Annotation of OpenXM_contrib/gmp/mpz/cmp_d.c, Revision 1.1
1.1 ! ohara 1: /* mpz_cmpabs_d -- compare absolute values of mpz and double.
! 2:
! 3: Copyright 2001, 2002 Free Software Foundation, Inc.
! 4:
! 5: This file is part of the GNU MP Library.
! 6:
! 7: The GNU MP Library is free software; you can redistribute it and/or modify
! 8: it under the terms of the GNU Lesser General Public License as published by
! 9: the Free Software Foundation; either version 2.1 of the License, or (at your
! 10: option) any later version.
! 11:
! 12: The GNU MP 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 Lesser General Public
! 15: License for more details.
! 16:
! 17: You should have received a copy of the GNU Lesser General Public License
! 18: along with the GNU MP 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:
! 23: #include "gmp.h"
! 24: #include "gmp-impl.h"
! 25:
! 26:
! 27: #define RETURN_CMP(zl, dl) \
! 28: do { \
! 29: zlimb = (zl); \
! 30: dlimb = (dl); \
! 31: if (zlimb != dlimb) \
! 32: return (zlimb >= dlimb ? ret : -ret); \
! 33: } while (0)
! 34:
! 35: #define RETURN_NONZERO(ptr, size, val) \
! 36: do { \
! 37: mp_size_t __i; \
! 38: for (__i = (size)-1; __i >= 0; __i--) \
! 39: if ((ptr)[__i] != 0) \
! 40: return val; \
! 41: return 0; \
! 42: } while (0)
! 43:
! 44:
! 45: int
! 46: mpz_cmp_d (mpz_srcptr z, double d)
! 47: {
! 48: mp_limb_t darray[LIMBS_PER_DOUBLE], zlimb, dlimb;
! 49: mp_srcptr zp;
! 50: mp_size_t zsize;
! 51: int dexp, ret;
! 52:
! 53: /* 1. Either operand zero. */
! 54: zsize = SIZ(z);
! 55: if (d == 0.0)
! 56: return zsize;
! 57: if (zsize == 0)
! 58: return (d < 0.0 ? 1 : -1);
! 59:
! 60: /* 2. Opposite signs. */
! 61: if (zsize >= 0)
! 62: {
! 63: if (d < 0.0)
! 64: return 1; /* >=0 cmp <0 */
! 65: ret = 1;
! 66: }
! 67: else
! 68: {
! 69: if (d >= 0.0)
! 70: return -1; /* <0 cmp >=0 */
! 71: ret = -1;
! 72: d = -d;
! 73: zsize = -zsize;
! 74: }
! 75:
! 76: /* 3. Small d, knowing abs(z) >= 1. */
! 77: if (d < 1.0)
! 78: return ret;
! 79:
! 80: dexp = __gmp_extract_double (darray, d);
! 81: ASSERT (dexp >= 1);
! 82:
! 83: /* 4. Different high limb positions. */
! 84: if (zsize != dexp)
! 85: return (zsize >= dexp ? ret : -ret);
! 86:
! 87: /* 5. Limb data. */
! 88: zp = PTR(z);
! 89:
! 90: #if LIMBS_PER_DOUBLE == 2
! 91: RETURN_CMP (zp[zsize-1], darray[1]);
! 92: if (zsize == 1)
! 93: return (darray[0] != 0 ? -ret : 0);
! 94:
! 95: RETURN_CMP (zp[zsize-2], darray[0]);
! 96: RETURN_NONZERO (zp, zsize-2, ret);
! 97:
! 98: #else
! 99: #if LIMBS_PER_DOUBLE == 3
! 100: RETURN_CMP (zp[zsize-1], darray[2]);
! 101: if (zsize == 1)
! 102: return ((darray[0] | darray[1]) != 0 ? -ret : 0);
! 103:
! 104: RETURN_CMP (zp[zsize-2], darray[1]);
! 105: if (zsize == 2)
! 106: return (darray[0] != 0 ? -ret : 0);
! 107:
! 108: RETURN_CMP (zp[zsize-3], darray[0]);
! 109: RETURN_NONZERO (zp, zsize-3, ret);
! 110:
! 111: #else
! 112: for (i = 1; i <= LIMBS_PER_DOUBLE; i++)
! 113: {
! 114: RETURN_CMP (zp[zsize-i], darray[LIMBS_PER_DOUBLE-i]);
! 115: if (i >= zsize)
! 116: RETURN_NONZERO (darray, LIMBS_PER_DOUBLE-i, -ret);
! 117: }
! 118: RETURN_NONZERO (zp, zsize-LIMBS_PER_DOUBLE, ret);
! 119: #endif
! 120: #endif
! 121: }
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