simpleAtomicIntrinsics_kernel.cuh

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/* Simple kernel demonstrating atomic functions in device code. */

#ifndef _SIMPLEATOMICS_KERNEL_H_
#define _SIMPLEATOMICS_KERNEL_H_

////////////////////////////////////////////////////////////////////////////////
//! Simple test kernel for atomic instructions
//! @param g_idata  input data in global memory
//! @param g_odata  output data in global memory
////////////////////////////////////////////////////////////////////////////////
__global__ void testKernel(int *g_odata) {
  // access thread id
  const unsigned int tid = blockDim.x * blockIdx.x + threadIdx.x;

  // Test various atomic instructions

  // Arithmetic atomic instructions

  // Atomic addition
  atomicAdd(&g_odata[0], 10);

  // Atomic subtraction (final should be 0)
  atomicSub(&g_odata[1], 10);

  // Atomic exchange
  atomicExch(&g_odata[2], tid);

  // Atomic maximum
  atomicMax(&g_odata[3], tid);

  // Atomic minimum
  atomicMin(&g_odata[4], tid);

  // Atomic increment (modulo 17+1)
  atomicInc((unsigned int *)&g_odata[5], 17);

  // Atomic decrement
  atomicDec((unsigned int *)&g_odata[6], 137);

  // Atomic compare-and-swap
  atomicCAS(&g_odata[7], tid - 1, tid);

  // Bitwise atomic instructions

  // Atomic AND
  atomicAnd(&g_odata[8], 2 * tid + 7);

  // Atomic OR
  atomicOr(&g_odata[9], 1 << tid);

  // Atomic XOR
  atomicXor(&g_odata[10], tid);
}

#endif  // #ifndef _SIMPLEATOMICS_KERNEL_H_