Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
Showing
2 changed files
with
35 additions
and
0 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,34 @@ | ||
#include "libm.h" | ||
|
||
#if FLT_EVAL_METHOD==0 || FLT_EVAL_METHOD==1 | ||
#define EPS DBL_EPSILON | ||
#elif FLT_EVAL_METHOD==2 | ||
#define EPS LDBL_EPSILON | ||
#endif | ||
static const double_t toint = 1/EPS; | ||
|
||
double round(double x) { | ||
union {double f; uint64_t i;} u = {x}; | ||
int e = u.i >> 52 & 0x7ff; | ||
double_t y; | ||
|
||
if (e >= 0x3ff+52) | ||
return x; | ||
if (u.i >> 63) | ||
x = -x; | ||
if (e < 0x3ff-1) { | ||
/* raise inexact if x!=0 */ | ||
FORCE_EVAL(x + toint); | ||
return 0*u.f; | ||
} | ||
y = x + toint - toint - x; | ||
if (y > 0.5) | ||
y = y + x - 1; | ||
else if (y <= -0.5) | ||
y = y + x + 1; | ||
else | ||
y = y + x; | ||
if (u.i >> 63) | ||
y = -y; | ||
return y; | ||
} |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters