Fix OpenCL 1.2 double as an optional core feature behaviour

In OpenCL 1.2, using double no longer requires using the pragma cl_khr_fp64,
instead a kernel is allowed to use double, but must first have queried
clGetDeviceInfo's CL_DEVICE_DOUBLE_FP_CONFIG.

Page 197, section 6.1.1 of the OpenCL 1.2 specification has a footnote 23
describing this behaviour.

I've also added test cases such that the pragma must be used if targeting
OpenCL 1.0 or 1.1, but is ignored in 1.2 and 2.0.

Patch by Neil Henning!

Reviewers: Pekka Jääskeläinen

Differential Revision: http://reviews.llvm.org/D7245

llvm-svn: 227565

clang/lib/Sema/SemaExpr.cpp

@@ -3266,7 +3266,9 @@ ExprResult Sema::ActOnNumericConstant(const Token &Tok, Scope *UDLScope) {
     if (Ty == Context.DoubleTy) {
       if (getLangOpts().SinglePrecisionConstants) {
         Res = ImpCastExprToType(Res, Context.FloatTy, CK_FloatingCast).get();
-      } else if (getLangOpts().OpenCL && !getOpenCLOptions().cl_khr_fp64) {
+      } else if (getLangOpts().OpenCL &&
+                 !((getLangOpts().OpenCLVersion >= 120) ||
+                   getOpenCLOptions().cl_khr_fp64)) {
         Diag(Tok.getLocation(), diag::warn_double_const_requires_fp64);
         Res = ImpCastExprToType(Res, Context.FloatTy, CK_FloatingCast).get();
       }

clang/lib/Sema/SemaType.cpp

@@ -868,7 +868,9 @@ static QualType ConvertDeclSpecToType(TypeProcessingState &state) {
     else
       Result = Context.DoubleTy;
 
-    if (S.getLangOpts().OpenCL && !S.getOpenCLOptions().cl_khr_fp64) {
+    if (S.getLangOpts().OpenCL &&
+        !((S.getLangOpts().OpenCLVersion >= 120) ||
+          S.getOpenCLOptions().cl_khr_fp64)) {
       S.Diag(DS.getTypeSpecTypeLoc(), diag::err_double_requires_fp64);
       declarator.setInvalidType(true);
     }

clang/test/SemaOpenCL/extension-fp64-cl1.1.cl

@@ -0,0 +1,19 @@
+// RUN: %clang_cc1 %s -verify -pedantic -fsyntax-only -cl-std=CL1.1
+
+void f1(double da) { // expected-error {{type 'double' requires cl_khr_fp64 extension}}
+  double d; // expected-error {{type 'double' requires cl_khr_fp64 extension}}
+  (void) 1.0; // expected-warning {{double precision constant requires cl_khr_fp64}}
+}
+
+#pragma OPENCL EXTENSION cl_khr_fp64 : enable
+
+void f2(void) {
+  double d;
+  (void) 1.0;
+}
+
+#pragma OPENCL EXTENSION cl_khr_fp64 : disable
+
+void f3(void) {
+  double d; // expected-error {{type 'double' requires cl_khr_fp64 extension}}
+}

clang/test/SemaOpenCL/optional-core-fp64-cl1.2.cl

@@ -0,0 +1,20 @@
+// RUN: %clang_cc1 %s -verify -pedantic -fsyntax-only -cl-std=CL1.2
+// expected-no-diagnostics
+
+void f1(double da) {
+  double d;
+  (void) 1.0;
+}
+
+#pragma OPENCL EXTENSION cl_khr_fp64 : enable
+
+void f2(void) {
+  double d;
+  (void) 1.0;
+}
+
+#pragma OPENCL EXTENSION cl_khr_fp64 : disable
+
+void f3(void) {
+  double d;
+}

clang/test/SemaOpenCL/optional-core-fp64-cl2.0.cl

@@ -0,0 +1,20 @@
+// RUN: %clang_cc1 %s -verify -pedantic -fsyntax-only -cl-std=CL2.0
+// expected-no-diagnostics
+
+void f1(double da) {
+  double d;
+  (void) 1.0;
+}
+
+#pragma OPENCL EXTENSION cl_khr_fp64 : enable
+
+void f2(void) {
+  double d;
+  (void) 1.0;
+}
+
+#pragma OPENCL EXTENSION cl_khr_fp64 : disable
+
+void f3(void) {
+  double d;
+}