49 lines
1,009 B
Text
49 lines
1,009 B
Text
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/*
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(c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
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See the copyright notice in the ACK home directory, in the file "Copyright".
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*/
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/* $Header$ */
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/*
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MULTIPLY AND DISMEMBER PARTS (FIF 8)
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*/
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#include "FP_types.h"
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#include "FP_shift.h"
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void
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fif8(p,x,y)
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DOUBLE x,y;
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struct fif8_returns *p;
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{
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EXTEND e1,e2;
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extend(&y.d[0],&e1,sizeof(DOUBLE));
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extend(&x.d[0],&e2,sizeof(DOUBLE));
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/* do a multiply */
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mul_ext(&e1,&e2);
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e2 = e1;
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compact(&e2, &y.d[0], sizeof(DOUBLE));
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if (e1.exp < 0) {
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p->ipart.d[0] = 0;
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p->ipart.d[1] = 0;
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p->fpart = y;
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return;
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}
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if (e1.exp > 62 - DBL_M1LEFT) {
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p->ipart = y;
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p->fpart.d[0] = 0;
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p->fpart.d[1] = 0;
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return;
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}
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b64_sft(&e1.mantissa, 63 - e1.exp);
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b64_sft(&e1.mantissa, e1.exp - 63); /* "loose" low order bits */
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compact(&e1, &(p->ipart.d[0]), sizeof(DOUBLE));
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extend(&(p->ipart.d[0]), &e2, sizeof(DOUBLE));
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extend(&y.d[0], &e1, sizeof(DOUBLE));
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sub_ext(&e1, &e2);
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compact(&e1, &(p->fpart.d[0]), sizeof(DOUBLE));
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}
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