s_roundPackToF64.c File Reference

#include <stdbool.h>
#include <stdint.h>
#include "platform.h"
#include "internals.h"
#include "softfloat.h"

Include dependency graph for s_roundPackToF64.c:

Go to the source code of this file.

Functions
float64_t	softfloat_roundPackToF64 (bool sign, int_fast16_t exp, uint_fast64_t sig)

Function Documentation

softfloat_roundPackToF64()

float64_t softfloat_roundPackToF64	(	bool	sign,
		int_fast16_t	exp,
		uint_fast64_t	sig )

Definition at line 44 of file s_roundPackToF64.c.

{
    uint_fast8_t roundingMode;
    bool roundNearEven;
    uint_fast16_t roundIncrement, roundBits;
    bool isTiny;
    uint_fast64_t uiZ;
    union ui64_f64 uZ;
 
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    roundingMode = softfloat_roundingMode;
    roundNearEven = (roundingMode == softfloat_round_near_even);
    roundIncrement = 0x200;
    if ( ! roundNearEven && (roundingMode != softfloat_round_near_maxMag) ) {
        roundIncrement =
            (roundingMode
                 == (sign ? softfloat_round_min : softfloat_round_max))
                ? 0x3FF
                : 0;
    }
    roundBits = sig & 0x3FF;
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    if ( 0x7FD <= (uint16_t) exp ) {
        if ( exp < 0 ) {
            /*----------------------------------------------------------------
            *----------------------------------------------------------------*/
            isTiny =
                (softfloat_detectTininess == softfloat_tininess_beforeRounding)
                    || (exp < -1)
                    || (sig + roundIncrement < UINT64_C( 0x8000000000000000 ));
            sig = softfloat_shiftRightJam64( sig, -exp );
            exp = 0;
            roundBits = sig & 0x3FF;
            if ( isTiny && roundBits ) {
                softfloat_raiseFlags( softfloat_flag_underflow );
            }
        } else if (
            (0x7FD < exp)
                || (UINT64_C( 0x8000000000000000 ) <= sig + roundIncrement)
        ) {
            /*----------------------------------------------------------------
            *----------------------------------------------------------------*/
            softfloat_raiseFlags(
                softfloat_flag_overflow | softfloat_flag_inexact );
            uiZ = packToF64UI( sign, 0x7FF, 0 ) - ! roundIncrement;
            goto uiZ;
        }
    }
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    sig = (sig + roundIncrement)>>10;
    if ( roundBits ) {
        softfloat_exceptionFlags |= softfloat_flag_inexact;
#ifdef SOFTFLOAT_ROUND_ODD
        if ( roundingMode == softfloat_round_odd ) {
            sig |= 1;
            goto packReturn;
        }
#endif
    }
    sig &= ~(uint_fast64_t) (! (roundBits ^ 0x200) & roundNearEven);
    if ( ! sig ) exp = 0;
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
 packReturn:
    uiZ = packToF64UI( sign, exp, sig );
 uiZ:
    uZ.ui = uiZ;
    return uZ.f;
 
}