On Sat, Nov 16, 2019 at 04:25:18PM -0500, Jeffrey Walton wrote: > On Sat, Nov 16, 2019 at 1:26 PM Jonathan Wakely <jwakely.gcc@xxxxxxxxx> wrote: > > ... > > I already sent the following to Jeffrey 8 hours ago (off-list, because > > I could only send HTML mail at the time): > > > > "Those are the docs for GCC trunk. That function is not listed in the > > docs for GCC 7." > > GCC tells me it supports the load by accepting -mcpu=power9 and > defining _ARCH_PWR9. It does no such thing. GCC does not claim it implements this, and the ELF v2 spec says "The two optional built-in vector functions in Table 6.4 [...]", and defines no specific way to detect it either. > The problems with GCC seem to be a little larger then inaccurate docs. The GCC docs are perfectly accurate for this as well. GCC 7 is older than this revision of the ELFv2 specification, and we never backported this feature: only very important features are backported. It could have made 7.2, over two years ago, but it wasn't considered important enough to backport. Segher
