Do away with addLegalFPImmediate. Add a target hook isFPImmLegal which returns true if the fp immediate can be natively codegened by target.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85281 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Target/TargetLowering.h

@@ -325,12 +325,11 @@ public:
   /// scalarizing vs using the wider vector type.
   virtual EVT getWidenVectorType(EVT VT) const;
 
-  typedef std::vector<APFloat>::const_iterator legal_fpimm_iterator;
-  legal_fpimm_iterator legal_fpimm_begin() const {
-    return LegalFPImmediates.begin();
-  }
-  legal_fpimm_iterator legal_fpimm_end() const {
-    return LegalFPImmediates.end();
+  /// isFPImmLegal - Returns true if the target can instruction select the
+  /// specified FP immediate natively. If false, the legalizer will materialize
+  /// the FP immediate as a load from a constant pool.
+  virtual bool isFPImmLegal(const APFloat &Imm) const {
+    return false;
   }
   
   /// isShuffleMaskLegal - Targets can use this to indicate that they only
@@ -1051,12 +1050,6 @@ protected:
     PromoteToType[std::make_pair(Opc, OrigVT.SimpleTy)] = DestVT.SimpleTy;
   }
 
-  /// addLegalFPImmediate - Indicate that this target can instruction select
-  /// the specified FP immediate natively.
-  void addLegalFPImmediate(const APFloat& Imm) {
-    LegalFPImmediates.push_back(Imm);
-  }
-
   /// setTargetDAGCombine - Targets should invoke this method for each target
   /// independent node that they want to provide a custom DAG combiner for by
   /// implementing the PerformDAGCombine virtual method.
@@ -1696,8 +1689,6 @@ private:
 
   ValueTypeActionImpl ValueTypeActions;
 
-  std::vector<APFloat> LegalFPImmediates;
-
   std::vector<std::pair<EVT, TargetRegisterClass*> > AvailableRegClasses;
 
   /// TargetDAGCombineArray - Targets can specify ISD nodes that they would

lib/CodeGen/SelectionDAG/LegalizeDAG.cpp

@@ -2573,16 +2573,8 @@ void SelectionDAGLegalize::ExpandNode(SDNode *Node,
   case ISD::ConstantFP: {
     ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(Node);
     // Check to see if this FP immediate is already legal.
-    bool isLegal = false;
-    for (TargetLowering::legal_fpimm_iterator I = TLI.legal_fpimm_begin(),
-            E = TLI.legal_fpimm_end(); I != E; ++I) {
-      if (CFP->isExactlyValue(*I)) {
-        isLegal = true;
-        break;
-      }
-    }
     // If this is a legal constant, turn it into a TargetConstantFP node.
-    if (isLegal)
+    if (TLI.isFPImmLegal(CFP->getValueAPF()))
       Results.push_back(SDValue(Node, 0));
     else
       Results.push_back(ExpandConstantFP(CFP, true, DAG, TLI));

lib/CodeGen/SelectionDAG/TargetLowering.cpp

@@ -481,7 +481,7 @@ TargetLowering::TargetLowering(TargetMachine &tm,TargetLoweringObjectFile *tlof)
   setOperationAction(ISD::PREFETCH, MVT::Other, Expand);
   
   // ConstantFP nodes default to expand.  Targets can either change this to 
-  // Legal, in which case all fp constants are legal, or use addLegalFPImmediate
+  // Legal, in which case all fp constants are legal, or use isFPImmLegal()
   // to optimize expansions for certain constants.
   setOperationAction(ISD::ConstantFP, MVT::f32, Expand);
   setOperationAction(ISD::ConstantFP, MVT::f64, Expand);

lib/Target/Alpha/AlphaISelLowering.cpp

@@ -157,11 +157,6 @@ AlphaTargetLowering::AlphaTargetLowering(TargetMachine &TM)
 
   setStackPointerRegisterToSaveRestore(Alpha::R30);
 
-  addLegalFPImmediate(APFloat(+0.0)); //F31
-  addLegalFPImmediate(APFloat(+0.0f)); //F31
-  addLegalFPImmediate(APFloat(-0.0)); //-F31
-  addLegalFPImmediate(APFloat(-0.0f)); //-F31
-
   setJumpBufSize(272);
   setJumpBufAlignment(16);
 
@@ -919,3 +914,11 @@ AlphaTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
   // The Alpha target isn't yet aware of offsets.
   return false;
 }
+
+bool AlphaTargetLowering::isFPImmLegal(const APFloat &Imm) const {
+  // +0.0   F31
+  // +0.0f  F31
+  // -0.0  -F31
+  // -0.0f -F31
+  return Imm.isZero() || Imm.isNegZero();
+}

lib/Target/Alpha/AlphaISelLowering.h

@@ -102,6 +102,11 @@ namespace llvm {
     /// getFunctionAlignment - Return the Log2 alignment of this function.
     virtual unsigned getFunctionAlignment(const Function *F) const;
 
+    /// isFPImmLegal - Returns true if the target can instruction select the
+    /// specified FP immediate natively. If false, the legalizer will
+    /// materialize the FP immediate as a load from a constant pool.
+    virtual bool isFPImmLegal(const APFloat &Imm) const;
+
   private:
     // Helpers for custom lowering.
     void LowerVAARG(SDNode *N, SDValue &Chain, SDValue &DataPtr,

lib/Target/Mips/MipsISelLowering.cpp

@@ -72,9 +72,6 @@ MipsTargetLowering(MipsTargetMachine &TM)
     if (!Subtarget->isFP64bit())
       addRegisterClass(MVT::f64, Mips::AFGR64RegisterClass);
 
