s_roundPackMToF128M.c File Reference

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

Include dependency graph for s_roundPackMToF128M.c:

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Functions
void	softfloat_roundPackMToF128M (bool sign, int32_t exp, uint32_t *extSigPtr, uint32_t *zWPtr)

Function Documentation

softfloat_roundPackMToF128M()

void softfloat_roundPackMToF128M	(	bool	sign,
		int32_t	exp,
		uint32_t *	extSigPtr,
		uint32_t *	zWPtr )

Definition at line 44 of file s_roundPackMToF128M.c.

{
    uint_fast8_t roundingMode;
    bool roundNearEven;
    uint32_t sigExtra;
    bool doIncrement, isTiny;
    static const uint32_t maxSig[4] =
        INIT_UINTM4( 0x0001FFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF );
    uint32_t ui, uj;
 
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    roundingMode = softfloat_roundingMode;
    roundNearEven = (roundingMode == softfloat_round_near_even);
    sigExtra = extSigPtr[indexWordLo( 5 )];
    doIncrement = (0x80000000 <= sigExtra);
    if ( ! roundNearEven && (roundingMode != softfloat_round_near_maxMag) ) {
        doIncrement =
            (roundingMode
                 == (sign ? softfloat_round_min : softfloat_round_max))
                && sigExtra;
    }
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    if ( 0x7FFD <= (uint32_t) exp ) {
        if ( exp < 0 ) {
            /*----------------------------------------------------------------
            *----------------------------------------------------------------*/
            isTiny =
                   (softfloat_detectTininess
                        == softfloat_tininess_beforeRounding)
                || (exp < -1)
                || ! doIncrement
                || (softfloat_compare128M(
                        extSigPtr + indexMultiwordHi( 5, 4 ), maxSig )
                        < 0);
            softfloat_shiftRightJam160M( extSigPtr, -exp, extSigPtr );
            exp = 0;
            sigExtra = extSigPtr[indexWordLo( 5 )];
            if ( isTiny && sigExtra ) {
                softfloat_raiseFlags( softfloat_flag_underflow );
            }
            doIncrement = (0x80000000 <= sigExtra);
            if (
                   ! roundNearEven
                && (roundingMode != softfloat_round_near_maxMag)
            ) {
                doIncrement =
                    (roundingMode
                         == (sign ? softfloat_round_min : softfloat_round_max))
                        && sigExtra;
            }
        } else if (
               (0x7FFD < exp)
            || ((exp == 0x7FFD) && doIncrement
                    && (softfloat_compare128M(
                            extSigPtr + indexMultiwordHi( 5, 4 ), maxSig )
                            == 0))
        ) {
            /*----------------------------------------------------------------
            *----------------------------------------------------------------*/
            softfloat_raiseFlags(
                softfloat_flag_overflow | softfloat_flag_inexact );
            if (
                   roundNearEven
                || (roundingMode == softfloat_round_near_maxMag)
                || (roundingMode
                        == (sign ? softfloat_round_min : softfloat_round_max))
            ) {
                ui = packToF128UI96( sign, 0x7FFF, 0 );
                uj = 0;
            } else {
                ui = packToF128UI96( sign, 0x7FFE, 0x0000FFFF );
                uj = 0xFFFFFFFF;
            }
            zWPtr[indexWordHi( 4 )] = ui;
            zWPtr[indexWord( 4, 2 )] = uj;
            zWPtr[indexWord( 4, 1 )] = uj;
            zWPtr[indexWord( 4, 0 )] = uj;
            return;
        }
    }
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    uj = extSigPtr[indexWord( 5, 1 )];
    if ( sigExtra ) {
        softfloat_exceptionFlags |= softfloat_flag_inexact;
#ifdef SOFTFLOAT_ROUND_ODD
        if ( roundingMode == softfloat_round_odd ) {
            uj |= 1;
            goto noIncrementPackReturn;
        }
#endif
    }
    if ( doIncrement ) {
        ++uj;
        if ( uj ) {
            if ( ! (sigExtra & 0x7FFFFFFF) && roundNearEven ) uj &= ~1;
            zWPtr[indexWord( 4, 2 )] = extSigPtr[indexWord( 5, 3 )];
            zWPtr[indexWord( 4, 1 )] = extSigPtr[indexWord( 5, 2 )];
            zWPtr[indexWord( 4, 0 )] = uj;
            ui = extSigPtr[indexWordHi( 5 )];
        } else {
            zWPtr[indexWord( 4, 0 )] = uj;
            ui = extSigPtr[indexWord( 5, 2 )] + 1;
            zWPtr[indexWord( 4, 1 )] = ui;
            uj = extSigPtr[indexWord( 5, 3 )];
            if ( ui ) {
                zWPtr[indexWord( 4, 2 )] = uj;
                ui = extSigPtr[indexWordHi( 5 )];
            } else {
                ++uj;
                zWPtr[indexWord( 4, 2 )] = uj;
                ui = extSigPtr[indexWordHi( 5 )];
                if ( ! uj ) ++ui;
            }
        }
    } else {
 noIncrementPackReturn:
        zWPtr[indexWord( 4, 0 )] = uj;
        ui = extSigPtr[indexWord( 5, 2 )];
        zWPtr[indexWord( 4, 1 )] = ui;
        uj |= ui;
        ui = extSigPtr[indexWord( 5, 3 )];
        zWPtr[indexWord( 4, 2 )] = ui;
        uj |= ui;
        ui = extSigPtr[indexWordHi( 5 )];
        uj |= ui;
        if ( ! uj ) exp = 0;
    }
    zWPtr[indexWordHi( 4 )] = packToF128UI96( sign, exp, ui );
 
}