47 lines
910 B
C
47 lines
910 B
C
/*
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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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_double sbf8();
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fif8(x,y)
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_double x,y;
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{
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EXTEND e1,e2;
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extend(&y,&e1,sizeof(_double));
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extend(&x,&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, sizeof(_double));
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e1.exp--; /* additional bias correction */
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if (e1.exp < 1) {
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x.__double[0] = 0;
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x.__double[1] = 0;
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return;
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}
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if (e1.exp > 63 - DBL_M1LEFT) {
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x.__double[0] = y.__double[0];
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x.__double[1] = y.__double[1];
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y.__double[0] = 0;
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y.__double[1] = 0;
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return;
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}
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b64_sft(&e1.m1, 64 - e1.exp);
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b64_sft(&e1.m1, e1.exp - 64); /* "loose" low order bits */
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e1.exp++;
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compact(&e1, &x, sizeof(DOUBLE));
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y = sbf8(x, y);
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}
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