Reland [MachineCopyPropagation] Extend MCP to do trivial copy backward propagation.

Fix assertion error
```
bool llvm::MachineOperand::isRenamable() const: Assertion `Register::isPhysicalRegister(ge

Reland [MachineCopyPropagation] Extend MCP to do trivial copy backward propagation.

Fix assertion error
```
bool llvm::MachineOperand::isRenamable() const: Assertion `Register::isPhysicalRegister(getReg()) && "isRenamable should only be checked on physical registers"' failed.
```
by checking if the register is 0 before invoking `isRenamable`.

show more ...

Revert "[MachineCopyPropagation] Extend MCP to do trivial copy backward propagation"

This reverts commit 75b3a1c318ccad0f96c38689279bc5db63e2ad05, since it
breaks bootstrap build.

[MachineCopyPropagation] Extend MCP to do trivial copy backward propagation

Summary:
This patch mainly do such transformation
```
$R0 = OP ...
... // No read/clobber of $R0 and $R1
$R1 = COPY $R0 //

[MachineCopyPropagation] Extend MCP to do trivial copy backward propagation

Summary:
This patch mainly do such transformation
```
$R0 = OP ...
... // No read/clobber of $R0 and $R1
$R1 = COPY $R0 // $R0 is killed
```
Replace $R0 with $R1 and remove the COPY, we have
```
$R1 = OP ...
```
This transformation can also expose more opportunities for existing
copy elimination in MCP.

Differential Revision: https://reviews.llvm.org/D67794

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Sink all InitializePasses.h includes

This file lists every pass in LLVM, and is included by Pass.h, which is
very popular. Every time we add, remove, or rename a pass in LLVM, it
caused lots of reco

Sink all InitializePasses.h includes

This file lists every pass in LLVM, and is included by Pass.h, which is
very popular. Every time we add, remove, or rename a pass in LLVM, it
caused lots of recompilation.

I found this fact by looking at this table, which is sorted by the
number of times a file was changed over the last 100,000 git commits
multiplied by the number of object files that depend on it in the
current checkout:
recompiles touches affected_files header
342380 95 3604 llvm/include/llvm/ADT/STLExtras.h
314730 234 1345 llvm/include/llvm/InitializePasses.h
307036 118 2602 llvm/include/llvm/ADT/APInt.h
213049 59 3611 llvm/include/llvm/Support/MathExtras.h
170422 47 3626 llvm/include/llvm/Support/Compiler.h
162225 45 3605 llvm/include/llvm/ADT/Optional.h
158319 63 2513 llvm/include/llvm/ADT/Triple.h
140322 39 3598 llvm/include/llvm/ADT/StringRef.h
137647 59 2333 llvm/include/llvm/Support/Error.h
131619 73 1803 llvm/include/llvm/Support/FileSystem.h

Before this change, touching InitializePasses.h would cause 1345 files
to recompile. After this change, touching it only causes 550 compiles in
an incremental rebuild.

Reviewers: bkramer, asbirlea, bollu, jdoerfert

Differential Revision: https://reviews.llvm.org/D70211

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MCP: Fixed bug with dest overlapping copy source

In MachineCopyPropagation, when propagating the source of a copy into
the operand of a later instruction, bail if a destination overlaps
(partly defi

MCP: Fixed bug with dest overlapping copy source

In MachineCopyPropagation, when propagating the source of a copy into
the operand of a later instruction, bail if a destination overlaps
(partly defines) the copy source. If the instruction where the
substitution is happening is also a copy, allowing the propagation
confuses the tracking mechanism.

