[OpenCL] Disable __opencl_c_ext_fp64_* features if cl_khr_fp64 is not supported (#169252)

Fix kernel build when cl_khr_fp64 is not enabled:
opencl-c.h:13785:50: error: unknown type name 'atomic_double'
13785 | double __ovld atomic_fetch_min(volatile __global atomic_double
*, double);
opencl-c.h:13785:67: error: use of type 'double' requires cl_khr_fp64
and __opencl_c_fp64 support
13785 | double __ovld atomic_fetch_min(volatile __global atomic_double
*, double);

This is a regression introduced by 423bdb2. Before that commit,
__opencl_c_ext_fp64_global_atomic_add was guarded by cl_khr_fp64 in
opencl-c-base.h.

Author: wenju-he

clang/include/clang/Basic/TargetInfo.h

@@ -1848,6 +1848,9 @@ class TargetInfo : public TransferrableTargetInfo,
     }
   }
 
+  /// Set features that depend on other features.
+  virtual void setDependentOpenCLOpts();
+
   /// Get supported OpenCL extensions and optional core features.
   llvm::StringMap<bool> &getSupportedOpenCLOpts() {
     return getTargetOpts().OpenCLFeaturesMap;

clang/lib/Basic/TargetInfo.cpp

@@ -640,6 +640,17 @@ bool TargetInfo::areDefaultedSMFStillPOD(const LangOptions &LangOpts) const {
   return LangOpts.getClangABICompat() > LangOptions::ClangABI::Ver15;
 }
 
+void TargetInfo::setDependentOpenCLOpts() {
+  auto &Opts = getSupportedOpenCLOpts();
+  if (!hasFeatureEnabled(Opts, "cl_khr_fp64") ||
+      !hasFeatureEnabled(Opts, "__opencl_c_fp64")) {
+    setFeatureEnabled(Opts, "__opencl_c_ext_fp64_global_atomic_add", false);
+    setFeatureEnabled(Opts, "__opencl_c_ext_fp64_local_atomic_add", false);
+    setFeatureEnabled(Opts, "__opencl_c_ext_fp64_global_atomic_min_max", false);
+    setFeatureEnabled(Opts, "__opencl_c_ext_fp64_local_atomic_min_max", false);
+  }
+}
+
 LangAS TargetInfo::getOpenCLTypeAddrSpace(OpenCLTypeKind TK) const {
   switch (TK) {
   case OCLTK_Image:

clang/lib/Basic/Targets.cpp

@@ -862,6 +862,7 @@ TargetInfo *TargetInfo::CreateTargetInfo(DiagnosticsEngine &Diags,
 
   Target->setSupportedOpenCLOpts();
   Target->setCommandLineOpenCLOpts();
+  Target->setDependentOpenCLOpts();
   Target->setMaxAtomicWidth();
 
   if (!Opts->DarwinTargetVariantTriple.empty())

clang/test/Misc/opencl-c-3.0.incorrect_define.cl

@@ -0,0 +1,17 @@
+// RUN: %clang_cc1 -verify -triple spir-unknown-unknown -cl-std=CL3.0 -cl-ext=-__opencl_c_fp64,-cl_khr_fp64 %s
+// RUN: %clang_cc1 -verify -triple spir-unknown-unknown -cl-std=clc++2021 -cl-ext=-__opencl_c_fp64,-cl_khr_fp64 %s
+
+#if __opencl_c_ext_fp64_global_atomic_add != 0
+#error "Incorrectly defined __opencl_c_ext_fp64_global_atomic_add"
+#endif
+#if __opencl_c_ext_fp64_local_atomic_add != 0
+#error "Incorrectly defined __opencl_c_ext_fp64_local_atomic_add"
+#endif
+#if __opencl_c_ext_fp64_global_atomic_min_max != 0
+#error "Incorrectly defined __opencl_c_ext_fp64_global_atomic_min_max"
+#endif
+#if __opencl_c_ext_fp64_local_atomic_min_max != 0
+#error "Incorrectly defined __opencl_c_ext_fp64_local_atomic_min_max"
+#endif
+
+// expected-no-diagnostics