ErrorOr<void> represents an operation that returns nothing, but can still fail.
It should be used in cases where you need the aditional user data that ErrorOr
provides over error_code.
llvm-svn: 173209
A SparseMultiSet adds multiset behavior to SparseSet, while retaining SparseSet's desirable properties. Essentially, SparseMultiSet provides multiset behavior by storing its dense data in doubly linked lists that are inlined into the dense vector. This allows it to provide good data locality as well as vector-like constant-time clear() and fast constant time find(), insert(), and erase(). It also allows SparseMultiSet to have a builtin recycler rather than keeping SparseSet's behavior of always swapping upon removal, which allows it to preserve more iterators. It's often a better alternative to a SparseSet of a growable container or vector-of-vector.
llvm-svn: 173064
In r143502, we renamed getHostTriple() to getDefaultTargetTriple()
as part of work to allow the user to supply a different default
target triple at configure time. This change also affected the JIT.
However, it is inappropriate to use the default target triple in the
JIT in most circumstances because this will not necessarily match
the current architecture used by the process, leading to illegal
instruction and other such errors at run time.
Introduce the getProcessTriple() function for use in the JIT and
its clients, and cause the JIT to use it. On architectures with a
single bitness, the host and process triples are identical. On other
architectures, the host triple represents the architecture of the
host CPU, while the process triple represents the architecture used
by the host CPU to interpret machine code within the current process.
For example, when executing 32-bit code on a 64-bit Linux machine,
the host triple may be 'x86_64-unknown-linux-gnu', while the process
triple may be 'i386-unknown-linux-gnu'.
This fixes JIT for the 32-on-64-bit (and vice versa) build on non-Apple
platforms.
Differential Revision: http://llvm-reviews.chandlerc.com/D254
llvm-svn: 172627
This is similar to the existing Recycler allocator, but instead of
recycling individual objects from a BumpPtrAllocator, arrays of
different sizes can be allocated.
llvm-svn: 171581
wall time, user time, and system time since a process started.
For walltime, we currently use TimeValue's interface and a global
initializer to compute a close approximation of total process runtime.
For user time, this adds support for an somewhat more precise timing
mechanism -- clock_gettime with the CLOCK_PROCESS_CPUTIME_ID clock
selected.
For system time, we have to do a full getrusage call to extract the
system time from the OS. This is expensive but unavoidable.
In passing, clean up the implementation of the old APIs and fix some
latent bugs in the Windows code. This might have manifested on Windows
ARM systems or other systems with strange 64-bit integer behavior.
The old API for this both user time and system time simultaneously from
a single getrusage call. While this results in fewer system calls, it
also results in a lower precision user time and if only user time is
desired, it introduces a higher overhead. It may be worthwhile to switch
some of the pass timers to not track system time and directly track user
and wall time. The old API also tracked walltime in a confusing way --
it just set it to the current walltime rather than providing any measure
of wall time since the process started the way buth user and system time
are tracked. The new API is more consistent here.
The plan is to eventually implement these methods for a *child* process
by using the wait3(2) system call to populate an rusage struct
representing the whole subprocess execution. That way, after waiting on
a child process its stats will become accurate and cheap to query.
llvm-svn: 171551
The iplist::clear() function can be quite expensive because it traverses
the entire list, calling deleteNode() and removeNodeFromList() on each
element. If node destruction and deallocation can be handled some other
way, clearAndLeakNodesUnsafely() can be used to jettison all nodes
without bringing them into cache.
The function name is meant to be ominous.
llvm-svn: 171540
* Add support for specifying the alignment to use.
* Add the concept of native endianness. Used for unaligned native types.
The native alignment and read/write simplification is based on a patch by Richard Smith.
llvm-svn: 171406
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.
There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.
The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.
I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).
I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.
llvm-svn: 171366
Implement the old API in terms of the new one. This simplifies the
implementation on Windows which can now re-use the self_process's once
initialization.
llvm-svn: 171330
This adds AlignedCharArray<Alignment, Size>. A templated struct that contains
a member named buffer of type char[Size] that is aligned to Alignment.
llvm-svn: 171319
The coding style used here is not LLVM's style because this is modeled
after a Boost interface and thus done in the style of a candidate C++
standard library interface. I'll probably end up proposing it as
a standard C++ library if it proves to be reasonably portable and
useful.
