On Mon, Jun 23, 2025 at 11:10:45AM -0400, Tom Lane wrote: > Nathan Bossart <nathandboss...@gmail.com> writes: >> On Mon, Jun 23, 2025 at 10:51:21AM -0400, Tom Lane wrote: >>> This has broken the build completely on my RHEL8 x86_64 box, >>> with gcc 8.5.0: > >> Unfortunately, this will probably require more than replacing >> _mm512_castsi512_si128 with _mm512_zextsi512_si128 because the latter >> doesn't exist. > > I was imagining just including _mm512_zextsi128_si512() in the > code being tested during configure, so that we fall back to > the non-AVX-512 code if the compiler is too old to have it. > I don't really feel a need to work harder than that.
Sorry, my note wasn't clear. Right now, the configure test uses _mm512_castsi512_si128(), so we can't just do a simple s/cast/zext. We'll need to make a slightly bigger modification to the test to make sure the zext intrinsics are understood. I agree that we needn't work any harder than that. -- nathan
