This patch adds a getPlan accessor to VPBlockBase, which finds the entry
block of the plan containing the block and returns the plan set for this
block.

VPBlockBase contains a VPlan pointer, but it should only be set for
the entry block of a plan. This allows moving blocks without updating
the pointer for each moved block and in the future we might introduce a
parent relationship between plans and blocks, similar to the one in LLVM IR.

Reviewers: rengolin, hsaito, fhahn, Ayal, dorit, gilr

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D74445

getReductionVars, getInductionVars and getFirstOrderRecurrences were all
being returned from LoopVectorizationLegality as pointers to lists. This
just changes them to be references, cleaning up the interface slightly.

Differential Revision: https://reviews.llvm.org/D75448

Summary: This fixes the crash that led to the revert of D69591.

Reviewers: davidxl

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75307

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

Reviewers: jdoerfert, sstefan1, uenoku

Reviewed By: jdoerfert

Subscribers: mgorny, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72885

replaceDbgDeclare is used to update the descriptions of stack variables
when they are moved (e.g. by ASan or SafeStack). A side effect of
replaceDbgDeclare is that it moves dbg.declares around in the
instruction stream (typically by hoisting them into the entry block).
This behavior was introduced in llvm/r227544 to fix an assertion failure
(llvm.org/PR22386), but no longer appears to be necessary.

Hoisting a dbg.declare generally does not create problems. Usually,
dbg.declare either describes an argument or an alloca in the entry
block, and backends have special handling to emit locations for these.
In optimized builds, LowerDbgDeclare places dbg.values in the right
spots regardless of where the dbg.declare is. And no one uses
replaceDbgDeclare to handle things like VLAs.

However, there doesn't seem to be a positive case for moving
dbg.declares around anymore, and this reordering can get in the way of
understanding other bugs. I propose getting rid of it.

Testing: stage2 RelWithDebInfo sanitized build, check-llvm

rdar://59397340

Differential Revision: https://reviews.llvm.org/D74517

Summary: It attempts to devirtualize a call on alloca through vtable loads.

Reviewers: davidxl

Subscribers: mgorny, Prazek, hiraditya, llvm-commits

Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71308

During extraction, stale llvm.assume handles may be retained in the
original function. The setup is:

1) CodeExtractor unregisters assumptions in the blocks that are to be
   extracted.

2) Extraction happens. There are now two functions: f1 and f1.extracted.

3) Leftover assumptions in f1 (/not/ removed as they were not in the set of
   blocks to be extracted) now have affected-value llvm.assume handles in
   f1.extracted.

When assumptions for a value used in f1 are looked up, ValueTracking can assert
as some of the handles are in the wrong function. To fix this, simply erase the
llvm.assume calls in the extracted function.

Alternatives include flushing the assumption cache in the original function, or
walking all values used in the original function to prune stale affected-value
handles. Both seem more expensive.

Testing: check-llvm, LNT run with -mllvm -hot-cold-split enabled

rdar://58460728

Summary:
Currently IsControlFlowEquivalent determine if two blocks are control
flow equivalent by checking if A dominates B and B post dominates A.
There exists blocks that are control flow equivalent even if they don't
satisfy the A dominates B and B post dominates A condition.
For example,

if (cond)
  A
if (cond)
  B
In the PR, we determine if two blocks are control flow equivalent by
also checking if the two sets of conditions A and B depends on are
equivalent.
Reviewer: jdoerfert, Meinersbur, dmgreen, etiotto, bmahjour, fhahn,
hfinkel, kbarton
Reviewed By: fhahn
Subscribers: hiraditya, llvm-commits
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D71578

In case of loops with multiple exit where all-but-one exit are deoptimizing
it might happen that the first rotation will end up with latch having a deoptimizing
exit. This makes the loop unsuitable for trip-count analysis (say, getLoopEstimatedTripCount)
as well as for loop transformations that know how to handle multple deoptimizing exits.

It pretty much means that canonical form in multple-deoptimizing-exits case should be
with non-deoptimizing exit at latch.
Teach loop-rotation to reach this canonical form by repeating rotation.

-loop-rotate-multi option introduced to control this behavior, currently disabled by default.

