Make MachineCopyPropagation preserve CFG

This doesn't touch it as far as I can tell.

llvm-svn: 271445

Re-commit optimization bisect support (r267022) without new pass manager support.

The original commit was reverted because of a buildbot problem with LazyCallGraph::SCC handling (not related to the

Re-commit optimization bisect support (r267022) without new pass manager support.

The original commit was reverted because of a buildbot problem with LazyCallGraph::SCC handling (not related to the OptBisect handling).

Differential Revision: http://reviews.llvm.org/D19172

llvm-svn: 267231

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Revert "Initial implementation of optimization bisect support."

This reverts commit r267022, due to an ASan failure:

http://lab.llvm.org:8080/green/job/clang-stage2-cmake-RgSan_check/1549

llvm-s

Revert "Initial implementation of optimization bisect support."

This reverts commit r267022, due to an ASan failure:

http://lab.llvm.org:8080/green/job/clang-stage2-cmake-RgSan_check/1549

llvm-svn: 267115

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Initial implementation of optimization bisect support.

This patch implements a optimization bisect feature, which will allow optimizations to be selectively disabled at compile time in order to trac

Initial implementation of optimization bisect support.

This patch implements a optimization bisect feature, which will allow optimizations to be selectively disabled at compile time in order to track down test failures that are caused by incorrect optimizations.

The bisection is enabled using a new command line option (-opt-bisect-limit). Individual passes that may be skipped call the OptBisect object (via an LLVMContext) to see if they should be skipped based on the bisect limit. A finer level of control (disabling individual transformations) can be managed through an addition OptBisect method, but this is not yet used.

The skip checking in this implementation is based on (and replaces) the skipOptnoneFunction check. Where that check was being called, a new call has been inserted in its place which checks the bisect limit and the optnone attribute. A new function call has been added for module and SCC passes that behaves in a similar way.

Differential Revision: http://reviews.llvm.org/D19172

llvm-svn: 267022

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Introduce MachineFunctionProperties and the AllVRegsAllocated property

MachineFunctionProperties represents a set of properties that a MachineFunction
can have at particular points in time. Existing

Introduce MachineFunctionProperties and the AllVRegsAllocated property

MachineFunctionProperties represents a set of properties that a MachineFunction
can have at particular points in time. Existing examples of this idea are
MachineRegisterInfo::isSSA() and MachineRegisterInfo::tracksLiveness() which
will eventually be switched to use this mechanism.
This change introduces the AllVRegsAllocated property; i.e. the property that
all virtual registers have been allocated and there are no VReg operands
left.

With this mechanism, passes can declare that they require a particular property
to be set, or that they set or clear properties by implementing e.g.
MachineFunctionPass::getRequiredProperties(). The MachineFunctionPass base class
verifies that the requirements are met, and handles the setting and clearing
based on the delcarations. Passes can also directly query and update the current
properties of the MF if they want to have conditional behavior.

This change annotates the target-independent post-regalloc passes; future
changes will also annotate target-specific ones.

Reviewers: qcolombet, hfinkel

Differential Revision: http://reviews.llvm.org/D18421

llvm-svn: 264593

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[MachineCopyPropagation] Expose more dead copies across instructions with regmasks

When encountering instructions with regmasks, instead of cleaning up all the
elements in MaybeDeadCopies map, remov

[MachineCopyPropagation] Expose more dead copies across instructions with regmasks

When encountering instructions with regmasks, instead of cleaning up all the
elements in MaybeDeadCopies map, remove only the instructions erased. By keeping
more instruction in MaybeDeadCopies, this change will expose more dead copies
across instructions with regmasks.

llvm-svn: 264462

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MachineCopyPropagation: Catch copies of the form A<-B;A<-B

Differential Revision: http://reviews.llvm.org/D17475

llvm-svn: 261966

MachineCopyPropagation: Keep scanning through instructions with regmasks

This also simplifies the code by removing the overly conservative
NoInterveningSideEffect() function. This function checked:

MachineCopyPropagation: Keep scanning through instructions with regmasks

This also simplifies the code by removing the overly conservative
NoInterveningSideEffect() function. This function checked:
- That the two copies belong to the same block: We only process one
block at a time and clear our maps in between it is impossible to find a
copy from a different block.
- There is no terminator between the two copy instructions: This is not
allowed anyway (the MachineVerifier would complain)
- Does not have instructions with hasUnmodeledSideEffects() or isCall()
set: Even for those instructuction we must have all clobbers/defs of
registers explicit as an operand. If the register is explicitely
clobbered we would never come to the point of checking for
NoInterveningSideEffect() anyway.

