Update in clock function

Change-Id: I5819aa62693dc3b9b5d7e39944d1e58aadc72027


[ROCm/hip commit: d46b3446de]

projects/hip/docs/markdown/hip_kernel_language.md

@@ -420,17 +420,7 @@ HIP provides the following built-in functions for reading a high-resolution time
 clock_t clock()
 long long int clock64()
 ```
-
-AMD devices employ a per-GPU timer that increments at a constant time interval regardless of any dynamic frequency changes. All compute units in the system share the timer. 
-Nvidia devices implement the timer as a per-compute-unit clock that increments on every clock cycle.  
-
-To obtain the clock frequency, use the hipDeviceProp_t.clockInstructionRate field:
-
-```
-hipGetDeviceProperties(&deviceProps, deviceId);
-// Compute time in ms--device_ticks is based on values reported from clock() device function
-float time = device_ticks / (float)deviceProps.clockInstructionRate;
-```
+Returns the value of counter that is incremented every clock cycle on device. Difference in values returned provides the cycles used.
 
 ## Atomic Functions
 

projects/hip/src/device_util.cpp

@@ -501,8 +501,8 @@ __device__ double trunc(double x)
 
 const int warpSize = 64;
 
-__device__ long long int clock64() { return (long long int)hc::__clock_u64(); };
-__device__ clock_t clock() { return (clock_t)hc::__clock_u64(); };
+__device__ long long int clock64() { return (long long int)hc::__cycle_u64(); };
+__device__ clock_t clock() { return (clock_t)hc::__cycle_u64(); };
 
 
 //atomicAdd()