This is just the most basic parts of the interface -- getting the
process ID out of it. However, it helps sketch out some of the boiler
plate such as the base class, derived class, shared code, and static
factory function. It also introduces a unittest so that I can
incrementally ensure this stuff works.
However, I've not even compiled this code for Windows yet. I'll try to
fix any Windows fallout from the bots, and if I can't fix it I'll revert
and get someone on Windows to help out. There isn't a lot more that is
mandatory, so soon I'll switch to just stubbing out the Windows side and
get Michael Spencer to help with implementation as he can test it
directly.
llvm-svn: 171289
The single-element ilist::splice() function supports a noop move:
List.splice(I, List, I);
The corresponding std::list function doesn't allow that, so add a unit
test to document that behavior.
This also means that
List.splice(I, List, F);
is somewhat surprisingly not equivalent to
List.splice(I, List, F, next(F));
This patch adds an assertion to catch the illegal case I == F above.
Alternatively, we could make I == F a legal noop, but that would make
ilist differ even more from std::list.
llvm-svn: 170443
structures to and from YAML using traits. The first client will
be the test suite of lld. The documentation will show up at:
http://llvm.org/docs/YamlIO.html
llvm-svn: 170019
Rationale:
1) This was the name in the comment block. ;]
2) It matches Clang's __has_feature naming convention.
3) It matches other compiler-feature-test conventions.
Sorry for the noise. =]
I've also switch the comment block to use a \brief tag and not duplicate
the name.
llvm-svn: 168996
appropriate unit tests. This change in itself is not expected to
affect any functionality at this point, but it will serve as a
stepping stone to improve FileCheck's variable matching capabilities.
Luckily, our regex implementation already supports backreferences,
although a bit of hacking is required to enable it. It supports both
Basic Regular Expressions (BREs) and Extended Regular Expressions
(EREs), without supporting backrefs for EREs, following POSIX strictly
in this respect. And EREs is what we actually use (rightly). This is
contrary to many implementations (including the default on Linux) of
POSIX regexes, that do allow backrefs in EREs.
Adding backref support to our EREs is a very simple change in the
regcomp parsing code. I fail to think of significant cases where it
would clash with existing things, and can bring more versatility to
the regexes we write. There's always the danger of a backref in a
specially crafted regex causing exponential matching times, but since
we mainly use them for testing purposes I don't think it's a big
problem. [it can also be placed behind a flag specific to FileCheck,
if needed].
For more details, see:
* http://lists.cs.uiuc.edu/pipermail/llvmdev/2012-November/055840.html
* http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20121126/156878.html
llvm-svn: 168802
The SectionMemoryManager now supports (and requires) applying section-specific page permissions. Clients using this memory manager must call either MCJIT::finalizeObject() or SectionMemoryManager::applyPermissions() before executing JITed code.
See r168718 for changes from the previous implementation.
llvm-svn: 168721
This commit is primarily here for the revision history. I'm about to move the SectionMemoryManager into the RuntimeDyld library, but I wanted to check the changes in here so people could see the differences in the updated implementation.
llvm-svn: 168718
The rationale is to get YAML filenames in diagnostics from
yaml::Stream::printError -- currently the filename is hard-coded as
"YAML" because there's no buffer information available.
Patch by Kim Gräsman!
llvm-svn: 168341
These tests were all failing since the old JIT doesn't work
for PowerPC (any more), and there are no plans to attempt to
fix it again (instead, work focuses on MCJIT).
llvm-svn: 167133
treating it as if it were an IEEE floating-point type with 106-bit
mantissa.
This makes compile-time arithmetic on "long double" for PowerPC
in clang (in particular parsing of floating point constants)
work, and fixes all "long double" related failures in the test
suite.
llvm-svn: 166951
When building with LTO, the internalize pass is hiding some global symbols
that are necessary for the JIT unittests. It seems like that may be a bug in
LTO to do that by default, but until that gets fixed, this change makes sure
that we export the necessary symbols for the tests to pass.
llvm-svn: 166220
Additionally, all such cases are handled with no dynamic check.
