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Annotation of cci/usr/src/usr.lib/libF77/cabs.c, revision 1.1

1.1     ! root        1: /*
        !             2:  *     "@(#)cabs.c     1.1"
        !             3:  */
        !             4: /*
        !             5:  *     THIS IS STRONGLY BASED ON THE TAHOE FLOATING POINT REPRESENTATION!
        !             6:  *     The casts are meant to speed things up by avoiding double precision
        !             7:  *     instructions.
        !             8:  */
        !             9: 
        !            10: #include <FP.h>
        !            11: 
        !            12: float cabs(real, imag)
        !            13: float real, imag;
        !            14: {
        !            15: float temp;
        !            16: fortran float sqrt();
        !            17: 
        !            18: if(real < 0)
        !            19:        ((sp_format *)&real)->sign = 0;         /* real = -real; */
        !            20: if(imag < 0)
        !            21:        ((sp_format *)&imag)->sign = 0;         /* imag = -imag; */
        !            22: if(imag > real){
        !            23:        temp = *(float *)&real;
        !            24:        *(float *)&real = *(float *)&imag;
        !            25:        *(float *)&imag = temp;
        !            26: }
        !            27: if(*(float *)&imag == 0)               /* originally if((real+imag)==real) ! */
        !            28:        return(*(float *)&real);
        !            29: 
        !            30: temp = (*(float *)&imag)/(*(float *)&real);
        !            31: temp = (*(float *)&real)*sqrt(1.0 + temp*temp);  /*overflow!!*/
        !            32: return(temp);
        !            33: }

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