55 lines
1.1 KiB
C
55 lines
1.1 KiB
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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ADD TWO FLOATS - SINGLE
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*/
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#include "FP_types.h"
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_float
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adf4(s2,s1)
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_float s1,s2;
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{
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EXTEND e1,e2;
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int swap = 0;
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extend((_double *)&s1,&e1,sizeof(SINGLE));
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extend((_double *)&s2,&e2,sizeof(SINGLE));
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/* if signs differ do subtraction */
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/* result in e1 */
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if (e1.sign ^ e2.sign) {
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#ifdef DEBUG
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printf("\t\t\tADF calls SUBTRACT\n");
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#endif DEBUG
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/* set sign of e1 to sign of largest */
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swap = (e2.exp > e1.exp) ? 1 : (e2.exp < e1.exp) ? 0 :
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(e2.m1 > e1.m1 ) ? 1 : 0;
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/* adjust mantissas to equal powers */
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sft_ext(&e1,&e2);
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/* subtract the extended formats */
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if (swap) {
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#ifdef DEBUG
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printf("\t\t\t\tSWAP\n");
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#endif DEBUG
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sub_ext(&e2,&e1);
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e1 = e2;
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}
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else
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sub_ext(&e1,&e2);
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}
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else {
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#ifdef DEBUG
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printf("\t\t\tADF calls ADDITION\n");
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#endif DEBUG
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/* adjust mantissas to equal powers */
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sft_ext(&e1,&e2);
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add_ext(&e1,&e2);
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}
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compact(&e1,(_double *)&s1,sizeof(SINGLE));
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return(s1);
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}
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