From 95bb2c374ff88c0ddf4ab03f8a088c70da928db6 Mon Sep 17 00:00:00 2001
From: Markus Kowalewski <markus.kowalewski@fysik.su.se>
Date: Tue, 25 May 2021 10:22:25 +0200
Subject: [PATCH] openblas: disable AVX512, make optional

This effectly reverts 383075f38b94b25ff30ec68a1bb19b35dc9ce4e8.

Some AVX512 optimized kernels seem to be broken in openblas.
See https://github.com/NixOS/nixpkgs/issues/124250.

(cherry picked from commit 5946bc724fe4f7f37ba907ae01d851f070fc97e0)
---
 .../development/libraries/science/math/openblas/default.nix | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/pkgs/development/libraries/science/math/openblas/default.nix b/pkgs/development/libraries/science/math/openblas/default.nix
index f464a755f6e..fe7f088a411 100644
--- a/pkgs/development/libraries/science/math/openblas/default.nix
+++ b/pkgs/development/libraries/science/math/openblas/default.nix
@@ -17,6 +17,10 @@
 , target ? null
 # Select whether DYNAMIC_ARCH is enabled or not.
 , dynamicArch ? null
+# enable AVX512 optimized kernels.
+# These kernels have been a source of trouble in the past.
+# Use with caution.
+, enableAVX512 ? false
 , enableStatic ? stdenv.hostPlatform.isStatic
 , enableShared ? !stdenv.hostPlatform.isStatic
 }:
@@ -71,6 +75,7 @@ let
       BINARY = 64;
       TARGET = setTarget "ATHLON";
       DYNAMIC_ARCH = setDynamicArch true;
+      NO_AVX512 = !enableAVX512;
       USE_OPENMP = false;
       MACOSX_DEPLOYMENT_TARGET = "10.7";
     };
@@ -79,6 +84,7 @@ let
       BINARY = 64;
       TARGET = setTarget "ATHLON";
       DYNAMIC_ARCH = setDynamicArch true;
+      NO_AVX512 = !enableAVX512;
       USE_OPENMP = !stdenv.hostPlatform.isMusl;
     };