Reviewers: skatkov, asbirlea, reames, fhahn
Reviewed By: skatkov

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73058

This reverts commit 51ef53f3, as it
breaks some bots.

SCEVExpander modifies the underlying function so it is more suitable in
Transforms/Utils, rather than Analysis. This allows using other
transform utils in SCEVExpander.

Reviewers: sanjoy.google, efriedma, reames

Reviewed By: sanjoy.google

Differential Revision: https://reviews.llvm.org/D71537

Commit d77ae155
("[DebugInfo] Support to emit debugInfo for extern variables")
added deebugInfo for extern variables for BPF target.
The commit is reverted by 891e25b0
as the committed tests using %clang instead of %clang_cc1 causing
test failed in certain scenarios as reported by Reid Kleckner.

This patch fixed the tests by using %clang_cc1.

Differential Revision: https://reviews.llvm.org/D71818

This reverts commit d77ae155.

The tests committed along with this change do not pass, and should be
changed to use %clang_cc1.

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

This reverts commit cd09fee3.
This reverts commit c066ff11.

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

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

Extern variable usage in BPF is different from traditional
pure user space application. Recent discussion in linux bpf
mailing list has two use cases where debug info types are
required to use extern variables:
  - extern types are required to have a suitable interface
    in libbpf (bpf loader) to provide kernel config parameters
    to bpf programs.
    https://lore.kernel.org/bpf/CAEf4BzYCNo5GeVGMhp3fhysQ=_axAf=23PtwaZs-yAyafmXC9g@mail.gmail.com/T/#t
  - extern types are required so kernel bpf verifier can
    verify program which uses external functions more precisely.
    This will make later link with actual external function no
    need to reverify.
    https://lore.kernel.org/bpf/87eez4odqp.fsf@toke.dk/T/#m8d5c3e87ffe7f2764e02d722cb0d8cbc136880ed

This patch added clang support to emit debuginfo for extern variables
with a TargetInfo hook to enable it. The debuginfo for the
extern variable is emitted only if that extern variable is
referenced in the current compilation unit.

Currently, only BPF target enables to generate debug info for
extern variables. The emission of such debuginfo is disabled for C++
 at this moment since BPF only supports a subset of C language.
Emission with C++ can be enabled later if an appropriate use case
is identified.

-fstandalone-debug permits us to see more debuginfo with the cost
of bloated binary size. This patch did not add emission of extern
variable debug info with -fstandalone-debug. This can be
re-evaluated if there is a real need.

Differential Revision: https://reviews.llvm.org/D70696

AssumptionCache can be null in SimplifyCFGOptions. However, FoldCondBranchOnPHI() was not properly handling that when passing a null AssumptionCache to simplifyCFG.

Patch by Rodrigo Caetano Rocha <rcor.cs@gmail.com>

Reviewers: fhahn, lebedev.ri, spatel

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D69963

The file is intended to gather various VPlan transformations, not only
CFG related transforms. Actually, the only transformation there is not
CFG related.

Reviewers: Ayal, gilr, hsaito, rengolin

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D70732

InnerLoopVectorizer's code called during VPlan execution still relies on
original IR's def-use relations to decide which vector code to generate,
limiting VPlan transformations ability to modify def-use relations and still
have ILV generate the vector code.
This commit moves GEP operand queries controlling how GEPs are widened to a
dedicated recipe and extracts GEP widening code to its own ILV method taking
those recorded decisions as arguments. This reduces ingredient def-use usage by
ILV as a step towards full VPlan-based def-use relations.

Differential revision: https://reviews.llvm.org/D69067

[PGO][PGSO] Distinguish queries from unit tests and explicitly enable for the existing IR passes only. NFC.

Summary:
This is one more prep step necessary before the code gen pass instrumentation
code could go in.

Reviewers: davidxl

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70988

Summary:
Related bug: https://bugs.llvm.org/show_bug.cgi?id=40648

Static helper function rewriteDebugUsers in Local.cpp deletes dbg.value
intrinsics when it cannot move or rewrite them, or salvage the deleted
instruction's value. It should instead undef them in this case.

