[InstCombine] Rewrite bswap/bitreverse handling completely.

There are several requirements that ended up with this design;
1. Matching bitreversals is too heavyweight for InstCombine and doesn't r

[InstCombine] Rewrite bswap/bitreverse handling completely.

There are several requirements that ended up with this design;
1. Matching bitreversals is too heavyweight for InstCombine and doesn't really need to be done so early.
2. Bitreversals and byteswaps are very related in their matching logic.
3. We want to implement support for matching more advanced bswap/bitreverse patterns like partial bswaps/bitreverses.
4. Bswaps are best matched early in InstCombine.

The result of these is that a new utility function is created in Transforms/Utils/Local.h that can be configured to search for bswaps, bitreverses or both. InstCombine uses it to find only bswaps, CGP uses it to find only bitreversals.

We can then extend the matching logic in one place only.

llvm-svn: 257875

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[Utils] Fix incorrect dbg.declare store conversion

Summary: The dbg.declare -> dbg.value conversion did not check which operand of
the store instruction the alloca was passed to. As a result code th

[Utils] Fix incorrect dbg.declare store conversion

Summary: The dbg.declare -> dbg.value conversion did not check which operand of
the store instruction the alloca was passed to. As a result code that stored the
address of an alloca, rather than storing to the alloca, would still trigger
the conversion routine, leading to the insertion of an incorrect dbg.value
intrinsic.

Reviewers: aprantl

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D16169

llvm-svn: 257787

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Revert "Stop increasing alignment of externally-visible globals on ELF platforms."

This reverts commit r257719, due to PR26144.

llvm-svn: 257775

Stop increasing alignment of externally-visible globals on ELF
platforms.

With ELF, the alignment of a global variable in a shared library will
get copied into an executables linked against it, if t

Stop increasing alignment of externally-visible globals on ELF
platforms.

With ELF, the alignment of a global variable in a shared library will
get copied into an executables linked against it, if the executable even
accesss the variable. So, it's not possible to implicitly increase
alignment based on access patterns, or you'll break existing binaries.

This happened to affect libc++'s std::cout symbol, for example. See
thread: http://thread.gmane.org/gmane.comp.compilers.clang.devel/45311

llvm-svn: 257719

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[Utils] Insert DW_OP_bit_piece when only describing part of the variable

Summary: The dbg.declare -> dbg.value conversion looks through any zext/sext
to find a value to describe the variable (in the

[Utils] Insert DW_OP_bit_piece when only describing part of the variable

Summary: The dbg.declare -> dbg.value conversion looks through any zext/sext
to find a value to describe the variable (in the expectation that those
zext/sext instruction will go away later). However, those values do not
cover the entire variable and thus need a DW_OP_bit_piece.

Reviewers: aprantl
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D16061

llvm-svn: 257534

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[JumpThreading] Don't forget to report that the IR changed

JumpThreading's runOnFunction is supposed to return true if it made any
changes. JumpThreading has a call to removeUnreachableBlocks which

[JumpThreading] Don't forget to report that the IR changed

JumpThreading's runOnFunction is supposed to return true if it made any
changes. JumpThreading has a call to removeUnreachableBlocks which may
result in changes to the IR but runOnFunction didn't appropriate account
for this possibility, leading to badness.

While we are here, make sure to call LazyValueInfo::eraseBlock in
removeUnreachableBlocks; JumpThreading preserves LVI.

This fixes PR26096.

llvm-svn: 257279

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[Statepoints] Check for the "gc-leaf-function" attribute on call sites as well.

Reviewers: sanjoy, reames

Subscribers: sanjoy, llvm-commits

Differential Revision: http://reviews.llvm.org/D15900

l

[Statepoints] Check for the "gc-leaf-function" attribute on call sites as well.

Reviewers: sanjoy, reames

Subscribers: sanjoy, llvm-commits

Differential Revision: http://reviews.llvm.org/D15900

llvm-svn: 256875

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[SimplifyCFG] Further improve our ability to remove redundant catchpads

In r256814, we managed to remove catchpads which were trivially redudant
because they were the same SSA value. We can do bett

[SimplifyCFG] Further improve our ability to remove redundant catchpads

In r256814, we managed to remove catchpads which were trivially redudant
because they were the same SSA value. We can do better using the same
algorithm but with a smarter datastructure by hashing the SSA values
within the catchpad and comparing them structurally.

llvm-svn: 256815

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[SimplifyCFG] Remove redundant catchpads

Remove duplicate catchpad handlers from a catchswitch.

llvm-svn: 256814

Clean up the processing of dbg.value in various places

Summary:
First up is instcombine, where in the dbg.declare -> dbg.value conversion,
the llvm.dbg.value needs to be called on the actual loaded

Clean up the processing of dbg.value in various places

Summary:
First up is instcombine, where in the dbg.declare -> dbg.value conversion,
the llvm.dbg.value needs to be called on the actual loaded value, rather
than the address (since the whole point of this transformation is to be
able to get rid of the alloca). Further, now that that's cleaned up, we
can remove a hack in the backend, that would add an implicit OP_deref if
the argument to dbg.value was an alloca. This stems from before the
existence of DIExpression and is no longer necessary since the deref can
be expressed explicitly.

