Switch to APFloat constructor taking fltSemantics.

This change also makes the serialisation store the required semantics,
fixing an issue where PPC128 was always assumed when re-reading a
128-bit value.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173139 91177308-0d34-0410-b5e6-96231b3b80d8

9 files changed, 99 insertions, 15 deletions

diff --git a/include/clang/AST/Expr.h b/include/clang/AST/Expr.h
index 5b6e660832..715e6cbf9f 100644
--- a/include/clang/AST/Expr.h
+++ b/include/clang/AST/Expr.h
@@ -1214,8 +1214,8 @@ public:
 
 class APFloatStorage : private APNumericStorage {
 public:
-  llvm::APFloat getValue(bool IsIEEE) const {
-    return llvm::APFloat(getIntValue(), IsIEEE);
+  llvm::APFloat getValue(const llvm::fltSemantics &Semantics) const {
+    return llvm::APFloat(Semantics, getIntValue());
   }
   void setValue(ASTContext &C, const llvm::APFloat &Val) {
     setIntValue(C, Val.bitcastToAPInt());
@@ -1322,12 +1322,31 @@ public:
   static FloatingLiteral *Create(ASTContext &C, EmptyShell Empty);
 
   llvm::APFloat getValue() const {
-    return APFloatStorage::getValue(FloatingLiteralBits.IsIEEE);
+    return APFloatStorage::getValue(getSemantics());
   }
   void setValue(ASTContext &C, const llvm::APFloat &Val) {
+    assert(&getSemantics() == &Val.getSemantics() && "Inconsistent semantics");
     APFloatStorage::setValue(C, Val);
   }
 
+  /// Get a raw enumeration value representing the floating-point semantics of
+  /// this literal (32-bit IEEE, x87, ...), suitable for serialisation.
+  APFloatSemantics getRawSemantics() const {
+    return static_cast<APFloatSemantics>(FloatingLiteralBits.Semantics);
+  }
+
+  /// Set the raw enumeration value representing the floating-point semantics of
+  /// this literal (32-bit IEEE, x87, ...), suitable for serialisation.
+  void setRawSemantics(APFloatSemantics Sem) {
+    FloatingLiteralBits.Semantics = Sem;
+  }
+
+  /// Return the APFloat semantics this literal uses.
+  const llvm::fltSemantics &getSemantics() const;
+
+  /// Set the APFloat semantics this literal uses.
+  void setSemantics(const llvm::fltSemantics &Sem);
+
   bool isExact() const { return FloatingLiteralBits.IsExact; }
   void setExact(bool E) { FloatingLiteralBits.IsExact = E; }
 
diff --git a/include/clang/AST/Stmt.h b/include/clang/AST/Stmt.h
index e1073627bc..2a1af77b8c 100644
--- a/include/clang/AST/Stmt.h
+++ b/include/clang/AST/Stmt.h
@@ -174,11 +174,20 @@ protected:
     unsigned Kind : 2;
   };
 
+  enum APFloatSemantics {
+    IEEEhalf,
+    IEEEsingle,
+    IEEEdouble,
+    x87DoubleExtended,
+    IEEEquad,
+    PPCDoubleDouble
+  };
+
   class FloatingLiteralBitfields {
     friend class FloatingLiteral;
     unsigned : NumExprBits;
 
-    unsigned IsIEEE : 1; // Distinguishes between PPC128 and IEEE128.
+    unsigned Semantics : 3; // Provides semantics for APFloat construction
     unsigned IsExact : 1;
   };
 
diff --git a/include/clang/Serialization/ASTReader.h b/include/clang/Serialization/ASTReader.h
index 994008de44..3fe65de914 100644
--- a/include/clang/Serialization/ASTReader.h
+++ b/include/clang/Serialization/ASTReader.h
@@ -1658,7 +1658,8 @@ public:
   llvm::APSInt ReadAPSInt(const RecordData &Record, unsigned &Idx);
 
   /// \brief Read a floating-point value
-  llvm::APFloat ReadAPFloat(const RecordData &Record, unsigned &Idx);
+  llvm::APFloat ReadAPFloat(const RecordData &Record,
+                            const llvm::fltSemantics &Sem, unsigned &Idx);
 
