Saving...

Author: lemire

example.c

@@ -24,7 +24,8 @@ size_t compress(uint32_t * datain, size_t length, uint8_t * buffer) {
 
 
 int main() {
-    int N = 5000 * SIMDBlockSize;//SIMDBlockSize is 128
+    int REPEAT = 5;
+    int N = 1000000 * SIMDBlockSize;//SIMDBlockSize is 128
     uint32_t * datain = malloc(N * sizeof(uint32_t));
     size_t compsize;
     clock_t start, end;
@@ -39,20 +40,22 @@ int main() {
         uint32_t offset = 0;
         compsize = compress(datain,N,buffer);
         printf("compression rate = %f \n",  (N * sizeof(uint32_t))/ (compsize * 1.0 ));
-        uint8_t * decbuffer = buffer;
         start = clock();
         uint32_t bogus = 0;
-        for (int k = 0; k * SIMDBlockSize < N; ++k) {
+        for(int repeat = 0; repeat < REPEAT; ++repeat) {
+         uint8_t * decbuffer = buffer;
+         for (int k = 0; k * SIMDBlockSize < N; ++k) {
         	uint8_t b = *decbuffer++;
             simdunpackd1(offset, (__m128i *) decbuffer, backbuffer, b);
             // do something here with backbuffer
             bogus += backbuffer[3];
             decbuffer += b * sizeof(__m128i);
             offset = backbuffer[SIMDBlockSize - 1];
+         }
         }
         end = clock();
         double numberofseconds = (end-start)/(double)CLOCKS_PER_SEC;
-        printf("decoding speed in million of integers per second %f \n",N/(numberofseconds*1000.0*1000.0));
+        printf("decoding speed in million of integers per second %f \n",N*REPEAT/(numberofseconds*1000.0*1000.0));
         printf("ignore me %i \n",bogus);
     }
     free(buffer);