[X86] Add support 'tune' in target attribute

This adds parsing and codegen support for tune in target attribute.

I've implemented this so that arch in the target attribute implicitly disables tune from the command line. I'm not sure what gcc does here. But since -march implies -mtune. I assume 'arch' in the target attribute implies tune in the target attribute.

Differential Revision: https://reviews.llvm.org/D86187

1 files changed, 10 insertions, 4 deletions

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 23d35f6..65e5e27a 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -1770,9 +1770,14 @@ bool CodeGenModule::GetCPUAndFeaturesAttributes(GlobalDecl GD,
     // the function.
     if (TD) {
       ParsedTargetAttr ParsedAttr = TD->parse();
-      if (ParsedAttr.Architecture != "" &&
-          getTarget().isValidCPUName(ParsedAttr.Architecture))
+      if (!ParsedAttr.Architecture.empty() &&
+          getTarget().isValidCPUName(ParsedAttr.Architecture)) {
         TargetCPU = ParsedAttr.Architecture;
+        TuneCPU = ""; // Clear the tune CPU.
+      }
+      if (!ParsedAttr.Tune.empty() &&
+          getTarget().isValidCPUName(ParsedAttr.Tune))
+        TuneCPU = ParsedAttr.Tune;
     }
   } else {
     // Otherwise just add the existing target cpu and target features to the
@@ -1780,11 +1785,11 @@ bool CodeGenModule::GetCPUAndFeaturesAttributes(GlobalDecl GD,
     Features = getTarget().getTargetOpts().Features;
   }
 
-  if (TargetCPU != "") {
+  if (!TargetCPU.empty()) {
     Attrs.addAttribute("target-cpu", TargetCPU);
     AddedAttr = true;
   }
-  if (TuneCPU != "") {
+  if (!TuneCPU.empty()) {
     Attrs.addAttribute("tune-cpu", TuneCPU);
     AddedAttr = true;
   }
@@ -1826,6 +1831,7 @@ void CodeGenModule::setNonAliasAttributes(GlobalDecl GD,
         // new ones should replace the old.
         F->removeFnAttr("target-cpu");
         F->removeFnAttr("target-features");
+        F->removeFnAttr("tune-cpu");
         F->addAttributes(llvm::AttributeList::FunctionIndex, Attrs);
       }
     }