[llvm-commits] [llvm] r52302 - /llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp

[Chris Lattner]

Author: lattner
Date: Mon Jun 16 01:28:01 2008
New Revision: 52302

URL: http://llvm.org/viewvc/llvm-project?rev=52302&view=rev
Log:
Other parts of this code treat noalias arguments as objects for
the purposes of escape analysis.

Modified:
    llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp

Modified: llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp?rev=52302&r1=52301&r2=52302&view=diff

==============================================================================
--- llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp (original)
+++ llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp Mon Jun 16 01:28:01 2008
@@ -320,11 +320,15 @@
 /// isNonEscapingLocalObject - Return true if the pointer is to a function-local
 /// object that never escapes from the function.
 static bool isNonEscapingLocalObject(const Value *V) {
-  // If this is a local allocation or byval argument, check to see if it
-  // escapes.
-  if (isa<AllocationInst>(V) ||
-      (isa<Argument>(V) && cast<Argument>(V)->hasByValAttr()))
+  // If this is a local allocation, check to see if it escapes.
+  if (isa<AllocationInst>(V))
     return !AddressMightEscape(V);
+      
+  // If this is an argument that corresponds to a byval or noalias argument,
+  // it can't escape either.
+  if (const Argument *A = dyn_cast<Argument>(V))
+    if (A->hasByValAttr() || A->hasNoAliasAttr())
+      return !AddressMightEscape(V);
   return false;
 }