This patch fixes that and I've added a test which covers the failing test
case in bz40648. I've updated the unit test Local.ReplaceAllDbgUsesWith
to check for this behaviour (and fixed a typo in the test which would
cause the old test to always pass).

Reviewers: aprantl, vsk, djtodoro, probinson

Reviewed By: vsk

Subscribers: hiraditya, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D70604

moved before another instruction.
Summary:Added an API to check if an instruction can be safely moved
before another instruction. In future PRs, we will like to add support
of moving instructions between blocks that are not control flow
equivalent, and add other APIs to enhance usability, e.g. moving basic
blocks, moving list of instructions...
Loop Fusion will be its first user. When there is intervening code in
between two loops, fusion is currently unable to fuse them. Loop Fusion
can use this utility to check if the intervening code can be safely
moved before or after the two loops, and move them, then it can
successfully fuse them.
Reviewer:kbarton,jdoerfert,Meinersbur,bmahjour,etiotto
Reviewed By:bmahjour
Subscribers:mgorny,hiraditya,llvm-commits
Tag:LLVM
Differential Revision:https://reviews.llvm.org/D70049

E.g. the buildbot at

 http://lab.llvm.org:8011/builders/ppc64le-lld-multistage-test/builds/7259/steps/build-stage2-unified-tree/logs/stdio

failed with

/home/buildbots/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/unittests/Transforms/Utils/VFABIUtils.cpp:50:22: error: unused variable 'FnAttrs' [-Werror,-Wunused-variable]
  const AttributeSet FnAttrs = Attrs.getFnAttributes();
                     ^
1 error generated.

The attribute is stored at the `FunctionIndex` attribute set, with the
name "vector-function-abi-variant".

The get/set methods of the attribute have assertion to verify that:

1. Each name in the attribute is a valid VFABI mangled name.

2. Each name in the attribute correspond to a function declared in the
   module.

Differential Revision: https://reviews.llvm.org/D69976

This recommits 11ed1c02 (reverted in
9f08ce0d for failing an assert) with a fix:
tryToWidenMemory() now first checks if the widening decision is to interleave,
thus maintaining previous behavior where tryToInterleaveMemory() was called
first, giving priority to interleave decisions over widening/scalarization. This
commit adds the test case that exposed this bug as a LIT.

This reverts commit 11ed1c02 - causes an assert failure.

This recommits 100e797a (reverted in
009e0326 for failing an assert). While the
root cause was independently reverted in eaff3004,
this commit includes a LIT to make sure IVDescriptor's SinkAfter logic does not
try to sink branch instructions.

as it's causing assert failures.

This reverts commit 100e797a.

This recommits 2be17087 (reverted in
d3ec06d2 for heap-use-after-free) with a fix
in IAI's reset() which was not clearing the set of interleave groups after
deleting them.

This reverts commit 2be17087. Fails ASAN.

The sink-after and interleave-group vectorization decisions were so far applied to
VPlan during initial VPlan construction, which complicates VPlan construction – also because of
their inter-dependence. This patch refactors buildVPlanWithRecipes() to construct a simpler
initial VPlan and later apply both these vectorization decisions, in order, as VPlan-to-VPlan
transformations.

Differential Revision: https://reviews.llvm.org/D68577

Since SCEV can cache information about location of an instruction, it should be invalidated when the instruction is moved.
There should be similar bug in code sinking part of LICM, it will be fixed in a follow-up change.

Patch Author: Daniil Suchkov
Reviewers: asbirlea, mkazantsev, reames
Reviewed By: asbirlea
Subscribers: hiraditya, javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D69370

This unit test exposes a bug in LICM: when it hoists instructions it doesn't invalidate SCEV accordingly.
Similar test exposing lack of SCEV invalidation during code sinking will be submitted as a follow-up change.

Patch Author: Daniil Suchkov
Reviewers: mkazantsev, asbirlea, reames
Reviewed By: asbirlea
Subscribers: mgorny, javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D69369

Summary:
(Split of off D67120)

SizeOpts/MachineSizeOpts changes for profile guided size optimization.

(A second try after previously committed as r375254 and reverted as r375375.)

Subscribers: mgorny, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69409