diff --git a/clang/lib/Headers/opencl-c.h b/clang/lib/Headers/opencl-c.h
--- a/clang/lib/Headers/opencl-c.h
+++ b/clang/lib/Headers/opencl-c.h
@@ -7259,7 +7259,7 @@
  * Returns fmin(x - floor (x), 0x1.fffffep-1f ).
  * floor(x) is returned in iptr.
  */
-#if defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#if defined(__opencl_c_generic_address_space)
 float __ovld fract(float x, float *iptr);
 float2 __ovld fract(float2 x, float2 *iptr);
 float3 __ovld fract(float3 x, float3 *iptr);
@@ -7341,7 +7341,7 @@
 half8 __ovld fract(half8 x, __private half8 *iptr);
 half16 __ovld fract(half16 x, __private half16 *iptr);
 #endif //cl_khr_fp16
-#endif //defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#endif //defined(__opencl_c_generic_address_space)
 
 /**
  * Extract mantissa and exponent from x. For each
@@ -7349,7 +7349,7 @@
  * magnitude in the interval [1/2, 1) or 0. Each
  * component of x equals mantissa returned * 2^exp.
  */
-#if defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#if defined(__opencl_c_generic_address_space)
 float __ovld frexp(float x, int *exp);
 float2 __ovld frexp(float2 x, int2 *exp);
 float3 __ovld frexp(float3 x, int3 *exp);
@@ -7431,7 +7431,7 @@
 half8 __ovld frexp(half8 x, __private int8 *exp);
 half16 __ovld frexp(half16 x, __private int16 *exp);
 #endif //cl_khr_fp16
-#endif //defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#endif //defined(__opencl_c_generic_address_space)
 
 /**
  * Compute the value of the square root of x^2 + y^2
@@ -7556,7 +7556,7 @@
 half16 __ovld __cnfn lgamma(half16 x);
 #endif //cl_khr_fp16
 
-#if defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#if defined(__opencl_c_generic_address_space)
 float __ovld lgamma_r(float x, int *signp);
 float2 __ovld lgamma_r(float2 x, int2 *signp);
 float3 __ovld lgamma_r(float3 x, int3 *signp);
@@ -7638,7 +7638,7 @@
 half8 __ovld lgamma_r(half8 x, __private int8 *signp);
 half16 __ovld lgamma_r(half16 x, __private int16 *signp);
 #endif //cl_khr_fp16
-#endif //defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#endif //defined(__opencl_c_generic_address_space)
 
 /**
  * Compute natural logarithm.
@@ -7862,7 +7862,7 @@
  * the argument. It stores the integral part in the object
  * pointed to by iptr.
  */
-#if defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#if defined(__opencl_c_generic_address_space)
 float __ovld modf(float x, float *iptr);
 float2 __ovld modf(float2 x, float2 *iptr);
 float3 __ovld modf(float3 x, float3 *iptr);
@@ -7944,7 +7944,7 @@
 half8 __ovld modf(half8 x, __private half8 *iptr);
 half16 __ovld modf(half16 x, __private half16 *iptr);
 #endif //cl_khr_fp16
-#endif //defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#endif //defined(__opencl_c_generic_address_space)
 
