Initial implementation of global aliases emission for the declare
variant pragma with implementation vendor context selector set.

llvm-svn: 373387

Summary:
This patch adds Root Node to the DDG. The purpose of the root node is to create a single entry node that allows graph walk iterators to iterate through all nodes of the graph, making sure that no node is left unvisited during a graph walk (eg. SCC or DFS). Once the DDG is fully constructed it will have exactly one root node. Every node in the graph is reachable from the root. The algorithm for connecting the root node is based on depth-first-search that keeps track of visited nodes to try to avoid creating unnecessary edges.

Authored By: bmahjour

Reviewer: Meinersbur, fhahn, myhsu, xtian, dmgreen, kbarton, jdoerfert

Reviewed By: Meinersbur

Subscribers: ychen, arphaman, simoll, a.elovikov, mgorny, hiraditya, jfb, wuzish, llvm-commits, jsji, Whitney, etiotto, ppc-slack

Tag: #llvm

Differential Revision: https://reviews.llvm.org/D67970

llvm-svn: 373386

In reality, this workaround is for the fact that LIBCXX_CXX_ABI=libcxxabi
can't be specified on Linux, since libc++abi isn't shipped with the system.
Since the build bots explicitly specify LIBCXX_CXX_ABI=libcxxabi, they fail
unless we apply the workaround.

llvm-svn: 373385

I tried applying D63883 three times and could never get around to
making it work. I'm giving up on that for now, but soon this should
be irrelevant anyway since all builds will move to the monorepo
(where we're always using the in-tree libc++abi unless explicitly
specified otherwise).

llvm-svn: 373384

If a single predecessor is found, still check if the block is
unreachable. The test that found this had a self loop unreachable block.
Resolves PR43493.

llvm-svn: 373383

llvm-svn: 373382

This reduces the (circular) dependency of libc++abi on a C++ standard
library. Outside of the demangler which uses fancier C++ features, the
only C++ headers now required by libc++abi are pretty much <new> and
<exception>, and that's because libc++abi defines some types that are
declared in those headers.

llvm-svn: 373381

The check for "was there an access in this block" should be: is the last
access in this block and is it not a newly inserted phi.
Resolves new test in PR43438.

Also fix a typo when simplifying trivial Phis to match the comment.

llvm-svn: 373380

llvm-svn: 373379

llvm-svn: 373378

Summary:
PHIElimination modifies CFG and marks MachineDominatorTree as preserved. Therefore, it the CFG changes it should also update the MDT, when available. This patch teaches PHIElimination to recalculate MDT when necessary.

This fixes the `tailmerging_in_mbp.ll` test failure discovered after switching to generic DomTree verification algorithm in MachineDominators in D67976.

Reviewers: arsenm, hliao, alex-t, rampitec, vpykhtin, grosser

Reviewed By: rampitec

Subscribers: MatzeB, wdng, hiraditya, javed.absar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68154

llvm-svn: 373377

This reverts r373117 (git commit 159ef377)

Phabricator review: https://reviews.llvm.org/D67976.

llvm-svn: 373376

Forgot to run check-clang-semacxx.

llvm-svn: 373375

Fixed calculation the size of the array sections.

llvm-svn: 373374

llvm-svn: 373373

llvm-svn: 373372

Too many false positives, eg. in Chromium.

llvm-svn: 373371

Summary:
To trigger the index-only Whole Program Devirt support added to LLVM, we
need to be able to specify -fno-split-lto-unit in conjunction with
-fwhole-program-vtables. Keep the default for -fwhole-program-vtables as
-fsplit-lto-unit, but don't error on that option combination.

Reviewers: pcc

Subscribers: mehdi_amini, inglorion, steven_wu, dexonsmith, arphaman, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D68029

llvm-svn: 373370

llvm-svn: 373369

llvm-svn: 373368

Revert "compiler-rt: move all __GLIBC_PREREQ into own header file"

"move all __GLIBC_PREREQ" breaks build on some bots

This reverts commit 2d75ee93.
This reverts commit 7a6461fc.

llvm-svn: 373367

Summary:
This is a refactoring that will make future improvements to this pass easier.
This change should not change the behavior of the pass.