(I also checked this with a temporary build of the test-suite with all
potentially failing conditions in NoInterveningSideEffect() turned into
asserts)

Differential Revision: http://reviews.llvm.org/D17474

llvm-svn: 261965

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Revert "CodeGen: MachineInstr::getIterator() => getInstrIterator(), NFC"

This reverts commit r261504, since it's not obvious the new name is
better:
http://lists.llvm.org/pipermail/llvm-commits/Week

Revert "CodeGen: MachineInstr::getIterator() => getInstrIterator(), NFC"

This reverts commit r261504, since it's not obvious the new name is
better:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160222/334298.html

I'll recommit if we get consensus that it's the right direction.

llvm-svn: 261567

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CodeGen: MachineInstr::getIterator() => getInstrIterator(), NFC

Delete MachineInstr::getIterator(), since the term "iterator" is
overloaded when talking about MachineInstr.

- Downcast to ilist_node

CodeGen: MachineInstr::getIterator() => getInstrIterator(), NFC

Delete MachineInstr::getIterator(), since the term "iterator" is
overloaded when talking about MachineInstr.

- Downcast to ilist_node in iplist::getNextNode() and getPrevNode() so
that ilist_node::getIterator() is still available.
- Add it back as MachineInstr::getInstrIterator(). This matches the
naming in MachineBasicBlock.
- Add MachineInstr::getBundleIterator(). This is explicitly called
"bundle" (not matching MachineBasicBlock) to disintinguish it clearly
from ilist_node::getIterator().
- Update all calls. Some of these I switched to `auto` to remove
boiler-plate, since the new name is clear about the type.

There was one call I updated that looked fishy, but it wasn't clear what
the right answer was. This was in X86FrameLowering::inlineStackProbe(),
added in r252578 in lib/Target/X86/X86FrameLowering.cpp. I opted to
leave the behaviour unchanged, but I'll reply to the original commit on
the list in a moment.

llvm-svn: 261504

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MachineCopyPropagation: Introduce Reg2MIMap typedef; NFC

llvm-svn: 261408

MachineCopyPropagation: Move variables from function to pass

This avoids unnecessarily passing them around when calling helper
functions. It may also be slightly faster to call clear() on the
datast

MachineCopyPropagation: Move variables from function to pass

This avoids unnecessarily passing them around when calling helper
functions. It may also be slightly faster to call clear() on the
datastructures instead of freshly initializing them for each block.

llvm-svn: 261407

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MachineCopyPropagation: Use ranged for, cleanup; NFC

llvm-svn: 261406

MachineCopyPropagation: Use assert() instead of if{report_error()} for 'impossible' condition

llvm-svn: 261405

[MachineCopyPropagation] Fix comment. NFC

Reviewers: MatzeB, qcolombet, jmolloy, mcrosier

Subscribers: llvm-commits, mcrosier

Differential Revision: http://reviews.llvm.org/D16806

llvm-svn: 259656

Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)

Apparently, the style needs to be agreed upon first.

llvm-svn: 240390

Fixed/added namespace ending comments using clang-tidy. NFC

The patch is generated using this command:

tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
-checks=-*,llvm-namespace-c

Fixed/added namespace ending comments using clang-tidy. NFC

The patch is generated using this command:

tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
-checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
llvm/lib/


Thanks to Eugene Kosov for the original patch!

llvm-svn: 240137

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MachineCopyPropagation: Remove the copies instead of using KILL instructions.

For some history here see the commit messages of r199797 and r169060.

The original intent was to fix cases like:

%EAX<

MachineCopyPropagation: Remove the copies instead of using KILL instructions.

For some history here see the commit messages of r199797 and r169060.

