slightly improve mod/ref for DSAA by checking the globals graph for fallback
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20868 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/DataStructure/DataStructureAA.cpp b/lib/Analysis/DataStructure/DataStructureAA.cpp
index 6f1cb56..c2449c2 100644
--- a/lib/Analysis/DataStructure/DataStructureAA.cpp
+++ b/lib/Analysis/DataStructure/DataStructureAA.cpp
@@ -222,6 +222,18 @@
cast<GlobalVariable>(P)->getType()->getElementType()->isFirstClassType() &&
"This isn't a global that DSA inconsiderately dropped "
"from the graph?");
+
+ DSGraph &GG = *CallerTDGraph.getGlobalsGraph();
+ DSScalarMap::iterator NI = GG.getScalarMap().find(P);
+ if (NI != GG.getScalarMap().end() && !NI->second.isNull()) {
+ // Otherwise, if the node is only M or R, return this. This can be
+ // useful for globals that should be marked const but are not.
+ DSNode *N = NI->second.getNode();
+ if (!N->isModified())
+ Result = (ModRefResult)(Result & ~Mod);
+ if (!N->isRead())
+ Result = (ModRefResult)(Result & ~Ref);
+ }
}
return Result;
}