   // \brief Read a string
   static std::string ReadString(const RecordData &Record, unsigned &Idx);
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index e3ff29d2d0..6888c46ae4 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -646,16 +646,14 @@ FloatingLiteral::FloatingLiteral(ASTContext &C, const llvm::APFloat &V,
                                  bool isexact, QualType Type, SourceLocation L)
   : Expr(FloatingLiteralClass, Type, VK_RValue, OK_Ordinary, false, false,
          false, false), Loc(L) {
-  FloatingLiteralBits.IsIEEE =
-    &C.getTargetInfo().getLongDoubleFormat() == &llvm::APFloat::IEEEquad;
+  setSemantics(V.getSemantics());
   FloatingLiteralBits.IsExact = isexact;
   setValue(C, V);
 }
 
 FloatingLiteral::FloatingLiteral(ASTContext &C, EmptyShell Empty)
   : Expr(FloatingLiteralClass, Empty) {
-  FloatingLiteralBits.IsIEEE =
-    &C.getTargetInfo().getLongDoubleFormat() == &llvm::APFloat::IEEEquad;
+  setRawSemantics(IEEEhalf);
   FloatingLiteralBits.IsExact = false;
 }
 
@@ -670,6 +668,41 @@ FloatingLiteral::Create(ASTContext &C, EmptyShell Empty) {
   return new (C) FloatingLiteral(C, Empty);
 }
 
+const llvm::fltSemantics &FloatingLiteral::getSemantics() const {
+  switch(FloatingLiteralBits.Semantics) {
+  case IEEEhalf:
+    return llvm::APFloat::IEEEhalf;
+  case IEEEsingle:
+    return llvm::APFloat::IEEEsingle;
+  case IEEEdouble:
+    return llvm::APFloat::IEEEdouble;
+  case x87DoubleExtended:
+    return llvm::APFloat::x87DoubleExtended;
+  case IEEEquad:
+    return llvm::APFloat::IEEEquad;
+  case PPCDoubleDouble:
+    return llvm::APFloat::PPCDoubleDouble;
+  }
+  llvm_unreachable("Unrecognised floating semantics");
+}
+
+void FloatingLiteral::setSemantics(const llvm::fltSemantics &Sem) {
+  if (&Sem == &llvm::APFloat::IEEEhalf)
+    FloatingLiteralBits.Semantics = IEEEhalf;
+  else if (&Sem == &llvm::APFloat::IEEEsingle)
+    FloatingLiteralBits.Semantics = IEEEsingle;
+  else if (&Sem == &llvm::APFloat::IEEEdouble)
+    FloatingLiteralBits.Semantics = IEEEdouble;
+  else if (&Sem == &llvm::APFloat::x87DoubleExtended)
+    FloatingLiteralBits.Semantics = x87DoubleExtended;
+  else if (&Sem == &llvm::APFloat::IEEEquad)
+    FloatingLiteralBits.Semantics = IEEEquad;
+  else if (&Sem == &llvm::APFloat::PPCDoubleDouble)
+    FloatingLiteralBits.Semantics = PPCDoubleDouble;
+  else
+    llvm_unreachable("Unknown floating semantics");
+}
+
 /// getValueAsApproximateDouble - This returns the value as an inaccurate
 /// double.  Note that this may cause loss of precision, but is useful for
 /// debugging dumps, etc.
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index 64fd40b7a6..71489cb03c 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -3629,7 +3629,6 @@ bool VectorExprEvaluator::VisitCastExpr(const CastExpr* E) {
     SmallVector<APValue, 4> Elts;
     if (EltTy->isRealFloatingType()) {
       const llvm::fltSemantics &Sem = Info.Ctx.getFloatTypeSemantics(EltTy);
-      bool isIEESem = &Sem != &APFloat::PPCDoubleDouble;
       unsigned FloatEltSize = EltSize;
       if (&Sem == &APFloat::x87DoubleExtended)
         FloatEltSize = 80;
@@ -3639,7 +3638,7 @@ bool VectorExprEvaluator::VisitCastExpr(const CastExpr* E) {
           Elt = SValInt.rotl(i*EltSize+FloatEltSize).trunc(FloatEltSize);
         else
           Elt = SValInt.rotr(i*EltSize).trunc(FloatEltSize);
-        Elts.push_back(APValue(APFloat(Elt, isIEESem)));
+        Elts.push_back(APValue(APFloat(Sem, Elt)));
       }
     } else if (EltTy->isIntegerType()) {
       for (unsigned i = 0; i < NElts; i++) {
diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index 97766d0f7d..4e6e6db876 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -6669,8 +6669,10 @@ llvm::APSInt ASTReader::ReadAPSInt(const RecordData &Record, unsigned &Idx) {
 }
 
