commit d2d7c6b30967a8ffc949d1c8c238f2fa6a851bb4
author Owen Anderson <resistor@mac.com> Tue Feb 19 06:47:18 2008 +0000
committer Owen Anderson <resistor@mac.com> Tue Feb 19 06:47:18 2008 +0000
tree 1a26e73e80764d1ef176ccb559ece68450947570
parent d2a02fe840553c6d4b5826b595a83d6ab4363b6d

In addition to arguments passed to it, memcpy (and all other calls) can ModRef pointers that alias their arguments as well.  This fixes PR2057.

llvm-svn: 47317

llvm/lib/Analysis/BasicAliasAnalysis.cpp

diff --git a/llvm/lib/Analysis/BasicAliasAnalysis.cpp b/llvm/lib/Analysis/BasicAliasAnalysis.cpp
index 57d726d..200779f 100644
--- a/llvm/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/llvm/lib/Analysis/BasicAliasAnalysis.cpp
@@ -263,7 +263,8 @@
           for (CallSite::arg_iterator CI = CS.arg_begin(), CE = CS.arg_end();
               CI != CE; ++CI)
             if (isa<PointerType>((*CI)->getType()) &&
-                getUnderlyingObject(*CI) == P)
+                ( getUnderlyingObject(*CI) == P ||
+                  alias(cast<Value>(CI), ~0ULL, P, ~0ULL) != NoAlias) )
               passedAsArg = true;
           
           if (!passedAsArg)