| #include "libm.h" |
| |
| #if FLT_EVAL_METHOD == 0 |
| #define EPS FLT_EPSILON |
| #elif FLT_EVAL_METHOD == 1 |
| #define EPS DBL_EPSILON |
| #elif FLT_EVAL_METHOD == 2 |
| #define EPS LDBL_EPSILON |
| #endif |
| static const float_t toint = 1 / EPS; |
| |
| float roundf(float x) { |
| union { |
| float f; |
| uint32_t i; |
| } u = {x}; |
| int e = u.i >> 23 & 0xff; |
| float_t y; |
| |
| if (e >= 0x7f + 23) |
| return x; |
| if (u.i >> 31) |
| x = -x; |
| if (e < 0x7f - 1) { |
| FORCE_EVAL(x + toint); |
| return 0 * u.f; |
| } |
| y = x + toint - toint - x; |
| if (y > 0.5f) |
| y = y + x - 1; |
| else if (y <= -0.5f) |
| y = y + x + 1; |
| else |
| y = y + x; |
| if (u.i >> 31) |
| y = -y; |
| return y; |
| } |