Index: llvm/trunk/include/llvm/IR/IRBuilder.h
===================================================================
--- llvm/trunk/include/llvm/IR/IRBuilder.h
+++ llvm/trunk/include/llvm/IR/IRBuilder.h
@@ -1913,11 +1913,17 @@
     return V;
   }
 
-  Value *CreateFPToUI(Value *V, Type *DestTy, const Twine &Name = ""){
+  Value *CreateFPToUI(Value *V, Type *DestTy, const Twine &Name = "") {
+    if (IsFPConstrained)
+      return CreateConstrainedFPCast(Intrinsic::experimental_constrained_fptoui,
+                                     V, DestTy, nullptr, Name);
     return CreateCast(Instruction::FPToUI, V, DestTy, Name);
   }
 
-  Value *CreateFPToSI(Value *V, Type *DestTy, const Twine &Name = ""){
+  Value *CreateFPToSI(Value *V, Type *DestTy, const Twine &Name = "") {
+    if (IsFPConstrained)
+      return CreateConstrainedFPCast(Intrinsic::experimental_constrained_fptosi,
+                                     V, DestTy, nullptr, Name);
     return CreateCast(Instruction::FPToSI, V, DestTy, Name);
   }
 
@@ -2059,7 +2065,6 @@
       MDNode *FPMathTag = nullptr,
       Optional<ConstrainedFPIntrinsic::RoundingMode> Rounding = None,
       Optional<ConstrainedFPIntrinsic::ExceptionBehavior> Except = None) {
-    Value *RoundingV = getConstrainedFPRounding(Rounding);
     Value *ExceptV = getConstrainedFPExcept(Except);
 
     FastMathFlags UseFMF = FMF;
@@ -2067,13 +2072,22 @@
       UseFMF = FMFSource->getFastMathFlags();
 
     CallInst *C;
-    if (ID == Intrinsic::experimental_constrained_fpext)
-      C = CreateIntrinsic(ID, {DestTy, V->getType()}, {V, ExceptV}, nullptr,
-                          Name);
-    else
+    switch (ID) {
+    default: {
+      Value *RoundingV = getConstrainedFPRounding(Rounding);
       C = CreateIntrinsic(ID, {DestTy, V->getType()}, {V, RoundingV, ExceptV},
                           nullptr, Name);
-    return cast<CallInst>(setFPAttrs(C, FPMathTag, UseFMF));
+    } break;
+    case Intrinsic::experimental_constrained_fpext:
+    case Intrinsic::experimental_constrained_fptoui:
+    case Intrinsic::experimental_constrained_fptosi:
+      C = CreateIntrinsic(ID, {DestTy, V->getType()}, {V, ExceptV}, nullptr,
+                          Name);
+      break;
+    }
+    if (isa<FPMathOperator>(C))
+      C = cast<CallInst>(setFPAttrs(C, FPMathTag, UseFMF));
+    return C;
   }
 
   // Provided to resolve 'CreateIntCast(Ptr, Ptr, "...")', giving a
Index: llvm/trunk/unittests/IR/IRBuilderTest.cpp
===================================================================
--- llvm/trunk/unittests/IR/IRBuilderTest.cpp
+++ llvm/trunk/unittests/IR/IRBuilderTest.cpp
@@ -171,6 +171,7 @@
   IRBuilder<> Builder(BB);
   Value *V;
   Value *VDouble;
+  Value *VInt;
   CallInst *Call;
   IntrinsicInst *II;
   GlobalVariable *GVDouble = new GlobalVariable(*M, Type::getDoubleTy(Ctx),
@@ -208,6 +209,16 @@
   II = cast<IntrinsicInst>(V);
   EXPECT_EQ(II->getIntrinsicID(), Intrinsic::experimental_constrained_frem);
 
+  VInt = Builder.CreateFPToUI(VDouble, Builder.getInt32Ty());
+  ASSERT_TRUE(isa<IntrinsicInst>(VInt));
+  II = cast<IntrinsicInst>(VInt);
+  EXPECT_EQ(II->getIntrinsicID(), Intrinsic::experimental_constrained_fptoui);
+
+  VInt = Builder.CreateFPToSI(VDouble, Builder.getInt32Ty());
+  ASSERT_TRUE(isa<IntrinsicInst>(VInt));
+  II = cast<IntrinsicInst>(VInt);
+  EXPECT_EQ(II->getIntrinsicID(), Intrinsic::experimental_constrained_fptosi);
+
   V = Builder.CreateFPTrunc(VDouble, Type::getFloatTy(Ctx));
   ASSERT_TRUE(isa<IntrinsicInst>(V));
   II = cast<IntrinsicInst>(V);