trunc.c File Reference

Truncate function. More...

#include "prim.h"

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Functions
double	trunc (double x)
	Truncate function. More...

Detailed Description

Truncate function.

Definition in file trunc.c.

Function Documentation

trunc()

double trunc

(

double

x

)

Truncate function.

when x > 0
trunc(0)   = floor(x)

when x < 0
trunc(x)   = ceil(x)

Special case
trunc(0)   = 0
trunc(NaN) = NaN

Definition at line 52 of file trunc.c.

References ceil(), and floor().

Referenced by ctrunc(), DecimalSystem::GetText(), PositionalNumeralSystem::GetText(), PositionalNumeralSystem::IntegerToBuffer(), and RealNumber::Trunc().

{
    uint32_t hx, lx;
    GET_HIGH_WORD(hx, x);
    if ((hx & 0x7FF00000) == 0x7FF00000)
    {
        return NAN;
    }

    GET_LOW_WORD(lx, x);
    if (hx == 0 && lx == 0)
    {
        return 0.0;
    }

    if ((hx & 0x80000000) != 0x80000000)
    {
        return floor(x);
    }

    return ceil(x);
}

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