Differential Revision: https://reviews.llvm.org/D69953

Change-Id: Ic570754f878f2d91a4a50a9bdcf96fbaa240726d

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Revert "[MachineCopyPropagation] Remove redundant copies after TailDup via machine-cp"

This reverts commit 371359. I'm suspecting a miscompile, I posted a
reproducer to https://reviews.llvm.org/D652

Revert "[MachineCopyPropagation] Remove redundant copies after TailDup via machine-cp"

This reverts commit 371359. I'm suspecting a miscompile, I posted a
reproducer to https://reviews.llvm.org/D65267.

llvm-svn: 371421

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[MachineCopyPropagation] Remove redundant copies after TailDup via machine-cp

Summary:
After tailduplication, we have redundant copies. We can remove these
copies in machine-cp if it's safe to, i.e.

[MachineCopyPropagation] Remove redundant copies after TailDup via machine-cp

Summary:
After tailduplication, we have redundant copies. We can remove these
copies in machine-cp if it's safe to, i.e.
```
$reg0 = OP ...
... <<< No read or clobber of $reg0 and $reg1
$reg1 = COPY $reg0 <<< $reg0 is killed
...
<RET>
```
will be transformed to
```
$reg1 = OP ...
...
<RET>
```

Differential Revision: https://reviews.llvm.org/D65267

llvm-svn: 371359

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Apply llvm-prefer-register-over-unsigned from clang-tidy to LLVM

Summary:
This clang-tidy check is looking for unsigned integer variables whose initializer
starts with an implicit cast from llvm::Re

Apply llvm-prefer-register-over-unsigned from clang-tidy to LLVM

Summary:
This clang-tidy check is looking for unsigned integer variables whose initializer
starts with an implicit cast from llvm::Register and changes the type of the
variable to llvm::Register (dropping the llvm:: where possible).

Partial reverts in:
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
X86FixupLEAs.cpp - Some functions return unsigned and arguably should be MCRegister
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
HexagonBitSimplify.cpp - Function takes BitTracker::RegisterRef which appears to be unsigned&
MachineVerifier.cpp - Ambiguous operator==() given MCRegister and const Register
PPCFastISel.cpp - No Register::operator-=()
PeepholeOptimizer.cpp - TargetInstrInfo::optimizeLoadInstr() takes an unsigned&
MachineTraceMetrics.cpp - MachineTraceMetrics lacks a suitable constructor

Manual fixups in:
ARMFastISel.cpp - ARMEmitLoad() now takes a Register& instead of unsigned&
HexagonSplitDouble.cpp - Ternary operator was ambiguous between unsigned/Register
HexagonConstExtenders.cpp - Has a local class named Register, used llvm::Register instead of Register.
PPCFastISel.cpp - PPCEmitLoad() now takes a Register& instead of unsigned&

Depends on D65919

Reviewers: arsenm, bogner, craig.topper, RKSimon

Reviewed By: arsenm

Subscribers: RKSimon, craig.topper, lenary, aemerson, wuzish, jholewinski, MatzeB, qcolombet, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, wdng, nhaehnle, sbc100, jgravelle-google, kristof.beyls, hiraditya, aheejin, kbarton, fedor.sergeev, javed.absar, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, tpr, PkmX, jocewei, jsji, Petar.Avramovic, asbirlea, Jim, s.egerton, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65962

llvm-svn: 369041

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[DebugInfo] MCP: collect and update DBG_VALUEs encountered in local block

MCP currently uses changeDebugValuesDefReg / collectDebugValues to find
debug users of a register, however those functions a

[DebugInfo] MCP: collect and update DBG_VALUEs encountered in local block

MCP currently uses changeDebugValuesDefReg / collectDebugValues to find
debug users of a register, however those functions assume that all
DBG_VALUEs immediately follow the specified instruction, which isn't
necessarily true. This is going to become very often untrue when we turn
off CodeGenPrepare::placeDbgValues.

Instead of calling changeDebugValuesDefReg on an instruction to change its
debug users, in this patch we instead collect DBG_VALUEs of copies as we
iterate over insns, and update the debug users of copies that are made
dead. This isn't a non-functional change, because MCP will now update
DBG_VALUEs that aren't immediately after a copy, but refer to the same
register. I've hijacked the regression test for PR38773 to test for this
new behaviour, an entirely new test seemed overkill.