Reviewers: arsenm, pendingchaos, rampitec, nhaehnle, vpykhtin

Reviewed By: nhaehnle, vpykhtin

Subscribers: kzhuravl, jvesely, wdng, yaxunl, dstuttard, tpr, t-tye, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65496

llvm-svn: 373366

<string.h> is always included, so we don't need the additional #include
only in the _WIN32 case.

llvm-svn: 373365

Identical to it's trunc-less variant, just pretent-to hoist
trunc, and everything else still holds:
https://rise4fun.com/Alive/JRU

llvm-svn: 373364

https://rise4fun.com/Alive/yR4

llvm-svn: 373363

https://rise4fun.com/Alive/JRU
https://rise4fun.com/Alive/yR4 <- we can preserve 'exact'

llvm-svn: 373362

This patch replaces the LLDB's JSON implementation with the one from
LLVM in argdumper.

Differential revision: https://reviews.llvm.org/D68279

llvm-svn: 373361

This patch replaces the hand-rolled JSON decoding in StructuredData with
LLVM's JSON library.

Differential revision: https://reviews.llvm.org/D68282

llvm-svn: 373360

This patch replaces the hand-rolled JSON emission in StructuredData with
LLVM's JSON library.

Differential revision: https://reviews.llvm.org/D68248

llvm-svn: 373359

This adds a -mattr flag to llvm-mca, for cases where the -mcpu option does not
contain all optional features.

Differential Revision: https://reviews.llvm.org/D68190

llvm-svn: 373358

llvm-svn: 373357

llvm-svn: 373356

llvm-svn: 373355

llvm-svn: 373354

llvm-svn: 373353

llvm-svn: 373352

This patch implements a variation of a well known techniques for JIT compilers - we have an implementation in tree as LoopPredication - but with an interesting twist. This version does not assume the ability to execute a path which wasn't taken in the original program (such as a guard or widenable.condition intrinsic). The benefit is that this works for arbitrary IR from any frontend (including C/C++/Fortran). The tradeoff is that it's restricted to read only loops without implicit exits.

This builds on SCEV, and can thus eliminate the loop varying portion of the any early exit where all exits are understandable by SCEV. A key advantage is that fixing deficiency exposed in SCEV - already found one while writing test cases - will also benefit all of full redundancy elimination (and most other loop transforms).

I haven't seen anything in the literature which quite matches this. Given that, I'm not entirely sure that keeping the name "loop predication" is helpful. Anyone have suggestions for a better name? This is analogous to partial redundancy elimination - since we remove the condition flowing around the backedge - and has some parallels to our existing transforms which try to make conditions invariant in loops.

Factoring wise, I chose to put this in IndVarSimplify since it's a generally applicable to all workloads. I could split this off into it's own pass, but we'd then probably want to add that new pass every place we use IndVars.  One solid argument for splitting it off into it's own pass is that this transform is "too good". It breaks a huge number of existing IndVars test cases as they tend to be simple read only loops.  At the moment, I've opted it off by default, but if we add this to IndVars and enable, we'll have to update around 20 test files to add side effects or disable this transform.

Near term plan is to fuzz this extensively while off by default, reflect and discuss on the factoring issue mentioned just above, and then enable by default.  I also need to give some though to supporting widenable conditions in this framing.

Differential Revision: https://reviews.llvm.org/D67408

llvm-svn: 373351

There are 1024 bit register classes defined for AGPRs. Additionally
OpenCL defines vectors up to 16 x i64, and this helps those tests
legalize.

llvm-svn: 373350

Summary:
This adds the ISD opcode and a DAG combine to create it. There are
probably some places where we can directly create it, but I'll
leave that for future work.

This updates all of the isel patterns to look for this new node.
I had to add a few additional isel patterns for aligned extloads
which we should probably fix with a DAG combine or something. This
does mean that the broadcast load folding for avx512 can no
longer match a broadcasted aligned extload.

There's still some work to do here for combining a broadcast of
a broadcast_load. We also need to improve extractelement or
demanded vector elements of a broadcast_load. I'll try to get
those done before I submit this patch.

Reviewers: RKSimon, spatel

Reviewed By: RKSimon

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68198

llvm-svn: 373349

loop.

Missed check if the condition is also dependent when building final
expressions for the collapsed loop directives.

llvm-svn: 373348