Make APFloat constructor require explicit semantics.

Previously we tried to infer it from the bit width size, with an added
IsIEEE argument for the PPC/IEEE 128-bit case, which had a default
value. This default value allowed bugs to creep in, where it was
inappropriate.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173138 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 29 insertions, 42 deletions

diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index db3abafcba..d37edab66e 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -2805,7 +2805,8 @@ void SelectionDAGLegalize::ExpandNode(SDNode *Node) {
     SDValue True, False;
     EVT VT =  Node->getOperand(0).getValueType();
     EVT NVT = Node->getValueType(0);
-    APFloat apf(APInt::getNullValue(VT.getSizeInBits()));
+    APFloat apf(DAG.EVTToAPFloatSemantics(VT),
+                APInt::getNullValue(VT.getSizeInBits()));
     APInt x = APInt::getSignBit(NVT.getSizeInBits());
     (void)apf.convertFromAPInt(x, false, APFloat::rmNearestTiesToEven);
     Tmp1 = DAG.getConstantFP(apf, VT);
diff --git a/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp b/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp
index 4859ad0b34..1ee21921b4 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp
@@ -813,9 +813,11 @@ void DAGTypeLegalizer::ExpandFloatRes_ConstantFP(SDNode *N, SDValue &Lo,
   assert(NVT.getSizeInBits() == integerPartWidth &&
          "Do not know how to expand this float constant!");
   APInt C = cast<ConstantFPSDNode>(N)->getValueAPF().bitcastToAPInt();
-  Lo = DAG.getConstantFP(APFloat(APInt(integerPartWidth, C.getRawData()[1])),
+  Lo = DAG.getConstantFP(APFloat(DAG.EVTToAPFloatSemantics(NVT),
+                                 APInt(integerPartWidth, C.getRawData()[1])),
                          NVT);
-  Hi = DAG.getConstantFP(APFloat(APInt(integerPartWidth, C.getRawData()[0])),
+  Hi = DAG.getConstantFP(APFloat(DAG.EVTToAPFloatSemantics(NVT),
+                                 APInt(integerPartWidth, C.getRawData()[0])),
                          NVT);
 }
 
@@ -987,7 +989,8 @@ void DAGTypeLegalizer::ExpandFloatRes_FP_EXTEND(SDNode *N, SDValue &Lo,
                                                 SDValue &Hi) {
   EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), N->getValueType(0));
   Hi = DAG.getNode(ISD::FP_EXTEND, N->getDebugLoc(), NVT, N->getOperand(0));
-  Lo = DAG.getConstantFP(APFloat(APInt(NVT.getSizeInBits(), 0)), NVT);
+  Lo = DAG.getConstantFP(APFloat(DAG.EVTToAPFloatSemantics(NVT),
+                                 APInt(NVT.getSizeInBits(), 0)), NVT);
 }
 
 void DAGTypeLegalizer::ExpandFloatRes_FPOW(SDNode *N,
@@ -1082,7 +1085,8 @@ void DAGTypeLegalizer::ExpandFloatRes_LOAD(SDNode *N, SDValue &Lo,
   Chain = Hi.getValue(1);
 
   // The low part is zero.
-  Lo = DAG.getConstantFP(APFloat(APInt(NVT.getSizeInBits(), 0)), NVT);
+  Lo = DAG.getConstantFP(APFloat(DAG.EVTToAPFloatSemantics(NVT),
+                                 APInt(NVT.getSizeInBits(), 0)), NVT);
 
   // Modified the chain - switch anything that used the old chain to use the
   // new one.
@@ -1106,7 +1110,8 @@ void DAGTypeLegalizer::ExpandFloatRes_XINT_TO_FP(SDNode *N, SDValue &Lo,
     // The integer can be represented exactly in an f64.
     Src = DAG.getNode(isSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND, dl,
                       MVT::i32, Src);
-    Lo = DAG.getConstantFP(APFloat(APInt(NVT.getSizeInBits(), 0)), NVT);
+    Lo = DAG.getConstantFP(APFloat(DAG.EVTToAPFloatSemantics(NVT),
+                                   APInt(NVT.getSizeInBits(), 0)), NVT);
     Hi = DAG.getNode(ISD::SINT_TO_FP, dl, NVT, Src);
   } else {
     RTLIB::Libcall LC = RTLIB::UNKNOWN_LIBCALL;
@@ -1152,7 +1157,8 @@ void DAGTypeLegalizer::ExpandFloatRes_XINT_TO_FP(SDNode *N, SDValue &Lo,
   }
 
