1#include "libm.h" 2 3float modff(float x, float* iptr) { 4 union { 5 float f; 6 uint32_t i; 7 } u = {x}; 8 uint32_t mask; 9 int e = (int)(u.i >> 23 & 0xff) - 0x7f; 10 11 /* no fractional part */ 12 if (e >= 23) { 13 *iptr = x; 14 if (e == 0x80 && u.i << 9 != 0) { /* nan */ 15 return x; 16 } 17 u.i &= 0x80000000; 18 return u.f; 19 } 20 /* no integral part */ 21 if (e < 0) { 22 u.i &= 0x80000000; 23 *iptr = u.f; 24 return x; 25 } 26 27 mask = 0x007fffff >> e; 28 if ((u.i & mask) == 0) { 29 *iptr = x; 30 u.i &= 0x80000000; 31 return u.f; 32 } 33 u.i &= ~mask; 34 *iptr = u.f; 35 return x - u.f; 36} 37