f16_div.c File Reference

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

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Functions
float16_t	f16_div (float16_t a, float16_t b)

Variables
const uint16_t	softfloat_approxRecip_1k0s []
const uint16_t	softfloat_approxRecip_1k1s []

Function Documentation

f16_div()

float16_t f16_div	(	float16_t	a,
		float16_t	b )

Definition at line 47 of file f16_div.c.

{
    union ui16_f16 uA;
    uint_fast16_t uiA;
    bool signA;
    int_fast8_t expA;
    uint_fast16_t sigA;
    union ui16_f16 uB;
    uint_fast16_t uiB;
    bool signB;
    int_fast8_t expB;
    uint_fast16_t sigB;
    bool signZ;
    struct exp8_sig16 normExpSig;
    int_fast8_t expZ;
#ifdef SOFTFLOAT_FAST_DIV32TO16
    uint_fast32_t sig32A;
    uint_fast16_t sigZ;
#else
    int index;
    uint16_t r0;
    uint_fast16_t sigZ, rem;
#endif
    uint_fast16_t uiZ;
    union ui16_f16 uZ;
 
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    uA.f = a;
    uiA = uA.ui;
    signA = signF16UI( uiA );
    expA  = expF16UI( uiA );
    sigA  = fracF16UI( uiA );
    uB.f = b;
    uiB = uB.ui;
    signB = signF16UI( uiB );
    expB  = expF16UI( uiB );
    sigB  = fracF16UI( uiB );
    signZ = signA ^ signB;
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    if ( expA == 0x1F ) {
        if ( sigA ) goto propagateNaN;
        if ( expB == 0x1F ) {
            if ( sigB ) goto propagateNaN;
            goto invalid;
        }
        goto infinity;
    }
    if ( expB == 0x1F ) {
        if ( sigB ) goto propagateNaN;
        goto zero;
    }
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    if ( ! expB ) {
        if ( ! sigB ) {
            if ( ! (expA | sigA) ) goto invalid;
            softfloat_raiseFlags( softfloat_flag_infinite );
            goto infinity;
        }
        normExpSig = softfloat_normSubnormalF16Sig( sigB );
        expB = normExpSig.exp;
        sigB = normExpSig.sig;
    }
    if ( ! expA ) {
        if ( ! sigA ) goto zero;
        normExpSig = softfloat_normSubnormalF16Sig( sigA );
        expA = normExpSig.exp;
        sigA = normExpSig.sig;
    }
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    expZ = expA - expB + 0xE;
    sigA |= 0x0400;
    sigB |= 0x0400;
#ifdef SOFTFLOAT_FAST_DIV32TO16
    if ( sigA < sigB ) {
        --expZ;
        sig32A = (uint_fast32_t) sigA<<15;
    } else {
        sig32A = (uint_fast32_t) sigA<<14;
    }
    sigZ = sig32A / sigB;
    if ( ! (sigZ & 7) ) sigZ |= ((uint_fast32_t) sigB * sigZ != sig32A);
#else
    if ( sigA < sigB ) {
        --expZ;
        sigA <<= 5;
    } else {
        sigA <<= 4;
    }
    index = sigB>>6 & 0xF;
    r0 = softfloat_approxRecip_1k0s[index]
             - (((uint_fast32_t) softfloat_approxRecip_1k1s[index]
                     * (sigB & 0x3F))
                    >>10);
    sigZ = ((uint_fast32_t) sigA * r0)>>16;
    rem = (sigA<<10) - sigZ * sigB;
    sigZ += (rem * (uint_fast32_t) r0)>>26;
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
    ++sigZ;
    if ( ! (sigZ & 7) ) {
        sigZ &= ~1;
        rem = (sigA<<10) - sigZ * sigB;
        if ( rem & 0x8000 ) {
            sigZ -= 2;
        } else {
            if ( rem ) sigZ |= 1;
        }
    }
#endif
    return softfloat_roundPackToF16( signZ, expZ, sigZ );
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
 propagateNaN:
    uiZ = softfloat_propagateNaNF16UI( uiA, uiB );
    goto uiZ;
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
 invalid:
    softfloat_raiseFlags( softfloat_flag_invalid );
    uiZ = defaultNaNF16UI;
    goto uiZ;
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
 infinity:
    uiZ = packToF16UI( signZ, 0x1F, 0 );
    goto uiZ;
    /*------------------------------------------------------------------------
    *------------------------------------------------------------------------*/
 zero:
    uiZ = packToF16UI( signZ, 0, 0 );
 uiZ:
    uZ.ui = uiZ;
    return uZ.f;
 
}

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Variable Documentation

softfloat_approxRecip_1k0s

const uint16_t softfloat_approxRecip_1k0s[]

extern

Definition at line 41 of file s_approxRecip_1Ks.c.

                                                {
    0xFFC4, 0xF0BE, 0xE363, 0xD76F, 0xCCAD, 0xC2F0, 0xBA16, 0xB201,
    0xAA97, 0xA3C6, 0x9D7A, 0x97A6, 0x923C, 0x8D32, 0x887E, 0x8417
};

softfloat_approxRecip_1k1s

const uint16_t softfloat_approxRecip_1k1s[]

extern

Definition at line 45 of file s_approxRecip_1Ks.c.

                                                {
    0xF0F1, 0xD62C, 0xBFA1, 0xAC77, 0x9C0A, 0x8DDB, 0x8185, 0x76BA,
    0x6D3B, 0x64D4, 0x5D5C, 0x56B1, 0x50B6, 0x4B55, 0x4679, 0x4211
};