Changes

[NFC][ScalarEvolution] Precommit tests for D104075.

[AArch64][GlobalISel] Implement moreElements legalization for G_SHUFFLE_VECTOR.

Differential Revision: https://reviews.llvm.org/D103301

Revert "Prepare Compiler-RT for GnuInstallDirs, matching libcxx"

This reverts commit 9a9bc76c0eb72f0f2732c729a460abbd5239c2e3.

That commit broke "ninja install" when building compiler-rt for mingw
targets, building standalone (pointing cmake at the compiler-rt
directory) with cmake 3.16.3 (the one shipped in ubuntu 20.04), with
errors like this:

-- Install configuration: "Release"
CMake Error at cmake_install.cmake:44 (file):
  file cannot create directory: /include/sanitizer.  Maybe need
  administrative privileges.
Call Stack (most recent call first):
  /home/martin/code/llvm-mingw/src/llvm-project/compiler-rt/build-i686-sanitizers/cmake_install.cmake:37 (include)

FAILED: include/CMakeFiles/install-compiler-rt-headers
cd /home/martin/code/llvm-mingw/src/llvm-project/compiler-rt/build-i686-sanitizers/include && /usr/bin/cmake -DCMAKE_INSTALL_COMPONENT="compiler-rt-headers" -P /home/martin/code/llvm-mingw/src/llvm-project/compiler-rt/build-i686-sanitizers/cmake_install.cmake
ninja: build stopped: subcommand failed.

[InstructionCost] Add saturation support.

This patch makes the operations on InstructionCost saturate, so that when
costs are accumulated they saturate to <max value>.

One of the compelling reasons for wanting to have saturation support
is because in various places, arbitrary values are used to represent
a 'high' cost, but when accumulating the cost of some set of operations
or a loop, overflow is not taken into account, which may lead to unexpected
results. By defining the operations to saturate, we can express the cost
of something 'very expensive' as InstructionCost::getMax().

Reviewed By: kparzysz, dmgreen

Differential Revision: https://reviews.llvm.org/D105108

[LV] NFCI: Do cost comparison on InstructionCost directly.

Instead of performing the isMoreProfitable() operation on
InstructionCost::CostTy the operation is performed on InstructionCost
directly, so that it can handle the case where one of the costs is
Invalid.

This patch also changes the CostTy to be int64_t, so that the type is
wide enough to deal with multiplications with e.g. `unsigned MaxTripCount`.

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D105113

[llvm-mca][JSON] Further refactoring of the JSON printing logic.

This patch renames object "Resources" to "TargetInfo".

Moved the getJSONTargetInfo method from class InstructionView to the
PipelinePrinter.

Removed uses of std::stringstream.
Removed unused method View::printViewJSON().

[llvm-mca][JSON] Teach the PipelinePrinter how to deal with anonymous code regions (PR51008)

This patch addresses the last remaining problems reported in PR51008.

Previous fixes for PR51008 worked under the wrong assumption that code regions
are always named (except maybe for the default region, which was automatically
named "main").

In reality, it is quite common for users to declare multiple anonymous regions.
So we cannot really use the region name as the key string of a JSON object.  In
practice, code region names are completely optional.

Using "main" for the default region was also problematic because there can be
another region with that same name.

This patch fixes these issues by introducing a json::array of regions.  Each
region has a "Name" field, which would default to the empty string for anonymous
regions.

Added a few more tests to verify that the JSON file format is still valid, and
that multiple anonymous regions all appear in the final output.

[X86] Add tests from D93707 for fsub_strict(x,fneg(y)) -> fadd_strict(x,y) folds.

Also, add matching i686 coverage to strict-fadd-combines.ll and regenerate checks.

[AFDO] Require x86_64-linux in a testcase

This patch fixes a testcase failure by requring x86_64-linux in a
testcase.

[OpenMP] Avoid checking parent reference count in targetDataEnd

The patch has the following benefits:

* Eliminates a lock/unlock of the data mapping table.
* Clarifies the logic that determines whether a struct member's
  device-to-host transfer occurs.  The old logic, which checks the
  parent struct's reference count, is a leftover from back when we had
  a different map interface (as pointed out at
  <https://reviews.llvm.org/D104924#2846972>).

Reviewed By: grokos

Differential Revision: https://reviews.llvm.org/D104924

[OpenMP] Avoid checking parent reference count in targetDataBegin

This patch is an attempt to do for `targetDataBegin` what D104924 does
for `targetDataEnd`:

* Eliminates a lock/unlock of the data mapping table.
* Clarifies the logic that determines whether a struct member's
  host-to-device transfer occurs.  The old logic, which checks the
  parent struct's reference count, is a leftover from back when we had
  a different map interface (as pointed out at
  <https://reviews.llvm.org/D104924#2846972>).

Additionally, it eliminates the `DeviceTy::getMapEntryRefCnt`, which
is no longer used after this patch.

While D104924 does not change the computation of `IsLast`, I found I
needed to change the computation of `IsNew` for this patch.  As far as
I can tell, the change is correct, and this patch does not cause any
additional `openmp` tests to fail.  However, I'm not sure I've thought
of all use cases.  Please advise.

Reviewed By: jdoerfert, jhuber6, protze.joachim, tianshilei1992, grokos, RaviNarayanaswamy

Differential Revision: https://reviews.llvm.org/D105121

[mlir][NFC] Switched `interfaces` to a private member of SSANameState.

`interfaces` is passed through to the `numberValuesIn*` functions with exactly
the same value as when SSANameState is constructed.  This just seems cleaner.

Also, a dependent PR adds `printerFlags` which follows similar code paths.

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D105299

[mlir] Added OpPrintingFlags to AsmState and SSANameState.

This enables checking the printing flags when formatting names
in SSANameState.

Depends On D105299

Reviewed By: mehdi_amini, bondhugula

Differential Revision: https://reviews.llvm.org/D105300

[mlir] Gated calls to getAsm{Result,BlockArgument}Names on whether printing ops in generic form.

Depends On D105300

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D105301

[Attributor][FIX] Traverse uses even if a value is assumed constant

Not all attributes are able to handle the interprocedural step and
follow the uses into a call site. Let them be able to combine call site
uses instead. This might result in some unused values/arguments being
leftover but it removes problems where we misused "is dead" even though
it was actually "is simplified/replaced".

We explicitly check for dead values due to constant propagation in
`AAIsDeadValueImpl::areAllUsesAssumedDead` instead.

Differential Revision: https://reviews.llvm.org/D103858

[Attributor] Introduce an optimistic getUnderlyingObjects helper

As the `llvm::getUnderlyingObjects` helper, the optimistic version
collects objects that might be the base of a given pointer. In contrast
to the llvm variant, the optimistic one will use assumed information,
e.g., about select conditions or dead blocks, to provide a more precise
result.

Differential Revision: https://reviews.llvm.org/D103859

[Attributor] Use AAValueSimplify to simplify returned values

We should use AAValueSimplify for all value simplification, however
there was some leftover logic that predates AAValueSimplify in
AAReturnedValues. This remove the AAReturnedValues part and provides a
replacement by making AAValueSimplifyReturned strong enough to handle
all previously covered cases. Further, this improve
AAValueSimplifyCallSiteReturned to handle returned arguments.

AAReturnedValues is now much easier and the collected returned
values/instructions are now from the associated function only, making it
much more sane. We also do not have the brittle logic anymore that looks
for unresolved calls. Instead, we use AAValueSimplify to handle
recursion.

Useful code has been split into helper functions, e.g., an Attributor
interface to get a simplified value.

Differential Revision: https://reviews.llvm.org/D103860

[Attributor] Reorganize AAHeapToStack

In order to simplify future extensions, e.g., the merge of
AAHeapToShared in to AAHeapToStack, we reorganize AAHeapToStack and the
state we keep for each malloc-like call. The result is also less
confusing as we only track malloc-like calls, not all calls. Further, we
only perform the updates necessary for a malloc-like to argue it can go
to the stack, e.g., we won't check all uses if we moved on to the
"must-be-freed" argument.

This patch also uses Attributor helps to simplify the allocated size,
alignment, and the potentially freed objects.

Overall, this is mostly a reorganization and only the use of the
optimistic helpers should change (=improve) the capabilities a bit.