The original intent was to fix cases like:

%EAX<def> = COPY %ECX<kill>, %RAX<imp-def>
%RCX<def> = COPY %RAX<kill>

where simply removing the copies would have RCX undefined as in terms of
machine operands only the ECX part of it is defined. The machine
verifier would complain about this so 169060 changed such COPY
instructions into KILL instructions so some super-register imp-defs
would be preserved. In r199797 it was finally decided to always do this
regardless of super-register defs.

But this is wrong, consider:
R1 = COPY R0
...
R0 = COPY R1
getting changed to:
R1 = KILL R0
...
R0 = KILL R1

It now looks like R0 dies at the first KILL and won't be alive until the
second KILL, while in reality R0 is alive and must not change in this
part of the program.

As this only happens after register allocation there is not much code
still performing liveness queries so the issue was not noticed. In fact
I didn't manage to create a testcase for this, without unrelated changes
I am working on at the moment.

The fix is simple: As of r223896 the MachineVerifier allows reads from
partially defined registers, so the whole transforming COPY->KILL thing
is not necessary anymore. This patch also changes a similar (but more
benign case as the def and src are the same register) case in the
VirtRegRewriter.

Differential Revision: http://reviews.llvm.org/D10117

llvm-svn: 238588

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[MachineCopyPropagation] Fix a bug with undef handling when the value is actualy alive.
Test case will follow.

llvm-svn: 238518

[MachineCopyPropagation] Handle undef flags conservatively so that we do not
remove copies that are useful after breaking some hardware dependencies.
In other words, handle this kind of situations co

[MachineCopyPropagation] Handle undef flags conservatively so that we do not
remove copies that are useful after breaking some hardware dependencies.
In other words, handle this kind of situations conservatively by assuming reg2
is redefined by the undef flag.
reg1 = copy reg2
= inst reg2<undef>
reg2 = copy reg1
Copy propagation used to remove the last copy.
This is incorrect because the undef flag on reg2 in inst, allows next
passes to put whatever trashed value in reg2 that may help.
In practice we end up with this code:
reg1 = copy reg2
reg2 = 0
= inst reg2<undef>
reg2 = copy reg1

This fixes PR21743.

llvm-svn: 235647

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[MachineCopyPropagation] Fix a bug causing incorrect removal for the instruction sequences as follows
%Q5_Q6<def> = COPY %Q2_Q3
%D5<def> =
%D3<def> =
%D3<def> = COPY %D6 // Incorrectl

[MachineCopyPropagation] Fix a bug causing incorrect removal for the instruction sequences as follows
%Q5_Q6<def> = COPY %Q2_Q3
%D5<def> =
%D3<def> =
%D3<def> = COPY %D6 // Incorrectly removed in MachineCopyPropagation
Using of %D3 results in incorrect result ...

Reviewed in http://reviews.llvm.org/D8242

llvm-svn: 232142

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Have MachineFunction cache a pointer to the subtarget to make lookups
shorter/easier and have the DAG use that to do the same lookup. This
can be used in the future for TargetMachine based caching lo

Have MachineFunction cache a pointer to the subtarget to make lookups
shorter/easier and have the DAG use that to do the same lookup. This
can be used in the future for TargetMachine based caching lookups from
the MachineFunction easily.

Update the MIPS subtarget switching machinery to update this pointer
at the same time it runs.

llvm-svn: 214838

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Remove the TargetMachine forwards for TargetSubtargetInfo based
information and update all callers. No functional change.

llvm-svn: 214781

[Modules] Remove potential ODR violations by sinking the DEBUG_TYPE
define below all header includes in the lib/CodeGen/... tree. While the
current modules implementation doesn't check for this kind

[Modules] Remove potential ODR violations by sinking the DEBUG_TYPE
define below all header includes in the lib/CodeGen/... tree. While the
current modules implementation doesn't check for this kind of ODR
violation yet, it is likely to grow support for it in the future. It
also removes one layer of macro pollution across all the included
headers.

Other sub-trees will follow.

llvm-svn: 206837

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Disable each MachineFunctionPass for 'optnone' functions, unless that
pass normally runs at optimization level None, or is part of the
register allocation pipeline.

llvm-svn: 205228