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bugfix: 修复浮点数打印错误的bug

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This commit is contained in:
fslongjin
2022-07-12 13:19:51 +08:00
parent 676260c537
commit 7670031b11
16 changed files with 235 additions and 35 deletions
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43
kernel/common/math/round.c Normal file
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@ -0,0 +1,43 @@
#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 toint = 1 / EPS;
double round(double x)
{
union
{
double f;
uint64_t i;
} u = {x};
int e = u.i >> 52 & 0x7ff;
double 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;
}