62 lines
966 B
C
62 lines
966 B
C
/*
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libc/ieee_float/modf.c
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Created: Oct 14, 1993 by Philip Homburg <philip@cs.vu.nl>
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Implementation of modf that directly manipulates the exponent bits in an
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ieee float
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*/
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#include <sys/types.h>
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#include <math.h>
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#include "ieee_float.h"
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double modf(value, iptr)
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double value;
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double *iptr;
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{
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struct f64 *f64p;
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double tmp;
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int exp;
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int mask_bits;
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u32_t mant;
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f64p= (struct f64 *)&value;
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exp= F64_GET_EXP(f64p);
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exp -= F64_EXP_BIAS;
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if (exp < 0)
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{
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*iptr= 0;
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return value;
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}
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mask_bits= 52-exp;
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if (mask_bits <= 0)
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{
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*iptr= value;
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return 0;
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}
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tmp= value;
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if (mask_bits >= 32)
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{
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F64_SET_MANT_LOW(f64p, 0);
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mask_bits -= 32;
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mant= F64_GET_MANT_HIGH(f64p);
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mant &= ~((1 << mask_bits)-1);
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F64_SET_MANT_HIGH(f64p, mant);
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}
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else
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{
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mant= F64_GET_MANT_LOW(f64p);
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mant &= ~((1 << mask_bits)-1);
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F64_SET_MANT_LOW(f64p, mant);
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}
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*iptr= value;
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return tmp-value;
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}
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/*
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* $PchId: modf.c,v 1.3 1996/02/22 21:01:39 philip Exp $
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*/
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