All `classof()` of the form
class Foo {
[...]
static bool classof(const Bar *) { return true; }
[...]
}
where Foo is an ancestor of Bar are no longer necessary.
Don't write them!
Note: The exact test is `is_base_of<Foo, Bar>`, which is non-strict, so
that Foo is considered an ancestor of itself.
This leads to the following rule of thumb for LLVM-style RTTI:
The argument type of `classof()` should be a strict ancestor.
For more information about implementing LLVM-style RTTI, see
docs/HowToSetUpLLVMStyleRTTI.rst
llvm-svn: 165765
- The current_pos function is supposed to return all the written bytes, not the
current position of the underlying stream.
- This caused tell() to be broken whenever the underlying stream had buffered
content.
llvm-svn: 163948
TinyPtrVector. With these, it is sufficiently functional for my more
normal / pedestrian uses.
I've not included some r-value reference stuff here because the value
type for a TinyPtrVector is, necessarily, just a pointer.
I've added tests that cover the basic behavior of these routines, but
they aren't as comprehensive as I'd like. In particular, they don't
really test the iterator semantics as thoroughly as they should. Maybe
some brave soul will feel enterprising and flesh them out. ;]
llvm-svn: 161104
Since the llvm::sys::fs::map_file_pages() support function it relies on
is not yet implemented on Windows, the unit tests for FileOutputBuffer
are currently conditionalized to run only on unix.
llvm-svn: 161099
No new test case is added.
This patch makes test JITTest.FunctionIsRecompiledAndRelinked pass on mips
platform.
Patch by Petar Jovanovic.
llvm-svn: 161098
for this class. These tests exercise most of the basic properties, but
the API for TinyPtrVector is very strange currently. My plan is to start
fleshing out the API to match that of SmallVector, but I wanted a test
for what is there first.
Sadly, it doesn't look reasonable to just re-use the SmallVector tests,
as this container can only ever store pointers, and much of the
SmallVector testing is to get construction and destruction right.
Just to get this basic test working, I had to add value_type to the
interface.
While here I found a subtle bug in the combination of 'erase', 'begin',
and 'end'. Both 'begin' and 'end' wanted to use a null pointer to
indicate the "end" iterator of an empty vector, regardless of whether
there is actually a vector allocated or the pointer union is null.
Everything else was fine with this except for erase. If you erase the
last element of a vector after it has held more than one element, we
return the end iterator of the underlying SmallVector which need not be
a null pointer. Instead, simply use the pointer, and poniter + size()
begin/end definitions in the tiny case, and delegate to the inner vector
whenever it is present.
llvm-svn: 161024
test more than a single instantiation of SmallVector.
Add testing for 0, 1, 2, and 4 element sized "small" buffers. These
appear to be essentially untested in the unit tests until now.
Fix several tests to be robust in the face of a '0' small buffer. As
a consequence of this size buffer, the growth patterns are actually
observable in the test -- yes this means that many tests never caused
a grow to occur before. For some tests I've merely added a reserve call
to normalize behavior. For others, the growth is actually interesting,
and so I captured the fact that growth would occur and adjusted the
assertions to not assume how rapidly growth occured.
Also update the specialization for a '0' small buffer length to have all
the same interface points as the normal small vector.
llvm-svn: 161001
Added a basic unit test for this with CreateCondBr. I didn't go all the
way and test the switch side as the boilerplate for setting up the
switch IRBuilder unit tests is a lot more. Fortunately, the two share
all the interesting code paths.
llvm-svn: 160251
the move of *Builder classes into the Core library.
No uses of this builder in Clang or DragonEgg I could find.
If there is a desire to have an IR-building-support library that
contains all of these builders, that can be easily added, but currently
it seems likely that these add no real overhead to VMCore.
llvm-svn: 160243
IRBuilder, DIBuilder, etc.
This is the proper layering as MDBuilder can't be used (or implemented)
without the Core Metadata representation.
Patches to Clang and Dragonegg coming up.
llvm-svn: 160237
This was always part of the VMCore library out of necessity -- it deals
entirely in the IR. The .cpp file in fact was already part of the VMCore
library. This is just a mechanical move.
