 }
 
 // elementwise multiply
-#ifndef CUDA_VERSION_32
+#ifdef CUDA_VERSION_31
 static inline __host__ __device__ float4 operator*(float4 a, float4 b)
 {
     return make_float4(a.x * b.x, a.y * b.y, a.z * b.z,  a.w * b.w);

}

// float-float3
#ifndef CUDA_VERSION_32
static inline __host__ __device__ float3 operator-(float a, float3 b)
{
  return make_float3(a - b.x, a - b.y, a - b.z);

}

// float-float2
#ifdef CUDA_VERSION_31
static inline __host__ __device__ float2 operator-(float a, float2 b)
{
  return make_float2(a - b.x, a - b.y);
