Commit Graph

247 Commits

Author SHA1 Message Date
Philip Reames 1e07f19bfc Revert "Special case common branch patterns in breakLoopBackedge"
This reverts commit aec08e8600.

Several problems have been reported with malformed loopinfo after this change, see discussion on https://reviews.llvm.org/rGaec08e86004b.
2021-08-24 08:53:42 -07:00
Philip Reames aec08e8600 Special case common branch patterns in breakLoopBackedge
This special cases an unconditional latch and a conditional branch latch exit to improve codegen and test readability.  I am hoping to reuse this function in the runtime unroll code, but without this change, the test diffs are far too complex to assess.
2021-08-22 10:42:23 -07:00
Roman Lebedev febcedf18c
Revert "[NFCI][IndVars] rewriteLoopExitValues(): nowadays SCEV should not change `GEP` base pointer"
https://bugs.llvm.org/show_bug.cgi?id=51490 was filed.

This reverts commit 35a8bdc775.
2021-08-16 14:30:29 +03:00
David Sherwood 9b19b77883 [NFC] Remove unused code in llvm::createSimpleTargetReduction 2021-08-16 09:50:45 +01:00
Roman Lebedev 35a8bdc775
[NFCI][IndVars] rewriteLoopExitValues(): nowadays SCEV should not change `GEP` base pointer
Currently/previously, while SCEV guaranteed that it produces the same value,
the way it was produced may be illegal IR, so we have an ugly check that
the replacement is valid.

But now that the SCEV strictness wrt the pointer/integer types has been improved,
i believe this invariant is already upheld by the SCEV itself, natively.

I think we should add an assertion, wait for a week, and then, if all is good,
rip out all this checking.
Or we could just do the latter directly i guess.

This reverts commit rL127839.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D108043
2021-08-15 18:59:32 +03:00
Johannes Doerfert 25a3130d89 [Local] Do not introduce a new `llvm.trap` before `unreachable`
This is the second attempt to remove the `llvm.trap` insertion after
https://reviews.llvm.org/rGe14e7bc4b889dfaffb7180d176a03311df2d4ae6
reverted the first one. It is not clear what the exact issue was back
then and it might already be gone by now, it has been >5 years after
all.

Replaces D106299.

Differential Revision: https://reviews.llvm.org/D106308
2021-07-26 23:33:36 -05:00
Florian Hahn 6d753b0751
[LAA] Remove RuntimeCheckingPtrGroup::RtCheck member (NFC).
This patch removes RtCheck from RuntimeCheckingPtrGroup to make it
possible to construct RuntimeCheckingPtrGroup objects without a
RuntimePointerChecking object. This should make it easier to
re-use the code to generate runtime checks, e.g. in D102834.

RtCheck was only used to access the pointer info for a given index.
Instead, the start and end expressions can be passed directly.

For code-gen, we also need to know the address space to use. This can
also be explicitly passed at construction.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D105481
2021-07-26 17:38:10 +01:00
Mindong Chen e908e063d1 [LoopUtils] Fix incorrect RT check bounds of loop-invariant mem accesses
This fixes the lower and upper bound calculation of a
RuntimeCheckingPtrGroup when it has more than one loop
invariant pointers. Resolves PR50686.

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D104148
2021-07-19 19:38:24 +08:00
Simon Pilgrim 5e6bfb661e [Analysis] Pass RecurrenceDescriptor as const reference. NFCI.
We were passing the RecurrenceDescriptor by value to most of the reduction analysis methods, despite it being rather bulky with TrackingVH members (that can be costly to copy). In all these cases we're only using the RecurrenceDescriptor for rather basic purposes (access to types/kinds etc.).

Differential Revision: https://reviews.llvm.org/D104029
2021-06-11 10:24:14 +01:00
Philip Reames 7629b2a09c [LI] Add a cover function for checking if a loop is mustprogress [nfc]
Essentially, the cover function simply combines the loop level check and the function level scope into one call.  This simplifies several callers and is (subjectively) less error prone.
2021-06-10 13:37:32 -07:00
Philip Reames b6ee5f2b1d Move code for checking loop metadata into Analysis [nfc]
I need the mustprogress loop metadata in ScalarEvolution and it makes sense to keep all the accessors for quering loop metadate together.
2021-06-10 13:01:22 -07:00
Bardia Mahjour ddb3b26a12 [LV] Consider Loop Unroll Hints When Making Interleave Decisions
This patch causes the loop vectorizer to not interleave loops that have
nounroll loop hints (llvm.loop.unroll.disable and llvm.loop.unroll_count(1)).
Note that if a particular interleave count is being requested
(through llvm.loop.interleave_count), it will still be honoured, regardless
of the presence of nounroll hints.

Reviewed By: Meinersbur

Differential Revision: https://reviews.llvm.org/D101374
2021-04-28 17:27:52 -04:00
Benjamin Kramer ce4acb01b3 Avoid unused variable warning in Release builds 2021-04-06 16:25:19 +02:00
Kerry McLaughlin 7344f3d39a [LoopVectorize] Add strict in-order reduction support for fixed-width vectorization
Previously we could only vectorize FP reductions if fast math was enabled, as this allows us to
reorder FP operations. However, it may still be beneficial to vectorize the loop by moving
the reduction inside the vectorized loop and making sure that the scalar reduction value
be an input to the horizontal reduction, e.g:

  %phi = phi float [ 0.0, %entry ], [ %reduction, %vector_body ]
  %load = load <8 x float>
  %reduction = call float @llvm.vector.reduce.fadd.v8f32(float %phi, <8 x float> %load)

This patch adds a new flag (IsOrdered) to RecurrenceDescriptor and makes use of the changes added
by D75069 as much as possible, which already teaches the vectorizer about in-loop reductions.
For now in-order reduction support is off by default and controlled with the `-enable-strict-reductions` flag.

