llvm-svn: 367038

Later code in TryToSimplifyUncondBranchFromEmptyBlock() assumes that
we have cleaned up unreachable blocks, but that was not happening
with this switch transform.

llvm-svn: 367037

It doesn't like function attributes on definitions, only declarations.

llvm-svn: 367036

llvm-svn: 367035

As discussed in https://bugs.llvm.org/show_bug.cgi?id=42673
there is a TTI hook hasDivRemOp() that matters here.
While -div-rem-pairs will decompose 'rem' if that hook returns false,
nothing does the opposite transform.

We can't to this in InstCombine, because it does not currently
access TTI, and i'm not sure we should change that.

We may be able to teach DivRemPairs to do this, but this really is a
per-target perf optimization, and we seem to do the opposite transform
in backend if hasDivRemOp() returned false: https://godbolt.org/z/ttt4HZ
I think it makes sense to be consistent.

https://bugs.llvm.org/show_bug.cgi?id=42673

llvm-svn: 367034

Summary:
This is the first patch for the loop guard. We introduced
getLoopGuardBranch() and isGuarded().
This currently only works on simplified loop, as it requires a preheader
and a latch to identify the guard.
It will work on loops of the form:
/// GuardBB:
///   br cond1, Preheader, ExitSucc <== GuardBranch
/// Preheader:
///   br Header
/// Header:
///  ...
///   br Latch
/// Latch:
///   br cond2, Header, ExitBlock
/// ExitBlock:
///   br ExitSucc
/// ExitSucc:
Prior discussions leading upto the decision to introduce the loop guard
API: http://lists.llvm.org/pipermail/llvm-dev/2019-May/132607.html
Reviewer: reames, kbarton, hfinkel, jdoerfert, Meinersbur, dmgreen
Reviewed By: reames
Subscribers: wuzish, hiraditya, jsji, llvm-commits, bmahjour, etiotto
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D63885

llvm-svn: 367033

Summary:
This is useful for targets which have prefetch instructions for non-default address spaces.

<rdar://problem/42662136>

Subscribers: nemanjai, javed.absar, hiraditya, kbarton, jkorous, dexonsmith, cfe-commits, llvm-commits, RKSimon, hfinkel, t.p.northover, craig.topper, anemet

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D65254

llvm-svn: 367032

Summary:
Looking at the current Apple-specific code for crash handling it does a few
silly things that I think we should avoid while handling crashes:

  * Try real hard not to allocate.
  * Set the global crash reporter string early so that any crash while
    generating the stack trace will still report some info.
  * Prevent reordering of operations in the current thread.

<rdar://problem/53503334>

Subscribers: hiraditya, jkorous, dexonsmith, llvm-commits, beanz, Bigcheese, thakis, lattner, jordan_rose

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65235

llvm-svn: 367031

Currently, we expect the CO-RE offset relocation records
a string encoding the original getelementptr access index,
so kernel bpf loader can decode it correctly.

For example,
  struct s { int a; int b; };
  struct t { int c; int d; };
  #define _(x) (__builtin_preserve_access_index(x))
  int get_value(const void *addr1, const void *addr2);
  int test(struct s *arg1, struct t *arg2) {
    return get_value(_(&arg1->b), _(&arg2->d));
  }

We expect two offset relocations:
  reloc 1: type s, access index 0, 1
  reloc 2: type t, access index 0, 1

Two globals are created to retain access indexes for the
above two relocations with global variable names.
The first global has a name "0:1:". Unfortunately,
the second global has the name "0:1:.1" as the llvm
internals automatically add suffix ".1" to a global
with the same name. Later on, the BPF peels the last
character and record "0:1" and "0:1:." in the
relocation table.

This is not desirable. BPF backend could use the global
variable suffix knowledge to generate correct access str.
This patch rather took an approach not relying on
that knowledge. It generates "s:0:1:" and "t:0:1:" to
avoid global variable suffixes and later on generate
correct index access string "0:1" for both records.

