From d9c4afe5b7a183fec9f7cf6aa99e3534cd258feb Mon Sep 17 00:00:00 2001
From: Peter Georg <peter.georg@physik.uni-regensburg.de>
Date: Thu, 11 Mar 2021 12:58:49 +0100
Subject: [PATCH] Fix inconsistent configure option AVX512

Before this change AVX512 enabled different instruction sets depending
on the compiler:

For Intel C++ Compiler Classic (ICC):
    AVX512F, AVX512CD, AVX512DQ, AVX512BW, AVX512VL
    i.e. Intel Xeon Skylake and newer

For Intel ICX, gcc, clang:
    AVX512F, AVX512CD, AVX512ER, AVX512PF
    i.e. Intel Xeon Phi x200/x205 (KNL/KNM)

With this commit AVX512 now only enables the common instruction sets
supported by all CPUs supporting any AVX-512 instructions set:
AVX512F and AVX512CD (called COMMON-AVX512 by icc)
---
 configure.ac | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/configure.ac b/configure.ac
index 5f165412..afd5cbad 100644
--- a/configure.ac
+++ b/configure.ac
@@ -444,7 +444,7 @@ case ${ax_cv_cxx_compiler_vendor} in
         SIMD_FLAGS='-mavx2 -mfma -mf16c';;
       AVX512)
         AC_DEFINE([AVX512],[1],[AVX512 intrinsics])
-        SIMD_FLAGS='-mavx512f -mavx512pf -mavx512er -mavx512cd';;
+        SIMD_FLAGS='-mavx512f -mavx512cd';;
       SKL)
         AC_DEFINE([AVX512],[1],[AVX512 intrinsics for SkyLake Xeon])
         SIMD_FLAGS='-march=skylake-avx512';;
@@ -498,7 +498,7 @@ case ${ax_cv_cxx_compiler_vendor} in
         SIMD_FLAGS='-march=core-avx2 -xcore-avx2';;
       AVX512)
         AC_DEFINE([AVX512],[1],[AVX512 intrinsics])
-        SIMD_FLAGS='-xcore-avx512';;
+        SIMD_FLAGS='-xcommon-avx512';;
       KNC)
         AC_DEFINE([IMCI],[1],[IMCI Intrinsics for Knights Corner])
         SIMD_FLAGS='';;