Differential Revision: https://reviews.llvm.org/D104993

[Attributor] Look through selects in genericValueTraversal

If we can simplify the select condition we can avoid one value in the
traversal.

Differential Revision: https://reviews.llvm.org/D103861

[OpenMP] Unified entry point for SPMD & generic kernels in the device RTL

In the spirit of TRegions [0], this patch provides a simpler and uniform
interface for a kernel to set up the device runtime. The OMPIRBuilder is
used for reuse in Flang. A custom state machine will be generated in the
follow up patch.

The "surplus" threads of the "master warp" will not exit early anymore
so we need to use non-aligned barriers. The new runtime will not have an
extra warp but also require these non-aligned barriers.

[0] https://link.springer.com/chapter/10.1007/978-3-030-28596-8_11

This was in parts extracted from D59319.

Reviewed By: ABataev, JonChesterfield

Differential Revision: https://reviews.llvm.org/D101976

[OpenMP] Create custom state machines for generic target regions

In the spirit of TRegions [0], this patch creates a custom state
machine for a generic target region based on the potentially called
parallel regions.

The code analysis is done interprocedurally via an abstract attribute
(AAKernelInfo). All outermost parallel regions are collected and we
check if there might be unknown outermost parallel regions for which
we need an indirect call. Other AAKernelInfo extensions are expected.

[0] https://link.springer.com/chapter/10.1007/978-3-030-28596-8_11

Differential Revision: https://reviews.llvm.org/D101977

[Attributor][FIX] Do not replace a value with a non-dominating instruction

We have to be careful when we replace values to not use a non-dominating
instruction. It makes sense that simplification offers those as
"simplified values" but we can't manifest them in the IR without PHI
nodes. In the future we should consider potentially adding those PHI
nodes.

[Attributor][FIX] Sanitize queries to LVI and ScalarEvolution

When we talk to outside analyse, e.g., LVI and ScalarEvolution, we need
to be careful with the query. The particular error occurred because we
folded a PHI node before the LVI query but the context location was now
not dominated by the value anymore. This is not supported by LVI so we
have to filter these situations before we query the outside analyses.

[OpenMP] Remove checkXXXX device runtime functions

We had multiple functions to determine the execution mode (SPMD/Generic)
and runtime status (initialized/uninitialized) but that just increased
complexity without a real benefit. Especially with D102307 in mind it
is helpful to reduce the dependence on the `ident_t` flags.

Differential Revision: https://reviews.llvm.org/D105586

[OpenMP] Detect SPMD compatible kernels and execute them as such

In the spirit of TRegions [0], this patch analyzes a kernel and tracks
if it can be executed in SPMD-mode. If so, we flip the arguments of
the __kmpc_target_init and deinit call to enable the mode. We also
update the `<kernel>_exec_mode` flag to indicate to the runtime we
changed the mode to SPMD.

The code analysis is done interprocedurally by extending the
AAKernelInfo abstract attribute to track SPMD compatibility as well.

[0] https://link.springer.com/chapter/10.1007/978-3-030-28596-8_11

Differential Revision: https://reviews.llvm.org/D102307

[Attributor][NFCI] Add UsedAssumedInformation to more interfaces

As with other Attributor interfaces we often want to know if assumed
information was used to answer a query. This is important if only
known information is allowed or if known information can lead to an
early fixpoint. The users have been adjusted but none of them utilizes
the new information yet.

Revert "llvm-symbolizer: Fix "start file" to work with Split DWARF"

This reverts commit 04c203e310bd3fb58e16c936c0200d680100526e.
Test fails on Windows.

Reland "[clang-repl] Allow passing in code as positional arguments."

This reverts commit 3ec88ca60b24 which reverted e386871e1d21 due to a asan build
failure.

This patch removes the new lines in the test case which seem to introduce the
failure.

Differential revision: https://reviews.llvm.org/D104898

Revert Attributor patch series

Broke check-clang, see https://reviews.llvm.org/D102307#2869065
Ran `git revert -n ebbe149a6f08535ede848a531a601ae6591cfbc5..269416d41908bb670f67af689155d5ab8eea689a`

[Attributor][FIX] Traverse uses even if a value is assumed constant

Not all attributes are able to handle the interprocedural step and
follow the uses into a call site. Let them be able to combine call site
uses instead. This might result in some unused values/arguments being
leftover but it removes problems where we misused "is dead" even though
it was actually "is simplified/replaced".

