/* Here we compress the data in blocks of 128 integers with varying bit width */
int varying_bit_width_demo() {
size_t nn = 128 * 2;
uint32_t * datainn = malloc(nn * sizeof(uint32_t));
uint8_t * buffern = malloc(nn * sizeof(uint32_t) + nn / SIMDBlockSize);
uint32_t * backbuffern = malloc(nn * sizeof(uint32_t));
size_t k, compsize;
printf("== varying bit-width demo\n");
for(k=0;k<nn;++k){
datainn[k] = rand() % (k + 1);
}
compsize = varying_bit_width_compress(datainn,nn,buffern);
printf("encoded size: %u (original size: %u)\n", (unsigned)compsize,
(unsigned)(nn * sizeof(uint32_t)));
for (k = 0; k * SIMDBlockSize < nn; ++k) {
uint32_t b = *buffern;
buffern++;
simdunpack((const __m128i *)buffern, backbuffern + k * SIMDBlockSize, b);
buffern += b * sizeof(__m128i);
}
for (k = 0; k < nn; ++k){
if(backbuffern[k] != datainn[k]) { printf("bug\n"); return -1;}
}
printf("Code works!\n");
return 0;
}
int test() {
int N = 5000 * SIMDBlockSize, gap;
__m128i * buffer = malloc(SIMDBlockSize * sizeof(uint32_t));
uint32_t * datain = malloc(N * sizeof(uint32_t));
uint32_t * backbuffer = malloc(SIMDBlockSize * sizeof(uint32_t));
for (gap = 1; gap <= 387420489; gap *= 3) {
int k;
printf(" gap = %u \n", gap);
for (k = 0; k < N; ++k)
datain[k] = k * gap;
for (k = 0; k * SIMDBlockSize < N; ++k) {
/*
First part works for general arrays (sorted or unsorted)
*/
int j;
/* we compute the bit width */
const uint32_t b = maxbits(datain + k * SIMDBlockSize);
/* we read 128 integers at "datain + k * SIMDBlockSize" and
write b 128-bit vectors at "buffer" */
simdpackwithoutmask(datain + k * SIMDBlockSize, buffer, b);
/* we read back b1 128-bit vectors at "buffer" and write 128 integers at backbuffer */
simdunpack(buffer, backbuffer, b);/* uncompressed */
for (j = 0; j < SIMDBlockSize; ++j) {
if (backbuffer[j] != datain[k * SIMDBlockSize + j]) {
printf("bug in simdpack\n");
return -2;
}
}
{
/*
next part assumes that the data is sorted (uses differential coding)
*/
uint32_t offset = 0;
/* we compute the bit width */
const uint32_t b1 = simdmaxbitsd1(offset,
datain + k * SIMDBlockSize);
/* we read 128 integers at "datain + k * SIMDBlockSize" and
write b1 128-bit vectors at "buffer" */
simdpackwithoutmaskd1(offset, datain + k * SIMDBlockSize, buffer,
b1);
/* we read back b1 128-bit vectors at "buffer" and write 128 integers at backbuffer */
simdunpackd1(offset, buffer, backbuffer, b1);
for (j = 0; j < SIMDBlockSize; ++j) {
if (backbuffer[j] != datain[k * SIMDBlockSize + j]) {
printf("bug in simdpack d1\n");
return -3;
}
}
offset = datain[k * SIMDBlockSize + SIMDBlockSize - 1];
}
}
}
free(buffer);
free(datain);
free(backbuffer);
printf("Code looks good.\n");
return 0;
}
unsigned char *simdunpackn(uint32_t *in, uint32_t n, uint32_t b, uint32_t *out) {
uint32_t k, *out_;
for(out_ = out + n; out + 128 <= out_; out += 128, in += 4 * b) simdunpack((const __m128i *)in, out, b);
return (unsigned char *)in;
}
