The current approach isn't a long-term viable pattern. Given the set of
architectures A, vendors V, operating systems O, and environments E, it
does |A| * |V| * |O| * |E| * 4! tests. As LLVM grows, this test keeps
getting slower, despite my working very hard to make it get some
"optimizations" even in -O0 builds in order to lower the constant
factors. Fundamentally, we're doing an unreasonable amount of work.i
Looking at the specific thing being tested -- the goal seems very
clearly to be testing the *permutations*, not the *combinations*. The
combinations are driving up the complexity much more than anything else.
Instead, test every possible value for a given triple entry in every
permutation of *some* triple. This really seems to cover the core goal
of the test. Every single possible triple component is tested in every
position. But because we keep the rest of the triple constant, it does
so in a dramatically more scalable amount of time. With this model we do
(|A| + |V| + |O| + |E|) * 4! tests.
For me on a debug build, this goes from running for 19 seconds to 19
milliseconds, or a 1000x improvement. This makes a world of difference
for the critical path of 'ninja check-llvm' and other extremely common
workflows.
Thanks to Renato, Dean, and David for the helpful review comments and
helping me refine the explanation of the change.
Differential Revision: https://reviews.llvm.org/D23156
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277912 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: By generalize the interface, users are able to inject more flexible Node token into the algorithm, for example, a pair of vector<Node>* and index integer. Currently I only migrated SCCIterator to use NodeRef, but more is coming. It's a NFC.
Reviewers: dblaikie, chandlerc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D22937
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277399 91177308-0d34-0410-b5e6-96231b3b80d8
This adds versions of operator + and - which are optimized for the LHS/RHS of the
operator being RValue's. When an RValue is available, we can use its storage space
instead of allocating new space.
On code such as ConstantRange which makes heavy use of APInt's over 64-bits in size,
this results in significant numbers of saved allocations.
Thanks to David Blaikie for all the review and most of the code here.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276470 91177308-0d34-0410-b5e6-96231b3b80d8
This provides an elegant pattern to solve the "construct if not in map
already" problem we have many times in LLVM. Without try_emplace we
either have to rely on a sentinel value (nullptr) or do two lookups.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276277 91177308-0d34-0410-b5e6-96231b3b80d8
Coincidentally this function maps to the C++17 try_emplace. Rename it
for consistentcy with C++17 std::map. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276276 91177308-0d34-0410-b5e6-96231b3b80d8
Doing "I++" inside of an EXPECT_* triggers
warning: expression with side effects has no effect in an unevaluated context
because EXPECT_* partially expands to
EqHelper<(sizeof(::testing::internal::IsNullLiteralHelper(i++)) == 1)>
which is an unevaluated context.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275717 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: Normally when you do a bitwise operation on an enum value, you
get back an instance of the underlying type (e.g. int). But using this
macro, bitwise ops on your enum will return you back instances of the
enum. This is particularly useful for enums which represent a
combination of flags.
Suppose you have a function which takes an int and a set of flags. One
way to do this would be to take two numeric params:
enum SomeFlags { F1 = 1, F2 = 2, F3 = 4, ... };
void Fn(int Num, int Flags);
void foo() {
Fn(42, F2 | F3);
}
But now if you get the order of arguments wrong, you won't get an error.
You might try to fix this by changing the signature of Fn so it accepts
a SomeFlags arg:
enum SomeFlags { F1 = 1, F2 = 2, F3 = 4, ... };
void Fn(int Num, SomeFlags Flags);
void foo() {
Fn(42, static_cast<SomeFlags>(F2 | F3));
}
But now we need a static cast after doing "F2 | F3" because the result
of that computation is the enum's underlying type.
This patch adds a mechanism which gives us the safety of the second
approach with the brevity of the first.
enum SomeFlags {
F1 = 1, F2 = 2, F3 = 4, ..., F_MAX = 128,
LLVM_MARK_AS_BITMASK_ENUM(F_MAX)
};
void Fn(int Num, SomeFlags Flags);
void foo() {
Fn(42, F2 | F3); // No static_cast.
}
The LLVM_MARK_AS_BITMASK_ENUM macro enables overloads for bitwise
operators on SomeFlags. Critically, these operators return the enum
type, not its underlying type, so you don't need any static_casts.
An advantage of this solution over the previously-proposed BitMask class
[0, 1] is that we don't need any wrapper classes -- we can operate
directly on the enum itself.
