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Annotation of cci/usr/src/usr.lib/libF77/z_div.c, revision 1.1.1.1

1.1       root        1: /*
                      2:  *     @(#)z_div.c     2.1     6/7/85
                      3:  */
                      4: 
                      5: #include "complex"
                      6: #include <stdio.h>
                      7: #include <errno.h>
                      8: 
                      9: /* THIS IS BASED ON TAHOE FP REPRESENTATION! */
                     10: #include <FP.h>
                     11: 
                     12: z_div(c, a, b)
                     13: dcomplex *a, *b, *c;
                     14: {
                     15: double ratio, den;
                     16: double abr, abi;
                     17: 
                     18: if( (abr = b->dreal) < 0.)
                     19:        *((long int *)&abr) ^= SIGN_BIT;
                     20: if( (abi = b->dimag) < 0.)
                     21:        *((long int *)&abi) ^= SIGN_BIT;
                     22: if( abr <= abi )
                     23:        {
                     24:        if(abi == 0) {
                     25:                fprintf( stderr, "Double complex division by zero\n" );
                     26:                /* f77_abort(EDOM); */
                     27:        }
                     28:        ratio = b->dreal / b->dimag ;
                     29:        den = b->dimag * (1 + ratio*ratio);
                     30:        c->dreal = (a->dreal*ratio + a->dimag) / den;
                     31:        c->dimag = (a->dimag*ratio - a->dreal) / den;
                     32:        }
                     33: 
                     34: else
                     35:        {
                     36:        ratio = b->dimag / b->dreal ;
                     37:        den = b->dreal * (1 + ratio*ratio);
                     38:        c->dreal = (a->dreal + a->dimag*ratio) / den;
                     39:        c->dimag = (a->dimag - a->dreal*ratio) / den;
                     40:        }
                     41: 
                     42: }

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