Reviewed By: david-arm

Differential Revision: https://reviews.llvm.org/D98435
2021-04-06 14:45:34 +01:00
Jingu Kang e4abb64100 [LoopUnswitch] Use reference variables instead of pointer one
Differential Revision: https://reviews.llvm.org/D99496
2021-03-29 13:08:46 +01:00
Jingu Kang cfe87d4edd [NFC][LoopUnswitch] Move hasPartialIVCondition to LoopUtils
Differential revision: https://reviews.llvm.org/D99490
2021-03-29 10:29:45 +01:00
Sanjay Patel 79b1b4a581 [Vectorizers][TTI] remove option to bypass creation of vector reduction intrinsics
The vector reduction intrinsics started life as experimental ops, so backend support
was lacking. As part of promoting them to 1st-class intrinsics, however, codegen
support was added/improved:
D58015
D90247

So I think it is safe to now remove this complication from IR.

Note that we still have an IR-level codegen expansion pass for these as discussed
in D95690. Removing that is another step in simplifying the logic. Also note that
x86 was already unconditionally forming reductions in IR, so there should be no
difference for x86.

I spot checked a couple of the tests here by running them through opt+llc and did
not see any asm diffs.

If we do find functional differences for other targets, it should be possible
to (at least temporarily) restore the shuffle IR with the ExpandReductions IR
pass.

Differential Revision: https://reviews.llvm.org/D96552
2021-02-12 08:13:50 -05:00
Sanjay Patel bbed5f2f8a [LoopVectorize] improve IR fast-math-flags propagation in reductions
This is another step (see D95452) towards correcting fast-math-flags
bugs in vector reductions.

There are multiple bugs visible in the test diffs, and this is still
not working as it should. We still use function attributes (rather
than FMF) to drive part of the logic, but we are not checking for
the correct FP function attributes.

Note that FMF may not be propagated optimally on selects (example
in https://llvm.org/PR35607 ). That's why I'm proposing to union the
FMF of a fcmp+select pair and avoid regressions on existing vectorizer
tests.

Differential Revision: https://reviews.llvm.org/D95690
2021-02-01 16:21:36 -05:00
Florian Hahn 28410d17f5
[LoopUtils] Pass SCEVExpander instead SE to addRuntimeChecks.
This gives the user control over which expander to use, which in turn
allows the user to decide what to do with the expanded instructions.

Used in D75980.

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D94295
2021-01-27 17:36:19 +00:00
Sanjay Patel 09b1c56366 [LoopUtils] do not initialize Cmp predicate unnecessarily; NFC
The switch must set the predicate correctly; anything else
should lead to unreachable/assert.

I'm trying to fix FMF propagation here and the callers,
so this is a preliminary cleanup.
2021-01-26 11:22:51 -05:00
Philip Reames ef51eed37b [LoopDeletion] Handle inner loops w/untaken backedges
This builds on the restricted after initial revert form of D93906, and adds back support for breaking backedges of inner loops. It turns out the original invalidation logic wasn't quite right, specifically around the handling of LCSSA.

When breaking the backedge of an inner loop, we can cause blocks which were in the outer loop only because they were also included in a sub-loop to be removed from both loops. This results in the exit block set for our original parent loop changing, and thus a need for new LCSSA phi nodes.

This case happens when the inner loop has an exit block which is also an exit block of the parent, and there's a block in the child which reaches an exit to said block without also reaching an exit to the parent loop.

(I'm describing this in terms of the immediate parent, but the problem is general for any transitive parent in the nest.)

The approach implemented here involves a potentially expensive LCSSA rebuild.  Perf testing during review didn't show anything concerning, but we may end up needing to revert this if anyone encounters a practical compile time issue.

Differential Revision: https://reviews.llvm.org/D94378
2021-01-22 16:31:29 -08:00
Kazu Hirata dc300beba7 [STLExtras] Add a default value to drop_begin
This patch adds the default value of 1 to drop_begin.

In the llvm codebase, 70% of calls to drop_begin have 1 as the second
argument.  The interface similar to with std::next should improve
readability.

This patch converts a couple of calls to drop_begin as examples.

Differential Revision: https://reviews.llvm.org/D94858
2021-01-18 10:16:34 -08:00
Kazu Hirata 8a20e2b3d3 [llvm] Use Optional::getValueOr (NFC) 2021-01-12 21:43:50 -08:00
Philip Reames 4739dd67e7 [LoopDeletion] Break backedge of outermost loops when known not taken
This is a resubmit of dd6bb367 (which was reverted due to stage2 build failures in 7c63aac), with the additional restriction added to the transform to only consider outer most loops.

As shown in the added test case, ensuring LCSSA is up to date when deleting an inner loop is tricky as we may actually need to remove blocks from any outer loops, thus changing the exit block set.   For the moment, just avoid transforming this case.  I plan to return to this case in a follow up patch and see if we can do better.

Original commit message follows...

The basic idea is that if SCEV can prove the backedge isn't taken, we can go ahead and get rid of the backedge (and thus the loop) while leaving the rest of the control in place. This nicely handles cases with dispatch between multiple exits and internal side effects.

Differential Revision: https://reviews.llvm.org/D93906
2021-01-10 16:02:33 -08:00
Atmn Patel f88a797521 [LoopDeletion] Allows deletion of possibly infinite side-effect free loops
From C11 and C++11 onwards, a forward-progress requirement has been
introduced for both languages. In the case of C, loops with non-constant
conditionals that do not have any observable side-effects (as defined by
6.8.5p6) can be assumed by the implementation to terminate, and in the
case of C++, this assumption extends to all functions. The clang
frontend will emit the `mustprogress` function attribute for C++
functions (D86233, D85393, D86841) and emit the loop metadata
`llvm.loop.mustprogress` for every loop in C11 or later that has a
non-constant conditional.

This patch modifies LoopDeletion so that only loops with
the `llvm.loop.mustprogress` metadata or loops contained in functions
that are required to make progress (`mustprogress` or `willreturn`) are
checked for observable side-effects. If these loops do not have an
observable side-effect, then we delete them.

Loops without observable side-effects that do not satisfy the above
conditions will not be deleted.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D86844
2021-01-05 09:56:16 -05:00
Sanjay Patel 36263a7ccc [LoopUtils] remove redundant opcode parameter; NFC
While here, rename the inaccurate getRecurrenceBinOp()
because that was also used to get CmpInst opcodes.

The recurrence/reduction kind should always refer to the
expected opcode for a reduction. SLP appears to be the
only direct caller of createSimpleTargetReduction(), and
that calling code ideally should not be carrying around
both an opcode and a reduction kind.

