From 7a8fd724ea44dec812d57fa380375e71f6454828 Mon Sep 17 00:00:00 2001
From: Peter Hawkins <phawkins@google.com>
Date: Wed, 3 Jul 2019 08:59:35 -0700
Subject: [PATCH] [XLA:CPU] Disable AVX512 in XLA:CPU due to miscompilations.

PiperOrigin-RevId: 256377398
---
 .../compiler/xla/service/cpu/simple_orc_jit.cc   | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/tensorflow/compiler/xla/service/cpu/simple_orc_jit.cc b/tensorflow/compiler/xla/service/cpu/simple_orc_jit.cc
index d8b27f32e75..bf55e9e22cf 100644
--- a/tensorflow/compiler/xla/service/cpu/simple_orc_jit.cc
+++ b/tensorflow/compiler/xla/service/cpu/simple_orc_jit.cc
@@ -56,12 +56,24 @@ llvm::SmallVector<std::string, 0> DetectMachineAttributes() {
   if (llvm::sys::getHostCPUFeatures(host_features)) {
     for (auto& feature : host_features) {
       if (feature.second) {
-        result.push_back(feature.first());
+        llvm::StringRef feature_name = feature.first();
+        // Skip avx512 for now, it isn't quite ready in LLVM.
+        if (feature_name.startswith("avx512")) {
+          continue;
+        }
+        result.push_back(feature_name);
       }
     }
   }
   return result;
 }
+
+llvm::StringRef GetHostCpuName() {
+  auto cpu_name = llvm::sys::getHostCPUName();
+  // Skip avx512 for now, it isn't quite ready in LLVM.
+  cpu_name.consume_back("-avx512");
+  return cpu_name;
+}
 }  // namespace
 
 /*static*/ std::unique_ptr<llvm::TargetMachine>
@@ -74,7 +86,7 @@ SimpleOrcJIT::InferTargetMachineForJIT(
           .setOptLevel(opt_level)
           .selectTarget(
               /*TargetTriple=*/llvm::Triple(), /*MArch=*/"",
-              /*MCPU=*/llvm::sys::getHostCPUName(),
+              /*MCPU=*/GetHostCpuName(),
               /*MAttrs=*/DetectMachineAttributes()));
   CHECK(target_machine != nullptr);
   return target_machine;