Signed-off-by: Yonghong Song <yhs@fb.com>

Differential Revision: https://reviews.llvm.org/D65258

llvm-svn: 367030

This reverts commit bc4a63fd, this is a
speculative revert to fix a number of sanitizer bots (like
sanitizer-x86_64-linux-bootstrap-ubsan) that have started to see stage2
compiler crashes, presumably due to a miscompile.

llvm-svn: 367029

We do not need the SmallPtrSet to avoid adding duplicates to
OpsToRename, because we already keep a ValueInfo mapping. If we see an
op for the first time, Infos will be empty and we can also add it to
OpsToRename.

We process operands by visiting BBs depth-first and then iterate over
all instructions & users, so the order should be deterministic.
Therefore we can skip one round of sorting, which we purely needed for
guaranteeing a deterministic order when iterating over the SmallPtrSet.

Reviewers: efriedma, davide

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D64816

llvm-svn: 367028

As passed in the Cologne meeting and treated by Core as a DR,
[[nodiscard]] was applied to constructors so that they can be diagnosed
in cases where the user forgets a variable name for a type.

The intent is to enable the library to start using this on the
constructors of scope_guard/lock_guard.

Differential Revision: https://reviews.llvm.org/D64914

llvm-svn: 367027

The semantics of an empty basename passed to isDerivedFrom matchers
changed in r367022, so this test is no longer relevant.

llvm-svn: 367026

Summary:
According to the OpenMP standard, barrier operation must perform
implicit flush operation. Currently, if there is only one thread in the
team, barrier does not flush the memory. Patch fixes this problem.

Reviewers: grokos, gtbercea, kkwli0

Subscribers: guansong, jdoerfert, openmp-commits, caomhin

Tags: #openmp

Differential Revision: https://reviews.llvm.org/D62398

llvm-svn: 367024

Summary:
- As LCSSA is turned on just before isel, it may create PHI of the flow,
  which is consumed by pseudo structurized CFG instructions. When that
  PHIs are eliminated in O0, COPY may be placed wrongly as the these
  pseudo structurized CFG instructions are considering prologue of MBB.
- Run extra `unreachable-mbb-elimination` at the end of isel to clean up
  PHIs.

Reviewers: arsenm, rampitec

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64353

llvm-svn: 367023

Differential Revision: https://reviews.llvm.org/D65279

llvm-svn: 367022

This is a port of libomp for the RISC-V 64-bit Linux target.

We have tested this port on a HiFive Unleashed development board
using a downstream LLVM that has support for the missing bits in
upstream. As of now, all tests are passing, including OMPT.

Patch by Ferran Pallarès!

Differential Revision: https://reviews.llvm.org/D59880

llvm-svn: 367021

Summary:
Here's a replacement for D62504. I thought I could use LoadModules to implement this but in reality I can't because there are at few issues with it:
* The LoadModules assumes that the list returned by GetLoadedModuleList is comprehensive in the sense that reflects all the mapped segments, however, this is not true, for instance VDSO entry is not there since it's loaded manually by LoadVDSO using GetMemoryRegionInfo and it doesn't represent a specific shared object in disk. Because of this LoadModules will unload the VDSO module.
* The loader (interpreter) module might have also been loaded using GetMemoryRegionInfo, this is true when we launch the process and the rendezvous structure is not yet available (done through LoadInterpreterModule()). The problem here is that this entry will point to the same file name as the one found in /proc/pid/maps, however, when we read the same module from the r_debug.link_map structure it might be under a different name. This is true at least on CentOS where the loader is a symlink. Because of this LoadModules will unload and load the module in a way where the rendezvous breakpoint is unresolved but not resolved again (because we add the new module first and remove the old one after).

The symlink issue might be fixable by first unloading the old and loading the news (but sounds super brittle), however, I'm not sure how to fix the VDSO issue.
Since I can't trust it I'm just going to use GetLoadedModuleList directly with the same logic that we use today for when we read the linked list in lldb. The only safe thing to do here is to only calculate differences between different snapshots of the svr4 packet itself. This will also cut the dependency this plugin has from LoadModules.

