Improve handling of floating point literals in OpenCL to only use double precision if the target supports fp64.

This change makes sure single-precision floating point types are used if the 
cl_fp64 extension is not supported by the target.

Also removed the check to see whether the OpenCL version is >= 1.2, as this has
been incorporated into the extension setting code.

Differential Revision: https://reviews.llvm.org/D24235

llvm-svn: 286815

2 files changed, 23 insertions, 9 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index fae8bf0f548..61c9f26ab6a 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -705,9 +705,13 @@ ExprResult Sema::DefaultLvalueConversion(Expr *E) {
   if (getLangOpts().ObjCAutoRefCount &&
       E->getType().getObjCLifetime() == Qualifiers::OCL_Weak)
     Cleanup.setExprNeedsCleanups(true);
+  
+  ExprResult Res = E;
 
-  ExprResult Res = ImplicitCastExpr::Create(Context, T, CK_LValueToRValue, E,
-                                            nullptr, VK_RValue);
+  if ( T != E->getType()) {
+    Res = ImplicitCastExpr::Create(Context, T, CK_LValueToRValue, E,
+                                   nullptr, VK_RValue);
+  }
 
   // C11 6.3.2.1p2:
   //   ... if the lvalue has atomic type, the value has the non-atomic version 
@@ -817,8 +821,16 @@ ExprResult Sema::DefaultArgumentPromotion(Expr *E) {
   // double.
   const BuiltinType *BTy = Ty->getAs<BuiltinType>();
   if (BTy && (BTy->getKind() == BuiltinType::Half ||
-              BTy->getKind() == BuiltinType::Float))
-    E = ImpCastExprToType(E, Context.DoubleTy, CK_FloatingCast).get();
+              BTy->getKind() == BuiltinType::Float)) {
+    if (getLangOpts().OpenCL &&
+        !(getOpenCLOptions().cl_khr_fp64)) {
+        if (BTy->getKind() == BuiltinType::Half) {
+            E = ImpCastExprToType(E, Context.FloatTy, CK_FloatingCast).get();
+        }
+    } else {
+      E = ImpCastExprToType(E, Context.DoubleTy, CK_FloatingCast).get();
+    }
+  }
 
   // C++ performs lvalue-to-rvalue conversion as a default argument
   // promotion, even on class types, but note:
@@ -3397,10 +3409,13 @@ ExprResult Sema::ActOnNumericConstant(const Token &Tok, Scope *UDLScope) {
 
     if (Ty == Context.DoubleTy) {
       if (getLangOpts().SinglePrecisionConstants) {
-        Res = ImpCastExprToType(Res, Context.FloatTy, CK_FloatingCast).get();
+        const BuiltinType *BTy = Ty->getAs<BuiltinType>();
+        if (BTy->getKind() != BuiltinType::Float) {
+          Res = ImpCastExprToType(Res, Context.FloatTy, CK_FloatingCast).get();
+        }
       } else if (getLangOpts().OpenCL &&
-                 !((getLangOpts().OpenCLVersion >= 120) ||
-                   getOpenCLOptions().cl_khr_fp64)) {
+                 !(getOpenCLOptions().cl_khr_fp64)) {
+        // Impose single-precision float type when cl_khr_fp64 is not enabled.
         Diag(Tok.getLocation(), diag::warn_double_const_requires_fp64);
         Res = ImpCastExprToType(Res, Context.FloatTy, CK_FloatingCast).get();
       }
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 2f776f9fa49..70c3db4d791 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -1402,8 +1402,7 @@ static QualType ConvertDeclSpecToType(TypeProcessingState &state) {
       Result = Context.DoubleTy;
 
     if (S.getLangOpts().OpenCL &&
-        !((S.getLangOpts().OpenCLVersion >= 120) ||
-          S.getOpenCLOptions().cl_khr_fp64)) {
+        !(S.getOpenCLOptions().cl_khr_fp64)) {
       S.Diag(DS.getTypeSpecTypeLoc(), diag::err_type_requires_extension)
           << Result << "cl_khr_fp64";
       declarator.setInvalidType(true);