We explicitly check for dead values due to constant propagation in
`AAIsDeadValueImpl::areAllUsesAssumedDead` instead.

Differential Revision: https://reviews.llvm.org/D103858

[Attributor] Introduce an optimistic getUnderlyingObjects helper

As the `llvm::getUnderlyingObjects` helper, the optimistic version
collects objects that might be the base of a given pointer. In contrast
to the llvm variant, the optimistic one will use assumed information,
e.g., about select conditions or dead blocks, to provide a more precise
result.

Differential Revision: https://reviews.llvm.org/D103859

[Attributor] Use AAValueSimplify to simplify returned values

We should use AAValueSimplify for all value simplification, however
there was some leftover logic that predates AAValueSimplify in
AAReturnedValues. This remove the AAReturnedValues part and provides a
replacement by making AAValueSimplifyReturned strong enough to handle
all previously covered cases. Further, this improve
AAValueSimplifyCallSiteReturned to handle returned arguments.

AAReturnedValues is now much easier and the collected returned
values/instructions are now from the associated function only, making it
much more sane. We also do not have the brittle logic anymore that looks
for unresolved calls. Instead, we use AAValueSimplify to handle
recursion.

Useful code has been split into helper functions, e.g., an Attributor
interface to get a simplified value.

Differential Revision: https://reviews.llvm.org/D103860

[ARM] Extra widening and narrowing combinations tests. NFC

[Attributor][FIX] Do not replace a value with a non-dominating instruction

We have to be careful when we replace values to not use a non-dominating
instruction. It makes sense that simplification offers those as
"simplified values" but we can't manifest them in the IR without PHI
nodes. In the future we should consider potentially adding those PHI
nodes.

[Attributor] Reorganize AAHeapToStack

In order to simplify future extensions, e.g., the merge of
AAHeapToShared in to AAHeapToStack, we reorganize AAHeapToStack and the
state we keep for each malloc-like call. The result is also less
confusing as we only track malloc-like calls, not all calls. Further, we
only perform the updates necessary for a malloc-like to argue it can go
to the stack, e.g., we won't check all uses if we moved on to the
"must-be-freed" argument.

This patch also uses Attributor helps to simplify the allocated size,
alignment, and the potentially freed objects.

Overall, this is mostly a reorganization and only the use of the
optimistic helpers should change (=improve) the capabilities a bit.

Differential Revision: https://reviews.llvm.org/D104993

[OpenMP][FIX] Update remark in test file after rewording

[Attributor] Look through selects in genericValueTraversal

If we can simplify the select condition we can avoid one value in the
traversal.

Differential Revision: https://reviews.llvm.org/D103861

[Attributor][FIX] Sanitize queries to LVI and ScalarEvolution

When we talk to outside analyse, e.g., LVI and ScalarEvolution, we need
to be careful with the query. The particular error occurred because we
folded a PHI node before the LVI query but the context location was now
not dominated by the value anymore. This is not supported by LVI so we
have to filter these situations before we query the outside analyses.

[OpenMP] Unified entry point for SPMD & generic kernels in the device RTL

In the spirit of TRegions [0], this patch provides a simpler and uniform
interface for a kernel to set up the device runtime. The OMPIRBuilder is
used for reuse in Flang. A custom state machine will be generated in the
follow up patch.

The "surplus" threads of the "master warp" will not exit early anymore
so we need to use non-aligned barriers. The new runtime will not have an
extra warp but also require these non-aligned barriers.

[0] https://link.springer.com/chapter/10.1007/978-3-030-28596-8_11

This was in parts extracted from D59319.

Reviewed By: ABataev, JonChesterfield

Differential Revision: https://reviews.llvm.org/D101976

[OpenMP] Create custom state machines for generic target regions

In the spirit of TRegions [0], this patch creates a custom state
machine for a generic target region based on the potentially called
parallel regions.

