1 files changed, 68 insertions, 0 deletions
diff --git a/nixpkgs/pkgs/development/cuda-modules/saxpy/saxpy.cu b/nixpkgs/pkgs/development/cuda-modules/saxpy/saxpy.cu
new file mode 100644
index 000000000000..912a6d1647b1
--- /dev/null
+++ b/nixpkgs/pkgs/development/cuda-modules/saxpy/saxpy.cu
@@ -0,0 +1,68 @@
+#include <cublas_v2.h>
+#include <cuda_runtime.h>
+#include <vector>
+
+#include <stdio.h>
+
+static inline void check(cudaError_t err, const char *context) {
+  if (err != cudaSuccess) {
+    fprintf(stderr, "CUDA error at %s: %s\n", context, cudaGetErrorString(err));
+    std::exit(EXIT_FAILURE);
+  }
+}
+
+#define CHECK(x) check(x, #x)
+
+__global__ void saxpy(int n, float a, float *x, float *y) {
+  int i = blockIdx.x * blockDim.x + threadIdx.x;
+  if (i < n)
+    y[i] = a * x[i] + y[i];
+}
+
+int main(void) {
+  setbuf(stderr, NULL);
+  fprintf(stderr, "Start\n");
+
+  int rtVersion, driverVersion;
+  CHECK(cudaRuntimeGetVersion(&rtVersion));
+  CHECK(cudaDriverGetVersion(&driverVersion));
+
+  fprintf(stderr, "Runtime version: %d\n", rtVersion);
+  fprintf(stderr, "Driver version: %d\n", driverVersion);
+
+  constexpr int N = 1 << 10;
+
+  std::vector<float> xHost(N), yHost(N);
+  for (int i = 0; i < N; i++) {
+    xHost[i] = 1.0f;
+    yHost[i] = 2.0f;
+  }
+
+  fprintf(stderr, "Host memory initialized, copying to the device\n");
+  fflush(stderr);
+
+  float *xDevice, *yDevice;
+  CHECK(cudaMalloc(&xDevice, N * sizeof(float)));
+  CHECK(cudaMalloc(&yDevice, N * sizeof(float)));
+
+  CHECK(cudaMemcpy(xDevice, xHost.data(), N * sizeof(float),
+                   cudaMemcpyHostToDevice));
+  CHECK(cudaMemcpy(yDevice, yHost.data(), N * sizeof(float),
+                   cudaMemcpyHostToDevice));
+  fprintf(stderr, "Scheduled a cudaMemcpy, calling the kernel\n");
+
+  saxpy<<<(N + 255) / 256, 256>>>(N, 2.0f, xDevice, yDevice);
+  fprintf(stderr, "Scheduled a kernel call\n");
+  CHECK(cudaGetLastError());
+
+  CHECK(cudaMemcpy(yHost.data(), yDevice, N * sizeof(float),
+                   cudaMemcpyDeviceToHost));
+
+  float maxError = 0.0f;
+  for (int i = 0; i < N; i++)
+    maxError = max(maxError, abs(yHost[i] - 4.0f));
+  fprintf(stderr, "Max error: %f\n", maxError);
+
+  CHECK(cudaFree(xDevice));
+  CHECK(cudaFree(yDevice));
+}