I am forwarding this to cfe-dev as it might this sounds like a bug and cfe-users is not read that much.
-------- Weitergeleitete Nachricht -------- Betreff: [cfe-users] floor is vectorized, but not sin, cos or exp Datum: Tue, 11 Dec 2018 16:47:16 +0100 Von: Klaus Leppkes via cfe-users <cfe-users@lists.llvm.org> Antwort an: Klaus Leppkes <klaus.lepp...@rwth-aachen.de> An: cfe-users@lists.llvm.org Hi, according to the doc (https://releases.llvm.org/7.0.0/docs/Vectorizers.html) floor, sin, cos should be vectorized. I can confirm (using the great https://gcc.godbolt.org/ tool) that using the flags "-Ofast -mavx2 -fopenmp -ffast-math" the right avx2 opcode (vroundps) is emited for floor (in foo), but unfortunately not for sin, cos or exp (e.g. see sin in bar below). GCC 8.1+ and the Intel Compiler icc 13+ insert call to vectorized implementations (_ZGVbN4v_sinf or __svml_sinf4 ), but clang seems to have nothing like this. Here is my small testcode: #include<cmath> voidfoo(float* __restrict__attribute((aligned(32))) x , float* __restrict__attribute((aligned(32))) y) { for(inti = 0; i < 4; ++i) y[i] = floor(x[i]); } voidbar(float* __restrict__attribute((aligned(32))) x , float* __restrict__attribute((aligned(32))) y) { for(inti = 0; i < 4; ++i) y[i] = sin(x[i]); } I have reproduced this behavior on different machines. Maybe I am doing s.th. wrong here, but it seems like there is no vectorized implementation for sin, cos etc. I am using h2lib for now (http://h2lib.org/doc/d1/d89/simd__avx_8h_source.html) as a workaround, but I expect clang to do this job. Can anybody comment on this please? Cheers Klaus
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