Make BasicAliasAnalysis recognize the fact a noalias argument cannot alias another argument, even if the other argument is not itself marked noalias.

llvm-svn: 182755

1 files changed, 9 insertions, 0 deletions

diff --git a/llvm/lib/Analysis/AliasAnalysis.cpp b/llvm/lib/Analysis/AliasAnalysis.cpp
index 210b80ab63e..3454ce0be2b 100644
--- a/llvm/lib/Analysis/AliasAnalysis.cpp
+++ b/llvm/lib/Analysis/AliasAnalysis.cpp
@@ -537,6 +537,15 @@ bool llvm::isNoAliasCall(const Value *V) {
   return false;
 }
 
+/// isNoAliasArgument - Return true if this is an argument with the noalias
+/// attribute.
+bool llvm::isNoAliasArgument(const Value *V)
+{
+  if (const Argument *A = dyn_cast<Argument>(V))
+    return A->hasNoAliasAttr();
+  return false;
+}
+
 /// isIdentifiedObject - Return true if this pointer refers to a distinct and
 /// identifiable object.  This returns true for:
 ///    Global Variables and Functions (but not Global Aliases)