I separated the 2 logics into 2 different functions (remote and not remote) because I don't like mixing 2 different logics in the same function with if/else's. Two different functions makes it easier to reason with I believe. However, I did abstract away the logic that decides if we should take a snapshot or add/remove modules so both functions could reuse it.

The other difference between the two is that on the UpdateSOEntriesFromRemote I take the snapshot only once when state = Consistent because I didn't find a good reason to always update that, as we already got the list from state = Add | Remove. I probably should use the same logic on UpdateSOEntries though I don't see a reason not to since it's really using the same data, just read in different places. Any thoughts here?

It might also be worthwhile to add a test to make sure we don't unload modules that were not actually "unloaded" like the vdso. I haven't done this yet though.
This diff is also missing the option for svr4 like proposed in https://reviews.llvm.org/D62503#1564296, I'll start working on this but wanted to have this up first.

Reviewers: labath, jankratochvil, clayborg, xiaobai

Reviewed By: labath

Subscribers: srhines, JDevlieghere, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D64013

llvm-svn: 367020

... for the vector forms of `{SQ,UQ,}{INC,DEC}P` instructions. Also continue
supporting the exsting behaviour of not requiring an explicit size
specifier. The preferred disasembly is *with* the specifier.

This is implemented by redefining intruction forms to require vector predicates
with explicit size and adding aliases, which allow a predicate with no size.

Differential Revision: https://reviews.llvm.org/D65145

llvm-svn: 367019

llvm-svn: 367018

Summary:
It is a good idea to do as much matching inside of `match()` as possible.
If some checking is done afterwards, and we don't fold because of it,
chances are we may have missed some commutative pattern.

Reviewers: spatel, craig.topper, RKSimon

Reviewed By: spatel, RKSimon

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64038

llvm-svn: 367017

Summary:
I don't think it already exists? I don't see it at least.
It is important to have it because else we'll do some checks after `match()`,
and that may result in missed folds in commutative nodes.

Reviewers: spatel, craig.topper, RKSimon, majnemer

Reviewed By: spatel

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64037

llvm-svn: 367016

http://llvm.org/docs/CodingStandards.html#doxygen-use-in-documentation-comments

llvm-svn: 367015

All these args can be cheaply recomputed and it makes it much easier to use the function as a quick helper.

llvm-svn: 367014

llvm-svn: 367013

Summary:
r366702 added a set of new clang-cl -- specific openmp flags together with tests.
The way the newly added tests work is problematic: consider for example this
asertion:
```
// RUN: %clang_cl --target=x86_64-windows-msvc /openmp -### -- %s 2>&1 | FileCheck --check-prefix=CHECK-CC1-OPENMP %s
...
// CHECK-CC1-OPENMP: "-fopenmp"
```

It asserts that an `/openmp` flag should expand into `-fopenmp`. This however
depends on the default value of Clang's CLANG_DEFAULT_OPENMP_RUNTIME value.
Indeed, the code that adds `-fopenmp` to the output only does it if the default
runtime is `libomp` or `libiomp5`, not when it is `libgomp`.

I've updated the tests to not depend on the default value of this setting by
specifying the runtime to use explicitly in each assertion.

Reviewers: jdoerfert

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D65272

llvm-svn: 367012

trunc (load X) --> load (bitcast X to narrow type)

We have this transform in DAGCombiner::ReduceLoadWidth(), but the truncated
load pattern can interfere with other instcombine transforms, so I'd like to
allow the fold sooner.

Example:
https://bugs.llvm.org/show_bug.cgi?id=16739
...in that report, we have bitcasts bracketing these ops, so those could get
eliminated too.

We've generally ruled out widening of loads early in IR ( LoadCombine -
http://lists.llvm.org/pipermail/llvm-dev/2016-September/105291.html ), but
that reasoning may not apply to narrowing if we can preserve information
such as the dereferenceable range.

Differential Revision: https://reviews.llvm.org/D64432

llvm-svn: 367011

Differential Revision: https://reviews.llvm.org/D65092

llvm-svn: 367010

llvm-svn: 367009

Rename lang mode flag to -cl-std=clc++/-cl-std=CLC++
or -std=clc++/-std=CLC++.

