Files
TurboPFor-Integer-Compression/ext/simdcomp/example.c
2015-01-05 23:13:49 +01:00

67 lines
2.3 KiB
C

#include <stdio.h>
#include <time.h>
#include "simdcomp.h"
// compresses data from datain to buffer, returns how many bytes written
size_t compress(uint32_t * datain, size_t length, uint8_t * buffer) {
if(length/SIMDBlockSize*SIMDBlockSize != length) {
printf("Data length should be a multiple of %i \n",SIMDBlockSize);
}
uint32_t offset = 0;
uint8_t * initout = buffer;
for(size_t k = 0; k < length / SIMDBlockSize; ++k) {
uint32_t b = simdmaxbitsd1(offset,
datain + k * SIMDBlockSize);
*buffer++ = b;
simdpackwithoutmaskd1(offset, datain + k * SIMDBlockSize, (__m128i *) buffer,
b);
offset = datain[k * SIMDBlockSize + SIMDBlockSize - 1];
buffer += b * sizeof(__m128i);
}
return buffer - initout;
}
int main() {
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;
uint8_t * buffer = malloc(N * sizeof(uint32_t) + N / SIMDBlockSize); // output buffer
uint32_t * backbuffer = malloc(SIMDBlockSize * sizeof(uint32_t));
for (int gap = 1; gap <= 243; gap *= 3) {
printf("\n");
printf(" gap = %u \n", gap);
for (int k = 0; k < N; ++k)
datain[k] = k * gap;
uint32_t offset = 0;
compsize = compress(datain,N,buffer);
printf("compression rate = %f \n", (N * sizeof(uint32_t))/ (compsize * 1.0 ));
start = clock();
uint32_t bogus = 0;
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*REPEAT/(numberofseconds*1000.0*1000.0));
printf("ignore me %i \n",bogus);
}
free(buffer);
free(datain);
free(backbuffer);
return 0;
}