This should allow us to generalize reduction matching to
use intrinsics instead of only binops.
2021-01-04 17:05:28 -05:00
Sanjay Patel 9766957524 [LoopUtils] reduce code for creatng reduction; NFC
We can return from each case instead creating a temporary
variable just to have a common return.
2021-01-04 16:05:03 -05:00
Sanjay Patel 58b6c5d932 [LoopUtils] reorder logic for creating reduction; NFC
If we are using a shuffle reduction, we don't need to
go through the switch on opcode - return early.
2021-01-04 16:05:02 -05:00
Philip Reames 7c63aac7bd Revert "[LoopDeletion] Break backedge of loops when known not taken"
This reverts commit dd6bb367d1.

Multi-stage builders are showing an assertion failure w/LCSSA not being preserved on entry to IndVars.  Reason isn't clear, reverting while investigating.
2021-01-04 09:50:47 -08:00
Philip Reames dd6bb367d1 [LoopDeletion] Break backedge of loops when known not taken
The basic idea is that if SCEV can prove the backedge isn't taken, we can go ahead and get rid of the backedge (and thus the loop) while leaving the rest of the control in place. This nicely handles cases with dispatch between multiple exits and internal side effects.

Differential Revision: https://reviews.llvm.org/D93906
2021-01-04 09:19:29 -08:00
Sanjay Patel c74e8539ff [Analysis] flatten enums for recurrence types
This is almost all mechanical search-and-replace and
no-functional-change-intended (NFC). Having a single
enum makes it easier to match/reason about the
reduction cases.

The goal is to remove `Opcode` from reduction matching
code in the vectorizers because that makes it harder to
adapt the code to handle intrinsics.

The code in RecurrenceDescriptor::AddReductionVar() is
the only place that required closer inspection. It uses
a RecurrenceDescriptor and a second InstDesc to sometimes
overwrite part of the struct. It seem like we should be
able to simplify that logic, but it's not clear exactly
which cmp+sel patterns that we are trying to handle/avoid.
2021-01-01 12:20:16 -05:00
Bogdan Graur 8bee4d4e8f Revert "[LoopDeletion] Allows deletion of possibly infinite side-effect free loops"
Test clang/test/Misc/loop-opt-setup.c fails when executed in Release.

This reverts commit 6f1503d598.

Reviewed By: SureYeaah

Differential Revision: https://reviews.llvm.org/D93956
2020-12-31 11:47:49 +00:00
Atmn Patel 6f1503d598 [LoopDeletion] Allows deletion of possibly infinite side-effect free loops
From C11 and C++11 onwards, a forward-progress requirement has been
introduced for both languages. In the case of C, loops with non-constant
conditionals that do not have any observable side-effects (as defined by
6.8.5p6) can be assumed by the implementation to terminate, and in the
case of C++, this assumption extends to all functions. The clang
frontend will emit the `mustprogress` function attribute for C++
functions (D86233, D85393, D86841) and emit the loop metadata
`llvm.loop.mustprogress` for every loop in C11 or later that has a
non-constant conditional.

This patch modifies LoopDeletion so that only loops with
the `llvm.loop.mustprogress` metadata or loops contained in functions
that are required to make progress (`mustprogress` or `willreturn`) are
checked for observable side-effects. If these loops do not have an
observable side-effect, then we delete them.

Loops without observable side-effects that do not satisfy the above
conditions will not be deleted.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D86844
2020-12-30 21:43:01 -05:00
Sanjay Patel 8ca60db40b [LoopUtils] reduce FMF and min/max complexity when forming reductions
I don't know if there's some way this changes what the vectorizers
may produce for reductions, but I have added test coverage with
3567908 and 5ced712 to show that both passes already have bugs in
this area. Hopefully this does not make things worse before we can
really fix it.
2020-12-30 15:22:26 -05:00
Sanjay Patel e90ea76380 [IR] remove 'NoNan' param when creating FP reductions
This is no-functional-change-intended (AFAIK, we can't
isolate this difference in a regression test).

That's because the callers should be setting the IRBuilder's
FMF field when creating the reduction and/or setting those
flags after creating. It doesn't make sense to override this
one flag alone.

This is part of a multi-step process to clean up the FMF
setting/propagation. See PR35538 for an example.
2020-12-30 09:51:23 -05:00
Juneyoung Lee 9b29610228 Use unary CreateShuffleVector if possible
As mentioned in D93793, there are quite a few places where unary `IRBuilder::CreateShuffleVector(X, Mask)` can be used
instead of `IRBuilder::CreateShuffleVector(X, Undef, Mask)`.
Let's update them.

Actually, it would have been more natural if the patches were made in this order:
(1) let them use unary CreateShuffleVector first
(2) update IRBuilder::CreateShuffleVector to use poison as a placeholder value (D93793)

The order is swapped, but in terms of correctness it is still fine.

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D93923
2020-12-30 22:36:08 +09:00
Sanjay Patel 8d18bc8e6d [Utils] reduce code in createTargetReduction(); NFC
The switch duplicated the translation in getRecurrenceBinOp().
This code is still weird because it translates to the TTI
ReductionFlags for min/max, but then createSimpleTargetReduction()
converts that back to RecurrenceDescriptor::MinMaxRecurrenceKind.
2020-12-29 15:56:19 -05:00
David Sherwood 71bd59f0cb [SVE] Add support for scalable vectors with vectorize.scalable.enable loop attribute
In this patch I have added support for a new loop hint called
vectorize.scalable.enable that says whether we should enable scalable
vectorization or not. If a user wants to instruct the compiler to
vectorize a loop with scalable vectors they can now do this as
follows:

  br i1 %exitcond, label %for.end, label %for.body, !llvm.loop !2
  ...
  !2 = !{!2, !3, !4}
  !3 = !{!"llvm.loop.vectorize.width", i32 8}
  !4 = !{!"llvm.loop.vectorize.scalable.enable", i1 true}

Setting the hint to false simply reverts the behaviour back to the
default, using fixed width vectors.

