diff --git a/clang/lib/Headers/opencl-c-base.h b/clang/lib/Headers/opencl-c-base.h
--- a/clang/lib/Headers/opencl-c-base.h
+++ b/clang/lib/Headers/opencl-c-base.h
@@ -30,7 +30,7 @@
 #endif // (defined(__OPENCL_CPP_VERSION__) || __OPENCL_C_VERSION__ >= 200)
 
 // Define feature macros for OpenCL C 2.0
-#if (defined(__OPENCL_CPP_VERSION__) || __OPENCL_C_VERSION__ == 200)
+#if (__OPENCL_CPP_VERSION__ == 100 || __OPENCL_C_VERSION__ == 200)
 #define __opencl_c_pipes 1
 #define __opencl_c_generic_address_space 1
 #define __opencl_c_work_group_collective_functions 1
@@ -45,12 +45,12 @@
 #endif
 
 // Define header-only feature macros for OpenCL C 3.0.
-#if (__OPENCL_C_VERSION__ == 300)
+#if (__OPENCL_CPP_VERSION__ == 202100 || __OPENCL_C_VERSION__ == 300)
 // For the SPIR target all features are supported.
 #if defined(__SPIR__)
 #define __opencl_c_atomic_scope_all_devices 1
 #endif // defined(__SPIR__)
-#endif // (__OPENCL_C_VERSION__ == 300)
+#endif // (__OPENCL_CPP_VERSION__ == 202100 || __OPENCL_C_VERSION__ == 300)
 
 // built-in scalar data types:
 
diff --git a/clang/test/Headers/opencl-c-header.cl b/clang/test/Headers/opencl-c-header.cl
--- a/clang/test/Headers/opencl-c-header.cl
+++ b/clang/test/Headers/opencl-c-header.cl
@@ -175,13 +175,13 @@
 #endif //(defined(__OPENCL_CPP_VERSION__) || __OPENCL_C_VERSION__ >= 200)
 
 // OpenCL C features.
-#if (__OPENCL_C_VERSION__ == 300)
+#if (__OPENCL_CPP_VERSION__ == 202100 || __OPENCL_C_VERSION__ == 300)
 
 #if __opencl_c_atomic_scope_all_devices != 1
 #error "Incorrectly defined feature macro __opencl_c_atomic_scope_all_devices"
 #endif
 
-#elif (defined(__OPENCL_CPP_VERSION__) || __OPENCL_C_VERSION__ == 200)
+#elif (__OPENCL_CPP_VERSION__ == 100 || __OPENCL_C_VERSION__ == 200)
 
 #ifndef  __opencl_c_pipes
 #error "Feature macro __opencl_c_pipes should be defined"
@@ -262,6 +262,6 @@
 #error "Incorrect feature macro __opencl_c_subgroups define"
 #endif
 
-#endif //(defined(__OPENCL_CPP_VERSION__) || __OPENCL_C_VERSION__ == 200)
+#endif // (__OPENCL_CPP_VERSION__ == 202100 || __OPENCL_C_VERSION__ == 300)
 
 #endif // defined(__SPIR__)
diff --git a/clang/test/SemaOpenCL/features.cl b/clang/test/SemaOpenCL/features.cl
--- a/clang/test/SemaOpenCL/features.cl
+++ b/clang/test/SemaOpenCL/features.cl
@@ -6,6 +6,14 @@
 // RUN:   | FileCheck -match-full-lines %s  --check-prefix=NO-FEATURES
 // RUN: %clang_cc1 -triple r600-unknown-unknown %s -E -dM -o - -x cl -cl-std=CL3.0 -cl-ext=+all \
 // RUN:   | FileCheck -match-full-lines %s  --check-prefix=FEATURES
+// RUN: %clang_cc1 -triple spir-unknown-unknown %s -E -dM -o - -x cl -cl-std=clc++2021 -cl-ext=-all \
+// RUN:   | FileCheck -match-full-lines %s  --check-prefix=NO-FEATURES
+// RUN: %clang_cc1 -triple spir-unknown-unknown %s -E -dM -o - -x cl -cl-std=clc++2021 -cl-ext=+all \
+// RUN:   | FileCheck -match-full-lines %s  --check-prefix=FEATURES
+// RUN: %clang_cc1 -triple r600-unknown-unknown %s -E -dM -o - -x cl -cl-std=clc++2021 \
+// RUN:   | FileCheck -match-full-lines %s  --check-prefix=NO-FEATURES
+// RUN: %clang_cc1 -triple r600-unknown-unknown %s -E -dM -o - -x cl -cl-std=clc++2021 -cl-ext=+all \
+// RUN:   | FileCheck -match-full-lines %s  --check-prefix=FEATURES
 
 // For OpenCL C 2.0 feature macros are defined only in header, so test that earlier OpenCL
 // versions don't define feature macros accidentally and CL2.0 don't define them without header
@@ -15,7 +23,7 @@
 // RUN:   | FileCheck -match-full-lines %s  --check-prefix=NO-FEATURES
 // RUN: %clang_cc1 -triple spir-unknown-unknown %s -E -dM -o - -x cl -cl-std=CL2.0 \
 // RUN:   | FileCheck -match-full-lines %s  --check-prefix=NO-FEATURES
-// RUN: %clang_cc1 -triple spir-unknown-unknown %s -E -dM -o - -x cl -cl-std=CLC++ \
+// RUN: %clang_cc1 -triple spir-unknown-unknown %s -E -dM -o - -x cl -cl-std=clc++1.0 \
 // RUN:   | FileCheck -match-full-lines %s  --check-prefix=NO-FEATURES
 
 // Note that __opencl_c_int64 is always defined assuming