 /// \brief Read a floating-point value
-llvm::APFloat ASTReader::ReadAPFloat(const RecordData &Record, unsigned &Idx) {
-  return llvm::APFloat(ReadAPInt(Record, Idx));
+llvm::APFloat ASTReader::ReadAPFloat(const RecordData &Record,
+                                     const llvm::fltSemantics &Sem,
+                                     unsigned &Idx) {
+  return llvm::APFloat(Sem, ReadAPInt(Record, Idx));
 }
 
 // \brief Read a string
diff --git a/lib/Serialization/ASTReaderStmt.cpp b/lib/Serialization/ASTReaderStmt.cpp
index 6735c3cf00..7f26a1752b 100644
--- a/lib/Serialization/ASTReaderStmt.cpp
+++ b/lib/Serialization/ASTReaderStmt.cpp
@@ -378,8 +378,10 @@ void ASTStmtReader::VisitIntegerLiteral(IntegerLiteral *E) {
 
 void ASTStmtReader::VisitFloatingLiteral(FloatingLiteral *E) {
   VisitExpr(E);
-  E->setValue(Reader.getContext(), Reader.ReadAPFloat(Record, Idx));
+  E->setRawSemantics(static_cast<Stmt::APFloatSemantics>(Record[Idx++]));
   E->setExact(Record[Idx++]);
+  E->setValue(Reader.getContext(),
+              Reader.ReadAPFloat(Record, E->getSemantics(), Idx));
   E->setLocation(ReadSourceLocation(Record, Idx));
 }
 
diff --git a/lib/Serialization/ASTWriterStmt.cpp b/lib/Serialization/ASTWriterStmt.cpp
index 0c6dc5dba0..6b96c500c3 100644
--- a/lib/Serialization/ASTWriterStmt.cpp
+++ b/lib/Serialization/ASTWriterStmt.cpp
@@ -324,8 +324,9 @@ void ASTStmtWriter::VisitIntegerLiteral(IntegerLiteral *E) {
 
 void ASTStmtWriter::VisitFloatingLiteral(FloatingLiteral *E) {
   VisitExpr(E);
-  Writer.AddAPFloat(E->getValue(), Record);
+  Record.push_back(E->getRawSemantics());
   Record.push_back(E->isExact());
+  Writer.AddAPFloat(E->getValue(), Record);
   Writer.AddSourceLocation(E->getLocation(), Record);
   Code = serialization::EXPR_FLOATING_LITERAL;
 }
diff --git a/test/PCH/floating-literal.c b/test/PCH/floating-literal.c
new file mode 100644
index 0000000000..7bf10d4e79
--- /dev/null
+++ b/test/PCH/floating-literal.c
@@ -0,0 +1,18 @@
+// RUN: %clang_cc1 -triple mips64-none-linux-gnu -emit-pch -o %t %s
+// RUN: %clang_cc1 -x ast -ast-print %t | FileCheck %s
+
+// Make sure the semantics of FloatingLiterals are stored correctly in
+// the AST. Previously, the ASTWriter didn't store anything and the
+// reader assumed PPC 128-bit float semantics, which is incorrect for
+// targets with 128-bit IEEE long doubles.
+
+long double foo = 1.0E4000L;
+// CHECK: long double foo = 1.0E+4000L;
+
+// Just as well check the others are still sane while we're here...
+
+double bar = 1.0E300;
+// CHECK: double bar = 1.0E+300;
+
+float wibble = 1.0E40;
+// CHECK: float wibble = 1.0E+40;