Ted Kremenek 75627d3d2e Performance optimization on ImmutableMap/ImmutableSet: ...

- Use a DenseSet instead of a FoldingSet to cache
canonicalized nodes.  This reduces the overhead
of double-hashing.

- Use reference counts in ImutAVLTree to much
more aggressively recover tree nodes that are
no longer usable.  We can generate many
transient nodes while using add() and remove()
on ImmutableSet/ImmutableMaps to generate a final
set/map.

For the clang static analyzer (the main client
of these data structures), this results in
a slight speedup (0.5%) when analyzing sqlite3,
but much more importantly results in a 30-60%
reduction in peak memory usage when the analyzer
is analyzing a given function in a file.  On
average that's about a ** 44% reduction ** in the
memory footprint of the static analyzer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120459 91177308-0d34-0410-b5e6-96231b3b80d8

2010-11-30 20:26:45 +00:00

..

llvm

Performance optimization on ImmutableMap/ImmutableSet:

2010-11-30 20:26:45 +00:00

llvm-c

I swear I did a make clean and make before committing all this...

2010-11-29 18:47:54 +00:00