Sometimes std::copy can become a memmove call, and that is not a good idea when
copying relatively few bytes as we are doing. We also get a small win by
changing two loops into one.
llvm-svn: 120265
We always disallowed overlapping inserts with different values, and this makes
the insertion code smaller and faster.
If an overwriting insert is needed, it can be added as a separate method that
trims any existing intervals before inserting. The immediate use cases for
IntervalMap don't need this - they only use disjoint insertions.
llvm-svn: 120264
Implement iterator::erase() in a simple version that erases nodes when they
become empty, but doesn't try to redistribute elements among siblings for better
packing.
Handle coalescing across leaf nodes which may require erasing entries.
llvm-svn: 120226
situations where on the common path an API can return a pointer to some direct
memory, but which on an exceptional path may need to return a pointer to a
temporary struct.
llvm-svn: 120201
- Double the vector's capacity when growing to avoid unneeccesary reallocation.
- Do the reallocation with realloc(3) which can expand the memory in place.
llvm-svn: 120183
The path also holds a reference to the root node, and that allows important
iterator accessors like start() and stop() to have no conditional code. (When
the compiler is clever enough to remove it.)
llvm-svn: 120165
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
This doesn't quite work yet because the calls to treeDecrement and treeIncrement
operate at the leaf level, not on pathNode(Level) as required.
llvm-svn: 120068
It is now possible to navigate the B+-tree using NodeRef::subtree() and
NodeRef::size() without knowing the key and value template types used in the
tree.
llvm-svn: 119880
Key and value objects may not be destructed instantly when they are erased from
the container, but they will be destructed eventually by the IntervalMap
destructor.
llvm-svn: 119873
llvm/include/llvm/ADT/IntervalMap.h:334: error: '((llvm::IntervalMapImpl::DesiredNodeBytes / static_cast<unsigned int>(((2 * sizeof (KeyT)) + sizeof (ValT)))) >? 3u)' is not a valid template argument for type 'unsigned int' because it is a non-constant expression
llvm-svn: 119790
This is a sorted interval map data structure for small keys and values with
automatic coalescing and bidirectional iteration over coalesced intervals.
Except for coalescing intervals, it provides similar functionality to std::map.
It is however much more compact for small keys and values, and hopefully faster
too.
The container object itself can hold the first few intervals without any
allocations, then it switches to a cache conscious B+-tree representation. A
recycling allocator can be shared between many containers, even between
containers holding different types.
The IntervalMap is initially intended to be used with SlotIndex intervals for:
- Backing store for LiveIntervalUnion that is smaller and faster than std::set.
- Backing store for LiveInterval with less overhead than std::vector for typical
intervals and O(N log N) merging of large intervals. 99% of virtual registers
need 4 entries or less and would benefit from the small object optimization.
- Backing store for LiveDebugVariable which doesn't exist yet, but will track
debug variables during register allocation.
This is a work in progress. Missing items are:
- Performance metrics.
- erase().
- insert() shrinkage.
- clear().
- More performance metrics.
- Simplification and detemplatization.
llvm-svn: 119787
This is a sorted interval map data structure for small keys and values with
automatic coalescing and bidirectional iteration over coalesced intervals.
Except for coalescing intervals, it provides similar functionality to std::map.
It is however much more compact for small keys and values, and hopefully faster
too.
The container object itself can hold the first few intervals without any
allocations, then it switches to a cache conscious B+-tree representation. A
recycling allocator can be shared between many containers, even between
containers holding different types.
The IntervalMap is initially intended to be used with SlotIndex intervals for:
- Backing store for LiveIntervalUnion that is smaller and faster than std::set.
- Backing store for LiveInterval with less overhead than std::vector for typical
intervals and O(N log N) merging of large intervals. 99% of virtual registers
need 4 entries or less and would benefit from the small object optimization.
- Backing store for LiveDebugVariable which doesn't exist yet, but will track
debug variables during register allocation.
This is a work in progress. Missing items are:
- Performance metrics.
- erase().
- insert() shrinkage.
- clear().
- More performance metrics.
- Simplification and detemplatization.
llvm-svn: 119772
specializations provided here. This is a little annoying because its size
changes from platform to platform. If possible, I may follow up with a patch
that uses standard constants to simplify much of this, but assuming for now
that was avoided for a reason.
llvm-svn: 117880
logic to use the new APInt methods. Among other things this
implements rdar://8501501 - llvm.smul.with.overflow.i32 should constant fold
which comes from "clang -ftrapv", originally brought to my attention from PR8221.
llvm-svn: 116457
is partly because this attribute caused trouble in the past (the
SmallVector one had to be changed from aligned to aligned(8) due
to causing crashes on i386 for example; in theory the same might
be needed in the Allocator case...). But it's mostly because
there seems to be no point in special casing gcc here. Using the
same implementation for all compilers results in better testing.
llvm-svn: 115462
