added unit 2 lecture quizzes and moved some things around

Author: Chillee

LectureQuizzes/2_18.cu

@@ -0,0 +1,23 @@
+#include <stdio.h>
+
+#define NUM_BLOCKS 16
+#define BLOCK_WIDTH 1
+
+__global__ void hello()
+{
+    printf("Hello world! I'm a thread in block %d\n", blockIdx.x);
+}
+
+
+int main(int argc,char **argv)
+{
+    // launch the kernel
+    hello<<<NUM_BLOCKS, BLOCK_WIDTH>>>();
+
+    // force the printf()s to flush
+    cudaDeviceSynchronize();
+
+    printf("That's all!\n");
+
+    return 0;
+}

LectureQuizzes/2_37.cu

@@ -0,0 +1,79 @@
+#include <stdio.h>
+#include "gputimer.h"
+
+#define NUM_THREADS 1000000
+#define ARRAY_SIZE  100
+bool atomic = true;
+
+#define BLOCK_WIDTH 1000
+
+void print_array(int *array, int size)
+{
+    printf("{ ");
+    for (int i = 0; i < size; i++)  { printf("%d ", array[i]); }
+    printf("}\n");
+}
+
+__global__ void increment_naive(int *g)
+{
+	// which thread is this?
+	int i = blockIdx.x * blockDim.x + threadIdx.x; 
+
+	// each thread to increment consecutive elements, wrapping at ARRAY_SIZE
+	i = i % ARRAY_SIZE;  
+	g[i] = g[i] + 1;
+}
+
+__global__ void increment_atomic(int *g)
+{
+	// which thread is this?
+	int i = blockIdx.x * blockDim.x + threadIdx.x; 
+
+	// each thread to increment consecutive elements, wrapping at ARRAY_SIZE
+	i = i % ARRAY_SIZE;  
+	atomicAdd(& g[i], 1);
+}
+
+int main(int argc,char **argv)
+{   
+    GpuTimer timer;
+    if (atomic) {
+        printf("atomic %d total threads in %d blocks writing into %d array elements\n",
+           NUM_THREADS, NUM_THREADS / BLOCK_WIDTH, ARRAY_SIZE);
+    } else {
+        printf("%d total threads in %d blocks writing into %d array elements\n",
+           NUM_THREADS, NUM_THREADS / BLOCK_WIDTH, ARRAY_SIZE);
+    }
+
+    // declare and allocate host memory
+    int h_array[ARRAY_SIZE];
+    const int ARRAY_BYTES = ARRAY_SIZE * sizeof(int);
+ 
+    // declare, allocate, and zero out GPU memory
+    int * d_array;
+    cudaMalloc((void **) &d_array, ARRAY_BYTES);
+    cudaMemset((void *) d_array, 0, ARRAY_BYTES); 
+
+    // launch the kernel - comment out one of these
+    timer.Start();
+    
+    // Instructions: This program is needed for the next quiz
+    // uncomment increment_naive to measure speed and accuracy 
+    // of non-atomic increments or uncomment increment_atomic to
+    // measure speed and accuracy of  atomic icrements
+    if (atomic) {
+        increment_atomic<<<NUM_THREADS/BLOCK_WIDTH, BLOCK_WIDTH>>>(d_array);
+    } else {
+        increment_naive<<<NUM_THREADS/BLOCK_WIDTH, BLOCK_WIDTH>>>(d_array);
+    }
+    timer.Stop();
+    
+    // copy back the array of sums from GPU and print
+    cudaMemcpy(h_array, d_array, ARRAY_BYTES, cudaMemcpyDeviceToHost);
+    // print_array(h_array, ARRAY_SIZE);
+    printf("Time elapsed = %g ms\n", timer.Elapsed());
+ 
+    // free GPU memory allocation and exit
+    cudaFree(d_array);
+    return 0;
+}

LectureQuizzes/gputimer.h

@@ -0,0 +1,40 @@
+#ifndef __GPU_TIMER_H__
+#define __GPU_TIMER_H__
+
+struct GpuTimer
+{
+      cudaEvent_t start;
+      cudaEvent_t stop;
+ 
+      GpuTimer()
+      {
+            cudaEventCreate(&start);
+            cudaEventCreate(&stop);
+      }
+ 
+      ~GpuTimer()
+      {
+            cudaEventDestroy(start);
+            cudaEventDestroy(stop);
+      }
+ 
+      void Start()
+      {
+            cudaEventRecord(start, 0);
+      }
+ 
+      void Stop()
+      {
+            cudaEventRecord(stop, 0);
+      }
+ 
+      float Elapsed()
+      {
+            float elapsed;
+            cudaEventSynchronize(stop);
+            cudaEventElapsedTime(&elapsed, start, stop);
+            return elapsed;
+      }
+};
+
+#endif  /* __GPU_TIMER_H__ */

README.md

@@ -0,0 +1,23 @@
+These assignments require OpenCV as a prerequisite. The easiest way to install is probably with conda.
+
+To install OpenCV in a conda environment.
+```
+conda create -n cs344 -y
+conda activate cs344
+conda install -y -c anaconda opencv
+```
+
+To build
+```
+cd assignments
+mkdir build
+cd build
+cmake ..
+make
+```
+The binaries will then be contained within `assignments/bin`.
+
+# HW1 Passing Instructions
+From the `HW1` directory.
+
+Run `../bin/HW1 HW1/cinque_terre_small.jpg'`

assignments/README.md

@@ -9,6 +9,7 @@ conda install -y -c anaconda opencv
 
 To build
 ```
+cd assignments
 mkdir build
 cd build
 cmake ..