Cedric Roux
56c66c09aa
Pre-ci test passed git-svn-id: http://svn.eurecom.fr/openair4G/trunk@4000 818b1a75-f10b-46b9-bf7c-635c3b92a50f
51 lines
1.0 KiB
C
Executable File
51 lines
1.0 KiB
C
Executable File
//----------------------------------------------
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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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{
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++root;
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}
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return root;
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}
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