   Lo = DAG.getNode(ISD::FADD, dl, VT, Hi,
-                   DAG.getConstantFP(APFloat(APInt(128, Parts)),
+                   DAG.getConstantFP(APFloat(APFloat::PPCDoubleDouble,
+                                             APInt(128, Parts)),
                                      MVT::ppcf128));
   Lo = DAG.getNode(ISD::SELECT_CC, dl, VT, Src, DAG.getConstant(0, SrcVT),
                    Lo, Hi, DAG.getCondCode(ISD::SETLT));
@@ -1304,7 +1310,7 @@ SDValue DAGTypeLegalizer::ExpandFloatOp_FP_TO_UINT(SDNode *N) {
     assert(N->getOperand(0).getValueType() == MVT::ppcf128 &&
            "Logic only correct for ppcf128!");
     const uint64_t TwoE31[] = {0x41e0000000000000LL, 0};
-    APFloat APF = APFloat(APInt(128, TwoE31));
+    APFloat APF = APFloat(APFloat::PPCDoubleDouble, APInt(128, TwoE31));
     SDValue Tmp = DAG.getConstantFP(APF, MVT::ppcf128);
     //  X>=2^31 ? (int)(X-2^31)+0x80000000 : (int)X
     // FIXME: generated code sucks.
diff --git a/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp b/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
index 18748f5d17..5da6d29aab 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
@@ -2767,17 +2767,6 @@ SDValue DAGTypeLegalizer::ExpandIntOp_TRUNCATE(SDNode *N) {
   return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), N->getValueType(0), InL);
 }
 
-static const fltSemantics *EVTToAPFloatSemantics(EVT VT) {
-  switch (VT.getSimpleVT().SimpleTy) {
-  default: llvm_unreachable("Unknown FP format");
-  case MVT::f32:     return &APFloat::IEEEsingle;
-  case MVT::f64:     return &APFloat::IEEEdouble;
-  case MVT::f80:     return &APFloat::x87DoubleExtended;
-  case MVT::f128:    return &APFloat::IEEEquad;
-  case MVT::ppcf128: return &APFloat::PPCDoubleDouble;
-  }
-}
-
 SDValue DAGTypeLegalizer::ExpandIntOp_UINT_TO_FP(SDNode *N) {
   SDValue Op = N->getOperand(0);
   EVT SrcVT = Op.getValueType();
@@ -2787,8 +2776,8 @@ SDValue DAGTypeLegalizer::ExpandIntOp_UINT_TO_FP(SDNode *N) {
   // The following optimization is valid only if every value in SrcVT (when
   // treated as signed) is representable in DstVT.  Check that the mantissa
   // size of DstVT is >= than the number of bits in SrcVT -1.
-  const fltSemantics *sem = EVTToAPFloatSemantics(DstVT);
-  if (APFloat::semanticsPrecision(*sem) >= SrcVT.getSizeInBits()-1 &&
+  const fltSemantics &sem = DAG.EVTToAPFloatSemantics(DstVT);
+  if (APFloat::semanticsPrecision(sem) >= SrcVT.getSizeInBits()-1 &&
       TLI.getOperationAction(ISD::SINT_TO_FP, SrcVT) == TargetLowering::Custom){
     // Do a signed conversion then adjust the result.
     SDValue SignedConv = DAG.getNode(ISD::SINT_TO_FP, dl, DstVT, Op);
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 344d1447a8..b672926e9d 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -60,18 +60,6 @@ static SDVTList makeVTList(const EVT *VTs, unsigned NumVTs) {
   return Res;
 }
 
