hashable data. This matters when we have pair<T*, U*> as a key, which is
quite common in DenseMap, etc. To that end, we need to detect when this
is safe. The requirements on a generic std::pair<T, U> are:
1) Both T and U must satisfy the existing is_hashable_data trait. Note
that this includes the requirement that T and U have no internal
padding bits or other bits not contributing directly to equality.
2) The alignment constraints of std::pair<T, U> do not require padding
between consecutive objects.
3) The alignment constraints of U and the size of T do not conspire to
require padding between the first and second elements.
Grow two somewhat magical traits to detect this by forming a pod
structure and inspecting offset artifacts on it. Hopefully this won't
cause any compilers to panic.
Added and adjusted tests now that pairs, even nested pairs, are treated
as just sequences of data.
Thanks to Jeffrey Yasskin for helping me sort through this and reviewing
the somewhat subtle traits.
llvm-svn: 151883
an open question of whether we can do better than this by treating pairs
as boring data containers and directly hashing the two subobjects. This
at least makes the API reasonable.
In order to make this change, I reorganized the header a bit. I lifted
the declarations of the hash_value functions up to the top of the header
with their doxygen comments as these are intended for users to interact
with. They shouldn't have to wade through implementation details. I then
defined them at the very end so that they could be defined in terms of
hash_combine or any other hashing infrastructure.
Added various pair-hashing unittests.
llvm-svn: 151882
the hash_code. I'm not sure what I was thinking here, the use cases for
special values are in the *keys*, not in the hashes of those keys.
We can always resurrect this if needed, or clients can accomplish the
same goal themselves. This makes the general case somewhat faster (~5
cycles faster on my machine) and smaller with less branching.
llvm-svn: 151865
of the proposed standard hashing interfaces (N3333), and to use
a modified and tuned version of the CityHash algorithm.
Some of the highlights of this change:
-- Significantly higher quality hashing algorithm with very well
distributed results, and extremely few collisions. Should be close to
a checksum for up to 64-bit keys. Very little clustering or clumping of
hash codes, to better distribute load on probed hash tables.
-- Built-in support for reserved values.
-- Simplified API that composes cleanly with other C++ idioms and APIs.
-- Better scaling performance as keys grow. This is the fastest
algorithm I've found and measured for moderately sized keys (such as
show up in some of the uniquing and folding use cases)
-- Support for enabling per-execution seeds to prevent table ordering
or other artifacts of hashing algorithms to impact the output of
LLVM. The seeding would make each run different and highlight these
problems during bootstrap.
This implementation was tested extensively using the SMHasher test
suite, and pased with flying colors, doing better than the original
CityHash algorithm even.
I've included a unittest, although it is somewhat minimal at the moment.
I've also added (or refactored into the proper location) type traits
necessary to implement this, and converted users of GeneralHash over.
My only immediate concerns with this implementation is the performance
of hashing small keys. I've already started working to improve this, and
will continue to do so. Currently, the only algorithms faster produce
lower quality results, but it is likely there is a better compromise
than the current one.
Many thanks to Jeffrey Yasskin who did most of the work on the N3333
paper, pair-programmed some of this code, and reviewed much of it. Many
thanks also go to Geoff Pike Pike and Jyrki Alakuijala, the original
authors of CityHash on which this is heavily based, and Austin Appleby
who created MurmurHash and the SMHasher test suite.
Also thanks to Nadav, Tobias, Howard, Jay, Nick, Ahmed, and Duncan for
all of the review comments! If there are further comments or concerns,
please let me know and I'll jump on 'em.
llvm-svn: 151822
chip in r139383, and the PSP components of the triple are really
annoying to parse. Let's leave this chapter behind. There is no reason
to expect LLVM to see a PSP-related triple these days, and so no
reasonable motivation to support them.
