As motivated in D60598, this drops support for specifying both NUW and
NSW in makeGuaranteedNoWrapRegion(). None of the users of this function
currently make use of this.

When both NUW and NSW are specified, the exact nowrap region has two
disjoint parts and makeGNWR() returns one of them. This result doesn't
seem to be useful for anything, but makes the semantics of the function
fuzzier.

Differential Revision: https://reviews.llvm.org/D60632

llvm-svn: 358340

As pointed out in D60518 folding mulo(%x, undef) to {undef, undef}
isn't correct. As a correct version of this already exists in
InstructionSimplify (https://github.com/llvm-mirror/llvm/blob/bd8056ef326e075cc500f3f0cfcd1193bc200594/lib/Analysis/InstructionSimplify.cpp#L4750-L4757) this is just
dead code though. Drop it together with the mul(%x, 0) -> {0, false}
fold that is also already handled by InstSimplify.

Differential Revision: https://reviews.llvm.org/D60649

llvm-svn: 358339

We know all our values are limited to 64 bits here so we don't need an APInt.

This should save some generated code checking between large and small size.

llvm-svn: 358338

Summary: Add DefaultOption flag to CommandLineParser which provides a
default option or alias, but allows users to override it for some
other purpose as needed.

Also, add `-h` as a default alias to `-help`, which can be seamlessly
overridden by applications like llvm-objdump and llvm-readobj which
use `-h` as an alias for other options.

Reviewers: alexfh, klimek

Reviewed By: klimek

Subscribers: MaskRay, mehdi_amini, inglorion, dexonsmith, hiraditya, llvm-commits, jhenderson, arphaman, cfe-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D59746

llvm-svn: 358337

Summary: Use member function.

Reviewers: aheejin

Subscribers: sunfish, hiraditya, sbc100, jgravelle-google, dschuff, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60651

Patch by Hideto Ueno (uenoku)

llvm-svn: 358336

llvm-svn: 358335

It is no longer used after the AliasSetTracker updating logic was removed.

llvm-svn: 358334

llvm-svn: 358333

llvm-svn: 358332

Checked the wrong direction in the umul tests... fix predicated to
line up with the test name.

llvm-svn: 358331

llvm-svn: 358330

Do not use -nostdlib in target-symbols-add-unwind.test.  NetBSD uses
startup files to provide obligatory ELF notes in executables,
and therefore using -nostdlib requires providing specially tailored
input.  Otherwise, kernel rejects the result as invalid executable.

The replacement was suggested by Pavel Labath.

Differential Revision: https://reviews.llvm.org/D60648

llvm-svn: 358329

Differential Revision: https://reviews.llvm.org/D60647

llvm-svn: 358328

llvm-svn: 358327

A marker (matching /#[A-Za-z0-9_-]/) is specified by attaching a comment
containing the marker to the line at which the diagnostic is expected,
and then can be referenced from an expected-* directive after an @:

  foo // #1
  // expected-error@#1 {{undeclared identifier 'foo'}}

The intent is for markers to be used in situations where relative line
numbers are currently used, to avoid the need to renumber when the test
case is rearranged.

llvm-svn: 358326

This updates the StackMap parser in the llvm-readobj tool to parse version 3 StackMaps, which were bumped in https://reviews.llvm.org/D32629.

Version 3 StackMaps differ in that they have a uint16 sized "location size" field which was added to the Location block in a StackMap record. The record has additional padding for alignment. This was a backwards incompatible change resulting in a StackMap version bump.

Patch By: jacob.hughes@kcl.ac.uk (with a rewrite of tests by me)
Differential Revision: https://reviews.llvm.org/D59020

llvm-svn: 358325

The size field of a location can be different for each entry, so it is useful to have this displayed in the output of llvm-readobj -stackmap. Below is an example of how the output would look:

Record ID: 2882400000, instruction offset: 16
   3 locations:
     #1: Constant 1, size: 8
     #2: Constant 2, size: 8
     #3: Constant 3, size: 8
   0 live-outs: [ ]

Patch By: jacob.hughes@kcl.ac.uk (with heavy modification by me)
Differential Revision: https://reviews.llvm.org/D59169

llvm-svn: 358324

llvm-svn: 358323

Motivation is to reduce silly diffs when we change the format.  For instance, this causes most of D59020 to disappear.

llvm-svn: 358322

Writing stuff into an argument variable is usually equivalent to writing stuff
to a local variable: it will have no effect outside of the function.
There's an important exception from this rule: if the argument variable has
a non-trivial destructor, the destructor would be invoked on
the parent stack frame, exposing contents of the otherwise dead
argument variable to the caller.