This aligns with OpenCL C conversion and removes ambiguity
with OpenCL C++. 

Differential Revision: https://reviews.llvm.org/D65102

llvm-svn: 367008

Summary:
Add support for Cortex-A65, Cortex-A65AE, Neoverse E1 and Neoverse N1.
Neoverse E1 and Cortex-A65(&AE) only implement the AArch64 state of the
Arm architecture. Neoverse N1 implements both AArch32 and AArch64.

Cortex-A65:
https://developer.arm.com/ip-products/processors/cortex-a/cortex-a65

Cortex-A65AE:
https://developer.arm.com/ip-products/processors/cortex-a/cortex-a65ae

Neoverse E1:
https://developer.arm.com/ip-products/processors/neoverse/neoverse-e1

Neoverse N1:
https://developer.arm.com/ip-products/processors/neoverse/neoverse-n1

Patch by Diogo Sampaio and Pablo Barrio

Reviewers: samparker, LukeCheeseman, sbaranga, ostannard

Reviewed By: ostannard

Subscribers: ostannard, javed.absar, kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64406

llvm-svn: 367007

Summary:
When cross TU analysis is used it is possible that a macro expansion
is generated for a macro that is defined (and used) in other than
the main translation unit. To get the expansion for it the source
location in the original source file and original preprocessor
is needed.

Reviewers: martong, xazax.hun, Szelethus, ilya-biryukov

Reviewed By: Szelethus

Subscribers: mgorny, NoQ, ilya-biryukov, rnkovacs, dkrupp, Szelethus, gamesh411, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D64638

llvm-svn: 367006

If debugserver or any other framework tool gets built first, its post-build copy operation was using 'Resources' as the file name instead of the destination directory. It was not a problem with Ninja, because here the framework structure was alreaady created at configuration time. With this fix, both generators are happy.

llvm-svn: 367005

This allows every serializer format to implement metaSerializer() and
return the corresponding meta serializer.
........
Fix windows build bots
http://lab.llvm.org:8011/builders/llvm-clang-x86_64-win-fast
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast
http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-win

llvm-svn: 367004

With fix: do not use `stat` tool.

Original commit message:

This is a follow-up refactoring patch for recently
introduced functionality which which reduces the code duplication
and also makes possible to redefine all possible fields of
the first SHT_NULL section (previously it was only possible to set
sh_link and sh_size).

Differential revision: https://reviews.llvm.org/D65140

llvm-svn: 367003

llvm-svn: 367001

llvm-svn: 367000

We should only zap returns in functions, where all live users have a
replace-able value (are not overdefined). Unused return values should be
undefined.

This should make it easier to detect bugs like in PR42738.

Alternatively we could bail out of zapping the function returns, but I
think it would be better to address those divergences between function
and call-site values where they are actually caused.

Reviewers: davide, efriedma

Reviewed By: davide, efriedma

Differential Revision: https://reviews.llvm.org/D65222

llvm-svn: 366998

We reorder declarations in RecordDecls because they may have another order
in the "to" context than they have in the "from" context. This may happen
e.g when we import a class like this:
   struct declToImport {
       int a = c + b;
       int b = 1;
       int c = 2;
   };
During the import of `a` we import first the dependencies in sequence,
thus the order would be `c`, `b`, `a`. We will get the normal order by
first removing the already imported members and then adding them in the
order as they apper in the "from" context.

Keeping field order is vital because it determines structure layout.

Reviewers: a_sidorin, shafik

Tags: #clang

Differential Revision: https://reviews.llvm.org/D44100

llvm-svn: 366997

Summary:
After rL366893, the annoate tweak is not activated when we select the
whole file (the commonAncestor is TUDecl but we intend to return null).

This patch fixes this, and also avoid traversing the TUDecl.

Reviewers: sammccall

Subscribers: ilya-biryukov, MaskRay, jkorous, arphaman, kadircet, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D65210

llvm-svn: 366996