 /**
  * Returns a quiet NaN. The nancode may be placed
@@ -8122,7 +8122,7 @@
  * sign as x/y. It stores this signed value in the object
  * pointed to by quo.
  */
-#if defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#if defined(__opencl_c_generic_address_space)
 float __ovld remquo(float x, float y, int *quo);
 float2 __ovld remquo(float2 x, float2 y, int2 *quo);
 float3 __ovld remquo(float3 x, float3 y, int3 *quo);
@@ -8205,7 +8205,7 @@
 half8 __ovld remquo(half8 x, half8 y, __private int8 *quo);
 half16 __ovld remquo(half16 x, half16 y, __private int16 *quo);
 #endif //cl_khr_fp16
-#endif //defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#endif //defined(__opencl_c_generic_address_space)
 /**
  * Round to integral value (using round to nearest
  * even rounding mode) in floating-point format.
@@ -8346,7 +8346,7 @@
  * is the return value and computed cosine is returned
  * in cosval.
  */
-#if defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#if defined(__opencl_c_generic_address_space)
 float __ovld sincos(float x, float *cosval);
 float2 __ovld sincos(float2 x, float2 *cosval);
 float3 __ovld sincos(float3 x, float3 *cosval);
@@ -8428,7 +8428,7 @@
 half8 __ovld sincos(half8 x, __private half8 *cosval);
 half16 __ovld sincos(half16 x, __private half16 *cosval);
 #endif //cl_khr_fp16
-#endif //defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#endif //defined(__opencl_c_generic_address_space)
 
 /**
  * Compute hyperbolic sine.
@@ -11249,7 +11249,7 @@
 half16 __ovld vload16(size_t offset, const __constant half *p);
 #endif //cl_khr_fp16
 
-#if defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#if defined(__opencl_c_generic_address_space)
 char2 __ovld vload2(size_t offset, const char *p);
 uchar2 __ovld vload2(size_t offset, const uchar *p);
 short2 __ovld vload2(size_t offset, const short *p);
@@ -11487,9 +11487,9 @@
 half8 __ovld vload8(size_t offset, const __private half *p);
 half16 __ovld vload16(size_t offset, const __private half *p);
 #endif //cl_khr_fp16
-#endif //defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#endif //defined(__opencl_c_generic_address_space)
 
-#if defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#if defined(__opencl_c_generic_address_space)
 void __ovld vstore2(char2 data, size_t offset, char *p);
 void __ovld vstore2(uchar2 data, size_t offset, uchar *p);
 void __ovld vstore2(short2 data, size_t offset, short *p);
@@ -11723,7 +11723,7 @@
 void __ovld vstore8(half8 data, size_t offset, __private half *p);
 void __ovld vstore16(half16 data, size_t offset, __private half *p);
 #endif //cl_khr_fp16
-#endif //defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#endif //defined(__opencl_c_generic_address_space)
 
 /**
  * Read sizeof (half) bytes of data from address
@@ -11734,13 +11734,13 @@
  * must be 16-bit aligned.
  */
 float __ovld vload_half(size_t offset, const __constant half *p);
-#if defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#if defined(__opencl_c_generic_address_space)
 float __ovld vload_half(size_t offset, const half *p);
 #else
 float __ovld vload_half(size_t offset, const __global half *p);
 float __ovld vload_half(size_t offset, const __local half *p);
 float __ovld vload_half(size_t offset, const __private half *p);
-#endif //defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#endif //defined(__opencl_c_generic_address_space)
 
 /**
  * Read sizeof (halfn) bytes of data from address
@@ -11755,7 +11755,7 @@
 float4 __ovld vload_half4(size_t offset, const __constant half *p);
 float8 __ovld vload_half8(size_t offset, const __constant half *p);
 float16 __ovld vload_half16(size_t offset, const __constant half *p);
-#if defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#if defined(__opencl_c_generic_address_space)
 float2 __ovld vload_half2(size_t offset, const half *p);
 float3 __ovld vload_half3(size_t offset, const half *p);
 float4 __ovld vload_half4(size_t offset, const half *p);
@@ -11777,7 +11777,7 @@
 float4 __ovld vload_half4(size_t offset, const __private half *p);
 float8 __ovld vload_half8(size_t offset, const __private half *p);
 float16 __ovld vload_half16(size_t offset, const __private half *p);
-#endif //defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#endif //defined(__opencl_c_generic_address_space)
 
