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
@@ -10467,12 +10467,6 @@
 float __ovld __cnfn fast_distance(float2, float2);
 float __ovld __cnfn fast_distance(float3, float3);
 float __ovld __cnfn fast_distance(float4, float4);
-#ifdef cl_khr_fp16
-half __ovld __cnfn fast_distance(half, half);
-half __ovld __cnfn fast_distance(half2, half2);
-half __ovld __cnfn fast_distance(half3, half3);
-half __ovld __cnfn fast_distance(half4, half4);
-#endif //cl_khr_fp16
 
 /**
  * Returns the length of vector p computed as:
@@ -10482,12 +10476,6 @@
 float __ovld __cnfn fast_length(float2);
 float __ovld __cnfn fast_length(float3);
 float __ovld __cnfn fast_length(float4);
-#ifdef cl_khr_fp16
-half __ovld __cnfn fast_length(half);
-half __ovld __cnfn fast_length(half2);
-half __ovld __cnfn fast_length(half3);
-half __ovld __cnfn fast_length(half4);
-#endif //cl_khr_fp16
 
 /**
  * Returns a vector in the same direction as p but with a
@@ -10514,12 +10502,6 @@
 float2 __ovld __cnfn fast_normalize(float2);
 float3 __ovld __cnfn fast_normalize(float3);
 float4 __ovld __cnfn fast_normalize(float4);
-#ifdef cl_khr_fp16
-half __ovld __cnfn fast_normalize(half);
-half2 __ovld __cnfn fast_normalize(half2);
-half3 __ovld __cnfn fast_normalize(half3);
-half4 __ovld __cnfn fast_normalize(half4);
-#endif //cl_khr_fp16
 
 // OpenCL v1.1 s6.11.6, v1.2 s6.12.6, v2.0 s6.13.6 - Relational Functions