[LLVM-C] Add LLVMGetHostCPU{Name,Features}.

Without these functions it's hard to create a TargetMachine for
Orc JIT that creates efficient native code.

It's not sufficient to just expose LLVMGetHostCPUName(), because
for some CPUs there's fewer features actually available than
the CPU name indicates (e.g. AVX might be missing on some CPUs
identified as Skylake).

Differential Revision: https://reviews.llvm.org/D44861

llvm-svn: 329856

1 files changed, 16 insertions, 0 deletions

diff --git a/llvm/lib/Target/TargetMachineC.cpp b/llvm/lib/Target/TargetMachineC.cpp
index d6016efa246..d43124d7123 100644
--- a/llvm/lib/Target/TargetMachineC.cpp
+++ b/llvm/lib/Target/TargetMachineC.cpp
@@ -18,6 +18,7 @@
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Module.h"
+#include "llvm/MC/SubtargetFeature.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/FormattedStream.h"
 #include "llvm/Support/Host.h"
@@ -237,6 +238,21 @@ char *LLVMGetDefaultTargetTriple(void) {
   return strdup(sys::getDefaultTargetTriple().c_str());
 }
 
+char *LLVMGetHostCPUName(void) {
+  return strdup(sys::getHostCPUName().data());
+}
+
+char *LLVMGetHostCPUFeatures(void) {
+  SubtargetFeatures Features;
+  StringMap<bool> HostFeatures;
+
+  if (sys::getHostCPUFeatures(HostFeatures))
+    for (auto &F : HostFeatures)
+      Features.AddFeature(F.first(), F.second);
+
+  return strdup(Features.getString().c_str());
+}
+
 void LLVMAddAnalysisPasses(LLVMTargetMachineRef T, LLVMPassManagerRef PM) {
   unwrap(PM)->add(
       createTargetTransformInfoWrapperPass(unwrap(T)->getTargetIRAnalysis()));