Differential Revision: https://reviews.llvm.org/D88962
2020-12-02 13:23:43 +00:00
David Green c7e275388e [ARM] Don't aggressively unroll vector remainder loops
We already do not unroll loops with vector instructions under MVE, but
that does not include the remainder loops that the vectorizer produces.
These remainder loops will be rarely executed and are not worth
unrolling, as the trip count is likely to be low if they get executed at
all. Luckily they get llvm.loop.isvectorized to make recognizing them
simpler.

We have wanted to do this for a while but hit issues with low overhead
loops being reverted due to difficult registry allocation. With recent
changes that seems to be less of an issue now.

Differential Revision: https://reviews.llvm.org/D90055
2020-11-10 17:01:31 +00:00
Atmn Patel 04a0896487 Revert "[LoopDeletion] Allows deletion of possibly infinite side-effect free loops"
This reverts commit 0b17c6e447. This patch
causes a compile-time error in SCEV.
2020-11-07 00:32:12 -05:00
Atmn Patel 0b17c6e447 [LoopDeletion] Allows deletion of possibly infinite side-effect free loops
From C11 and C++11 onwards, a forward-progress requirement has been
introduced for both languages. In the case of C, loops with non-constant
conditionals that do not have any observable side-effects (as defined by
6.8.5p6) can be assumed by the implementation to terminate, and in the
case of C++, this assumption extends to all functions. The clang
frontend will emit the `mustprogress` function attribute for C++
functions (D86233, D85393, D86841) and emit the loop metadata
`llvm.loop.mustprogress` for every loop in C11 or later that has a
non-constant conditional.

This patch modifies LoopDeletion so that only loops with
the `llvm.loop.mustprogress` metadata or loops contained in functions
that are required to make progress (`mustprogress` or `willreturn`) are
checked for observable side-effects. If these loops do not have an
observable side-effect, then we delete them.

Loops without observable side-effects that do not satisfy the above
conditions will not be deleted.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D86844
2020-11-06 22:06:58 -05:00
Atmn Patel babc224c5d [LoopDeletion] Remove dead loops with no exit blocks
Currently, LoopDeletion refuses to remove dead loops with no exit blocks
because it cannot statically determine the control flow after it removes
the block. This leads to miscompiles if the loop is an infinite loop and
should've been removed.

Differential Revision: https://reviews.llvm.org/D90115
2020-11-06 17:08:34 -05:00
Nikita Popov 20b386aae0 [LoopUtils] Fix neutral value for vector.reduce.fadd
Use -0.0 instead of 0.0 as the start value. The previous use of 0.0
was fine for all existing uses of this function though, as it is
always generated with fast flags right now, and thus nsz.
2020-10-29 21:45:13 +01:00
Florian Hahn ad5541045a [LoopDeletion] Remove over-eager SCEV verification.
60b852092c introduced SCEV verification to
deleteDeadLoop, but it appears this check is currently a bit over-eager
and some users of deleteDeadLoop appear to only patch up SE after
calling it (e.g. PR47753).

Remove the extra check for now. We can consider adding it back after we
tracked down the source of the inconsistency for PR47753.
2020-10-12 16:18:30 +01:00
Florian Hahn 7bae2bc5a8 [LoopUtils] Only verify SE in builds with assertions.
Follow up to 60b852092c.
2020-09-29 13:39:23 +01:00
Florian Hahn 60b852092c [LoopDeletion] Forget loop before setting values to undef
After D71539, we need to forget the loop before setting the incoming
values of phi nodes in exit blocks, because we are looking through those
phi nodes now and the SCEV expression could depend on the loop phi. If
we update the phi nodes before forgetting the loop, we miss those users
during invalidation.

Reviewed By: reames

Differential Revision: https://reviews.llvm.org/D88167
2020-09-29 10:38:44 +01:00
Vitaly Buka 89051ebace [NFC] GetUnderlyingObject -> getUnderlyingObject
I am going to touch them in the next patch anyway
2020-07-30 21:08:24 -07:00
Nicolai Hähnle 76c5cb05a3 DomTree: Remove getChildren() accessor
Summary:
Avoid exposing details about how children are stored. This will enable
subsequent type-erasure changes.

New methods are introduced to cover common access patterns.

Change-Id: Idb5f4b1b9c84e4cc71ddb39bb52a388682f5674f

Reviewers: arsenm, RKSimon, mehdi_amini, courbet

Subscribers: qcolombet, sdardis, wdng, hiraditya, jrtc27, zzheng, atanasyan, asbirlea, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D83083
2020-07-06 21:58:11 +02:00
Serguei Katkov eae0d2e9b2 Revert "[Peeling] Extend the scope of peeling a bit"
This reverts commit 29b2c1ca72.

The patch causes the DT verifier failure like:
DominatorTree is different than a freshly computed one!

Not sure the patch itself it wrong but revert to investigate the failure.
2020-06-22 17:48:29 +07:00
Serguei Katkov 29b2c1ca72 [Peeling] Extend the scope of peeling a bit
Currently we allow peeling of the loops if there is a exiting latch block
and all other exits are blocks ending with deopt.

Actually we want that exit would end up with deopt unconditionally but
it is not required that exit itself ends with deopt.

Reviewers: reames, ashlykov, fhahn, apilipenko, fedor.sergeev
Reviewed By: apilipenko
Subscribers: hiraditya, zzheng, dantrushin, llvm-commits
Differential Revision: https://reviews.llvm.org/D81140
2020-06-22 12:17:44 +07:00
Christopher Tetreault 8d11ec66b6 [SVE] Remove calls to VectorType::getNumElements from Transforms/Utils
Reviewers: efriedma, c-rhodes, david-arm, Tyker, asbirlea

Reviewed By: david-arm

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D82057
2020-06-18 13:39:14 -07:00
Sanjay Patel 46a285ad9e [IRBuilder] add/use wrapper to create a generic compare based on predicate type; NFC
The predicate can always be used to distinguish between icmp and fcmp,
so we don't need to keep repeating this check in the callers.
2020-06-18 15:47:06 -04:00
Alina Sbirlea 519b019a0a Verify MemorySSA after all updates.
Verify after completing all updates.
Resolves PR46275.
2020-06-11 18:48:41 -07:00
Whitney Tsang 5d6c5b463c [LoopUtils] Use llvm::find
Summary: Fixes this build error:

llvm/lib/Transforms/Utils/LoopUtils.cpp:679:26: error: no matching
function for call to 'find'
      Loop::iterator I = find(ParentLoop->begin(), ParentLoop->end(),
L);
                         ^~~~
Authored By: orivej
Reviewer: Whitney
Reviewed By: Whitney
Subscribers: hiraditya, llvm-commits
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D80473
2020-05-25 13:34:56 +00:00
Roman Lebedev b2df961231
[IndVarSimplify][LoopUtils] Avoid TOCTOU/ordering issues (PR45835)
Summary:
Currently, `rewriteLoopExitValues()`'s logic is roughly as following:
> Loop over each incoming value in each PHI node.
> Query whether the SCEV for that incoming value is high-cost.
> Expand the SCEV.
> Perform sanity check (`isValidRewrite()`, D51582)
> Record the info
> Afterwards, see if we can drop the loop given replacements.
> Maybe perform replacements.