If such argument is the last place where a pointer is stored before the function
exits and the function is the one we've started our analysis from (i.e., we have
no caller context for it), we currently diagnose a leak. This is incorrect
because the destructor of the argument still has access to the pointer.
The destructor may deallocate the pointer or even pass it further.

Treat writes into such argument regions as "escapes" instead, suppressing
spurious memory leak reports but not messing with dead symbol removal.

Differential Revision: https://reviews.llvm.org/D60112

llvm-svn: 358321

[libFuzzer] speedup the merge step in the fork mode by merging only the files that have unique features.

llvm-svn: 358320

The reserved uint8 field in the location block of the stackmap record is used to denote the size of the location.

Patch By: jacob.hughes@kcl.ac.uk
Differential Revision: https://reviews.llvm.org/D59167

llvm-svn: 358319

This enables the simple copy combine that already exists in the CombinerHelper.
However, it exposed a bug in the GISelChangeObserver where it wouldn't clear a
set of MIs to process, and so would end up causing a crash when deleted MIs were
being added to the combiner worklist again.

Differential Revision: https://reviews.llvm.org/D60579

llvm-svn: 358318

llvm-svn: 358317

The libdispatch tests are now not tied to Darwin anymore. Move them to
their own platform-independent folder.

llvm-svn: 358316

Summary:
This ensures that object files will continue to validate as
WebAssembly modules in the presence of bulk memory operations. Engines
that don't support bulk memory operations will not recognize the
DataCount section and will report validation errors, but that's ok
because object files aren't supposed to be run directly anyway.

Reviewers: aheejin, dschuff, sbc100

Subscribers: jgravelle-google, hiraditya, sunfish, rupprecht, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60623

llvm-svn: 358315

This crash was introduced in r358032 as we try to construct an EVT from an MVT
in order to find the register type for the calling conv. Fall back instead of
trying to do this with an invalid MVT coming from i256.

llvm-svn: 358314

Summary:
When inserting a new Def, MemorySSA may be have non-minimal number of Phis.
While inserting, the walk to find the previous definition may cleanup minimal Phis.
When the last definition is trivial to obtain, we do not cache it.

It is possible while getting the previous definition for a Def to get two different answers:
- one that was straight-forward to find when walking the first path (a trivial phi in this case), and
- another that follows a cleanup of the trivial phi, it determines it may need additional Phi nodes, it inserts them and returns a new phi in the same position as the former trivial one.
While the Phis added for the second path are all redundant, they are not complete (the walk is only done upwards), and they are not properly cleaned up afterwards.

A way to fix this problem is to cache the straight-forward answer we got on the first walk.
The caching is only kept for the duration of a getPreviousDef call, and for Phis we use TrackingVH, so removing the trivial phi will lead to replacing it with the next dominating phi in the cache.
Resolves PR40749.

Reviewers: george.burgess.iv

Subscribers: jlebar, Prazek, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60634

llvm-svn: 358313

If a shufflevector's mask vector has an element with "undef" then the generic
instruction defining that element register is a G_IMPLICT_DEF instead of G_CONSTANT.
This fixes the selector to handle this case, and for now assumes that undef just means
zero. In future we'll optimize this case properly.

llvm-svn: 358312

Summary:
1. Do not create DFSan labels for the bytes which we do not trace. This is where we run out of labels at the first place.
2. When dumping the traces on the disk, make sure to offset the label identifiers by the number of the first byte in the trace range.
3. For the last label, make sure to write it at the last position of the trace bit string, as that label represents the input size, not any particular byte.

Also fixed the bug with division in python which I've introduced when migrated the scripts to Python3 (`//` is required for integral division).