-static const fltSemantics *EVTToAPFloatSemantics(EVT VT) {
-  switch (VT.getSimpleVT().SimpleTy) {
-  default: llvm_unreachable("Unknown FP format");
-  case MVT::f16:     return &APFloat::IEEEhalf;
-  case MVT::f32:     return &APFloat::IEEEsingle;
-  case MVT::f64:     return &APFloat::IEEEdouble;
-  case MVT::f80:     return &APFloat::x87DoubleExtended;
-  case MVT::f128:    return &APFloat::IEEEquad;
-  case MVT::ppcf128: return &APFloat::PPCDoubleDouble;
-  }
-}
-
 // Default null implementations of the callbacks.
 void SelectionDAG::DAGUpdateListener::NodeDeleted(SDNode*, SDNode*) {}
 void SelectionDAG::DAGUpdateListener::NodeUpdated(SDNode*) {}
@@ -95,7 +83,8 @@ bool ConstantFPSDNode::isValueValidForType(EVT VT,
   // convert modifies in place, so make a copy.
   APFloat Val2 = APFloat(Val);
   bool losesInfo;
-  (void) Val2.convert(*EVTToAPFloatSemantics(VT), APFloat::rmNearestTiesToEven,
+  (void) Val2.convert(SelectionDAG::EVTToAPFloatSemantics(VT),
+                      APFloat::rmNearestTiesToEven,
                       &losesInfo);
   return !losesInfo;
 }
@@ -1081,7 +1070,7 @@ SDValue SelectionDAG::getConstantFP(double Val, EVT VT, bool isTarget) {
            EltVT==MVT::f16) {
     bool ignored;
     APFloat apf = APFloat(Val);
-    apf.convert(*EVTToAPFloatSemantics(EltVT), APFloat::rmNearestTiesToEven,
+    apf.convert(EVTToAPFloatSemantics(EltVT), APFloat::rmNearestTiesToEven,
                 &ignored);
     return getConstantFP(apf, VT, isTarget);
   } else
@@ -2442,7 +2431,8 @@ SDValue SelectionDAG::getNode(unsigned Opcode, DebugLoc DL,
       return getConstant(Val.zextOrTrunc(VT.getSizeInBits()), VT);
     case ISD::UINT_TO_FP:
     case ISD::SINT_TO_FP: {
-      APFloat apf(APInt::getNullValue(VT.getSizeInBits()));
+      APFloat apf(EVTToAPFloatSemantics(VT),
+                  APInt::getNullValue(VT.getSizeInBits()));
       (void)apf.convertFromAPInt(Val,
                                  Opcode==ISD::SINT_TO_FP,
                                  APFloat::rmNearestTiesToEven);
@@ -2450,9 +2440,9 @@ SDValue SelectionDAG::getNode(unsigned Opcode, DebugLoc DL,
     }
     case ISD::BITCAST:
       if (VT == MVT::f32 && C->getValueType(0) == MVT::i32)
-        return getConstantFP(APFloat(Val), VT);
+        return getConstantFP(APFloat(APFloat::IEEEsingle, Val), VT);
       else if (VT == MVT::f64 && C->getValueType(0) == MVT::i64)
-        return getConstantFP(APFloat(Val), VT);
+        return getConstantFP(APFloat(APFloat::IEEEdouble, Val), VT);
       break;
     case ISD::BSWAP:
       return getConstant(Val.byteSwap(), VT);
@@ -2499,7 +2489,7 @@ SDValue SelectionDAG::getNode(unsigned Opcode, DebugLoc DL,
       bool ignored;
       // This can return overflow, underflow, or inexact; we don't care.
       // FIXME need to be more flexible about rounding mode.
-      (void)V.convert(*EVTToAPFloatSemantics(VT),
+      (void)V.convert(EVTToAPFloatSemantics(VT),
                       APFloat::rmNearestTiesToEven, &ignored);
       return getConstantFP(V, VT);
     }
@@ -3084,7 +3074,7 @@ SDValue SelectionDAG::getNode(unsigned Opcode, DebugLoc DL, EVT VT,
       bool ignored;
       // This can return overflow, underflow, or inexact; we don't care.
       // FIXME need to be more flexible about rounding mode.
-      (void)V.convert(*EVTToAPFloatSemantics(VT),
+      (void)V.convert(EVTToAPFloatSemantics(VT),
                       APFloat::rmNearestTiesToEven, &ignored);
       return getConstantFP(V, VT);
     }
@@ -3338,7 +3328,7 @@ static SDValue getMemsetValue(SDValue Value, EVT VT, SelectionDAG &DAG,
     APInt Val = SplatByte(NumBits, C->getZExtValue() & 255);
     if (VT.isInteger())
       return DAG.getConstant(Val, VT);
-    return DAG.getConstantFP(APFloat(Val), VT);
+    return DAG.getConstantFP(APFloat(DAG.EVTToAPFloatSemantics(VT), Val), VT);
   }
 
   Value = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, Value);
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index cf748600af..393a6befa3 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -3694,7 +3694,8 @@ GetExponent(SelectionDAG &DAG, SDValue Op, const TargetLowering &TLI,
 /// getF32Constant - Get 32-bit floating point constant.
 static SDValue
 getF32Constant(SelectionDAG &DAG, unsigned Flt) {
-  return DAG.getConstantFP(APFloat(APInt(32, Flt)), MVT::f32);
+  return DAG.getConstantFP(APFloat(APFloat::IEEEsingle, APInt(32, Flt)),
+                           MVT::f32);
 }
 
 /// expandExp - Lower an exp intrinsic. Handles the special sequences for