On Mon, Feb 8, 2016 at 2:42 PM, Richard Smith <rich...@metafoo.co.uk> wrote: > Do we really need an 'empty type' special case? > > The x86_64 psABI already seems clear that empty types with size <= 16 > are not passed at all. Following the algorithm in section 3.2.3, each > eightbyte is classified as NO_CLASS, and thus is not passed. So the > proposed change would only affect the behavior of types larger than 16 > bytes that contain no data. It doesn't seem worth breaking ABI to more > efficiently pass those. >
Clang isn't consistent between ia32 and x86-64. GCC isn't compatible with clang. My proposal will make GCC and clang compatible. It also makes GCC and clang behave the same on both ia32 and x86-64. -- H.J.
