version 1.1.1.1, 2000/09/09 14:12:19 |
version 1.1.1.2, 2003/08/25 16:06:06 |
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/* mpfr_cmp_ui -- compare a floating-point number with a machine integer |
/* 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 |
Copyright 1999, 2001, 2002 Free Software Foundation, Inc. |
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This file is part of the MPFR Library. |
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 |
The MPFR Library is free software; you can redistribute it and/or modify |
it under the terms of the GNU Library General Public License as published by |
it under the terms of the GNU Lesser General Public License as published by |
the Free Software Foundation; either version 2 of the License, or (at your |
the Free Software Foundation; either version 2.1 of the License, or (at your |
option) any later version. |
option) any later version. |
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The MPFR Library is distributed in the hope that it will be useful, but |
The MPFR Library is distributed in the hope that it will be useful, but |
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public |
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public |
License for more details. |
License for more details. |
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You should have received a copy of the GNU Library General Public License |
You should have received a copy of the GNU Lesser General Public License |
along with the MPFR Library; see the file COPYING.LIB. If not, write to |
along with the MPFR Library; see the file COPYING.LIB. If not, write to |
the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
MA 02111-1307, USA. */ |
MA 02111-1307, USA. */ |
Line 24 MA 02111-1307, USA. */ |
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Line 24 MA 02111-1307, USA. */ |
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#include "gmp-impl.h" |
#include "gmp-impl.h" |
#include "longlong.h" |
#include "longlong.h" |
#include "mpfr.h" |
#include "mpfr.h" |
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#include "mpfr-impl.h" |
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/* returns a positive value if b>i*2^f, |
/* returns a positive value if b>i*2^f, |
a negative value if b<i*2^f, |
a negative value if b<i*2^f, |
Line 31 MA 02111-1307, USA. */ |
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Line 32 MA 02111-1307, USA. */ |
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*/ |
*/ |
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int |
int |
#if __STDC__ |
mpfr_cmp_ui_2exp (mpfr_srcptr b, unsigned long int i, int f) |
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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{ |
{ |
int e, k, bn; mp_limb_t c, *bp; |
int e, k, bn; |
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mp_limb_t c, *bp; |
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if (SIGN(b)<0) return -1; |
MPFR_ASSERTN(!MPFR_IS_NAN(b)); |
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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if (MPFR_IS_INF(b)) |
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return MPFR_SIGN(b); |
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/* now b is neither NaN nor +/-Infinity */ |
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if (MPFR_IS_ZERO(b)) |
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return i ? -1 : 0; |
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else if (MPFR_SIGN(b) < 0) |
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return -1; |
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/* now b>0 */ |
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else if (i == 0) |
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return 1; |
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else |
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{ /* b>0, i>0 */ |
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e = MPFR_EXP(b); /* 2^(e-1) <= b < 2^e */ |
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if (e > f + BITS_PER_MP_LIMB) |
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return 1; |
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c = (mp_limb_t) i; |
c = (mp_limb_t) i; |
count_leading_zeros(k, c); |
count_leading_zeros(k, c); |
k = f+mp_bits_per_limb - k; /* 2^(k-1) <= i*2^f < 2^k */ |
k = f + BITS_PER_MP_LIMB - k; /* 2^(k-1) <= i*2^f < 2^k */ |
if (k!=e) return (e-k); |
if (k != e) |
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return e - k; |
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/* now k=e */ |
/* now k=e */ |
c <<= (f+mp_bits_per_limb-k); |
c <<= f + BITS_PER_MP_LIMB - k; |
bn = (PREC(b)-1)/mp_bits_per_limb; |
bn = (MPFR_PREC(b) - 1) / BITS_PER_MP_LIMB; |
bp = MANT(b) + bn; |
bp = MPFR_MANT(b) + bn; |
if (*bp>c) return 1; |
if (*bp > c) |
else if (*bp<c) return -1; |
return 1; |
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if (*bp < c) |
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return -1; |
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/* most significant limbs agree, check remaining limbs from b */ |
/* most significant limbs agree, check remaining limbs from b */ |
while (--bn>=0) |
while (--bn >= 0) |
if (*--bp) return 1; |
if (*--bp) |
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return 1; |
return 0; |
return 0; |
} |
} |
} |
} |
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/* returns a positive value if b>i*2^f, |
/* returns a positive value if b>i*2^f, |
Line 73 mpfr_cmp_ui_2exp (b, i, f) |
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Line 85 mpfr_cmp_ui_2exp (b, i, f) |
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*/ |
*/ |
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int |
int |
#if __STDC__ |
mpfr_cmp_si_2exp (mpfr_srcptr b, long int i, int f) |
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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{ |
{ |
int e, k, bn, si; mp_limb_t c, *bp; |
int e, k, bn, si; |
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mp_limb_t c, *bp; |
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si = (i<0) ? -1 : 1; /* sign of i */ |
MPFR_ASSERTN(!MPFR_IS_NAN(b)); |
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); |
si = i < 0 ? -1 : 1; /* sign of i */ |
count_leading_zeros(k, c); |
if (MPFR_IS_INF(b) || (MPFR_NOTZERO(b) && MPFR_SIGN(b) != si)) |
k = f+mp_bits_per_limb - k; /* 2^(k-1) <= i*2^f < 2^k */ |
return MPFR_SIGN(b); |
if (k!=e) return (si*(e-k)); |
/* both signs differ */ |
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else if (MPFR_IS_ZERO(b) || i == 0) |
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return i == 0 ? (MPFR_IS_ZERO(b) ? 0 : MPFR_SIGN(b)) : -si; |
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else |
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{ /* b and i are of same sign */ |
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e = MPFR_EXP(b); /* 2^(e-1) <= b < 2^e */ |
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if (e > f + BITS_PER_MP_LIMB) |
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return si; |
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/* now k=e */ |
c = i < 0 ? - (mp_limb_t) i : (mp_limb_t) i; |
c <<= (f+mp_bits_per_limb-k); |
count_leading_zeros(k, c); |
bn = (PREC(b)-1)/mp_bits_per_limb; |
k = f + BITS_PER_MP_LIMB - k; /* 2^(k-1) <= i*2^f < 2^k */ |
bp = MANT(b) + bn; |
if (k != e) |
if (*bp>c) return si; |
return si * (e - k); |
else if (*bp<c) return -si; |
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/* most significant limbs agree, check remaining limbs from b */ |
/* now k = e */ |
while (--bn>=0) |
c <<= f + BITS_PER_MP_LIMB - k; |
if (*--bp) return si; |
bn = (MPFR_PREC(b) - 1) / BITS_PER_MP_LIMB; |
return 0; |
bp = MPFR_MANT(b) + bn; |
} |
if (*bp > c) |
} |
return si; |
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if (*bp < c) |
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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) |
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return si; |
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return 0; |
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} |
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} |