I've tried to go through and re-apply the coding standard's preferred
header sort, but at 40-ish files, I may have gotten some wrong. Please
let me know if so.
I'll be committing the corresponding updates to Clang and Polly, and
Duncan has DragonEgg.
Thanks to Bill and Eric for giving the green light for this bit of cleanup.
llvm-svn: 159421
include/llvm/Analysis/DebugInfo.h to include/llvm/DebugInfo.h.
The reasoning is because the DebugInfo module is simply an interface to the
debug info MDNodes and has nothing to do with analysis.
llvm-svn: 159312
- LHS exclude RHS
- LHS intersect RHS (LHS successors will keeped)
- RHS exclude LHS
The complexity is N+M, where
N is size of LHS
M is size of RHS.
llvm-svn: 159201
Makefiles, the CMake files in every other part of the LLVM tree, and
sanity.
This should also restore the output tree structure of all the unit
tests, sorry for breaking that, and thanks for letting me know.
The fundamental change is to put a CMakeLists.txt file in the unittest
directory, with a single test binary produced from it. This has several
advantages:
- No more weird directory stripping in the unittest macro, allowing it
to be used more readily in other projects.
- No more directory prefixes on all the source files.
- Allows correct and precise use of LLVM's per-directory dependency
system.
- Allows use of the checking logic for source files that have not been
added to the CMake build. This uncovered a file being skipped with
CMake in LLVM and one in Clang's unit tests.
- Makes Specifying conditional compilation or other custom logic for JIT
tests easier.
It did require adding the concept of an explicit 'optional' source file
to the CMake build so that the missing-file check can skip cases where
the file is *supposed* to be missing. =]
This is another chunk of refactoring the CMake build in order to make it
usable for other clients like CompilerRT / ASan / TSan.
Note that this is interdependent with a Clang CMake change.
llvm-svn: 158909
facilities.
This was only used in one place in LLVM, and was used pervasively (but
with different code!) in Clang. It has no advantages over the standard
CMake facilities and in some cases disadvantages.
llvm-svn: 158889
The TEST_F macros actually declare *subclasses* of the test fixtures.
Even if they didn't we don't want them to declare external functions.
The entire unit test, including both the fixture class and the fixture
test cases should be wrapped in the anonymous namespace.
This issue was caught by the new '-Winternal-linkage-in-inline' warning.
llvm-svn: 158798
StringMap suffered from the same bug as DenseMap: when you explicitly
construct it with a small number of buckets, you can arrange for the
tombstone-based growth path to be followed when the number of buckets
was less than '8'. In that case, even with a full map, it would compare
'0' as not less than '0', and refuse to grow the table, leading to
inf-loops trying to find an empty bucket on the next insertion. The fix
is very simple: use '<=' as the comparison. The same fix was applied to
DenseMap as well during its recent refactoring.
Thanks to Alex Bolz for the great report and test case. =]
llvm-svn: 158725
It always returns the iterator for the first inserted element, or the passed in
iterator if the inserted range was empty. Flesh out the unit test more and fix
all the cases it uncovered so far.
llvm-svn: 158645
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.
llvm-svn: 158641
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.
llvm-svn: 158639
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. =]
llvm-svn: 158638
platforms.
Also, remove one assertion on MSVC because it produces a completely
preposterous result, claiming something needs 12-byte alignment.
llvm-svn: 158599
array of a suitable size and alignment for any of a number of different
types to be stored into the character array.
The mechanisms for producing an explicitly aligned type are fairly
complex because this operation is poorly supported on all compilers.
We've spent a fairly significant amount of time experimenting with
different implementations inside of Google, and the one using explicitly
expanded templates has been the most robust.
Credit goes to Nick Lewycky for writing the first 20 versions or so of
this logic we had inside of Google. I based this on the only one to
actually survive. In case anyone is worried, yes we are both explicitly
re-contributing and re-licensing it for LLVM. =]
Once the issues with actually specifying the alignment are finished, it
turns out that most compilers don't in turn align anything the way they
are instructed. Testing of this logic against both Clang and GCC
indicate that the alignment constraints are largely ignored by both
compilers! I've come up with and used a work-around by wrapping each
alignment-hinted type directly in a struct, and using that struct to
align the character array through a union. This elaborate hackery is
terrifying, but I've included testing that caught a terrifying number of
bugs in every other technique I've tried.