The problem is that we interleave SCEV cost checking and expansion.
This is A Problem, because `isHighCostExpansion()` takes special care
to not bill for the expansions that were already expanded, and we can reuse.

While it makes sense in general - if we know that we will expand some SCEV,
all the other SCEV's costs should account for that, which might cause
some of them to become non-high-cost too, and cause chain reaction.

But that isn't what we are doing here. We expand *all* SCEV's, unconditionally.
So every next SCEV's cost will be affected by the already-performed expansions
for previous SCEV's. Even if we are not planning on keeping
some of the expansions we performed.

Worse yet, this current "bonus" depends on the exact PHI node
incoming value processing order. This is completely wrong.

As an example of an issue, see @dmajor's `pr45835.ll` - if we happen to have
a PHI node with two(!) identical high-cost incoming values for the same basic blocks,
we would decide first time around that it is high-cost, expand it,
and immediately decide that it is not high-cost because we have an expansion
that we could reuse (because we expanded it right before, temporarily),
and replace the second incoming value but not the first one;
thus resulting in a broken PHI.

What we instead should do for now, is not perform any expansions
until after we've queried all the costs.

Later, in particular after `isValidRewrite()` is an assertion (D51582)
we could improve upon that, but in a more coherent fashion.

See [[ https://bugs.llvm.org/show_bug.cgi?id=45835 | PR45835 ]]

Reviewers: dmajor, reames, mkazantsev, fhahn, efriedma

Reviewed By: dmajor, mkazantsev

Subscribers: smeenai, nikic, hiraditya, javed.absar, llvm-commits, dmajor

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79787
2020-05-21 13:05:55 +03:00
Florian Hahn bcbd26bfe6 [SCEV] Move ScalarEvolutionExpander.cpp to Transforms/Utils (NFC).
SCEVExpander modifies the underlying function so it is more suitable in
Transforms/Utils, rather than Analysis. This allows using other
transform utils in SCEVExpander.

This patch was originally committed as b8a3c34eee, but broke the
modules build, as LoopAccessAnalysis was using the Expander.

The code-gen part of LAA was moved to lib/Transforms recently, so this
patch can be landed again.

Reviewers: sanjoy.google, efriedma, reames

Reviewed By: sanjoy.google

Differential Revision: https://reviews.llvm.org/D71537
2020-05-20 10:53:40 +01:00
Florian Hahn 8528186b9b [LAA] Move runtime-check generation to Transforms/Utils/loopUtils (NFC)
Currently LAA's uses of ScalarEvolutionExpander blocks moving the
expander from Analysis to Transforms. Conceptually the expander does not
fit into Analysis (it is only used for code generation) and
runtime-check generation also seems to be better suited as a
transformation utility.

Reviewers: Ayal, anemet

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D78460
2020-05-10 17:39:26 +01:00
Florian Hahn 616657b39c [LAA] Move CheckingPtrGroup/PointerCheck outside class (NFC).
This allows forward declarations of PointerCheck, which in turn reduce
the number of times LoopAccessAnalysis needs to be included.

Ultimately this helps with moving runtime check generation to
Transforms/Utils/LoopUtils.h, without having to include it there.

Reviewers: anemet, Ayal

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D78458
2020-04-28 21:47:31 +01:00
Florian Hahn 7a87e8f90b [LoopUtils] Clean up includes, use forward decls if appropriate (NFC).
Most of the includes in LoopUtils.h are not required in the header and
they can be replaced by forward declarations.

Unfortunately includes of TargetTransformInfo.h and IVDescriptors.h pull
in a bunch of additional things, but there is no easy way to get rid of
them at the moment I think.
2020-04-19 19:44:29 +01:00
Benjamin Kramer 6f64daca8f Upgrade calls to CreateShuffleVector to use the preferred form of passing an array of ints
No functionality change intended.
2020-04-15 12:51:38 +02:00
Christopher Tetreault 00a1032412 Clean up usages of asserting vector getters in Type
Summary:
Remove usages of asserting vector getters in Type in preparation for the
VectorType refactor. The existence of these functions complicates the
refactor while adding little value.

Reviewers: rriddle, sdesmalen, efriedma

Reviewed By: sdesmalen

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77260
2020-04-09 13:35:41 -07:00
Roman Lebedev 7d572ef2dd
Revert "[SCEV] rewriteLoopExitValues(): even if have hard uses, still rewrite if cheap (PR44668)"
As discussed in post-commit review in https://reviews.llvm.org/D73501
if the goal of this is to help vectorizer, then we should actually
be teaching vectorizer to do this, because right now this rewrite
is still budget-limited, which isn't what we'd want.

Additionally, while the rest of the patch series was universally profitable,
this particular patch is reportedly (https://reviews.llvm.org/D73501#1905171)
exposing cost-modeling issues on ARM.

So let's just back this particular patch out. Once there's an undo transform,
this could be considered for reintegration.

This reverts commit 44edc6fd2c.
2020-04-03 20:15:04 +03:00
David Green ec7e4a9a80 [LoopVectorizer] Add reduction tests for inloop reductions. NFC
Also adds a force-reduction-intrinsics option for testing, for forcing
the generation of reduction intrinsics even when the backend is not
requesting them.
2020-03-03 10:54:00 +00:00
Arkady Shlykov 3dcaf296ae [Loop Peeling] Add possibility to enable peeling on loop nests.
Summary:
Current peeling implementation bails out in case of loop nests.
The patch introduces a field in TargetTransformInfo structure that
certain targets can use to relax the constraints if it's
profitable (disabled by default).
Also additional option is added to enable peeling manually for
experimenting and testing purposes.

