X-Git-Url: https://oss.titaniummirror.com/gitweb?a=blobdiff_plain;f=gmp%2Fmpq%2Fcmp.c;fp=gmp%2Fmpq%2Fcmp.c;h=2ee540cad5178063e27ad92bf1a1a6d8326d1e21;hb=6fed43773c9b0ce596dca5686f37ac3fc0fa11c0;hp=0000000000000000000000000000000000000000;hpb=27b11d56b743098deb193d510b337ba22dc52e5c;p=msp430-gcc.git diff --git a/gmp/mpq/cmp.c b/gmp/mpq/cmp.c new file mode 100644 index 00000000..2ee540ca --- /dev/null +++ b/gmp/mpq/cmp.c @@ -0,0 +1,115 @@ +/* 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 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 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. + +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 Lesser General Public +License for more details. + +You should have received a copy of the GNU Lesser General Public License +along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */ + +#include "gmp.h" +#include "gmp-impl.h" +#include "longlong.h" + +int +mpq_cmp (const MP_RAT *op1, const MP_RAT *op2) +{ + mp_size_t num1_size = op1->_mp_num._mp_size; + mp_size_t den1_size = op1->_mp_den._mp_size; + mp_size_t num2_size = op2->_mp_num._mp_size; + mp_size_t den2_size = op2->_mp_den._mp_size; + 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); + 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 > 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; + unsigned long int bits1, bits2; + + count_leading_zeros (cnt1, op1->_mp_num._mp_d[num1_size - 1]); + count_leading_zeros (cnt2, op2->_mp_den._mp_d[den2_size - 1]); + bits1 = tmp1_size * GMP_NUMB_BITS - cnt1 - cnt2 + 2 * GMP_NAIL_BITS; + + count_leading_zeros (cnt1, op2->_mp_num._mp_d[num2_size - 1]); + count_leading_zeros (cnt2, op1->_mp_den._mp_d[den1_size - 1]); + bits2 = tmp2_size * GMP_NUMB_BITS - cnt1 - cnt2 + 2 * GMP_NAIL_BITS; + + if (bits1 > bits2 + 1) + return num1_sign; + if (bits2 > bits1 + 1) + return -num1_sign; + } + + /* 3. Finally, cross multiply and compare. */ + + TMP_MARK; + TMP_ALLOC_LIMBS_2 (tmp1_ptr,tmp1_size, tmp2_ptr,tmp2_size); + + if (num1_size >= den2_size) + tmp1_size -= 0 == mpn_mul (tmp1_ptr, + op1->_mp_num._mp_d, num1_size, + op2->_mp_den._mp_d, den2_size); + else + tmp1_size -= 0 == mpn_mul (tmp1_ptr, + op2->_mp_den._mp_d, den2_size, + op1->_mp_num._mp_d, num1_size); + + if (num2_size >= den1_size) + tmp2_size -= 0 == mpn_mul (tmp2_ptr, + op2->_mp_num._mp_d, num2_size, + op1->_mp_den._mp_d, den1_size); + else + tmp2_size -= 0 == mpn_mul (tmp2_ptr, + op1->_mp_den._mp_d, den1_size, + op2->_mp_num._mp_d, 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; +}