kc3-lang/libjpeg-turbo

2020-11-16T14:38:15

Build: Set FLOATTEST more intelligently The "32bit" vs. "64bit" floating point test results actually have nothing to do with the FPU. That was a fallacious assumption based on the observation that, with multiple CPU types, 32-bit and 64-bit builds produce different floating point test results. It seems that this is, in fact, due to differing compiler behavior-- more specifically, whether fused multiply-add (FMA) instructions are used to combine multiple floating point operations into a single instruction ("floating point expression contraction".) GCC does this by default if the target supports FMA instructions, which PowerPC and AArch64 targets both do. Fixes #468