Reviewers: fhahn, lebedev.ri, xbolva00

Reviewed By: xbolva00

Subscribers: RKSimon, xbolva00, hiraditya, zzheng, llvm-commits

Differential Revision: https://reviews.llvm.org/D70304
2020-03-02 08:37:11 -08:00
Roman Lebedev 44edc6fd2c
[SCEV] rewriteLoopExitValues(): even if have hard uses, still rewrite if cheap (PR44668)
Summary:
Replacing uses of IV outside of the loop is likely generally useful,
but `rewriteLoopExitValues()` is cautious, and if it isn't told to always
perform the replacement, and there are hard uses of IV in loop,
it doesn't replace.

In [[ https://bugs.llvm.org/show_bug.cgi?id=44668 | PR44668 ]],
that prevents `-indvars` from replacing uses of induction variable
after the loop, which might be one of the optimization failures
preventing that code from being vectorized.

Instead, now that the cost model is fixed, i believe we should be
a little bit more optimistic, and also perform replacement
if we believe it is within our budget.

Fixes [[ https://bugs.llvm.org/show_bug.cgi?id=44668 | PR44668 ]].

Reviewers: reames, mkazantsev, asbirlea, fhahn, skatkov

Reviewed By: mkazantsev

Subscribers: nikic, hiraditya, zzheng, javed.absar, dmgreen, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73501
2020-02-25 23:05:59 +03:00
Roman Lebedev b99c91a087
[NFC][SCEV] Piping to pass new SCEVCheapExpansionBudget option into SCEVExpander::isHighCostExpansionHelper()
Summary:
In future patches`SCEVExpander::isHighCostExpansionHelper()` will respect the budget allocated by performing TTI cost modelling.
This is a fully NFC patch to make things reviewable.

Reviewers: reames, mkazantsev, wmi, sanjoy

Reviewed By: mkazantsev

Subscribers: hiraditya, zzheng, javed.absar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73705
2020-02-25 23:05:57 +03:00
Roman Lebedev 0789f28048
[NFC][SCEV] Piping to pass TTI into SCEVExpander::isHighCostExpansionHelper()
Summary:
Future patches will make use of TTI to perform cost-model-driven `SCEVExpander::isHighCostExpansionHelper()`
This is a fully NFC patch to make things reviewable.

Reviewers: reames, mkazantsev, wmi, sanjoy

Reviewed By: mkazantsev

Subscribers: hiraditya, zzheng, javed.absar, dmgreen, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73704
2020-02-25 23:05:56 +03:00
Nikita Popov 28ffe38bba [LoopUtils] Accept IRBuilderBase; NFC 2020-02-18 17:58:46 +01:00
Alina Sbirlea 67904db23c [IRCE] Make IRCE a Function pass.
Summary: Make InductiveRangeCheckElimination a FunctionPass.

Reviewers: reames, mkazantsev

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73592
2020-02-05 09:22:41 -08:00
Alina Sbirlea 388de9dfcd [LoopUtils] Make duplicate method a utility. [NFCI]
Summary:
Method appendLoopsToWorklist is duplicate in LoopUnroll and in the
LoopPassManager as an internal method. Make it an utility.

Reviewers: dmgreen, chandlerc, fedor.sergeev, yamauchi

Subscribers: mehdi_amini, hiraditya, zzheng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73569
2020-02-03 10:24:18 -08:00
Sanjay Patel bc1148e7bc [PATCH] D73727: [SLP] drop poison-generating flags for shuffle reduction ops (PR44536)
We may calculate reassociable math ops in arbitrary order when creating a shuffle reduction,
so there's no guarantee that things like 'nsw' hold on those intermediate values. Drop all
poison-generating flags for safety.

This change is limited to shuffle reductions because I don't think we have a problem in the
general case (where we intersect flags of each scalar op that goes into a vector op), but if
there's evidence of other cases being wrong, we can extend this fix to cover those cases.

https://bugs.llvm.org/show_bug.cgi?id=44536

Differential Revision: https://reviews.llvm.org/D73727
2020-01-31 09:54:35 -05:00
Alina Sbirlea efb130fc93 [LoopDeletion] Teach LoopDeletion to preserve MemorySSA if available.
If MemorySSA analysis is analysis, LoopDeletion now preserves it.
2020-01-22 11:38:38 -08:00
Evgeniy Brevnov af7e158872 [LV] Vectorizer should adjust trip count in profile information
Summary: Vectorized loop processes VFxUF number of elements in one iteration thus total number of iterations decreases proportionally. In addition epilog loop may not have more than VFxUF - 1 iterations. This patch updates profile information accordingly.

Reviewers: hsaito, Ayal, fhahn, reames, silvas, dcaballe, SjoerdMeijer, mkuper, DaniilSuchkov

Reviewed By: Ayal, DaniilSuchkov

Subscribers: fedor.sergeev, hiraditya, rkruppe, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67905
2020-01-20 18:36:28 +07:00
Evgeniy Brevnov cfe97681cd [NFC][LoopUtils] Minor change in comment according to review D71990. 2020-01-20 17:10:10 +07:00
Evgeniy Brevnov 10357e1c89 [LoopUtils] Better accuracy for getLoopEstimatedTripCount.
Summary: Current implementation of getLoopEstimatedTripCount returns 1 iteration less than it should. The reason is that in bottom tested loop first iteration is executed before first back branch is taken. For example for loop with !{!"branch_weights", i32 1 // taken, i32 1 // exit} metadata getLoopEstimatedTripCount gives 1 while actual number of iterations is 2.

Reviewers: Ayal, fhahn

Reviewed By: Ayal

Subscribers: mgorny, hiraditya, zzheng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71990
2020-01-20 16:58:07 +07:00
Sjoerd Meijer 93175a5caa [IndVarSimplify][LoopUtils] rewriteLoopExitValues. NFCI
This moves `rewriteLoopExitValues()` from IndVarSimplify to LoopUtils thus
making it a generic loop utility function.  This allows to rewrite loop exit
values by just calling this function without running the whole IndVarSimplify
pass.