-  // Legal fp constants
-  addLegalFPImmediate(APFloat(+0.0f));
-
   // Load extented operations for i1 types must be promoted 
   setLoadExtAction(ISD::EXTLOAD,  MVT::i1,  Promote);
   setLoadExtAction(ISD::ZEXTLOAD, MVT::i1,  Promote);
@@ -1224,3 +1221,7 @@ MipsTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
   // The Mips target isn't yet aware of offsets.
   return false;
 }
+
+bool MipsTargetLowering::isFPImmLegal(const APFloat &Imm) const {
+  return Imm.isZero();
+}

lib/Target/Mips/MipsISelLowering.h

@@ -146,6 +146,11 @@ namespace llvm {
               EVT VT) const;
 
     virtual bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const;
+
+    /// isFPImmLegal - Returns true if the target can instruction select the
+    /// specified FP immediate natively. If false, the legalizer will
+    /// materialize the FP immediate as a load from a constant pool.
+    virtual bool isFPImmLegal(const APFloat &Imm) const;
   };
 }
 

lib/Target/SystemZ/SystemZISelLowering.cpp

@@ -53,11 +53,6 @@ SystemZTargetLowering::SystemZTargetLowering(SystemZTargetMachine &tm) :
   if (!UseSoftFloat) {
     addRegisterClass(MVT::f32, SystemZ::FP32RegisterClass);
     addRegisterClass(MVT::f64, SystemZ::FP64RegisterClass);
-
-    addLegalFPImmediate(APFloat(+0.0));  // lzer
-    addLegalFPImmediate(APFloat(+0.0f)); // lzdr
-    addLegalFPImmediate(APFloat(-0.0));  // lzer + lner
-    addLegalFPImmediate(APFloat(-0.0f)); // lzdr + lndr
   }
 
   // Compute derived properties from the register classes
@@ -169,6 +164,17 @@ SDValue SystemZTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) {
   }
 }
 
+bool SystemZTargetLowering::isFPImmLegal(const APFloat &Imm) const {
+  if (UseSoftFloat)
+    return false;
+
+  // +0.0  lzer
+  // +0.0f lzdr
+  // -0.0  lzer + lner
+  // -0.0f lzdr + lndr
+  return Imm.isZero() || Imm.isNegZero();
+}
+
 //===----------------------------------------------------------------------===//
 //                       SystemZ Inline Assembly Support
 //===----------------------------------------------------------------------===//

lib/Target/SystemZ/SystemZISelLowering.h

@@ -89,6 +89,11 @@ namespace llvm {
                                                    MachineBasicBlock *BB,
                     DenseMap<MachineBasicBlock*, MachineBasicBlock*> *EM) const;
 
+    /// isFPImmLegal - Returns true if the target can instruction select the
+    /// specified FP immediate natively. If false, the legalizer will
+    /// materialize the FP immediate as a load from a constant pool.
+    virtual bool isFPImmLegal(const APFloat &Imm) const;
+
   private:
     SDValue LowerCCCCallTo(SDValue Chain, SDValue Callee,
                            CallingConv::ID CallConv, bool isVarArg,

lib/Target/X86/X86ISelLowering.cpp

@@ -2310,6 +2310,17 @@ static bool hasFPCMov(unsigned X86CC) {
   }
 }
 
+/// isFPImmLegal - Returns true if the target can instruction select the
+/// specified FP immediate natively. If false, the legalizer will
+/// materialize the FP immediate as a load from a constant pool.
+bool X86TargetLowering::isFPImmLegal(const APFloat &Imm) const {
+  for (unsigned i = 0, e = LegalFPImmediates.size(); i != e; ++i) {
+    if (Imm.bitwiseIsEqual(LegalFPImmediates[i]))
+      return true;
+  }
+  return false;
+}
+
 /// isUndefOrInRange - Return true if Val is undef or if its value falls within
 /// the specified range (L, H].
 static bool isUndefOrInRange(int Val, int Low, int Hi) {

lib/Target/X86/X86ISelLowering.h

@@ -499,6 +499,11 @@ namespace llvm {
     /// from i32 to i8 but not from i32 to i16.
     virtual bool isNarrowingProfitable(EVT VT1, EVT VT2) const;
 
+    /// isFPImmLegal - Returns true if the target can instruction select the
+    /// specified FP immediate natively. If false, the legalizer will
+    /// materialize the FP immediate as a load from a constant pool.
+    virtual bool isFPImmLegal(const APFloat &Imm) const;
+
     /// isShuffleMaskLegal - Targets can use this to indicate that they only
     /// support *some* VECTOR_SHUFFLE operations, those with specific masks.
     /// By default, if a target supports the VECTOR_SHUFFLE node, all mask
@@ -584,6 +589,15 @@ namespace llvm {
     bool X86ScalarSSEf32;
     bool X86ScalarSSEf64;
 
+    /// LegalFPImmediates - A list of legal fp immediates.
+    std::vector<APFloat> LegalFPImmediates;
+
+    /// addLegalFPImmediate - Indicate that this x86 target can instruction
+    /// select the specified FP immediate natively.
+    void addLegalFPImmediate(const APFloat& Imm) {
+      LegalFPImmediates.push_back(Imm);
+    }
+
     SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
                             CallingConv::ID CallConv, bool isVarArg,
                             const SmallVectorImpl<ISD::InputArg> &Ins,