Fix OpenCL 1.2 double as an optional core feature behaviour

[sheredom]

Summary

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.

[pekka.jaaskelainen]

Are those if conditions that span to the next line indented correctly?

Apart from this nitpick, LGTM.

[sheredom]

Ran clang-format on the file, and there was a TON of line changes out-with the patch. Extracted the formatted lines from my original patch only, and updated the patch.

[pekka.jaaskelainen]

LGTM.

lib/Sema/SemaExpr.cpp

if (Literal.isFloatingLiteral()) {
     else
       Ty = Context.LongDoubleTy;
 
     Res = BuildFloatingLiteral(*this, Literal, Ty, Tok.getLocation());
 
     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();
       }
     }
   } else if (!Literal.isIntegerLiteral()) {
     return ExprError();
   } else {
     QualType Ty;

lib/Sema/SemaType.cpp

static QualType ConvertDeclSpecToType(TypeProcessingState &state) {
   case DeclSpec::TST_half: Result = Context.HalfTy; break;
   case DeclSpec::TST_float: Result = Context.FloatTy; break;
   case DeclSpec::TST_double:
     if (DS.getTypeSpecWidth() == DeclSpec::TSW_long)
       Result = Context.LongDoubleTy;
     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);
     }
     break;
   case DeclSpec::TST_bool: Result = Context.BoolTy; break; // _Bool or bool
   case DeclSpec::TST_decimal32:    // _Decimal32
   case DeclSpec::TST_decimal64:    // _Decimal64
   case DeclSpec::TST_decimal128:   // _Decimal128

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

+// 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}}
+}

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

+// 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;
+}

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

+// 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;
+}