to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351636 91177308-0d34-0410-b5e6-96231b3b80d8
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.
In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.
Differential Revision: https://reviews.llvm.org/D43624
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@332240 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
LoopPredication is not profitable when the loop is known to always exit
through some block other than the latch block.
A coarse grained latch check can cause loop predication to predicate the
loop, and unconditionally deoptimize.
However, without predicating the loop, the guard may never fail within the
loop during the dynamic execution because the non-latch loop termination
condition exits the loop before the latch condition causes the loop to
exit.
We teach LP about this using BranchProfileInfo pass.
Reviewers: apilipenko, skatkov, mkazantsev, reames
Reviewed by: skatkov
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D44667
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@328210 91177308-0d34-0410-b5e6-96231b3b80d8
Rename getLatchPredicateForGuard to more common name
getFlippedStrictnessPredicate and move it to ICmpInst class.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324717 91177308-0d34-0410-b5e6-96231b3b80d8
Add support of uge and sge latch condition to Loop Prediction for
reverse loops.
Reviewers: apilipenko, mkazantsev, sanjoy, anna
Reviewed By: anna
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D42837
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324589 91177308-0d34-0410-b5e6-96231b3b80d8
Factor out getting the predicate for latch condition in a guard to
utility function getLatchPredicateForGuard.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324450 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Currently, we only support predication for forward loops with step
of 1. This patch enables loop predication for reverse or
countdownLoops, which satisfy the following conditions:
1. The step of the IV is -1.
2. The loop has a singe latch as B(X) = X <pred>
latchLimit with pred as s> or u>
3. The IV of the guard is the decrement
IV of the latch condition (Guard is: G(X) = X-1 u< guardLimit).
This patch was downstream for a while and is the last series of patches
that's from our LP implementation downstream.
Reviewers: apilipenko, mkazantsev, sanjoy
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D40353
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319659 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Refactored the code to separate out common functions that are being
reused.
This is to reduce the changes for changes coming up wrt loop
predication with reverse loops.
This refactoring is what we have in our downstream code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@317324 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch allows us to predicate range checks that have a type narrower than
the latch check type. We leverage SCEV analysis to identify a truncate for the
latchLimit and latchStart.
There is also safety checks in place which requires the start and limit to be
known at compile time. We require this to make sure that the SCEV truncate expr
for the IV corresponding to the latch does not cause us to lose information
about the IV range.
Added tests show the loop predication over range checks that are of various
types and are narrower than the latch type.
This enhancement has been in our downstream tree for a while.
Reviewers: apilipenko, sanjoy, mkazantsev
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D39500
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@317269 91177308-0d34-0410-b5e6-96231b3b80d8
This is a follow up change for D37569.
Currently the transformation is limited to the case when:
* The loop has a single latch with the condition of the form: ++i <pred> latchLimit, where <pred> is u<, u<=, s<, or s<=.
* The step of the IV used in the latch condition is 1.
* The IV of the latch condition is the same as the post increment IV of the guard condition.
* The guard condition is of the form i u< guardLimit.
This patch enables the transform in the case when the latch is
latchStart + i <pred> latchLimit, where <pred> is u<, u<=, s<, or s<=.
And the guard is
guardStart + i u< guardLimit
Reviewed By: anna
Differential Revision: https://reviews.llvm.org/D39097
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316768 91177308-0d34-0410-b5e6-96231b3b80d8
We've found a serious issue with the current implementation of loop predication.
The current implementation relies on SCEV and this turned out to be problematic.
To fix the problem we had to rework the pass substantially. We have had the
reworked implementation in our downstream tree for a while. This is the initial
patch of the series of changes to upstream the new implementation.
For now the transformation is limited to the following case:
* The loop has a single latch with either ult or slt icmp condition.
* The step of the IV used in the latch condition is 1.
* The IV of the latch condition is the same as the post increment IV of the guard condition.
* The guard condition is ult.
See the review or the LoopPredication.cpp header for the details about the
problem and the new implementation.
Reviewed By: sanjoy, mkazantsev
Differential Revision: https://reviews.llvm.org/D37569
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@313981 91177308-0d34-0410-b5e6-96231b3b80d8
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.
I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.
This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.
Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304787 91177308-0d34-0410-b5e6-96231b3b80d8
This is a fix for a loop predication bug which resulted in malformed IR generation.
Loop invariant side of the widened condition is not guaranteed to be available in the preheader as is, so we need to expand it as well. See added unsigned_loop_0_to_n_hoist_length test for example.
Reviewed By: sanjoy, mkazantsev
Differential Revision: https://reviews.llvm.org/D30099
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296345 91177308-0d34-0410-b5e6-96231b3b80d8
This patch introduces guard based loop predication optimization. The new LoopPredication pass tries to convert loop variant range checks to loop invariant by widening checks across loop iterations. For example, it will convert
for (i = 0; i < n; i++) {
guard(i < len);
...
}
to
for (i = 0; i < n; i++) {
guard(n - 1 < len);
...
}
After this transformation the condition of the guard is loop invariant, so loop-unswitch can later unswitch the loop by this condition which basically predicates the loop by the widened condition:
if (n - 1 < len)
for (i = 0; i < n; i++) {
...
}
else
deoptimize
This patch relies on an NFC change to make ScalarEvolution::isMonotonicPredicate public (revision 293062).
Reviewed By: sanjoy
Differential Revision: https://reviews.llvm.org/D29034
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293064 91177308-0d34-0410-b5e6-96231b3b80d8