All of this in order to implement a poor C++98 programmers emulation of
C++11 unrestricted unions in classes such as SmallDenseMap.
llvm-svn: 158597
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.
llvm-svn: 158593
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.
llvm-svn: 158589
LLVM is now -Wunused-private-field clean except for
- lib/MC/MCDisassembler/Disassembler.h. Not sure why it keeps all those unaccessible fields.
- gtest.
llvm-svn: 158096
Changed type of Items collection: from std::vector to std::list.
Also some small fixes made in IntegersSubset.h, IntegersSubsetMapping.h and IntegersSubsetTest.cpp.
llvm-svn: 157987
Returning a temporary BitVector is very expensive. If you must, create
the temporary explicitly: Use BitVector(A).flip() instead of ~A.
llvm-svn: 156768
- FlatArrayMap. Very simple map container that uses flat array inside.
- MultiImplMap. Map container interface, that has two modes, one for small amount of elements and one for big amount.
- SmallMap. SmallMap is DenseMap compatible MultiImplMap. It uses FlatArrayMap for small mode, and DenseMap for big mode.
Also added unittests for new classes and update for ProgrammersManual.
For more details about new classes see ProgrammersManual and comments in sourcecode.
llvm-svn: 155557
This nicely handles the most common case of virtual register sets, but
also handles anticipated cases where we will map pointers to IDs.
The goal is not to develop a completely generic SparseSet
template. Instead we want to handle the expected uses within llvm
without any template antics in the client code. I'm adding a bit of
template nastiness here, and some assumption about expected usage in
order to make the client code very clean.
The expected common uses cases I'm designing for:
- integer keys that need to be reindexed, and may map to additional
data
- densely numbered objects where we want pointer keys because no
number->object map exists.
llvm-svn: 155227
through the use of 'fpmath' metadata. Currently this only provides a 'fpaccuracy'
value, which may be a number in ULPs or the keyword 'fast', however the intent is
that this will be extended with additional information about NaN's, infinities
etc later. No optimizations have been hooked up to this so far.
llvm-svn: 154822
(and hopefully on Windows). The bots have been down most of the day
because of this, and it's not clear to me what all will be required to
fix it.
The commits started with r153205, then r153207, r153208, and r153221.
The first commit seems to be the real culprit, but I couldn't revert
a smaller number of patches.
When resubmitting, r153207 and r153208 should be folded into r153205,
they were simple build fixes.
llvm-svn: 153241
1. Declare a virtual function getPointerToNamedFunction() in JITMemoryManager
2. Move the implementation of getPointerToNamedFunction() form JIT/MCJIT to DefaultJITMemoryManager.
llvm-svn: 153205
Also refactor the existing OProfile profiling code to reuse the same interfaces with the VTune profiling code.
In addition, unit tests for the profiling interfaces were added.
This patch was prepared by Andrew Kaylor and Daniel Malea, and reviewed in the llvm-commits list by Jim Grosbach
llvm-svn: 152620
integral and enumeration types. This is accomplished with a bit of
template type trait magic. Thanks to Richard Smith for the core idea
here to detect viable types by detecting the set of types which can be
default constructed in a template parameter.
This is used (in conjunction with a system for detecting nullptr_t
should it exist) to provide an is_integral_or_enum type trait that
doesn't need a whitelist or direct compiler support.
With this, the hashing is extended to the more general facility. This
will be used in a subsequent commit to hashing more things, but I wanted
to make sure the type trait magic went through the build bots separately
in case other compilers don't like this formulation.
llvm-svn: 152217
This currently assumes that both sets have the same SmallSize to keep the implementation simple,
a limitation that can be lifted if someone cares.
llvm-svn: 152143
just ensure that the number of bytes in the pair is the sum of the bytes
in each side of the pair. As long as thats true, there are no extra
bytes that might be padding.
Also add a few tests that previously would have slipped through the
checking. The more accurate checking mechanism catches these and ensures
they are handled conservatively correctly.
Thanks to Duncan for prodding me to do this right and more simply.
llvm-svn: 151891
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
Nick Lewycky