Created
February 23, 2012 01:53
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absolute function in c that does not branch
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| // branching function: | |
| // inline int abs(int x) | |
| // { | |
| // return (x<0) ? -x : x; | |
| // } | |
| inline int abs_no_branch(int x) | |
| { | |
| int m = (x >> (8 * sizeof(int)-1)); | |
| return ((x ^ m) - m); | |
| } | |
| inline int abs_no_branch_xor_and(int x) | |
| { | |
| return (~(1<<(8*sizeof(int)-1)))&n; | |
| } |
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