2 files changed, 16 insertions, 6 deletions

diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index 6db753f1686..c052cf245c4 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -1340,6 +1340,7 @@ void CodeGenModule::ConstructAttributeList(const CGFunctionInfo &FI,
                                            bool AttrOnCallSite) {
   llvm::AttrBuilder FuncAttrs;
   llvm::AttrBuilder RetAttrs;
+  bool HasOptnone = false;
 
   CallingConv = FI.getEffectiveCallingConvention();
 
@@ -1380,12 +1381,18 @@ void CodeGenModule::ConstructAttributeList(const CGFunctionInfo &FI,
       RetAttrs.addAttribute(llvm::Attribute::NoAlias);
     if (TargetDecl->hasAttr<ReturnsNonNullAttr>())
       RetAttrs.addAttribute(llvm::Attribute::NonNull);
+
+    HasOptnone = TargetDecl->hasAttr<OptimizeNoneAttr>();
+  }
+
+  // OptimizeNoneAttr takes precedence over -Os or -Oz. No warning needed.
+  if (!HasOptnone) {
+    if (CodeGenOpts.OptimizeSize)
+      FuncAttrs.addAttribute(llvm::Attribute::OptimizeForSize);
+    if (CodeGenOpts.OptimizeSize == 2)
+      FuncAttrs.addAttribute(llvm::Attribute::MinSize);
   }
 
-  if (CodeGenOpts.OptimizeSize)
-    FuncAttrs.addAttribute(llvm::Attribute::OptimizeForSize);
-  if (CodeGenOpts.OptimizeSize == 2)
-    FuncAttrs.addAttribute(llvm::Attribute::MinSize);
   if (CodeGenOpts.DisableRedZone)
     FuncAttrs.addAttribute(llvm::Attribute::NoRedZone);
   if (CodeGenOpts.NoImplicitFloat)
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 597fd364d78..06467fda6ef 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -725,7 +725,8 @@ void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
   }
 
   if (D->hasAttr<ColdAttr>()) {
-    B.addAttribute(llvm::Attribute::OptimizeForSize);
+    if (!D->hasAttr<OptimizeNoneAttr>())
+      B.addAttribute(llvm::Attribute::OptimizeForSize);
     B.addAttribute(llvm::Attribute::Cold);
   }
 
@@ -766,7 +767,9 @@ void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
     F->addFnAttr(llvm::Attribute::NoInline);
 
     // OptimizeNone wins over OptimizeForSize, MinSize, AlwaysInline.
-    F->removeFnAttr(llvm::Attribute::OptimizeForSize);
+    assert(!F->hasFnAttribute(llvm::Attribute::OptimizeForSize) &&
+           "OptimizeNone and OptimizeForSize on same function!");
+    // FIXME: Change these to asserts.
     F->removeFnAttr(llvm::Attribute::MinSize);
     F->removeFnAttr(llvm::Attribute::AlwaysInline);