Don't analyze arguments already marked 'nocapture'.

llvm-svn: 61532

3 files changed, 13 insertions, 1 deletions

diff --git a/llvm/include/llvm/Argument.h b/llvm/include/llvm/Argument.h
index 9faff549f26..9c063677984 100644
--- a/llvm/include/llvm/Argument.h
+++ b/llvm/include/llvm/Argument.h
@@ -56,6 +56,10 @@ public:
   /// it in its containing function.
   bool hasNoAliasAttr() const;
   
+  /// hasNoCaptureAttr - Return true if this argument has the nocapture
+  /// attribute on it in its containing function.
+  bool hasNoCaptureAttr() const;
+  
   /// hasSRetAttr - Return true if this argument has the sret attribute on it in
   /// its containing function.
   bool hasStructRetAttr() const;
diff --git a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
index 9ed605cf9f3..1824a710c51 100644
--- a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
+++ b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
@@ -263,7 +263,8 @@ bool FunctionAttrs::AddNoCaptureAttrs(const std::vector<CallGraphNode *> &SCC) {
       continue;
 
     for (Function::arg_iterator A = F->arg_begin(), E = F->arg_end(); A!=E; ++A)
-      if (isa<PointerType>(A->getType()) && !isCaptured(*F, A)) {
+      if (isa<PointerType>(A->getType()) && !A->hasNoCaptureAttr() &&
+          !isCaptured(*F, A)) {
         A->addAttr(Attribute::NoCapture);
         NumNoCapture++;
         Changed = true;
diff --git a/llvm/lib/VMCore/Function.cpp b/llvm/lib/VMCore/Function.cpp
index ddc6ace3278..f83fe435cd0 100644
--- a/llvm/lib/VMCore/Function.cpp
+++ b/llvm/lib/VMCore/Function.cpp
@@ -102,6 +102,13 @@ bool Argument::hasNoAliasAttr() const {
   return getParent()->paramHasAttr(getArgNo()+1, Attribute::NoAlias);
 }
 
+/// hasNoCaptureAttr - Return true if this argument has the nocapture attribute
+/// on it in its containing function.
+bool Argument::hasNoCaptureAttr() const {
+  if (!isa<PointerType>(getType())) return false;
+  return getParent()->paramHasAttr(getArgNo()+1, Attribute::NoCapture);
+}
+
 /// hasSRetAttr - Return true if this argument has the sret attribute on
 /// it in its containing function.
 bool Argument::hasStructRetAttr() const {