It might be reasonable to prune a few of the older MIPS triple forms in
general, but as those at least cause no burden on parsing (they aren't
both a chip and an OS!), I'm happy to leave them in for now.
llvm-svn: 151156
For objects that can be identified by small unsigned keys, SparseSet
provides constant time clear() and fast deterministic iteration. Insert,
erase, and find operations are typically faster than hash tables.
SparseSet is useful for keeping information about physical registers,
virtual registers, or numbered basic blocks.
llvm-svn: 151110
construction. Simplify its interface, implementation, and users
accordingly as there is no longer an 'uninitialized' state to check for.
Also, fixes a bug lurking in the interface as there was one method that
didn't correctly check for initialization.
llvm-svn: 151024
now that this handles the release / retain calls.
Adds a regression test for that bug (which is a compile-time
regression) and for the last two changes to the IntrusiveRefCntPtr,
especially tests for the memory leak due to copy construction of the
ref-counted object and ensuring that the traits are used for release /
retain calls.
llvm-svn: 149411
BitVector uses the native word size for its internal representation.
That doesn't work well for literal bit masks in source code.
This patch adds BitVector operations to efficiently apply literal bit
masks specified as arrays of uint32_t. Since each array entry always
holds exactly 32 bits, these portable bit masks can be source code
literals, probably produced by TableGen.
llvm-svn: 148272
make VariadicFunction actually be trivial. Do so, and also make it look
more like your standard trivial functor by making it a struct with no
access specifiers. The unit test is updated to initialize its functors
properly.
llvm-svn: 146827
variadic-like functions in C++98. See the comments in the header file
for a more detailed description of how these work. We plan to use these
extensively in the AST matching library. This code and idea were
originally authored by Zhanyong Wan. I've condensed it using macros
to reduce repeatition and adjusted it to fit better with LLVM's ADT.
Thanks to both David Blaikie and Doug Gregor for the review!
llvm-svn: 146729
was returning incorrect values in rare cases, and incorrectly marking
exact conversions as inexact in some more common cases. Fixes PR11406, and a
missed optimization in test/CodeGen/X86/fp-stack-O0.ll.
llvm-svn: 145141
Based on Horspool's simplified version of Boyer-Moore. We use a constant-sized table of
uint8_ts to keep cache thrashing low, needles bigger than 255 bytes are uncommon anyways.
The worst case is still O(n*m) but we do a lot better on the average case now.
llvm-svn: 142061
The APFloat "Zero" test was actually calling the
APFloat(const fltSemantics &, integerPart) constructor, and EXPECT_EQ was
treating 0 and -0 as equal.
llvm-svn: 138745
more graphs, like all graphs with 5 nodes or less. With a 32 bit
unsigned type, the maximum is graphs with 6 nodes or less, but that
would take a while to test - 5 nodes or less already requires a few
seconds.
llvm-svn: 136354
This computes every graph with 4 or fewer nodes, and checks that the SCC
class indeed returns exactly the simply connected components reachable
from the initial node.
llvm-svn: 136351
vec.insert(vec.begin(), vec[3]);
The issue was that vec[3] returns a reference into the vector, which is invalidated when insert() memmove's the elements down to make space. The method needs to specifically detect and handle this case to correctly match std::vector's semantics.
Thanks to Howard Hinnant for clarifying the correct behavior, and explaining how std::vector solves this problem.
llvm-svn: 134554
The idea is, that if an ieee 754 float is divided by a power of two, we can
turn the division into a cheaper multiplication. This function sees if we can
get an exact multiplicative inverse for a divisor and returns it if possible.
This is the hard part of PR9587.
I tested many inputs against llvm-gcc's frotend implementation of this
optimization and didn't find any difference. However, floating point is the
land of weird edge cases, so any review would be appreciated.
llvm-svn: 128545
of a constant had a minor typo introduced when copying it from the book, which
caused it to favor negative approximations over positive approximations in many
cases. Positive approximations require fewer operations beyond the multiplication.
