gauthier
c7518ecf42
git-svn-id: http://svn.eurecom.fr/openair4G/trunk@7885 818b1a75-f10b-46b9-bf7c-635c3b92a50f
78 lines
2.3 KiB
C
Executable File
78 lines
2.3 KiB
C
Executable File
/*******************************************************************************
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OpenAirInterface
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Copyright(c) 1999 - 2014 Eurecom
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OpenAirInterface is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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OpenAirInterface is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with OpenAirInterface.The full GNU General Public License is
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included in this distribution in the file called "COPYING". If not,
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see <http://www.gnu.org/licenses/>.
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Contact Information
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OpenAirInterface Admin: openair_admin@eurecom.fr
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OpenAirInterface Tech : openair_tech@eurecom.fr
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OpenAirInterface Dev : openair4g-devel@lists.eurecom.fr
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Address : Eurecom, Campus SophiaTech, 450 Route des Chappes, CS 50193 - 06904 Biot Sophia Antipolis cedex, FRANCE
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*******************************************************************************/
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//----------------------------------------------
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//
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// Integer square root. Take the square root of an integer.
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//
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#define step(shift) \
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if((0x40000000l >> shift) + root <= value) \
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{ \
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value -= (0x40000000l >> shift) + root; \
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root = (root >> 1) | (0x40000000l >> shift); \
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} \
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else \
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{ \
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root = root >> 1; \
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}
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int
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iSqrt(int value)
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{
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int root = 0;
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step( 0);
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step( 2);
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step( 4);
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step( 6);
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step( 8);
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step(10);
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step(12);
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step(14);
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step(16);
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step(18);
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step(20);
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step(22);
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step(24);
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step(26);
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step(28);
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step(30);
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// round to the nearest integer, cuts max error in half
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if(root < value) {
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++root;
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}
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return root;
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}
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