Make a few related changes:

1) add a new ASTContext::getFloatTypeSemantics method.
2) Use it from SemaExpr.cpp, CodeGenTypes.cpp and other places.
3) Change the TargetInfo.h get*Format methods to return their 
   fltSemantics byref instead of by pointer.
4) Change CodeGenFunction::EmitBuiltinExpr to allow builtins which
   sometimes expand specially and othertimes fall back to libm.
5) Add support for __builtin_nan("") to codegen, cases that don't pass
   in an empty string are currently lowered to libm calls.
6) Fix codegen of __builtin_infl.

llvm-svn: 52914

1 files changed, 14 insertions, 0 deletions

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 08a2bb1357b..fa12364c52f 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -182,6 +182,20 @@ void ASTContext::InitBuiltinTypes() {
 //                         Type Sizing and Analysis
 //===----------------------------------------------------------------------===//
 
+/// getFloatTypeSemantics - Return the APFloat 'semantics' for the specified
+/// scalar floating point type.
+const llvm::fltSemantics &ASTContext::getFloatTypeSemantics(QualType T) const {
+  const BuiltinType *BT = T->getAsBuiltinType();
+  assert(BT && "Not a floating point type!");
+  switch (BT->getKind()) {
+  default: assert(0 && "Not a floating point type!");
+  case BuiltinType::Float:      return Target.getFloatFormat();
+  case BuiltinType::Double:     return Target.getDoubleFormat();
+  case BuiltinType::LongDouble: return Target.getLongDoubleFormat();
+  }
+}
+
+
 /// getTypeSize - Return the size of the specified type, in bits.  This method
 /// does not work on incomplete types.
 std::pair<uint64_t, unsigned>