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
target triple and straightens it out. This does less than gcc's script
config.sub, for example it turns i386-mingw32 into i386--mingw32 not
i386-pc-mingw32, but it does a decent job of turning funky triples into
something that the rest of the Triple class can understand. The plan
is to use this to canonicalize triple's when they are first provided
by users, and have the rest of LLVM only deal with canonical triples.
Once this is done the special case workarounds in the Triple constructor
can be removed, making the class more regular and easier to use. The
comments and unittests for the Triple class are already adjusted in this
patch appropriately for this brave new world of increased uniformity.
llvm-svn: 110909
handles with a pointer to the containing map. When a map is copied, these
pointers need to be corrected to point to the new map. If not, then consider
the case of a map M1 which maps a value V to something. Create a copy M2 of
M1. At this point there are two value handles on V, one representing V as a
key in M1, the other representing V as a key in M2. But both value handles
point to M1 as the containing map. Now delete V. The value handles remove
themselves from their containing map (which destroys them), but only the first
value handle is successful: the second one cannot remove itself from M1 as
(once the first one has removed itself) there is nothing there to remove; it
is therefore not destroyed. This causes an assertion failure "All references
to V were not removed?".
llvm-svn: 109851
- This provides a convenient alternative to using something llvm::prior or
manual iterator access, for example::
if (T *Prev = foo->getPrevNode())
...
instead of::
iterator it(foo);
if (it != begin()) {
--it;
...
}
- Chris, please review.
llvm-svn: 103647
payloads. APFloat's internal folding routines always make QNaNs now,
instead of sometimes making QNaNs and sometimes SNaNs depending on the
type.
llvm-svn: 97364
It fails with a release build only, for reasons
as yet unknown. (If there's a better way to Xfail
things here let me know, doesn't seem to be any
prior art in unittests.)
llvm-svn: 95700
a single pointer (PointerIntPair) member. In "small" mode, the
pointer field is reinterpreted as a set of bits. In "large" mode,
the pointer points to a heap-allocated object.
Also, give BitVector empty and swap functions.
And, add some simple unittests for BitVector and SmallBitVector.
llvm-svn: 92730
argument-dependent lookup can find it. This is another case where an
LLVM bug (not making operator<< visible) was masked by a GCC bug
(looking in the global namespace when it shouldn't).
llvm-svn: 92144
smallest-normalized-magnitude values in a given FP semantics.
Provide an APFloat-to-string conversion which I am quite ready to admit could
be much more efficient.
llvm-svn: 92126
