From 11da511c784eca003deb90c23570f0873954e0de Mon Sep 17 00:00:00 2001 From: Duncan Wilkie Date: Sat, 18 Nov 2023 06:11:09 -0600 Subject: Initial commit. --- gmp-6.3.0/mpq/cmp.c | 169 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 169 insertions(+) create mode 100644 gmp-6.3.0/mpq/cmp.c (limited to 'gmp-6.3.0/mpq/cmp.c') diff --git a/gmp-6.3.0/mpq/cmp.c b/gmp-6.3.0/mpq/cmp.c new file mode 100644 index 0000000..495e77e --- /dev/null +++ b/gmp-6.3.0/mpq/cmp.c @@ -0,0 +1,169 @@ +/* mpq_cmp(u,v) -- Compare U, V. Return positive, zero, or negative + based on if U > V, U == V, or U < V. + +Copyright 1991, 1994, 1996, 2001, 2002, 2005, 2015 Free Software Foundation, Inc. + +This file is part of the GNU MP Library. + +The GNU MP Library is free software; you can redistribute it and/or modify +it under the terms of either: + + * the GNU Lesser General Public License as published by the Free + Software Foundation; either version 3 of the License, or (at your + option) any later version. + +or + + * the GNU General Public License as published by the Free Software + Foundation; either version 2 of the License, or (at your option) any + later version. + +or both in parallel, as here. + +The GNU MP Library is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY +or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received copies of the GNU General Public License and the +GNU Lesser General Public License along with the GNU MP Library. If not, +see https://www.gnu.org/licenses/. */ + +#include "gmp-impl.h" +#include "longlong.h" + +static int +mpq_cmp_numden (mpq_srcptr op1, mpz_srcptr num_op2, mpz_srcptr den_op2) +{ + mp_size_t num1_size = SIZ(NUM(op1)); + mp_size_t den1_size = SIZ(DEN(op1)); + mp_size_t num2_size = SIZ(num_op2); + mp_size_t den2_size = SIZ(den_op2); + int op2_is_int; + mp_limb_t d1h, d2h; + mp_size_t tmp1_size, tmp2_size; + mp_ptr tmp1_ptr, tmp2_ptr; + mp_size_t num1_sign; + int cc; + TMP_DECL; + + /* need canonical signs to get right result */ + ASSERT (den1_size > 0); + ASSERT (den2_size > 0); + + if (num1_size == 0) + return -num2_size; + if (num2_size == 0) + return num1_size; + if ((num1_size ^ num2_size) < 0) /* I.e. are the signs different? */ + return num1_size; + + num1_sign = num1_size; + num1_size = ABS (num1_size); + + /* THINK: Does storing d1h and d2h make sense? */ + d1h = PTR(DEN(op1))[den1_size - 1]; + d2h = PTR(den_op2)[den2_size - 1]; + op2_is_int = (den2_size | d2h) == 1; + if ((unsigned) op2_is_int == (den1_size | d1h)) /* Both ops are integers */ + /* return mpz_cmp (NUM (op1), num_op2); */ + { + int cmp; + + /* Cannot use num1_sign - num2_size, may overflow an "int" */ + if (num1_sign != num2_size) + return (num1_sign > num2_size) ? 1 : -1; + + cmp = mpn_cmp (PTR(NUM(op1)), PTR(num_op2), num1_size); + return (num1_sign > 0 ? cmp : -cmp); + } + + num2_size = ABS (num2_size); + + tmp1_size = num1_size + den2_size; + tmp2_size = num2_size + den1_size; + + /* 1. Check to see if we can tell which operand is larger by just looking at + the number of limbs. */ + + /* NUM1 x DEN2 is either TMP1_SIZE limbs or TMP1_SIZE-1 limbs. + Same for NUM1 x DEN1 with respect to TMP2_SIZE. */ + if (tmp1_size > tmp2_size + 1) + /* NUM1 x DEN2 is surely larger in magnitude than NUM2 x DEN1. */ + return num1_sign; + if (tmp2_size + op2_is_int > tmp1_size + 1) + /* NUM1 x DEN2 is surely smaller in magnitude than NUM2 x DEN1. */ + return -num1_sign; + + /* 2. Same, but compare the number of significant bits. */ + { + int cnt1, cnt2; + mp_bitcnt_t bits1, bits2; + + count_leading_zeros (cnt1, PTR(NUM(op1))[num1_size - 1]); + count_leading_zeros (cnt2, d2h); + bits1 = (mp_bitcnt_t) tmp1_size * GMP_NUMB_BITS - cnt1 - cnt2 + 2 * GMP_NAIL_BITS; + + count_leading_zeros (cnt1, PTR(num_op2)[num2_size - 1]); + count_leading_zeros (cnt2, d1h); + bits2 = (mp_bitcnt_t) tmp2_size * GMP_NUMB_BITS - cnt1 - cnt2 + 2 * GMP_NAIL_BITS; + + if (bits1 > bits2 + 1) + return num1_sign; + if (bits2 + op2_is_int > bits1 + 1) + return -num1_sign; + } + + /* 3. Finally, cross multiply and compare. */ + + TMP_MARK; + if (op2_is_int) + { + tmp2_ptr = TMP_ALLOC_LIMBS (tmp2_size); + tmp1_ptr = PTR(NUM(op1)); + --tmp1_size; + } + else + { + TMP_ALLOC_LIMBS_2 (tmp1_ptr,tmp1_size, tmp2_ptr,tmp2_size); + + if (num1_size >= den2_size) + tmp1_size -= 0 == mpn_mul (tmp1_ptr, + PTR(NUM(op1)), num1_size, + PTR(den_op2), den2_size); + else + tmp1_size -= 0 == mpn_mul (tmp1_ptr, + PTR(den_op2), den2_size, + PTR(NUM(op1)), num1_size); + } + + if (num2_size >= den1_size) + tmp2_size -= 0 == mpn_mul (tmp2_ptr, + PTR(num_op2), num2_size, + PTR(DEN(op1)), den1_size); + else + tmp2_size -= 0 == mpn_mul (tmp2_ptr, + PTR(DEN(op1)), den1_size, + PTR(num_op2), num2_size); + + + cc = tmp1_size - tmp2_size != 0 + ? tmp1_size - tmp2_size : mpn_cmp (tmp1_ptr, tmp2_ptr, tmp1_size); + TMP_FREE; + return num1_sign < 0 ? -cc : cc; +} + +int +mpq_cmp (mpq_srcptr op1, mpq_srcptr op2) +{ + return mpq_cmp_numden (op1, NUM(op2), DEN(op2)); +} + +int +mpq_cmp_z (mpq_srcptr op1, mpz_srcptr op2) +{ + const static mp_limb_t one = 1; + const static mpz_t den = MPZ_ROINIT_N ((mp_limb_t *) &one, 1); + + return mpq_cmp_numden (op1, op2, den); +} -- cgit v1.2.3