#include "timing.h" #include <stdio.h> #ifndef LIBNAME #define LIBNAME UNKNOWN #endif #define LIBSTRING LIBSTRINGX(LIBNAME) #define LIBSTRINGX(a) LIBSTRINGXX(a) #define LIBSTRINGXX(a) #a double __floatundidf(uint64_t x); int main(int argc, char *argv[]) { #define INPUT_SIZE 512 uint64_t input[INPUT_SIZE]; int i, j; srand(42); // Initialize the input array with data of various sizes. for (i=0; i<INPUT_SIZE; ++i) input[i] = (((uint64_t)rand() << 32) | (uint64_t)rand()) >> (rand() & 63); double bestTime = __builtin_inf(); void *dummyp; for (j=0; j<1024; ++j) { uint64_t startTime = mach_absolute_time(); for (i=0; i<INPUT_SIZE; ++i) __floatundidf(input[i]); uint64_t endTime = mach_absolute_time(); double thisTime = intervalInCycles(startTime, endTime); bestTime = __builtin_fmin(thisTime, bestTime); // Move the stack alignment between trials to eliminate (mostly) aliasing effects dummyp = alloca(1); } printf("%16s: %f cycles.\n", LIBSTRING, bestTime / (double) INPUT_SIZE); return 0; } |