Now, in order to make sure that the tests pass with this change, we need to
correct the printing of DEBUG_VALUE comments to take into account the
expression, which wasn't taken into account before.

Unfortunately, for both these changes, there were a number of incorrect
test cases (mostly the wrong number of DW_OP_derefs, but also a couple
where the test itself was broken more badly). aprantl and I have gone
through and adjusted these test case in order to make them pass with
these fixes and in some cases to make sure they're actually testing
what they are meant to test.

Reviewers: aprantl

Subscribers: dsanders

Differential Revision: http://reviews.llvm.org/D14186

llvm-svn: 256077

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[WinEH] Use operand bundles to describe call sites

SimplifyCFG allows tail merging with code which terminates in
unreachable which, in turn, makes it possible for an invoke to end up in
a funclet wh

[WinEH] Use operand bundles to describe call sites

SimplifyCFG allows tail merging with code which terminates in
unreachable which, in turn, makes it possible for an invoke to end up in
a funclet which it was not originally part of.

Using operand bundles on invokes allows us to determine whether or not
an invoke was part of a funclet in the source program.

Furthermore, it allows us to unambiguously answer questions about the
legality of inlining into call sites which the personality may have
trouble with.

Differential Revision: http://reviews.llvm.org/D15517

llvm-svn: 255674

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[IR] Remove terminatepad

It turns out that terminatepad gives little benefit over a cleanuppad
which calls the termination function. This is not sufficient to
implement fully generic filters but MS

[IR] Remove terminatepad

It turns out that terminatepad gives little benefit over a cleanuppad
which calls the termination function. This is not sufficient to
implement fully generic filters but MSVC doesn't support them which
makes terminatepad a little over-designed.

Depends on D15478.

Differential Revision: http://reviews.llvm.org/D15479

llvm-svn: 255522

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[IR] Reformulate LLVM's EH funclet IR

While we have successfully implemented a funclet-oriented EH scheme on
top of LLVM IR, our scheme has some notable deficiencies:
- catchendpad and cleanupendpad

[IR] Reformulate LLVM's EH funclet IR

While we have successfully implemented a funclet-oriented EH scheme on
top of LLVM IR, our scheme has some notable deficiencies:
- catchendpad and cleanupendpad are necessary in the current design
but they are difficult to explain to others, even to seasoned LLVM
experts.
- catchendpad and cleanupendpad are optimization barriers. They cannot
be split and force all potentially throwing call-sites to be invokes.
This has a noticable effect on the quality of our code generation.
- catchpad, while similar in some aspects to invoke, is fairly awkward.
It is unsplittable, starts a funclet, and has control flow to other
funclets.
- The nesting relationship between funclets is currently a property of
control flow edges. Because of this, we are forced to carefully
analyze the flow graph to see if there might potentially exist illegal
nesting among funclets. While we have logic to clone funclets when
they are illegally nested, it would be nicer if we had a
representation which forbade them upfront.

Let's clean this up a bit by doing the following:
- Instead, make catchpad more like cleanuppad and landingpad: no control
flow, just a bunch of simple operands; catchpad would be splittable.
- Introduce catchswitch, a control flow instruction designed to model
the constraints of funclet oriented EH.
- Make funclet scoping explicit by having funclet instructions consume
the token produced by the funclet which contains them.
- Remove catchendpad and cleanupendpad. Their presence can be inferred
implicitly using coloring information.

N.B. The state numbering code for the CLR has been updated but the
veracity of it's output cannot be spoken for. An expert should take a
look to make sure the results are reasonable.

Reviewers: rnk, JosephTremoulet, andrew.w.kaylor

Differential Revision: http://reviews.llvm.org/D15139

llvm-svn: 255422

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Add arg_begin() and arg_end() to CallInst and InvokeInst; NFCI

- This simplifies the CallSite class, arg_begin / arg_end are now
simple wrapper getters.

