c++ Programming Glossary: reduction

http://stackoverflow.com/questions/11095309/openmp-set-num-threads-is-not-working

groupsize omp_set_num_threads 4 sum 0 #pragma omp for reduction sum for int i 0 i n i sum i n 10 cout sum sum endl cout threads..

Sum of products of Fibonacci numbers [closed]

http://stackoverflow.com/questions/12248587/sum-of-products-of-fibonacci-numbers

below algorithm is O n log n . The fact that allows this reduction is that Fibonacci numbers like all numbers in a sequence defined..

Performance degradation due to default initialisation of elements in standard containers

http://stackoverflow.com/questions/15952412/performance-degradation-due-to-default-initialisation-of-elements-in-standard-co

With g 4.5 I was able to realize an approximate 20 reduction in runtime from v0 1.0s to 0.8s and slightly less from 0.95s..

A way of achieving lazy evaluation in C++

http://stackoverflow.com/questions/16701108/a-way-of-achieving-lazy-evaluation-in-c

a new argument sqrtx . There is also the so called optimal reduction. I don't think there are other ways of doing it. Why is it a.. in essence if you look at the implementation of a graph reduction machine if you look at how the stack evolves you see that basically..

May compiler optimizations be inhibited by multi-threading?

http://stackoverflow.com/questions/16807766/may-compiler-optimizations-be-inhibited-by-multi-threading

example int b ... int c ... int a 0 #omp parallel for reduction a for i 0 i 100 i a b i c i This code should be converted to..

A fast method to round a double to a 32-bit int explained

http://stackoverflow.com/questions/17035464/a-fast-method-to-round-a-double-to-a-32-bit-int-explained

representation of a again minus the upper two bits . Since reduction of a 2's complement number to a smaller width is done just by..

How can I measure CPU time and wall clock time on both Linux/Windows?

http://stackoverflow.com/questions/17432502/how-can-i-measure-cpu-time-and-wall-clock-time-on-both-linux-windows

some computation. double sum 0 #pragma omp parallel for reduction sum for long long i 1 i 10000000000 i sum log double i Stop..

Is it possible to do a reduction on an array with openmp?

http://stackoverflow.com/questions/3775147/is-it-possible-to-do-a-reduction-on-an-array-with-openmp

it possible to do a reduction on an array with openmp Does OpenMP natively support reduction.. on an array with openmp Does OpenMP natively support reduction of a variable that represents an array This would work something.. 4 sizeof float omp_set_num_threads 13 #pragma omp parallel reduction a for i 0 i 4 i a i 1 Thread local copy of a incremented by..

Class members that are objects - Pointers or not? C++

http://stackoverflow.com/questions/3871429/class-members-that-are-objects-pointers-or-not-c

a specified offset so... it helps optimization and binary reduction at a few levels. there will be a few cases where you know you'll..

Brute-force, single-threaded prime factorization

http://stackoverflow.com/questions/3918968/brute-force-single-threaded-prime-factorization

one prime per cycle. Then factor of improvement is the reduction in division operations i.e. five times. This is borne out by..

OpenMP: Huge performance differences between Visual C++ 2008 and 2010

http://stackoverflow.com/questions/4738045/openmp-huge-performance-differences-between-visual-c-2008-and-2010

some simple OpenMP parallel loop #pragma omp parallel for reduction sum for int j 0 j size j sum my_array j This loop eats 5 of..

Concurrent writes in the same global memory location

http://stackoverflow.com/questions/5953955/concurrent-writes-in-the-same-global-memory-location

can either use a shared memory flag set atomically or a reduction operation to determine whether the value should be set. Which.. to be. The more zeroes there are the more attractive the reduction will be. CUDA includes warp level __any and __all operators..

Emulate “double” using 2 “float”s

http://stackoverflow.com/questions/6769881/emulate-double-using-2-floats

of single precision arithmetic accompanied by a slight reduction of the single precision exponent range due to intermediate underflow..

Should we still be optimizing “in the small”?

http://stackoverflow.com/questions/763656/should-we-still-be-optimizing-in-the-small

loop unrolling loop jamming loop inversion strength reduction and many others. Are these still relevant What low level code.. the compiler can do that easily. Same goes for strength reduction. Swapping inner and outer loops is trickier because the compiler..

OpenCV C++/Obj-C: Detecting a sheet of paper / Square Detection

http://stackoverflow.com/questions/8667818/opencv-c-obj-c-detecting-a-sheet-of-paper-square-detection

interested in the four corner points of the paper for skew reduction like that and further processing p Input Output Original image..