mirror of https://github.com/macssh/macssh.git
117 lines
3.1 KiB
C
Executable File
117 lines
3.1 KiB
C
Executable File
/* mpfr_cmp_ui -- compare a floating-point number with a machine integer
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Copyright (C) 1999 PolKA project, Inria Lorraine and Loria
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This file is part of the MPFR Library.
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The MPFR Library is free software; you can redistribute it and/or modify
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it under the terms of the GNU Library General Public License as published by
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the Free Software Foundation; either version 2 of the License, or (at your
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option) any later version.
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The MPFR Library is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
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License for more details.
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You should have received a copy of the GNU Library General Public License
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along with the MPFR Library; see the file COPYING.LIB. If not, write to
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the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
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MA 02111-1307, USA. */
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#include <stdio.h>
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#include "gmp.h"
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#include "gmp-impl.h"
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#include "longlong.h"
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#include "mpfr.h"
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/* returns a positive value if b>i*2^f,
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a negative value if b<i*2^f,
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zero if b=i*2^f
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*/
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int
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#if __STDC__
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mpfr_cmp_ui_2exp ( mpfr_srcptr b, unsigned long int i, int f )
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#else
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mpfr_cmp_ui_2exp (b, i, f)
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mpfr_srcptr b;
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unsigned long int i;
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int f;
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#endif
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{
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int e, k, bn; mp_limb_t c, *bp;
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if (SIGN(b)<0) return -1;
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else if (!NOTZERO(b)) return((i) ? -1 : 0);
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else { /* b>0 */
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e = EXP(b); /* 2^(e-1) <= b < 2^e */
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if (e>f+mp_bits_per_limb) return 1;
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c = (mp_limb_t) i;
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count_leading_zeros(k, c);
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k = f+mp_bits_per_limb - k; /* 2^(k-1) <= i*2^f < 2^k */
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if (k!=e) return (e-k);
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/* now k=e */
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c <<= (f+mp_bits_per_limb-k);
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bn = (PREC(b)-1)/mp_bits_per_limb;
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bp = MANT(b) + bn;
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if (*bp>c) return 1;
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else if (*bp<c) return -1;
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/* most significant limbs agree, check remaining limbs from b */
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while (--bn>=0)
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if (*--bp) return 1;
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return 0;
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}
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}
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/* returns a positive value if b>i*2^f,
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a negative value if b<i*2^f,
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zero if b=i*2^f
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*/
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int
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#if __STDC__
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mpfr_cmp_si_2exp ( mpfr_srcptr b, long int i, int f )
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#else
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mpfr_cmp_si_2exp(b, i, f)
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mpfr_srcptr b;
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long int i;
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int f;
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#endif
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{
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int e, k, bn, si; mp_limb_t c, *bp;
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si = (i<0) ? -1 : 1; /* sign of i */
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if (SIGN(b)*i<0) return SIGN(b); /* both signs differ */
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else if (!NOTZERO(b) || (i==0)) { /* one is zero */
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if (i==0) return ((NOTZERO(b)) ? SIGN(b) : 0);
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else return si; /* b is zero */
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}
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else { /* b and i are of same sign */
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e = EXP(b); /* 2^(e-1) <= b < 2^e */
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if (e>f+mp_bits_per_limb) return si;
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c = (mp_limb_t) ((i<0) ? -i : i);
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count_leading_zeros(k, c);
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k = f+mp_bits_per_limb - k; /* 2^(k-1) <= i*2^f < 2^k */
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if (k!=e) return (si*(e-k));
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/* now k=e */
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c <<= (f+mp_bits_per_limb-k);
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bn = (PREC(b)-1)/mp_bits_per_limb;
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bp = MANT(b) + bn;
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if (*bp>c) return si;
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else if (*bp<c) return -si;
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/* most significant limbs agree, check remaining limbs from b */
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while (--bn>=0)
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if (*--bp) return si;
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return 0;
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}
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}
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