ARROW-7399: [C++][Gandiva] set Mcpu based on host cpu

Pindikura Ravindra · Pindikura Ravindra · commit 6b2bf28ae62e · 2019-12-17T16:43:55.000+05:30
- llvm doesn't auto detect cpu features based on host cpu. so, explicitly set the same in EngineBuilder. Closes apache#6038 from pravindra/arrow-7399 and squashes the following commits: f99694a <Pindikura Ravindra> use static variable for getHostCpuName 7604eb0 <Pindikura Ravindra> ARROW-7399: set Mcpu based on host cpu Authored-by: Pindikura Ravindra <ravindra@dremio.com> Signed-off-by: Pindikura Ravindra <ravindra@dremio.com>
diff --git a/cpp/src/gandiva/engine.cc b/cpp/src/gandiva/engine.cc
@@ -92,6 +92,7 @@ void Engine::InitOnce() {
 /// factory method to construct the engine.
 Status Engine::Make(std::shared_ptr<Configuration> config,
                     std::unique_ptr<Engine>* engine) {
+  static auto host_cpu_name = llvm::sys::getHostCPUName();
   std::unique_ptr<Engine> engine_obj(new Engine());
 
   std::call_once(init_once_flag, [&engine_obj] { engine_obj->InitOnce(); });
@@ -105,6 +106,7 @@ Status Engine::Make(std::shared_ptr<Configuration> config,
   engine_obj->module_ = cg_module.get();
 
   llvm::EngineBuilder engineBuilder(std::move(cg_module));
+  engineBuilder.setMCPU(host_cpu_name);
   engineBuilder.setEngineKind(llvm::EngineKind::JIT);
   engineBuilder.setOptLevel(llvm::CodeGenOpt::Aggressive);
   engineBuilder.setErrorStr(&(engine_obj->llvm_error_));
