Index: clang/lib/StaticAnalyzer/Checkers/UndefResultChecker.cpp
===================================================================
--- clang/lib/StaticAnalyzer/Checkers/UndefResultChecker.cpp
+++ clang/lib/StaticAnalyzer/Checkers/UndefResultChecker.cpp
@@ -69,6 +69,7 @@
   ProgramStateRef State = C.getState();
   const llvm::APSInt *LHS = SB.getKnownValue(State, C.getSVal(B->getLHS()));
   const llvm::APSInt *RHS = SB.getKnownValue(State, C.getSVal(B->getRHS()));
+  assert(LHS && RHS && "Values unknown, inconsistent state");
   return (unsigned)RHS->getZExtValue() > LHS->countLeadingZeros();
 }
 
Index: clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp
===================================================================
--- clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp
+++ clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp
@@ -1209,6 +1209,7 @@
 
 const llvm::APSInt *SimpleSValBuilder::getKnownValue(ProgramStateRef state,
                                                    SVal V) {
+  V = simplifySVal(state, V);
   if (V.isUnknownOrUndef())
     return nullptr;
 
Index: clang/test/Analysis/casts.c
===================================================================
--- clang/test/Analysis/casts.c
+++ clang/test/Analysis/casts.c
@@ -1,5 +1,6 @@
-// RUN: %clang_analyze_cc1 -triple x86_64-apple-darwin9 -analyzer-checker=core,alpha.core,debug.ExprInspection -analyzer-store=region -verify %s
-// RUN: %clang_analyze_cc1 -triple i386-apple-darwin9 -analyzer-checker=core,alpha.core,debug.ExprInspection -analyzer-store=region -verify %s
+// RUN: %clang_analyze_cc1 -triple x86_64-apple-darwin9 -analyzer-checker=core,alpha.core,debug.ExprInspection -analyzer-store=region -verify -analyzer-config eagerly-assume=false %s
+// RUN: %clang_analyze_cc1 -triple i386-apple-darwin9 -analyzer-checker=core,alpha.core,debug.ExprInspection -analyzer-store=region -verify -analyzer-config eagerly-assume=false %s
+// RUN: %clang_analyze_cc1 -analyzer-checker=core,alpha.core,debug.ExprInspection -verify -DEAGERLY_ASSUME=1 -w %s
 
 extern void clang_analyzer_eval(_Bool);
 
@@ -16,6 +17,8 @@
 
 void getsockname();
 
+#ifndef EAGERLY_ASSUME
+
 void f(int sock) {
   struct sockaddr_storage storage;
   struct sockaddr* sockaddr = (struct sockaddr*)&storage; // expected-warning{{Casting data to a larger structure type and accessing a field can lead to memory access errors or data corruption}}
@@ -189,12 +192,20 @@
   }
 }
 
-int globalA;
+#endif
+
+#ifdef EAGERLY_ASSUME
+
+// expected-no-diagnostics
+
+int globalA; // TODO: the example is not representative.
 extern int globalFunc();
 void no_crash_on_symsym_cast_to_long() {
   char c = globalFunc() - 5;
-  (void)(c == 0);
+  c == 0;
   globalA -= c;
-  (void)(globalA == 3);
-  (void)((long)globalA << 48); // no-crash
+  globalA == 3;
+  (long)globalA << 48; // no-crash
 }
+
+#endif