In addition to arguments passed to it, memcpy (and all other calls) can ModRef pointers that alias their arguments as well. This fixes PR2057.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47317 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index 57d726d..200779f 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/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)