const size_t initialSize=24;
const size_t sizeForMult1=initialSize+initialSize;
const size_t finalSize=sizeForMult1+initialSize;
class imSoHuge{
public:
    bool isNegative;
    uint8_t r[finalSize];
    void load(float v){
        isNegative=false;
        for(size_t p=0;p<finalSize;p++)r[p]=0;
        union{
            uint8_t b[4];
            uint32_t u;
            float f;
        } reunion;
        reunion.f=v;
        if((reunion.b[3]&0x80) != 0x00)isNegative=true;
        uint32_t m, eu;
        eu=reunion.u<<1; //get rid of the sign;
        eu>>=24;
        m=reunion.u&(0x007fffff);
        if(eu==0){//zero or denormal
            if(m==0)return; //zero
        }else{
            m|=(0x00800000); //implicit leading one if it's not denormal
        }
        int32_t e=(int32_t)eu-127; //exponent is now in [e]. Debiased (does this word exists?)
        reunion.u=m;
        r[finalSize-1]=reunion.b[3];
        r[finalSize-2]=reunion.b[2];
        r[finalSize-3]=reunion.b[1];
        r[finalSize-4]=reunion.b[0];
        rollArrayRight(r, finalSize, e-(sizeForMult1*8)); //correct position for fixed-point
    }
    explicit imSoHuge(float v){
        load(v);
    }
};

float a[]={0.0097905760, 0.0223784577, 0.9997016787};

float b[]={0.8248013854, 0.4413521587, 0.3534274995};

float c[]={0.4152690768, 0.3959976136, 0.8189856410};

float fTripleProduct(float*a, float*b, float*c){
    float crossAB[3];
    crossAB[0]=(a[1]*b[2])-(a[2]*b[1]);
    crossAB[1]=(a[2]*b[0])-(a[0]*b[2]);
    crossAB[2]=(a[0]*b[1])-(a[1]*b[0]);
    float tripleP=(crossAB[0]*c[0])+(crossAB[1]*c[1])+(crossAB[2]*c[2]);
    return tripleP;
}

imSoHuge tripleProduct(float*a, float*b, float*c){
    imSoHuge crossAB[3];
    crossAB[0]=(imSoHuge(a[1])*imSoHuge(b[2]))-(imSoHuge(a[2])*imSoHuge(b[1]));
    crossAB[1]=(imSoHuge(a[2])*imSoHuge(b[0]))-(imSoHuge(a[0])*imSoHuge(b[2]));
    crossAB[2]=(imSoHuge(a[0])*imSoHuge(b[1]))-(imSoHuge(a[1])*imSoHuge(b[0]));
    imSoHuge tripleP=(crossAB[0]*imSoHuge(c[0]))+(crossAB[1]*imSoHuge(c[1]))+(crossAB[2]*imSoHuge(c[2]));
    return tripleP;
}

0  0  0  4 46 b9  4 69 39 3f 53 b8 19 e0  ...

0  0  0  4 46 b9  4 85 93 82 df ba 7d 80  ...

Using class: second result is greater
casting to float:
first reasult: 1.336331e-001
second result: 1.336331e-001
as floats, the results are the same: 1.336331e-001