Commit Graph

10 Commits

Author SHA1 Message Date
Pete Cooper
fbaf206f47 Fixed bug in SmallDenseMap where it wouldn't leave enough space for an empty bucket if the number of values was exactly equal to the small capacity. This led to an infinite loop when finding a non-existent element
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166492 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-23 18:47:35 +00:00
Chandler Carruth
8dffa4a106 Add a unit test for 'swap', and fix a pile of bugs in
SmallDenseMap::swap.

First, make it parse cleanly. Yay for uninstantiated methods.

Second, make the inline-buckets case work correctly. This is way
trickier than it should be due to the uninitialized values in empty and
tombstone buckets.

Finally fix a few typos that caused construction/destruction mismatches
in the counting unittest.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158641 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-17 11:28:13 +00:00
Chandler Carruth
6446d7e6d6 Add tests for *DenesMap for both key and value types' construction and
destruction and fix a bug in SmallDenseMap they caught.

This is kind of a poor-man's version of the testing that just adds the
addresses to a set on construction and removes them on destruction. We
check that double construction and double destruction don't occur.
Amusingly enough, this is enough to catch a lot of SmallDenseMap issues
because we spend a lot of time with fixed stable addresses in the inline
buffer.

The SmallDenseMap bug fix included makes grow() not double-destroy in
some cases. It also fixes a FIXME there, the code was pretty crappy. We
now don't have any wasted initialization, but we do move the entries in
inline bucket array an extra time. It's probably a better tradeoff, and
is much easier to get correct.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158639 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-17 10:33:51 +00:00
Chandler Carruth
dd9d38d57b Introduce a SmallDenseMap container that re-uses the existing DenseMap
implementation.

This type includes an inline bucket array which is used initially. Once
it is exceeded, an array of 64 buckets is allocated on the heap. The
bucket count grows from there as needed. Some highlights of this
implementation:

- The inline buffer is very carefully aligned, and so supports types
  with alignment constraints.
- It works hard to avoid aliasing issues.
- Supports types with non-trivial constructors, destructors, copy
  constructions, etc. It works reasonably hard to minimize copies and
  unnecessary initialization. The most common initialization is to set
  keys to the empty key, and so that should be fast if at all possible.

This class has a performance / space trade-off. It tries to optimize for
relatively small maps, and so packs the inline bucket array densely into
the object. It will be marginally slower than a normal DenseMap in a few
use patterns, so it isn't appropriate everywhere.

The unit tests for DenseMap have been generalized a bit to support
running over different map implementations in addition to different
key/value types. They've then been automatically extended to cover the
new container through the magic of GoogleTest's typed tests.

All of this is still a bit rough though. I'm going to be cleaning up
some aspects of the implementation, documenting things better, and
adding tests which include non-trivial types. As soon as I'm comfortable
with the correctness, I plan to switch existing users of SmallMap over
to this class as it is already more correct w.r.t. construction and
destruction of objects iin the map.

Thanks to Benjamin Kramer for all the reviews of this and the lead-up
patches. That said, more review on this would really be appreciated. As
I've noted a few times, I'm quite surprised how hard it is to get the
semantics for a hashtable-based map container with a small buffer
optimization correct. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158638 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-17 09:05:09 +00:00
Chandler Carruth
7027ba92dd Work around a bug with MSVC 10 where it fails to recognize a valid use
of typename. GCC and Clang were fine with this, but MSVC won't accept
it. Fortunately, it also doesn't need it. Yuck.

Thanks to Nakamura for pointing this out in IRC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158593 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-16 03:54:11 +00:00
Chandler Carruth
e5c7bc65c3 Type parameterize the DenseMap unit tests.
These were already trying to be type parameterized over different
key/value pairs. I've realized this goal using GoogleTest's typed test
functionality. This allows us to easily replicate the tests across
different key/value combinations and soon different mapping templates.

I've fixed a few bugs in the tests and extended them a bit in the
process as many tests were only applying to the int->int mapping.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158589 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-16 01:31:33 +00:00
Talin
babd5980d8 DenseMap::find_as() and unit tests.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149229 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-30 06:55:43 +00:00
Jeffrey Yasskin
81cf432569 Fix DenseMap iterator constness.
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!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86636 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10 01:02:17 +00:00
Misha Brukman
c870bb5c96 Minor cleanup for unittest:
* Fixed {copy,assignment} constructor test names
* s/EXPECT_EQ(true, ...)/ASSERT_TRUE(...)/

Patch by Talin.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61883 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-07 21:13:53 +00:00
Misha Brukman
8fb520eb4f Original patch by Talin.
* Added the first LLVM unittest -- DenseMap.
* Updated mkpatch utility to include llvm/unittests dir
* Added top-level target "unittests" to run all unittests


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61541 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-01 02:24:48 +00:00