Index: llvm/lib/Analysis/ScalarEvolution.cpp
===================================================================
--- llvm/lib/Analysis/ScalarEvolution.cpp
+++ llvm/lib/Analysis/ScalarEvolution.cpp
@@ -148,8 +148,11 @@
 STATISTIC(NumFoundPhiSCCs,
           "Number of found Phi-composed strongly connected components");
 
-// FIXME: Enable this with EXPENSIVE_CHECKS when the test suite is clean.
+#ifdef EXPENSIVE_CHECKS
+bool llvm::VerifySCEV = true;
+#else
 bool llvm::VerifySCEV = false;
+#endif
 
 static cl::opt<unsigned>
 MaxBruteForceIterations("scalar-evolution-max-iterations", cl::ReallyHidden,