Integrate the readonly/readnone logic more deeply

into alias analysis.  This meant updating the API
which now has versions of the getModRefBehavior,
doesNotAccessMemory and onlyReadsMemory methods
which take a callsite parameter.  These should be
used unless the callsite is not known, since in
general they can do a better job than the versions
that take a function.  Also, users should no longer
call the version of getModRefBehavior that takes
both a function and a callsite.  To reduce the
chance of misuse it is now protected.

llvm-svn: 44487

1 files changed, 2 insertions, 4 deletions

diff --git a/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp b/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
index dd567aac95d..8c5f216f539 100644
--- a/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
+++ b/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
@@ -94,11 +94,9 @@ Instruction* MemoryDependenceAnalysis::getCallSiteDependency(CallSite C,
       
       // FreeInsts erase the entire structure
       pointerSize = ~0UL;
-    } else if (CallSite::get(QI).getInstruction() != 0 &&
-               cast<CallInst>(QI)->getCalledFunction()) {
+    } else if (isa<CallInst>(QI)) {
       AliasAnalysis::ModRefBehavior result =
-                   AA.getModRefBehavior(cast<CallInst>(QI)->getCalledFunction(),
-                                        CallSite::get(QI));
+                   AA.getModRefBehavior(CallSite::get(QI));
       if (result != AliasAnalysis::DoesNotAccessMemory &&
           result != AliasAnalysis::OnlyReadsMemory) {
         if (!start && !block) {