Differential Revision: https://reviews.llvm.org/D56265

llvm-svn: 368835

show more ...

Finish moving TargetRegisterInfo::isVirtualRegister() and friends to llvm::Register as started by r367614. NFC

llvm-svn: 367633

Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the ne

Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636

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Reapply "[MachineCopyPropagation] Reimplement CopyTracker in terms of register units"

Recommits r342942, which was reverted in r343189, with a fix for an
issue where we would propagate unsafely if w

Reapply "[MachineCopyPropagation] Reimplement CopyTracker in terms of register units"

Recommits r342942, which was reverted in r343189, with a fix for an
issue where we would propagate unsafely if we defined only the upper
part of a register.

Original message:

Change the copy tracker to keep a single map of register units
instead of 3 maps of registers. This gives a very significant
compile time performance improvement to the pass. I measured a
30-40% decrease in time spent in MCP on x86 and AArch64 and much
more significant improvements on out of tree targets with more
registers.

llvm-svn: 344942

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[DebugInfo][Dexter] Incorrect DBG_VALUE after MCP dead copy instruction removal.

When MachineCopyPropagation eliminates a dead 'copy', its associated debug information becomes invalid. as the record

[DebugInfo][Dexter] Incorrect DBG_VALUE after MCP dead copy instruction removal.

When MachineCopyPropagation eliminates a dead 'copy', its associated debug information becomes invalid. as the recorded register has been removed. It causes the debugger to display wrong variable value.

Differential Revision: https://reviews.llvm.org/D52614

llvm-svn: 343445

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Revert r342942 "[MachineCopyPropagation] Reimplement CopyTracker in terms of register units"

It seems to have broken several targets, see comments on the llvm-commits thread.

> Change the copy trac

Revert r342942 "[MachineCopyPropagation] Reimplement CopyTracker in terms of register units"

It seems to have broken several targets, see comments on the llvm-commits thread.

> Change the copy tracker to keep a single map of register units instead
> of 3 maps of registers. This gives a very significant compile time
> performance improvement to the pass. I measured a 30-40% decrease in
> time spent in MCP on x86 and AArch64 and much more significant
> improvements on out of tree targets with more registers.
>
> Differential Revision: https://reviews.llvm.org/D52374

llvm-svn: 343189

show more ...

[MachineCopyPropagation] Reimplement CopyTracker in terms of register units

Change the copy tracker to keep a single map of register units instead
of 3 maps of registers. This gives a very significa

[MachineCopyPropagation] Reimplement CopyTracker in terms of register units

Change the copy tracker to keep a single map of register units instead
of 3 maps of registers. This gives a very significant compile time
performance improvement to the pass. I measured a 30-40% decrease in
time spent in MCP on x86 and AArch64 and much more significant
improvements on out of tree targets with more registers.

Differential Revision: https://reviews.llvm.org/D52374

llvm-svn: 342942

show more ...

[MachineCopyPropagation] Rework how we manage RegMask clobbers

Instead of updating the CopyTracker's maps each time we come across a
RegMask, defer checking for this kind of interference until we're

[MachineCopyPropagation] Rework how we manage RegMask clobbers

Instead of updating the CopyTracker's maps each time we come across a
RegMask, defer checking for this kind of interference until we're
actually trying to propagate a copy. This avoids the need to
repeatedly iterate over maps in the cases where we don't end up doing
any work.

This is a slight compile time improvement for MachineCopyPropagation
as is, but it also enables a much bigger improvement that I'll follow
up with soon.