 /**
  * The float value given by data is first
@@ -11790,7 +11790,7 @@
  * The default current rounding mode is round to
  * nearest even.
  */
-#if defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#if defined(__opencl_c_generic_address_space)
 void __ovld vstore_half(float data, size_t offset, half *p);
 void __ovld vstore_half_rte(float data, size_t offset, half *p);
 void __ovld vstore_half_rtz(float data, size_t offset, half *p);
@@ -11836,7 +11836,7 @@
 void __ovld vstore_half_rtp(double data, size_t offset, __private half *p);
 void __ovld vstore_half_rtn(double data, size_t offset, __private half *p);
 #endif //cl_khr_fp64
-#endif //defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#endif //defined(__opencl_c_generic_address_space)
 
 /**
  * The floatn value given by data is converted to
@@ -11849,7 +11849,7 @@
  * The default current rounding mode is round to
  * nearest even.
  */
-#if defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#if defined(__opencl_c_generic_address_space)
 void __ovld vstore_half2(float2 data, size_t offset, half *p);
 void __ovld vstore_half3(float3 data, size_t offset, half *p);
 void __ovld vstore_half4(float4 data, size_t offset, half *p);
@@ -12055,7 +12055,7 @@
 void __ovld vstore_half8_rtn(double8 data, size_t offset, __private half *p);
 void __ovld vstore_half16_rtn(double16 data, size_t offset, __private half *p);
 #endif //cl_khr_fp64
-#endif //defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#endif //defined(__opencl_c_generic_address_space)
 
 /**
  * For n = 1, 2, 4, 8 and 16 read sizeof (halfn)
@@ -12076,7 +12076,7 @@
 float4 __ovld vloada_half4(size_t offset, const __constant half *p);
 float8 __ovld vloada_half8(size_t offset, const __constant half *p);
 float16 __ovld vloada_half16(size_t offset, const __constant half *p);
-#if defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#if defined(__opencl_c_generic_address_space)
 float __ovld vloada_half(size_t offset, const half *p);
 float2 __ovld vloada_half2(size_t offset, const half *p);
 float3 __ovld vloada_half3(size_t offset, const half *p);
@@ -12102,7 +12102,7 @@
 float4 __ovld vloada_half4(size_t offset, const __private half *p);
 float8 __ovld vloada_half8(size_t offset, const __private half *p);
 float16 __ovld vloada_half16(size_t offset, const __private half *p);
-#endif //defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#endif //defined(__opencl_c_generic_address_space)
 
 /**
  * The floatn value given by data is converted to
@@ -12120,7 +12120,7 @@
  * mode. The default current rounding mode is
  * round to nearest even.
  */
-#if defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#if defined(__opencl_c_generic_address_space)
 void __ovld vstorea_half(float data, size_t offset, half *p);
 void __ovld vstorea_half2(float2 data, size_t offset, half *p);
 void __ovld vstorea_half3(float3 data, size_t offset, half *p);
@@ -12405,7 +12405,7 @@
 void __ovld vstorea_half8_rtn(double8 data,size_t offset, __private half *p);
 void __ovld vstorea_half16_rtn(double16 data,size_t offset, __private half *p);
 #endif //cl_khr_fp64
-#endif //defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#endif //defined(__opencl_c_generic_address_space)
 
 // OpenCL v1.1 s6.11.8, v1.2 s6.12.8, v2.0 s6.13.8 - Synchronization Functions
 
@@ -12489,7 +12489,7 @@
 
 // OpenCL v2.0 s6.13.9 - Address Space Qualifier Functions
 
-#if defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#if defined(__opencl_c_generic_address_space)
 cl_mem_fence_flags __ovld get_fence(const void *ptr);
 cl_mem_fence_flags __ovld get_fence(void *ptr);
 
@@ -12500,7 +12500,7 @@
  * where gentype is builtin type or user defined type.
  */
 
-#endif //defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#endif //defined(__opencl_c_generic_address_space)
 
 // OpenCL v1.1 s6.11.10, v1.2 s6.12.10, v2.0 s6.13.10 - Async Copies from Global to Local Memory, Local to Global Memory, and Prefetch