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;
}
/* Another illustration ... */
void simple_demo() {
size_t REPEAT = 10, gap;
size_t N = 1000 * 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));
printf("== simple demo\n");
for (gap = 1; gap <= 243; gap *= 3) {
size_t k, repeat;
uint32_t offset = 0;
uint32_t bogus = 0;
double numberofseconds;
printf("\n");
printf(" gap = %lu \n", (unsigned long) gap);
datain[0] = 0;
for (k = 1; k < N; ++k)
datain[k] = datain[k-1] + ( rand() % (gap + 1) );
compsize = compress(datain,N,buffer);
printf("compression ratio = %f \n", (N * sizeof(uint32_t))/ (compsize * 1.0 ));
start = clock();
for(repeat = 0; repeat < REPEAT; ++repeat) {
uint8_t * decbuffer = buffer;
for (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();
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));
start = clock();
for(repeat = 0; repeat < REPEAT; ++repeat) {
uint8_t * decbuffer = buffer;
for (k = 0; k * SIMDBlockSize < N; ++k) {
memcpy(backbuffer,decbuffer+k*SIMDBlockSize,SIMDBlockSize*sizeof(uint32_t));
bogus += backbuffer[3] - backbuffer[100];
}
}
end = clock();
numberofseconds = (end-start)/(double)CLOCKS_PER_SEC;
printf("memcpy speed in million of integers per second %f \n",N*REPEAT/(numberofseconds*1000.0*1000.0));
printf("ignore me %i \n",bogus);
printf("All tests are in CPU cache. Avoid out-of-cache decoding in applications.\n");
}
free(buffer);
free(datain);
free(backbuffer);
}
int test_simdpackedsearch_advanced() {
uint32_t buffer[128];
uint32_t backbuffer[128];
uint32_t out[128];
uint32_t result = 0;
uint32_t b, i;
uint32_t init = 0;
__m128i initial = _mm_set1_epi32(init);
/* this test creates delta encoded buffers with different bits, then
* performs lower bound searches for each key */
for (b = 0; b <= 32; b++) {
uint32_t prev = init;
/* initialize the buffer */
for (i = 0; i < 128; i++) {
buffer[i] = ((uint32_t)(1431655765 * i + 0xFFFFFFFF)) ;
if(b < 32) buffer[i] %= (1<<b);
}
qsort(buffer,128, sizeof(uint32_t), uint32_cmp);
for (i = 0; i < 128; i++) {
buffer[i] = buffer[i] + prev;
prev = buffer[i];
}
for (i = 1; i < 128; i++) {
if(buffer[i] < buffer[i-1] )
buffer[i] = buffer[i-1];
}
assert(simdmaxbitsd1(init, buffer)<=b);
for (i = 0; i < 128; i++) {
out[i] = 0; /* memset would do too */
}
/* delta-encode to 'i' bits */
simdpackwithoutmaskd1(init, buffer, (__m128i *)out, b);
simdunpackd1(init, (__m128i *)out, backbuffer, b);
for (i = 0; i < 128; i++) {
assert(buffer[i] == backbuffer[i]);
}
printf("advanced simdsearchd1: %d bits\n", b);
for (i = 0; i < 128; i++) {
int pos;
initial = _mm_set1_epi32(init);
pos = simdsearchd1(&initial, (__m128i *)out, b,
buffer[i], &result);
assert(pos == simdsearchwithlengthd1(init, (__m128i *)out, b, 128,
buffer[i], &result));
assert(buffer[pos] == buffer[i]);
if(pos > 0)
assert(buffer[pos - 1] < buffer[i]);
assert(result == buffer[i]);
}
for (i = 0; i < 128; i++) {
int pos;
if(buffer[i] == 0) continue;
initial = _mm_set1_epi32(init);
pos = simdsearchd1(&initial, (__m128i *)out, b,
buffer[i] - 1, &result);
assert(pos == simdsearchwithlengthd1(init, (__m128i *)out, b, 128,
buffer[i] - 1, &result));
assert(buffer[pos] >= buffer[i] - 1);
if(pos > 0)
assert(buffer[pos - 1] < buffer[i] - 1);
assert(result == buffer[pos]);
}
for (i = 0; i < 128; i++) {
int pos;
if (buffer[i] + 1 == 0)
continue;
initial = _mm_set1_epi32(init);
pos = simdsearchd1(&initial, (__m128i *) out, b,
buffer[i] + 1, &result);
assert(pos == simdsearchwithlengthd1(init, (__m128i *)out, b, 128,
buffer[i] + 1, &result));
if(pos == 128) {
assert(buffer[i] == buffer[127]);
} else {
assert(buffer[pos] >= buffer[i] + 1);
if (pos > 0)
assert(buffer[pos - 1] < buffer[i] + 1);
assert(result == buffer[pos]);
}
}
}
printf("advanced simdsearchd1: ok\n");
return 0;
}
unsigned char *simdunpackn1(uint32_t *in, uint32_t n, uint32_t b, uint32_t start, uint32_t *out) {
uint32_t k, *out_;
for(out_ = out + n; out + 128 <= out_; out += 128, in += 4 * b) simdunpackd1(start, (__m128i *)in, out, b);
return (unsigned char *)in;
}