Differential Revision: https://reviews.llvm.org/D52370

llvm-svn: 342940

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[MachineCopyPropagation] Refactor copy tracking into a class. NFC

This is a bit easier to follow than handling the copy and src maps
directly in the pass, and will make upcoming changes to how this

[MachineCopyPropagation] Refactor copy tracking into a class. NFC

This is a bit easier to follow than handling the copy and src maps
directly in the pass, and will make upcoming changes to how this is
done easier to follow.

llvm-svn: 342703

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[MachineCopyPropagation] Minor clang-formatting. NFC

llvm-svn: 342700

[CodeGen] Ignore debug uses in MachineCopyPropagation

Debug uses should not count as real uses, since the presence of debug
information could affect the generated code.

llvm-svn: 336803

Rename DEBUG macro to LLVM_DEBUG.

The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/

Rename DEBUG macro to LLVM_DEBUG.

The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.

In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.

Differential Revision: https://reviews.llvm.org/D43624

llvm-svn: 332240

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[MachineCopyPropagation] Handle COPY with overlapping source/dest.

MachineCopyPropagation::CopyPropagateBlock has a bunch of special
handling for COPY instructions. This handling assumes that COPY
i

[MachineCopyPropagation] Handle COPY with overlapping source/dest.

MachineCopyPropagation::CopyPropagateBlock has a bunch of special
handling for COPY instructions. This handling assumes that COPY
instructions do not modify the source of the copy; this is wrong if
the COPY destination overlaps the source.

To fix the bug, check explicitly for this situation, and fall back to
the generic instruction handling.

This bug can't happen for most register classes because they don't
have this sort of overlap, but there are a few register classes
where this is possible. The testcase uses the AArch64 QQQQ register
class.

Differential Revision: https://reviews.llvm.org/D44911

llvm-svn: 328851

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Re-enable "[MachineCopyPropagation] Extend pass to do COPY source forwarding"

Re-enable commit r323991 now that r325931 has been committed to make
MachineOperand::isRenamable() check more conservati

Re-enable "[MachineCopyPropagation] Extend pass to do COPY source forwarding"

Re-enable commit r323991 now that r325931 has been committed to make
MachineOperand::isRenamable() check more conservative w.r.t. code
changes and opt-in on a per-target basis.

llvm-svn: 326208

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Revert "[MachineCopyPropagation] Extend pass to do COPY source forwarding"

This reverts commit r323991.

This commit breaks target that don't model all the register constraints
in TableGen. So far t

Revert "[MachineCopyPropagation] Extend pass to do COPY source forwarding"

This reverts commit r323991.

This commit breaks target that don't model all the register constraints
in TableGen. So far the workaround was to set the
hasExtraXXXRegAllocReq, but it proves that it doesn't cover all the
cases.
For instance, when mutating an instruction (like in the lowering of
COPYs) the isRenamable flag is not properly updated. The same problem
will happen when attaching machine operand from one instruction to
another.

Geoff Berry is working on a fix in https://reviews.llvm.org/D43042.

llvm-svn: 325421

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[MachineCopyPropagation] Extend pass to do COPY source forwarding

Summary:
This change extends MachineCopyPropagation to do COPY source forwarding
and adds an additional run of the pass to the defau

[MachineCopyPropagation] Extend pass to do COPY source forwarding

Summary:
This change extends MachineCopyPropagation to do COPY source forwarding
and adds an additional run of the pass to the default pass pipeline just
after register allocation.

This version of this patch uses the newly added
MachineOperand::isRenamable bit to avoid forwarding registers is such a
way as to violate constraints that aren't captured in the
Machine IR (e.g. ABI or ISA constraints).

This change is a continuation of the work started in D30751.

Reviewers: qcolombet, javed.absar, MatzeB, jonpa, tstellar

Subscribers: tpr, mgorny, mcrosier, nhaehnle, nemanjai, jyknight, hfinkel, arsenm, inouehrs, eraman, sdardis, guyblank, fedor.sergeev, aheejin, dschuff, jfb, myatsina, llvm-commits

Differential Revision: https://reviews.llvm.org/D41835

llvm-svn: 323991

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MachineFunction: Return reference from getFunction(); NFC

The Function can never be nullptr so we can return a reference.

llvm-svn: 320884