Annotation of OpenXM_contrib/gmp/mpfr/cmp_ui.c, Revision 1.1
1.1 ! maekawa 1: /* mpfr_cmp_ui -- compare a floating-point number with a machine integer
! 2:
! 3: Copyright (C) 1999 PolKA project, Inria Lorraine and Loria
! 4:
! 5: This file is part of the MPFR Library.
! 6:
! 7: The MPFR Library is free software; you can redistribute it and/or modify
! 8: it under the terms of the GNU Library General Public License as published by
! 9: the Free Software Foundation; either version 2 of the License, or (at your
! 10: option) any later version.
! 11:
! 12: The MPFR Library is distributed in the hope that it will be useful, but
! 13: WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
! 14: or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
! 15: License for more details.
! 16:
! 17: You should have received a copy of the GNU Library General Public License
! 18: along with the MPFR Library; see the file COPYING.LIB. If not, write to
! 19: the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
! 20: MA 02111-1307, USA. */
! 21:
! 22: #include <stdio.h>
! 23: #include "gmp.h"
! 24: #include "gmp-impl.h"
! 25: #include "longlong.h"
! 26: #include "mpfr.h"
! 27:
! 28: /* returns a positive value if b>i*2^f,
! 29: a negative value if b<i*2^f,
! 30: zero if b=i*2^f
! 31: */
! 32:
! 33: int
! 34: #if __STDC__
! 35: mpfr_cmp_ui_2exp ( mpfr_srcptr b, unsigned long int i, int f )
! 36: #else
! 37: mpfr_cmp_ui_2exp (b, i, f)
! 38: mpfr_srcptr b;
! 39: unsigned long int i;
! 40: int f;
! 41: #endif
! 42: {
! 43: int e, k, bn; mp_limb_t c, *bp;
! 44:
! 45: if (SIGN(b)<0) return -1;
! 46: else if (!NOTZERO(b)) return((i) ? -1 : 0);
! 47: else { /* b>0 */
! 48: e = EXP(b); /* 2^(e-1) <= b < 2^e */
! 49: if (e>f+mp_bits_per_limb) return 1;
! 50:
! 51: c = (mp_limb_t) i;
! 52: count_leading_zeros(k, c);
! 53: k = f+mp_bits_per_limb - k; /* 2^(k-1) <= i*2^f < 2^k */
! 54: if (k!=e) return (e-k);
! 55:
! 56: /* now k=e */
! 57: c <<= (f+mp_bits_per_limb-k);
! 58: bn = (PREC(b)-1)/mp_bits_per_limb;
! 59: bp = MANT(b) + bn;
! 60: if (*bp>c) return 1;
! 61: else if (*bp<c) return -1;
! 62:
! 63: /* most significant limbs agree, check remaining limbs from b */
! 64: while (--bn>=0)
! 65: if (*--bp) return 1;
! 66: return 0;
! 67: }
! 68: }
! 69:
! 70: /* returns a positive value if b>i*2^f,
! 71: a negative value if b<i*2^f,
! 72: zero if b=i*2^f
! 73: */
! 74:
! 75: int
! 76: #if __STDC__
! 77: mpfr_cmp_si_2exp ( mpfr_srcptr b, long int i, int f )
! 78: #else
! 79: mpfr_cmp_si_2exp(b, i, f)
! 80: mpfr_srcptr b;
! 81: long int i;
! 82: int f;
! 83: #endif
! 84: {
! 85: int e, k, bn, si; mp_limb_t c, *bp;
! 86:
! 87: si = (i<0) ? -1 : 1; /* sign of i */
! 88: if (SIGN(b)*i<0) return SIGN(b); /* both signs differ */
! 89: else if (!NOTZERO(b) || (i==0)) { /* one is zero */
! 90: if (i==0) return ((NOTZERO(b)) ? SIGN(b) : 0);
! 91: else return si; /* b is zero */
! 92:
! 93: }
! 94: else { /* b and i are of same sign */
! 95: e = EXP(b); /* 2^(e-1) <= b < 2^e */
! 96: if (e>f+mp_bits_per_limb) return si;
! 97:
! 98: c = (mp_limb_t) ((i<0) ? -i : i);
! 99: count_leading_zeros(k, c);
! 100: k = f+mp_bits_per_limb - k; /* 2^(k-1) <= i*2^f < 2^k */
! 101: if (k!=e) return (si*(e-k));
! 102:
! 103: /* now k=e */
! 104: c <<= (f+mp_bits_per_limb-k);
! 105: bn = (PREC(b)-1)/mp_bits_per_limb;
! 106: bp = MANT(b) + bn;
! 107: if (*bp>c) return si;
! 108: else if (*bp<c) return -si;
! 109:
! 110: /* most significant limbs agree, check remaining limbs from b */
! 111: while (--bn>=0)
! 112: if (*--bp) return si;
! 113: return 0;
! 114: }
! 115: }
! 116:
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