69 lines
1.1 KiB
C
69 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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#define PRT_EXT
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SHIFT TWO EXTENDED NUMBERS INTO PROPER
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ALIGNMENT FOR ADDITION (exponents are equal)
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*/
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#include "FP_types.h"
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sft_ext(e1,e2)
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EXTEND *e1,*e2;
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{
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register EXTEND *s;
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register short diff;
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long tmp;
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#ifdef PRT_EXT
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prt_ext("enter sft_ext e1:",e1);
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prt_ext("enter sft_ext e2:",e2);
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#endif PRT_EXT
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diff = e1->exp - e2->exp;
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if (!diff)
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return; /* exponents are equal */
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if (diff < 0) { /* e2 is larger */
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/* shift e1 */
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diff = -diff;
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s = e1;
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}
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else /* e1 is larger */
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/* shift e2 */
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s = e2;
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s->exp += diff;
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if (diff > 63) { /* no relative value */
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s->m1 = 0L;
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s->m2 = 0L;
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return;
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}
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if (diff > 32) {
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diff -= 32;
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s->m2 = s->m1;
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s->m1 = 0L;
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}
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if (diff) {
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if (s->m1) {
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tmp = s->m1;
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tmp <<= (32-diff);
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s->m1 >>= diff;
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}
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else
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tmp = 0L;
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s->m2 >>= diff;
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s->m2 |= tmp;
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}
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#ifdef PRT_EXT
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prt_ext("exit sft_ext e1:",e1);
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prt_ext("exit sft_ext e2:",e2);
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#endif PRT_EXT
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}
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