ImmutAVLTree uses random unsigned values as keys into a DenseMap,
which could possibly happen to be the same value as the Tombstone or
Entry keys in the DenseMap.
Test case is hard to come up with. We randomly get failures on the
internal static analyzer bot, which most likely hits this issue
(hard to be 100% sure without the full stack).
llvm-svn: 153148
- 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.
llvm-svn: 120459
to use lowercase letters for the start of most
method names and to replace some method names
with more descriptive names (e.g., "getLeft()"
instead of "Left()"). No real functionality
change.
llvm-svn: 120070
Add or Remove operation complete, and not while building the intermediate tree.
This trades a little bit more memory usage for less accesses to the FoldingSet. On a benchmark for the clang static analyzer, this shaves off another 13% of execution time when using field/array sensitivity.
llvm-svn: 80955
ImutAVLTree. This was accidentally left out, and essentially caused
digest caching to be ignored in ImmutableMap and ImmutableSet (this
bug was detected from shark traces that showed ComputeDigest was in
the hot path in the clang static analyzer).
This reduces the running time of the clang static analyzer on an
example benchmark by ~32% for both RegionStore (field-sensitivty) and
BasicStore (without field-sensitivity).
llvm-svn: 80877
is still mutable. My experiments show this reduces the amount of times we
compute a full tree digest by over 50% on very small cases, and potentially much
larger on others.
llvm-svn: 75207
BumpPtrAllocator argument to their constructors. This BumpPtrAllocator
will be used to allocate trees. If no BumpPtrAllocator is provided, one
is created (as before).
llvm-svn: 46975
unique ImutAVLTree* for profiling.
Modified ImutAVLTree:
(1) changed ComputeHash() to ComputeDigest() and
(2) changed Profile() to use the computed digest and
(3) modified insertion of IMutAVLTree into the FoldingSet owned by
the ImutAVLTreeFactory object to use profiling instead of computing
a direct hash. This fixes a bug where our abuse of the FoldingSet would
not work when the FoldingSet was resized.
llvm-svn: 46753
node in the FoldingSet of nodes held by the Factory object. If we
we find a node with a matching hash, we do a full structural comparison.
Nodes are also now inserted into the FoldingSet only when we mark them
Immutable, as their children can change during intermediate-rebalancing.
The 'Profile' method for ImutAVLTree is no longer used when looking up
existing ImutAVLTrees with a given set of contents; instead the Profile method
is used by other clients that wish to insert such a tree into a folding set.
This means that we are not using FoldingSet in ImutAVLTreeFactory in the way
it was intended, but instead are using it as an opaque hashtable.
llvm-svn: 46717
problem was that we previously hashed based on the pointers of the left and
right children, but this is bogus: we can easily have different trees that
represent the same set. Now we use a hashing based scheme that compares the
*contents* of the trees, but not without having to do a full scan of a tree. The
only caveat is that with hashing is that we may have collisions, which result in
two different trees being falsely labeled as equivalent. If this becomes a
problem, we can add extra data to the profile to hopefully resolve most
collisions.
llvm-svn: 46224
and not just the key value when comparing trees. To do this we added data_type
and data_type_ref to the ImutContainerInfo trait classes. For values stored in
the tree that do not have separate key and data components, data_type is simply
a typedef of bool, and isDataEqual() always evaluates to true. This allows us to
support both ImmutableSet and ImmutableMap using the same underlying logic.
llvm-svn: 46130
void*. This is hint that we are returning uninitialized memory rather
than a constructed object.
Patched ImutAVLTree to conform to this new interface.
llvm-svn: 43106