The approach here is somewhat similar to OpenOffice's typed_flags_set
[2]. But we skirt the need for a wrapper class (and a good deal of
complexity) by judicious use of enable_if. We SFINAE on the presence of
a particular enumerator (added by the LLVM_MARK_AS_BITMASK_ENUM macro)
instead of using a traits class so that it's impossible to use the enum
before the overloads are present. The solution here also seamlessly
works across multiple namespaces.
[0] http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20150622/283369.html
[1] http://lists.llvm.org/pipermail/llvm-commits/attachments/20150623/073434b6/attachment.obj
[2] https://cgit.freedesktop.org/libreoffice/core/tree/include/o3tl/typed_flags_set.hxx
Reviewers: chandlerc, rsmith
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D22279
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275292 91177308-0d34-0410-b5e6-96231b3b80d8
re-insertion of entries into the worklist moves them to the end.
This is fairly similar to a SetVector, but helps in the case where in
addition to not inserting duplicates you want to adjust the sequence of
a pop-off-the-back worklist.
I'm not at all attached to the name of this data structure if others
have better suggestions, but this is one that David Majnemer brought up
in IRC discussions that seems plausible.
I've trimmed the interface down somewhat from SetVector's interface
because several things make less sense here IMO: iteration primarily.
I'd prefer to add these back as we have users that need them. My use
case doesn't even need all of what is provided here. =]
I've also included a basic unittest to make sure this functions
reasonably.
Differential Revision: http://reviews.llvm.org/D21866
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274198 91177308-0d34-0410-b5e6-96231b3b80d8
Current implementation leaves the object in an invalid state.
This reverts commit bf0c389ac683cd6c0e5959b16537e59e5f4589e3.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@272965 91177308-0d34-0410-b5e6-96231b3b80d8
Also fix slice wrappers drop_front and drop_back.
The unittests are pretty awkward, but do the job; alternatives
welcome!
..and yes, I do have ArrayRefs with more than 4 billion elements.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271546 91177308-0d34-0410-b5e6-96231b3b80d8
APInt::slt was copying the LHS and RHS in to temporaries then making
them unsigned so that it could use an unsigned comparision. It did
this even on the paths which were trivial to give results for, such
as the sign bit of the LHS being set while RHS was not set.
This changes the logic to return out immediately in the trivial cases,
and use an unsigned comparison in the remaining cases. But this time,
just use the unsigned comparison directly without creating any temporaries.
This works because, for example:
true = (-2 slt -1) = (0xFE ult 0xFF)
Also added some tests explicitly for slt with APInt's larger than 64-bits
so that this new code is tested.
Using the memory for 'opt -O2 verify-uselistorder.lto.opt.bc -o opt.bc'
(see r236629 for details), this reduces the number of allocations from
26.8M to 23.9M.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@270881 91177308-0d34-0410-b5e6-96231b3b80d8
a sequence of values.
It increments through the values in the half-open range: [Begin, End),
producing those values when indirecting the iterator. It should support
integers, iterators, and any other type providing these basic arithmetic
operations.
This came up in the C++ standards committee meeting, and it seemed like
a useful construct that LLVM might want as well, and I wanted to
understand how easily we could solve it. I suspect this can be used to
write simpler counting loops even in LLVM along the lines of:
for (int i : seq(0, v.size())) {
...
};
As part of this, I had to fix the lack of a proxy object returned from
the operator[] in our iterator facade.
Differential Revision: http://reviews.llvm.org/D17870
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@269390 91177308-0d34-0410-b5e6-96231b3b80d8
We have it for StringRef but not ArrayRef, and ArrayRef has drop_back,
so I see no reason it shouldn't have drop_front. Splitting this out of a
change that I have that will use this funcitonality.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268434 91177308-0d34-0410-b5e6-96231b3b80d8
A DenseMap doesn't store the hashes, so it needs to recompute them when
the table is resized.
In some applications the hashing cost is noticeable. That is the case
for example in lld for symbol names (StringRef).
This patch adds a templated structure that can wraps any value that can
go in a DenseMap and caches the hash.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266981 91177308-0d34-0410-b5e6-96231b3b80d8
There is code under review that requires StringMap to have a copy constructor,
and this makes StringMap more consistent with our other containers (like
DenseMap) that have copy constructors.
