64 lines
1.2 KiB
C
64 lines
1.2 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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CONVERT INTEGER TO FLOAT
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THIS ROUTINE WORKS BY FILLING AN EXTENDED
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WITH THE INTEGER VALUE IN EXTENDED FORMAT
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AND USES COMPACT() TO PUT IT INTO THE PROPER
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FLOATING POINT PRECISION.
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*/
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#include "FP_types.h"
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_float
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cuf4(ss,src)
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int ss; /* source size */
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long src; /* largest possible integer to convert */
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{
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EXTEND buf;
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short *ipt;
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_float *result;
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long i_src;
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zrf_ext(&buf);
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if (ss == sizeof(long)) {
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buf.exp = 33;
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i_src = src;
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result = (_float *) &src;
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}
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else {
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ipt = (short *) &src;
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i_src = (long) *ipt;
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buf.exp = 17;
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result = (_float *) &ss;
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}
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#ifdef PRT_STDERR
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fprintf(stderr,"CUF4(ds(%d),ss(%d),src(%D))\n\n",4,ss,i_src);
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#endif
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if (i_src == 0) {
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*result = (_float) 0L;
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return (_float) 0L;
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}
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/* ESTABLISHED THAT src != 0 */
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/* adjust exponent field */
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if (ss != sizeof(long))
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i_src <<= 16;
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/* move to mantissa field */
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buf.m1 = i_src;
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/* adjust mantissa field */
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nrm_ext(&buf);
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#ifdef PRT_STDERR
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fprintf(stderr,"CUF() buf.exp after nrm_ext() == %d\n\n",buf.exp);
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#endif
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compact(&buf,(_double *) result,4);
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return *result;
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}
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