In the case of division by 3, we still generate code that is a single instruction
larger than GCC's code.
llvm-svn: 126097
may be useful to understand "none", this is not the place for it. Tweak
the fix to Normalize while there: the fix added in 123990 works correctly,
but I like this way better. Finally, now that Triple understands some
non-trivial environment values, teach the unittests about them.
llvm-svn: 124720
This implementation already exists as ConnectedVNInfoEqClasses in
LiveInterval.cpp, and it seems to be generally useful to have a light-weight way
of forming equivalence classes of small integers.
IntEqClasses doesn't allow enumeration of the elements in a class.
llvm-svn: 122293
moves the iterator to end(), and it is valid to call it on end().
That means it is valid to call advanceTo() with any monotonic key sequence.
llvm-svn: 122092
editing of the current interval.
These methods may cause coalescing, there are corresponding set*Unchecked
methods for editing without coalescing. The non-coalescing methods are useful
for applying monotonic transforms to all keys or values in a map without
accidentally coalescing transformed and untransformed intervals.
llvm-svn: 120829
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
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 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
This patch forbids implicit conversion of DenseMap::const_iterator to
DenseMap::iterator which was possible because DenseMapIterator inherited
(publicly) from DenseMapConstIterator. Conversion the other way around is now
allowed as one may expect.
The template DenseMapConstIterator is removed and the template parameter
IsConst which specifies whether the iterator is constant is added to
DenseMapIterator.
Actually IsConst parameter is not necessary since the constness can be
determined from KeyT but this is not relevant to the fix and can be addressed
later.
Patch by Victor Zverovich!
llvm-svn: 86636
even when keys get RAUWed and deleted during its lifetime. By default the keys
act like WeakVHs, but users can pass a third template parameter to configure
how updates work and whether to do anything beyond updating the map on each
action.
It's also possible to automatically acquire a lock around ValueMap updates
triggered by RAUWs and deletes, to support the ExecutionEngine.
llvm-svn: 84890
means that raw_ostream no longer has to #include <iosfwd>. Nothing in llvm
should use raw_os_ostream.h, but llvm-gcc and some unit tests do.
llvm-svn: 79886
- These allow clients to make use of the extra elements in the vector which
have already been allocated, without requiring them to be value initialized.
llvm-svn: 79433
- Provides static constructors for doing number to string conversions without
using temporaries.
- There are several ways to do this, I think given the Twine constraints this
is the simplest one.
- One FIXME for fast number -> hex conversion.
- Added another comment on one last major bit of perf work Twines need, which
is to make raw_svector_ostream more efficient.
llvm-svn: 77445
- Yay for '-'s and simplifications!
- I kept StringMap::GetOrCreateValue for compatibility purposes, this can
eventually go away. Likewise the StringMapEntry Create functions still follow
the old style.
- NIFC.
llvm-svn: 76888
EXPECT_EQ(expected, actual) . This will make error messages understandable as
it uses terms such as "expected" and "actual" based on the order of arguments.
llvm-svn: 73150
- The code is silly, I'm just amusing myself. Rewrite to be efficient
if you like. :)
Also, if you wish to debate the proper names of the triple components
I'm all ears.
llvm-svn: 68252
causing assertion failures in getSExtValue().
Fix it by making highWordBits actually contain what its name says,
and add some more unit-tests for APInt.
This fixes PR3419.
llvm-svn: 63107
The way this worked before was to test APInt by running
"lli -force-interpreter=true" knowing the lli uses APInt under the hood to
store its values. Now, we test APInt directly.
llvm-svn: 62514
StringMapEntryInitializer classes. Leave it for the compiler to figure out what
the type is and what "0" should be transformed into.
* Un-disable the unit tests which test the StringMapEntryInitializer class.
llvm-svn: 61922
* Added the first LLVM unittest -- DenseMap.
* Updated mkpatch utility to include llvm/unittests dir
* Added top-level target "unittests" to run all unittests
llvm-svn: 61541
Chandler Carruth