We use this in D72714 to rematerialise the iteration count in exit blocks, so
that we can clean-up loop update expressions inside the hardware-loops later.

Differential Revision: https://reviews.llvm.org/D72602
2020-01-20 09:05:00 +00:00
Evgeniy Brevnov f0abe820ee [LoopUtils][NFC] Minor refactoring in getLoopEstimatedTripCount. 2020-01-09 16:49:15 +07:00
Florian Hahn 99f74a64a2 [SCEV] Remove unused ScalarEvolutionExpander.h includes (NFC). 2020-01-04 18:29:35 +00:00
Whitney Tsang 9883d7edc6 [LoopUtils] Updated deleteDeadLoop() to handle loop nest.
Reviewer: kariddi, sanjoy, reames, Meinersbur, bmahjour, etiotto,
kbarton
Reviewed By: Meinersbur
Subscribers: mgorny, hiraditya, llvm-commits
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D70939
2019-12-18 15:59:45 +00:00
Whitney Tsang ec4749e3b8 Revert "[LoopUtils] Updated deleteDeadLoop() to handle loop nest."
This reverts commit cd09fee3d6.
This reverts commit c066ff11d8.
2019-12-17 03:51:41 +00:00
Whitney Tsang c066ff11d8 [LoopUtils] Updated deleteDeadLoop() to handle loop nest.
Reviewer: kariddi, sanjoy, reames, Meinersbur, bmahjour, etiotto,
kbarton
Reviewed By: Meinersbur
Subscribers: mgorny, hiraditya, llvm-commits
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D70939
2019-12-17 01:06:14 +00:00
Reid Kleckner 05da2fe521 Sink all InitializePasses.h includes
This file lists every pass in LLVM, and is included by Pass.h, which is
very popular. Every time we add, remove, or rename a pass in LLVM, it
caused lots of recompilation.

I found this fact by looking at this table, which is sorted by the
number of times a file was changed over the last 100,000 git commits
multiplied by the number of object files that depend on it in the
current checkout:
  recompiles    touches affected_files  header
  342380        95      3604    llvm/include/llvm/ADT/STLExtras.h
  314730        234     1345    llvm/include/llvm/InitializePasses.h
  307036        118     2602    llvm/include/llvm/ADT/APInt.h
  213049        59      3611    llvm/include/llvm/Support/MathExtras.h
  170422        47      3626    llvm/include/llvm/Support/Compiler.h
  162225        45      3605    llvm/include/llvm/ADT/Optional.h
  158319        63      2513    llvm/include/llvm/ADT/Triple.h
  140322        39      3598    llvm/include/llvm/ADT/StringRef.h
  137647        59      2333    llvm/include/llvm/Support/Error.h
  131619        73      1803    llvm/include/llvm/Support/FileSystem.h

Before this change, touching InitializePasses.h would cause 1345 files
to recompile. After this change, touching it only causes 550 compiles in
an incremental rebuild.

Reviewers: bkramer, asbirlea, bollu, jdoerfert

Differential Revision: https://reviews.llvm.org/D70211
2019-11-13 16:34:37 -08:00
Alina Sbirlea 6da79ce1fe [MemorySSA] Re-enable MemorySSA use.
Differential Revision: https://reviews.llvm.org/D58311

llvm-svn: 370957
2019-09-04 19:16:04 +00:00
Alina Sbirlea ccb1862bc9 [MemorySSA] Disable MemorySSA use.
Differential Revision: https://reviews.llvm.org/D58311

llvm-svn: 370821
2019-09-03 21:20:46 +00:00
Alina Sbirlea e331d50534 [MemorySSA] Re-enable MemorySSA use.
Differential Revision: https://reviews.llvm.org/D58311

llvm-svn: 370811
2019-09-03 19:28:37 +00:00
Alina Sbirlea 4b87023bae Revert enabling MemorySSA.
Breaks sanitizers bots.

Differential Revision: https://reviews.llvm.org/D58311

llvm-svn: 370397
2019-08-29 19:01:23 +00:00
Alina Sbirlea 6289ee941d [MemorySSA & LoopPassManager] Enable MemorySSA as loop dependency. Update tests.
Summary:
I'm not planning to check this in at the moment, but feedback is very welcome, in particular how this affects performance.
The feedback obtains here will guide the next steps towards enabling this.

This patch enables the use of MemorySSA in the loop pass manager.

Passes that currently use MemorySSA:
 - EarlyCSE
Passes that use MemorySSA after this patch:
 - EarlyCSE
 - LICM
 - SimpleLoopUnswitch
Loop passes that update MemorySSA (and do not use it yet, but could use it after this patch):
 - LoopInstSimplify
 - LoopSimplifyCFG
 - LoopUnswitch
 - LoopRotate
 - LoopSimplify
 - LCSSA
Loop passes that do *not* update MemorySSA:
 - IndVarSimplify
 - LoopDelete
 - LoopIdiom
 - LoopSink
 - LoopUnroll
 - LoopInterchange
 - LoopUnrollAndJam
 - LoopVectorize
 - LoopReroll
 - IRCE

Reviewers: chandlerc, george.burgess.iv, davide, sanjoy, gberry

Subscribers: jlebar, Prazek, dmgreen, jdoerfert, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58311

llvm-svn: 370384
2019-08-29 17:08:13 +00:00
Tim Corringham 4f64f1ba3c Add llvm.licm.disable metadata
For some targets the LICM pass can result in sub-optimal code in some
cases where it would be better not to run the pass, but it isn't
always possible to suppress the transformations heuristically.

Where the front-end has insight into such cases it is beneficial
to attach loop metadata to disable the pass - this change adds the
llvm.licm.disable metadata to enable that.

Differential Revision: https://reviews.llvm.org/D64557

llvm-svn: 368296
2019-08-08 13:46:17 +00:00
Serguei Katkov 7f8c809592 [Loop Utils] Extend the scope of addStringMetadataToLoop.
To avoid duplicates in loop metadata, if the string to add is
already there, just update the value.