The code analysis is done interprocedurally via an abstract attribute
(AAKernelInfo). All outermost parallel regions are collected and we
check if there might be unknown outermost parallel regions for which
we need an indirect call. Other AAKernelInfo extensions are expected.

[0] https://link.springer.com/chapter/10.1007/978-3-030-28596-8_11

Differential Revision: https://reviews.llvm.org/D101977

[OpenMP][NFCI] Re-enable two remarks tests after D101977 landed

[OpenMP] Remove checkXXXX device runtime functions

We had multiple functions to determine the execution mode (SPMD/Generic)
and runtime status (initialized/uninitialized) but that just increased
complexity without a real benefit. Especially with D102307 in mind it
is helpful to reduce the dependence on the `ident_t` flags.

Differential Revision: https://reviews.llvm.org/D105586

[OpenMP][FIX] Add missing `)` to remark

[OpenMP] Detect SPMD compatible kernels and execute them as such

In the spirit of TRegions [0], this patch analyzes a kernel and tracks
if it can be executed in SPMD-mode. If so, we flip the arguments of
the __kmpc_target_init and deinit call to enable the mode. We also
update the `<kernel>_exec_mode` flag to indicate to the runtime we
changed the mode to SPMD.

The code analysis is done interprocedurally by extending the
AAKernelInfo abstract attribute to track SPMD compatibility as well.

[0] https://link.springer.com/chapter/10.1007/978-3-030-28596-8_11

Differential Revision: https://reviews.llvm.org/D102307

[Attributor][FIX] Destroy bump allocator objects to avoid leaks

AllocationInfo and DeallocationInfo objects themselves are allocated
with the Attributor bump allocator and do not need to be deallocated.
That said, the sets in AllocationInfo and DeallocationInfo need to be
destroyed to avoid memory leaks.

[RISCV] Add test cases for div/rem with constant left hand side. NFC

Some of these would produce better code if we used W instructions,
but constant LHS currently prevents that.

[Analysis] Remove changeCondBranchToUnconditionalTo (NFC)

The last use was removed on Jan 21, 2021 in commit
0895b836d74ed333468ddece2102140494eb33b6.

[RISCV] Restore non-constant srem test I accidentally deleted. NFC

[DivRemPairs] Add test cases for D87555. NFC

Reapply "llvm-symbolizer: Fix "start file" to work with Split DWARF"

Originally committed as 04c203e310bd3fb58e16c936c0200d680100526e
Reverted in 768510632c5ddbf9438693d9c7db1903e39295ad due to the test
failing when encountering windows directory separators.

Fix the path separator platform issue with a FileCheck pattern {{[/\\]}}

Original commit message:

A followup to the feature added in 69da27c7496ea373567ce5121e6fe8613846e7a5
that added the optional "start file name" to match "start line" - but this
didn't work with Split DWARF because of the need for the decl file number
resolution code to refer back to the skeleton unit to find its .debug_line
contribution. So this patch adds the necessary infrastructure to track the
skeleton unit corresponding to a split full unit for the purpose of this
lookup.

Fix windows directory separator some more for test from b447b9dce0d105e7f0b22db719fe8624108e99dc

[InstCombine] Add optimization to prevent poison from being propagated.

In D104569, Freeze was inserted just before br to solve the `branching on undef` miscompilation problem.
But value analysis was being disturbed by added freeze.

```
v = load ptr
cond = freeze(icmp (and v, const), const')
br cond, ...
```
The case in which value analysis disturbed is as above.
By changing freeze to add immediately after load, value analysis will be successful again.

```
v = load ptr
freeze(icmp (and v, const), const')
=>
v = load ptr
v' = freeze v
icmp (and v', const), const'
```
In this patch, I propose the above optimization.
With this patch, the poison will not spread as the freeze is performed early.

Reviewed By: nikic, lebedev.ri

Differential Revision: https://reviews.llvm.org/D105392

[lld-macho][nfc] Expand the compact unwind symbol reloc test

Add a bit more detail to the comments, and check that the final binary
does indeed have a `__unwind_info` section (D105557 previosly regressed
this).

Also rename the test to emphasize that we are testing relocations
compact unwind, not relocations in general.