- In several places, we were creating C

Add arg_begin() and arg_end() to CallInst and InvokeInst; NFCI

- This simplifies the CallSite class, arg_begin / arg_end are now
simple wrapper getters.

- In several places, we were creating CallSite instances solely to call
arg_begin and arg_end. With this change, that's no longer required.

llvm-svn: 255226

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[OperandBundles] Fix a transform in simplifycfg

Reviewers: pcc, majnemer, reames

Subscribers: reames, llvm-commits

Differential Revision: http://reviews.llvm.org/D15345

llvm-svn: 255062

Move EH-specific helper functions to a more appropriate place

No functionality change is intended.

llvm-svn: 254562

[safestack] Protect byval function arguments.

Detect unsafe byval function arguments and move them to the unsafe
stack.

llvm-svn: 254353

Preserve load alignment and dereferenceable metadata during some transformations

Reviewed By: hfinkel

Differential Revision: http://reviews.llvm.org/D13953

llvm-svn: 251809

TransformUtils: Remove implicit ilist iterator conversions, NFC

Continuing the work from last week to remove implicit ilist iterator
conversions. First related commit was probably r249767, with som

TransformUtils: Remove implicit ilist iterator conversions, NFC

Continuing the work from last week to remove implicit ilist iterator
conversions. First related commit was probably r249767, with some more
motivation in r249925. This edition gets LLVMTransformUtils compiling
without the implicit conversions.

No functional change intended.

llvm-svn: 250142

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[PlaceSafeopints] Extract out `callsGCLeafFunction`, NFC

Summary:
This will be used in a later change to RewriteStatepointsForGC.

Reviewers: reames, swaroop.sridhar

Subscribers: llvm-commits

Diff

[PlaceSafeopints] Extract out `callsGCLeafFunction`, NFC

Summary:
This will be used in a later change to RewriteStatepointsForGC.

Reviewers: reames, swaroop.sridhar

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D13490

llvm-svn: 249777

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inariant.group handling in GVN

The most important part required to make clang
devirtualization works ( ͡°͜ʖ ͡°).
The code is able to find non local dependencies, but unfortunatelly
because the calle

inariant.group handling in GVN

The most important part required to make clang
devirtualization works ( ͡°͜ʖ ͡°).
The code is able to find non local dependencies, but unfortunatelly
because the caller can only handle local dependencies, I had to add
some restrictions to look for dependencies only in the same BB.

http://reviews.llvm.org/D12992

llvm-svn: 249196

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Fix debug info with SafeStack.

llvm-svn: 248933

Move dbg.declare intrinsics when merging and replacing allocas.

Place new and update dbg.declare calls immediately after the
corresponding alloca.

Current code in replaceDbgDeclareForAlloca puts th

Move dbg.declare intrinsics when merging and replacing allocas.

Place new and update dbg.declare calls immediately after the
corresponding alloca.

Current code in replaceDbgDeclareForAlloca puts the new dbg.declare
at the end of the basic block. LLVM codegen has problems emitting
debug info in a situation when dbg.declare appears after all uses of
the variable. This usually kinda works for inlining and ASan (two
users of this function) but not for SafeStack (see the pending change
in http://reviews.llvm.org/D13178).

llvm-svn: 248769

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Improve performance of SimplifyInstructionsInBlock

1. Use a worklist, not a recursive approach, to avoid needless
revisitation and being repeatedly forced to jump back to the
start of the BB i

Improve performance of SimplifyInstructionsInBlock

1. Use a worklist, not a recursive approach, to avoid needless
revisitation and being repeatedly forced to jump back to the
start of the BB if a handle is invalidated.

2. Only insert operands to the worklist if they become unused
after a dead instruction is removed, so we don’t have to
visit them again in most cases.

3. Use a SmallSetVector to track the worklist.

4. Instead of pre-initting the SmallSetVector like in
DeadCodeEliminationPass, only put things into the worklist
if they have to be revisited after the first run-through.
This minimizes how much the actual SmallSetVector gets used,
which saves a lot of time.

llvm-svn: 248727

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[EH] Create removeUnwindEdge utility

Summary:
Factor the code that rewrites invokes to calls and rewrites WinEH
terminators to their "unwind to caller" equivalents into a helper in
Utils/Local, and

[EH] Create removeUnwindEdge utility

Summary:
Factor the code that rewrites invokes to calls and rewrites WinEH
terminators to their "unwind to caller" equivalents into a helper in
Utils/Local, and use it in the three places I'm aware of that need to do
this.


Reviewers: andrew.w.kaylor, majnemer, rnk

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D13152

llvm-svn: 248677

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