Reviewers: reames, Ashutosh
Reviewed By: reames
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D65265

llvm-svn: 367087
2019-07-26 07:04:34 +00:00
Serguei Katkov 3c3a76527e [Loop Utils] Move utilty addStringMetadataToLoop to LoopUtils.cpp. NFC.
Just move the utility function to LoopUtils.cpp to re-use it in loop peeling.

Reviewers: reames, Ashutosh
Reviewed By: reames
Subscribers: hiraditya, asbirlea, llvm-commits
Differential Revision: https://reviews.llvm.org/D65264

llvm-svn: 367085
2019-07-26 06:10:08 +00:00
Serguei Katkov 45c43e7d04 [LoopUtils] Extend the scope of getLoopEstimatedTripCount
With this patch the getLoopEstimatedTripCount function will
accept also the loops where there are more than one exit but
all exits except latch block should ends up with a call to deopt.

This side exits should not impact the estimated trip count.

Reviewers: reames, mkuper, danielcdh
Reviewed By: reames
Subscribers: fhahn, lebedev.ri, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D64553

llvm-svn: 366042
2019-07-15 06:42:39 +00:00
Sander de Smalen cbeb563cfb Change semantics of fadd/fmul vector reductions.
This patch changes how LLVM handles the accumulator/start value
in the reduction, by never ignoring it regardless of the presence of
fast-math flags on callsites. This change introduces the following
new intrinsics to replace the existing ones:

  llvm.experimental.vector.reduce.fadd -> llvm.experimental.vector.reduce.v2.fadd
  llvm.experimental.vector.reduce.fmul -> llvm.experimental.vector.reduce.v2.fmul

and adds functionality to auto-upgrade existing LLVM IR and bitcode.

Reviewers: RKSimon, greened, dmgreen, nikic, simoll, aemerson

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D60261

llvm-svn: 363035
2019-06-11 08:22:10 +00:00
Sanjay Patel ad62a3a299 [LoopUtils][SLPVectorizer] clean up management of fast-math-flags
Instead of passing around fast-math-flags as a parameter, we can set those
using an IRBuilder guard object. This is no-functional-change-intended.

The motivation is to eventually fix the vectorizers to use and set the
correct fast-math-flags for reductions. Examples of that not behaving as
expected are:
https://bugs.llvm.org/show_bug.cgi?id=23116 (should be able to reduce with less than 'fast')
https://bugs.llvm.org/show_bug.cgi?id=35538 (possible miscompile for -0.0)
D61802 (should be able to reduce with IR-level FMF)

Differential Revision: https://reviews.llvm.org/D62272

llvm-svn: 362612
2019-06-05 14:58:04 +00:00
Roman Lebedev e5be660e25 [NFC][Utils] deleteDeadLoop(): add an assert that exit block has some non-PHI instruction
Summary:
If `deleteDeadLoop()` is called on such a loop, that has "bad" exit block,
one that e.g. has no terminator instruction, the `DIBuilder::insertDbgValueIntrinsic()`
will be told to insert the Dbg Value Intrinsic after `nullptr`
(since there is no first non-PHI instruction), which will cause it to not insert
those instructions into any basic block. The instructions will be parent-less,
and IR verifier will complain. It is rather obvious to track down the root cause
when that happens, so let's just assert it never happens.

Reviewers: sanjoy, davide, vsk

Reviewed By: vsk

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61008

llvm-svn: 359993
2019-05-05 18:59:12 +00:00
Sanjoy Das 3f5ce18658 Reland "Relax constraints for reduction vectorization"
Change from original commit: move test (that uses an X86 triple) into the X86
subdirectory.

Original description:
Gating vectorizing reductions on *all* fastmath flags seems unnecessary;
`reassoc` should be sufficient.

Reviewers: tvvikram, mkuper, kristof.beyls, sdesmalen, Ayal

Reviewed By: sdesmalen

Subscribers: dcaballe, huntergr, jmolloy, mcrosier, jlebar, bixia, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57728

llvm-svn: 355889
2019-03-12 01:31:44 +00:00
Sanjoy Das 2136a5bc49 Revert "Relax constraints for reduction vectorization"
This reverts commit r355868.  Breaks hexagon.

llvm-svn: 355873
2019-03-11 22:37:31 +00:00
Sanjoy Das 93f8cc186a Relax constraints for reduction vectorization
Summary:
Gating vectorizing reductions on *all* fastmath flags seems unnecessary;
`reassoc` should be sufficient.

Reviewers: tvvikram, mkuper, kristof.beyls, sdesmalen, Ayal

Reviewed By: sdesmalen

Subscribers: dcaballe, huntergr, jmolloy, mcrosier, jlebar, bixia, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57728

llvm-svn: 355868
2019-03-11 21:36:41 +00:00
Chijun Sima f131d6110e [DTU] Deprecate insertEdge*/deleteEdge*
Summary: This patch converts all existing `insertEdge*/deleteEdge*` to `applyUpdates` and marks `insertEdge*/deleteEdge*` as deprecated.

Reviewers: kuhar, brzycki

Reviewed By: kuhar, brzycki

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58443

llvm-svn: 354652
2019-02-22 05:41:43 +00:00
Alina Sbirlea 97468e9282 [MemorySSA & LoopPassManager] Update MemorySSA in formDedicatedExitBlocks.
MemorySSA is now updated when forming dedicated exit blocks.
Resolves PR40037.

llvm-svn: 354623
2019-02-21 21:13:34 +00:00
Craig Topper 784929d045 Implementation of asm-goto support in LLVM
This patch accompanies the RFC posted here:
http://lists.llvm.org/pipermail/llvm-dev/2018-October/127239.html

This patch adds a new CallBr IR instruction to support asm-goto
inline assembly like gcc as used by the linux kernel. This
instruction is both a call instruction and a terminator
instruction with multiple successors. Only inline assembly
usage is supported today.

This also adds a new INLINEASM_BR opcode to SelectionDAG and
MachineIR to represent an INLINEASM block that is also
considered a terminator instruction.

There will likely be more bug fixes and optimizations to follow
this, but we felt it had reached a point where we would like to
switch to an incremental development model.

Patch by Craig Topper, Alexander Ivchenko, Mikhail Dvoretckii

Differential Revision: https://reviews.llvm.org/D53765

llvm-svn: 353563
2019-02-08 20:48:56 +00:00