRC gcc used the i386 floating-point hardware, which is 80 bits wide (whereas PHP was expecting 64-bit doubles). GCC is arguably correct by

Well, a GCC "bug" - IIRC gcc used the i386 floating-point hardware, which is 80 bits wide (whereas PHP was expecting 64-bit doubles). GCC is arguably correct by preferring the wider type - people should just learn that == and floating point don't match.