diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 492a43f..c7ab34f 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -2008,24 +2008,48 @@
     return Result;
   }
   assert(!isSigned && "Legalize cannot Expand SINT_TO_FP for i64 yet");
+  SDValue Tmp1 = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Op0);
 
-  // Implementation following __floatundidf in compiler_rt.
-  SDValue TwoP52 =
-    DAG.getConstant(UINT64_C(0x4330000000000000), MVT::i64);
-  SDValue TwoP84PlusTwoP52 =
-    DAG.getConstantFP(BitsToDouble(UINT64_C(0x4530000000100000)), MVT::f64);
-  SDValue TwoP84 =
-    DAG.getConstant(UINT64_C(0x4530000000000000), MVT::i64);
+  SDValue SignSet = DAG.getSetCC(dl, TLI.getSetCCResultType(Op0.getValueType()),
+                                 Op0, DAG.getConstant(0, Op0.getValueType()),
+                                 ISD::SETLT);
+  SDValue Zero = DAG.getIntPtrConstant(0), Four = DAG.getIntPtrConstant(4);
+  SDValue CstOffset = DAG.getNode(ISD::SELECT, dl, Zero.getValueType(),
+                                    SignSet, Four, Zero);
 
-  SDValue Lo = DAG.getZeroExtendInReg(Op0, dl, MVT::i32);
-  SDValue Hi = DAG.getNode(ISD::SRL, dl, MVT::i64, Op0,
-                           DAG.getConstant(32, MVT::i64));
-  SDValue LoOr = DAG.getNode(ISD::OR, dl, MVT::i64, Lo, TwoP52);
-  SDValue HiOr = DAG.getNode(ISD::OR, dl, MVT::i64, Hi, TwoP84);
-  SDValue LoFlt = DAG.getNode(ISD::BIT_CONVERT, dl, MVT::f64, LoOr);
-  SDValue HiFlt = DAG.getNode(ISD::BIT_CONVERT, dl, MVT::f64, HiOr);
-  SDValue HiSub = DAG.getNode(ISD::FSUB, dl, MVT::f64, HiFlt, TwoP84PlusTwoP52);
-  return DAG.getNode(ISD::FADD, dl, MVT::f64, LoFlt, HiSub);
+  // If the sign bit of the integer is set, the large number will be treated
+  // as a negative number.  To counteract this, the dynamic code adds an
+  // offset depending on the data type.
+  uint64_t FF;
+  switch (Op0.getValueType().getSimpleVT().SimpleTy) {
+  default: llvm_unreachable("Unsupported integer type!");
+  case MVT::i8 : FF = 0x43800000ULL; break;  // 2^8  (as a float)
+  case MVT::i16: FF = 0x47800000ULL; break;  // 2^16 (as a float)
+  case MVT::i32: FF = 0x4F800000ULL; break;  // 2^32 (as a float)
+  case MVT::i64: FF = 0x5F800000ULL; break;  // 2^64 (as a float)
+  }
+  if (TLI.isLittleEndian()) FF <<= 32;
+  Constant *FudgeFactor = ConstantInt::get(
+                                       Type::getInt64Ty(*DAG.getContext()), FF);
+
+  SDValue CPIdx = DAG.getConstantPool(FudgeFactor, TLI.getPointerTy());
+  unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
+  CPIdx = DAG.getNode(ISD::ADD, dl, TLI.getPointerTy(), CPIdx, CstOffset);
+  Alignment = std::min(Alignment, 4u);
+  SDValue FudgeInReg;
+  if (DestVT == MVT::f32)
+    FudgeInReg = DAG.getLoad(MVT::f32, dl, DAG.getEntryNode(), CPIdx,
+                             PseudoSourceValue::getConstantPool(), 0,
+                             false, false, Alignment);
+  else {
+    FudgeInReg =
+      LegalizeOp(DAG.getExtLoad(ISD::EXTLOAD, dl, DestVT,
+                                DAG.getEntryNode(), CPIdx,
+                                PseudoSourceValue::getConstantPool(), 0,
+                                MVT::f32, false, false, Alignment));
+  }
+
+  return DAG.getNode(ISD::FADD, dl, DestVT, Tmp1, FudgeInReg);
 }
 
 /// PromoteLegalINT_TO_FP - This function is responsible for legalizing a