various coordinate performance improvements #258
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
avoids creating new Unit in often called MVEpoch::getTime()
Avoid creating a temporary MVPosition object in the 3x3 matrix-vector product by using temporary stack variables.
MVPosition are often created as temporaries where the allocation overhead of the size 3 vector is large. To reduce this add a very simple cache for these vectors that holds a couple already allocated vectors.
Euler objects are often created as temporaries where the allocation overhead of the size 3 vectors is large. To reduce this add a very simple cache for these vectors that holds a couple already allocated vectors.
the compiler cannot remove then as it must assume memory aliasing.
juliantaylor
force-pushed
the
perf-improvements
branch
2 times, most recently
from
9a24a2e
to
72c0e23
Compare
Returns derivative of MeasTable::posArg and aber*Arg Polynomial, which is also computed only once and the cached. Avoids unnecessary Polynomial creations in some places which involved several small Array allocations.
juliantaylor
force-pushed
the
perf-improvements
branch
from
72c0e23
to
fdd1928
Compare
dpetry
added a commit
that referenced
this pull request
Oct 27, 2015
various coordinate performance improvements
|
This looks great, Julian. Thanks. |
|
I run the casa regression tests on casacore PRs already, though I didn't find the time to integrate the result reporting with github yet. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
coordinate transformations in casa are spending most of their time allocating memory instead of actually computing. This set of patches improves this a situation a bit via a few small changes, see the commits for details.
The largest change is using a small Vector cache to avoid creating new Vectors for each MVPosition and Euler temporary object that are created en mass in the conversion code.
This cache could in theory be moved lower into the stack, e.g. in the allocator itself and the Array object would need to use placement new's to create its Block object, though this is quite tricky to get right so I opted for the simpler change of just caching the objects that are problematic.
A disadvantage is that the small cache is never free'd so it would show up in valgrind, but that can be handled with a suppression file.