+AliasAnalysis::ModRefResult
+AliasAnalysis::getModRefInfo(const VAArgInst *V, const Value *P, unsigned Size) {
+ // If the va_arg address cannot alias the pointer in question, then the
+ // specified memory cannot be accessed by the va_arg.
+ if (!alias(V->getOperand(0), UnknownSize, P, Size))
+ return NoModRef;
+
+ // If the pointer is a pointer to constant memory, then it could not have been
+ // modified by this va_arg.
+ if (pointsToConstantMemory(P))
+ return NoModRef;
+
+ // Otherwise, a va_arg reads and writes.
+ return ModRef;
+}
+
+