Differential Revision: http://reviews.llvm.org/D18506
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264906 91177308-0d34-0410-b5e6-96231b3b80d8
This makes us no longer relying on move-construction elision by the compiler.
Suggested by D. Blaikie.
From: Mehdi Amini <mehdi.amini@apple.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264475 91177308-0d34-0410-b5e6-96231b3b80d8
This is a recommit of r264414 after fixing the buildbot failure caused by
incompatible use of std::vector.erase().
The original message:
Add erase() which returns an iterator pointing to the next element after the
erased one. This makes it possible to erase selected elements while iterating
over the SetVector :
while (I != E)
if (test(*I))
I = SetVector.erase(I);
else
++I;
Reviewers: qcolombet, mcrosier, MatzeB, dblaikie
Subscribers: dberlin, dblaikie, mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D18281
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264450 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Add erase() which returns an iterator pointing to the next element after the
erased one. This makes it possible to erase selected elements while iterating
over the SetVector :
while (I != E)
if (test(*I))
I = SetVector.erase(I);
else
++I;
Reviewers: qcolombet, mcrosier, MatzeB, dblaikie
Subscribers: dberlin, dblaikie, mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D18281
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264414 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Loading IR with debug info improves MDString::get() from 19ms to 10ms.
This is a rework of D16597 with adding an "emplace" method on the StringMap
to avoid requiring the MDString move ctor to be public.
Reviewers: dexonsmith
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D17920
From: Mehdi Amini <mehdi.amini@apple.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264386 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
StringMap ctor accepts an initialize size, but expect it to be
rounded to the next power of 2. The ctor can handle that directly
instead of expecting clients to round it. Also, since the map will
resize itself when 75% full, take this into account an initialize
a larger initial size to avoid any growth.
Reviewers: dblaikie
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D18344
From: Mehdi Amini <mehdi.amini@apple.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264385 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Just running the loop in the unittests for a few more iterations
(till 48) exhibit that the condition on the limit was not handled
properly in r263522.
Rewrite the test to use a class to count move/copies that happens
when inserting into the map.
Also take the opportunity to refactor the logic to compute the
number of buckets required for a given number of entries in the map.
Use this when constructing a DenseMap with a desired size given to
the constructor (and add a tests for this).
Reviewers: dblaikie
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D18345
From: Mehdi Amini <mehdi.amini@apple.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264384 91177308-0d34-0410-b5e6-96231b3b80d8
The BumpPtrAllocator currently doesn't handle zero length allocations well.
The discussion for how to fix that is ongoing. However, there's no need
for StringRef::copy to actually allocate anything here anyway, so just
return StringRef() when we get a zero length copy.
Reviewed by David Blaikie
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264201 91177308-0d34-0410-b5e6-96231b3b80d8
MSVC as usual:
C:\Buildbot\Slave\llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast\llvm.src\include\llvm/ADT/STLExtras.h(120):
error C2100: illegal indirection
C:\Buildbot\Slave\llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast\llvm.src\include\llvm/IR/Instructions.h(3966):
note: see reference to class template instantiation
'llvm::mapped_iterator<llvm::User::op_iterator,llvm::CatchSwitchInst::DerefFnTy>'
being compiled
This reverts commit e091dd63f1f34e043748e28ad160d3bc17731168.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263760 91177308-0d34-0410-b5e6-96231b3b80d8
In some places, like InstCombine, we resize a DenseMap to fit the elements
we intend to put in it, then insert those elements (to avoid continual
reallocations as it grows). But .resize(foo) doesn't actually do what
people think; it resizes to foo buckets (which is really an
implementation detail the user of DenseMap probably shouldn't care about),
not the space required to fit foo elements. DenseMap grows if 3/4 of its
buckets are full, so this actually causes one forced reallocation every
time instead of avoiding a reallocation.
This patch makes .resize(foo) do the intuitive thing: it grows to the size
necessary to fit foo elements without new allocations.
Also include a test to verify that .resize() actually does what we think it
does.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263522 91177308-0d34-0410-b5e6-96231b3b80d8
Add support for trimming a single kind of character from a StringRef.
This makes the common case of trimming null bytes much neater. It's also
probably a bit speedier too, since it avoids creating a std::bitset in
find_{first,last}_not_of.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260925 91177308-0d34-0410-b5e6-96231b3b80d8