Otherwise, the scripts are wasting too much time unsuccessfully trying to
collect and process traces from the long inputs. For more context, see
https://github.com/google/oss-fuzz/issues/1632#issuecomment-481761789

Reviewers: kcc

Reviewed By: kcc

Subscribers: delcypher, #sanitizers, llvm-commits

Tags: #llvm, #sanitizers

Differential Revision: https://reviews.llvm.org/D60538

llvm-svn: 358311

Summary: This brings the backend in line with Clang.

Reviewers: aheejin, dschuff

Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60594

llvm-svn: 358310

Now that our tests don't depend on Foundation anymore,
don't link it in.

llvm-svn: 358309

After this change, most tests don't have a dependency on Foundation.

Note: To hold the file name `tempnam` allocates a new buffer. We leak
      this buffer (omit the free), but I don't think we need to care.

Reviewed By: kubamracek

Differential Revision: https://reviews.llvm.org/D60591

llvm-svn: 358308

[MS] Add metadata for __declspec(allocator)

Original summary:
Emit !heapallocsite in the metadata for calls to functions marked with
__declspec(allocator). Eventually this will be emitted as S_HEAPALLOCSITE debug
info in codeview.

Differential Revision: https://reviews.llvm.org/D60237

llvm-svn: 358307

[libFuzzer] support -runs=N in the fork mode. Make sure we see one-line reports from ubsan in the fork mode. Test both

llvm-svn: 358306

makeGuaranteedNoWrapRegion() is actually makeExactNoWrapRegion() as
long as only one of NUW or NSW is specified. This is not obvious from
the current documentation, and some code seems to think that it is
only exact for single-element ranges. Clarify docs and add tests to
be more confident this really holds.

There are currently no users of makeGuaranteedNoWrapRegion() that
pass both NUW and NSW. I think it would be best to drop support for
this entirely and then rename the function to makeExactNoWrapRegion().

Knowing that the no-wrap region is exact is useful, because we can
backwards-constrain values. What I have in mind in particular is
that LVI should be able to constrain values on edges where the
with.overflow overflow flag is false.

Differential Revision: https://reviews.llvm.org/D60598

llvm-svn: 358305

Summary:
Create a method to forget everything in SCEV.
Add a cl::opt and PassManagerBuilder option to use this in LoopUnroll.

Motivation: Certain Halide applications spend a very long time compiling in forgetLoop, and prefer to forget everything and rebuild SCEV from scratch.
Sample difference in compile time reduction: 21.04 to 14.78 using current ToT release build.
Testcase showcasing this cannot be opensourced and is fairly large.

The option disabled by default, but it may be desirable to enable by
default. Evidence in favor (two difference runs on different days/ToT state):

File Before (s) After (s)
clang-9.bc 7267.91 6639.14
llvm-as.bc 194.12 194.12
llvm-dis.bc 62.50 62.50
opt.bc 1855.85 1857.53

File Before (s) After (s)
clang-9.bc 8588.70 7812.83
llvm-as.bc 196.20 194.78
llvm-dis.bc 61.55 61.97
opt.bc 1739.78 1886.26

Reviewers: sanjoy

Subscribers: mehdi_amini, jlebar, zzheng, javed.absar, dmgreen, jdoerfert, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60144

llvm-svn: 358304

Summary:
After introducing the limit for clobber walking, `walkToPhiOrClobber` would assert that the limit is at least 1 on entry.
The test included triggered that assert.

The callsite in `tryOptimizePhi` making the calls to `walkToPhiOrClobber` is structured like this:
```
while (true) {
   if (getBlockingAccess()) { // calls walkToPhiOrClobber
   }
   for (...) {
     walkToPhiOrClobber();
   }
}
```

The cleanest fix is to check if the limit was reached inside `walkToPhiOrClobber`, and give an allowence of 1.
This approach not make any alias() calls (no calls to instructionClobbersQuery), so the performance condition is enforced.
The limit is set back to 0 if not used, as this provides info on the fact that we stopped before reaching a true clobber.

Reviewers: george.burgess.iv

Subscribers: jlebar, Prazek, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60479

llvm-svn: 358303

llvm-svn: 358302

Not all compilers support attributes before `extern "C"`. gcc is the main one
that doesn't support it.

llvm-svn: 358301