On Mon, Aug 26, 2024 at 06:44:55PM +0000, Amonson, Paul D wrote: >> I'm curious about where exactly the regression is coming from. Is it >> possible >> that your build for the SSE 4.2 tests was using it unconditionally, i.e., >> optimizing away the function pointer? > > I am calling the SSE 4.2 implementation directly; I am not even building > the pg_sse42_*_choose.c file with the AVX512 choice. As best I can tell > there is one extra function call and one extra int64 conditional test > when bytes are <256 and a of course a JMP instruction to skip the AVX512 > implementation.
And this still shows the ~14% regression in your original post? -- nathan
