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

8 files changed, 63 insertions, 13 deletions

diff --git a/lib/Target/Alpha/AlphaISelLowering.cpp b/lib/Target/Alpha/AlphaISelLowering.cpp
index b3f865cf4a..b2b738db2e 100644
--- a/lib/Target/Alpha/AlphaISelLowering.cpp
+++ b/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();
+}
diff --git a/lib/Target/Alpha/AlphaISelLowering.h b/lib/Target/Alpha/AlphaISelLowering.h
index b580c9d712..fbffbed939 100644
--- a/lib/Target/Alpha/AlphaISelLowering.h
+++ b/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,
diff --git a/lib/Target/Mips/MipsISelLowering.cpp b/lib/Target/Mips/MipsISelLowering.cpp
index ab8790ad7d..48d1cdc08a 100644
--- a/lib/Target/Mips/MipsISelLowering.cpp
+++ b/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();
+}
diff --git a/lib/Target/Mips/MipsISelLowering.h b/lib/Target/Mips/MipsISelLowering.h
index dddba4291d..2765295528 100644
--- a/lib/Target/Mips/MipsISelLowering.h
+++ b/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;
   };
 }
 
diff --git a/lib/Target/SystemZ/SystemZISelLowering.cpp b/lib/Target/SystemZ/SystemZISelLowering.cpp
index 07e0d83058..eb4d250504 100644
--- a/lib/Target/SystemZ/SystemZISelLowering.cpp
+++ b/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
 //===----------------------------------------------------------------------===//
diff --git a/lib/Target/SystemZ/SystemZISelLowering.h b/lib/Target/SystemZ/SystemZISelLowering.h
index c2c24bc1f3..76af03de0a 100644
--- a/lib/Target/SystemZ/SystemZISelLowering.h
+++ b/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,
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index e5e7bc8bb7..83ede5dd4a 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/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) {
diff --git a/lib/Target/X86/X86ISelLowering.h b/lib/Target/X86/X86ISelLowering.h
index 66a9107f94..3d334a064b 100644
--- a/lib/Target/X86/X86ISelLowering.h
+++ b/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,