diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
index 9bd8bb521b7d..a4be03a84411 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
@@ -267,7 +267,7 @@ SDValue DAGTypeLegalizer::PromoteIntRes_Constant(SDNode *N) {
   // matter in theory which one we pick, but this tends to give better code?
   unsigned Opc = VT.isByteSized() ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
   SDValue Result = DAG.getNode(Opc, TLI.getTypeToTransformTo(VT),
-                                 SDValue(N, 0));
+                               SDValue(N, 0));
   assert(isa<ConstantSDNode>(Result) && "Didn't constant fold ext?");
   return Result;
 }
@@ -350,22 +350,27 @@ SDValue DAGTypeLegalizer::PromoteIntRes_EXTRACT_VECTOR_ELT(SDNode *N) {
 }
 
 SDValue DAGTypeLegalizer::PromoteIntRes_FP_TO_XINT(SDNode *N) {
-  unsigned NewOpc = N->getOpcode();
   MVT NVT = TLI.getTypeToTransformTo(N->getValueType(0));
+  unsigned NewOpc = N->getOpcode();
 
   // If we're promoting a UINT to a larger size, check to see if the new node
   // will be legal.  If it isn't, check to see if FP_TO_SINT is legal, since
   // we can use that instead.  This allows us to generate better code for
   // FP_TO_UINT for small destination sizes on targets where FP_TO_UINT is not
   // legal, such as PowerPC.
-  if (N->getOpcode() == ISD::FP_TO_UINT) {
-    if (!TLI.isOperationLegal(ISD::FP_TO_UINT, NVT) &&
-        (TLI.isOperationLegal(ISD::FP_TO_SINT, NVT) ||
-         TLI.getOperationAction(ISD::FP_TO_SINT, NVT)==TargetLowering::Custom))
-      NewOpc = ISD::FP_TO_SINT;
-  }
+  if (N->getOpcode() == ISD::FP_TO_UINT &&
+      !TLI.isOperationLegal(ISD::FP_TO_UINT, NVT) &&
+      TLI.isOperationLegal(ISD::FP_TO_SINT, NVT))
+    NewOpc = ISD::FP_TO_SINT;
 
-  return DAG.getNode(NewOpc, NVT, N->getOperand(0));
+  SDValue Res = DAG.getNode(NewOpc, NVT, N->getOperand(0));
+
+  // Assert that the converted value fits in the original type.  If it doesn't
+  // (eg: because the value being converted is too big), then the result of the
+  // original operation was undefined anyway, so the assert is still correct.
+  return DAG.getNode(N->getOpcode() == ISD::FP_TO_UINT ?
+                     ISD::AssertZext : ISD::AssertSext,
+                     NVT, Res, DAG.getValueType(N->getValueType(0)));
 }
 
 SDValue DAGTypeLegalizer::PromoteIntRes_INT_EXTEND(SDNode *N) {
diff --git a/llvm/test/CodeGen/X86/trunc-to-bool.ll b/llvm/test/CodeGen/X86/trunc-to-bool.ll
index 9dd14252ace8..25a1191d8f14 100644
--- a/llvm/test/CodeGen/X86/trunc-to-bool.ll
+++ b/llvm/test/CodeGen/X86/trunc-to-bool.ll
@@ -2,7 +2,7 @@
 ; sure only the LSBit survives. Test that this is the case both for a returned
 ; value and as the operand of a branch.
 ; RUN: llvm-as < %s | llc -march=x86 | grep {\\(and\\)\\|\\(test.*\\\$1\\)} | \
-; RUN:   count 6
+; RUN:   count 5
 
 define i1 @test1(i32 %X) zeroext {
     %Y = trunc i32 %X to i1
@@ -40,15 +40,6 @@ cond_false:
     ret i32 42
 }
 
-define i32 @test5(float %f) {
-    %tmp = fptoui float %f to i1
-    br i1 %tmp, label %cond_true, label %cond_false
-cond_true:
-    ret i32 21
-cond_false:
-    ret i32 42
-}
-
 define i32 @test6(double %d) {
     %tmp = fptosi double %d to i1
     br i1 %tmp, label %cond_true, label %cond_false