Skip debuginfo intrinsic in markLiveBlocks.

Summary:
The optimizer is 10%+ slower with vs without debuginfo. I started checking where
the difference is coming from.

I compiled sqlite3.c with and wi

Skip debuginfo intrinsic in markLiveBlocks.

Summary:
The optimizer is 10%+ slower with vs without debuginfo. I started checking where
the difference is coming from.

I compiled sqlite3.c with and without debug info from CTMark and compare the time difference.

I use Xcode Instrument to find where time is spent. This brings about 20ms, out of ~20s.

Reviewers: davide, hfinkel

Reviewed By: hfinkel

Subscribers: hfinkel, aprantl, JDevlieghere, llvm-commits

Differential Revision: https://reviews.llvm.org/D49337

llvm-svn: 337416

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Fix comments which mixed up 'before' and 'after', NFC

llvm-svn: 337061

llvm: Add support for "-fno-delete-null-pointer-checks"

Summary:
Support for this option is needed for building Linux kernel.
This is a very frequently requested feature by kernel developers.

More

llvm: Add support for "-fno-delete-null-pointer-checks"

Summary:
Support for this option is needed for building Linux kernel.
This is a very frequently requested feature by kernel developers.

More details : https://lkml.org/lkml/2018/4/4/601

GCC option description for -fdelete-null-pointer-checks:
This Assume that programs cannot safely dereference null pointers,
and that no code or data element resides at address zero.

-fno-delete-null-pointer-checks is the inverse of this implying that
null pointer dereferencing is not undefined.

This feature is implemented in LLVM IR in this CL as the function attribute
"null-pointer-is-valid"="true" in IR (Under review at D47894).
The CL updates several passes that assumed null pointer dereferencing is
undefined to not optimize when the "null-pointer-is-valid"="true"
attribute is present.

Reviewers: t.p.northover, efriedma, jyknight, chandlerc, rnk, srhines, void, george.burgess.iv

Reviewed By: efriedma, george.burgess.iv

Subscribers: eraman, haicheng, george.burgess.iv, drinkcat, theraven, reames, sanjoy, xbolva00, llvm-commits

Differential Revision: https://reviews.llvm.org/D47895

llvm-svn: 336613

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[Local] replaceAllDbgUsesWith: Update debug values before RAUW

The replaceAllDbgUsesWith utility helps passes preserve debug info when
replacing one value with another.

This improves upon the exist

[Local] replaceAllDbgUsesWith: Update debug values before RAUW

The replaceAllDbgUsesWith utility helps passes preserve debug info when
replacing one value with another.

This improves upon the existing insertReplacementDbgValues API by:

- Updating debug intrinsics in-place, while preventing use-before-def of
the replacement value.
- Falling back to salvageDebugInfo when a replacement can't be made.
- Moving the responsibiliy for rewriting llvm.dbg.* DIExpressions into
common utility code.

Along with the API change, this teaches replaceAllDbgUsesWith how to
create DIExpressions for three basic integer and pointer conversions:

- The no-op conversion. Applies when the values have the same width, or
have bit-for-bit compatible pointer representations.
- Truncation. Applies when the new value is wider than the old one.
- Zero/sign extension. Applies when the new value is narrower than the
old one.

Testing:

- check-llvm, check-clang, a stage2 `-g -O3` build of clang,
regression/unit testing.
- This resolves a number of mis-sized dbg.value diagnostics from
Debugify.

Differential Revision: https://reviews.llvm.org/D48676

llvm-svn: 336451

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[DebugInfo] Corrections for salvageDebugInfo

Summary:
When salvaging a dbg.declare/dbg.addr we should not add
DW_OP_stack_value to the DIExpression
(see test/Transforms/InstCombine/salvage-dbg-decla

[DebugInfo] Corrections for salvageDebugInfo

Summary:
When salvaging a dbg.declare/dbg.addr we should not add
DW_OP_stack_value to the DIExpression
(see test/Transforms/InstCombine/salvage-dbg-declare.ll).

Consider this example
%vla = alloca i32, i64 2
call void @llvm.dbg.declare(metadata i32* %vla, metadata !1, metadata !DIExpression())

Instcombine will turn it into
%vla1 = alloca [2 x i32]
%vla1.sub = getelementptr inbounds [2 x i32], [2 x i32]* %vla, i64 0, i64 0
call void @llvm.dbg.declare(metadata [2 x i32]* %vla1.sub, metadata !19, metadata !DIExpression())

If the GEP can be eliminated, then the dbg.declare will be salvaged
and we should get
%vla1 = alloca [2 x i32]
call void @llvm.dbg.declare(metadata [2 x i32]* %vla1, metadata !19, metadata !DIExpression())

The problem was that salvageDebugInfo did not recognize dbg.declare
as being indirect (%vla1 points to the value, it does not hold the
value), so we incorrectly got
call void @llvm.dbg.declare(metadata [2 x i32]* %vla1, metadata !19, metadata !DIExpression(DW_OP_stack_value))

I also made sure that llvm::salvageDebugInfo and
DIExpression::prependOpcodes do not add DW_OP_stack_value to
the DIExpression in case no new operands are added to the
DIExpression. That way we avoid to, unneccessarily, turn a
register location expression into an implicit location expression
in some situations (see test11 in test/Transforms/LICM/sinking.ll).

Reviewers: aprantl, vsk

Reviewed By: aprantl, vsk

Subscribers: JDevlieghere, llvm-commits

Differential Revision: https://reviews.llvm.org/D48837

llvm-svn: 336191

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Use a variable to appease a no-asserts bot, NFC

Failure URL:
http://lab.llvm.org:8011/builders/lld-x86_64-darwin13/builds/22836

llvm-svn: 335648

[Local] Add a convenient insertReplacementDbgValues overload, NFC

Add an overload for the common case where the replacement dbg.values
have the same DIExpressions as the originals.

llvm-svn: 335643

[Local] Sink salvageDI's early exit into helper functions, NFC

salvageDebugInfo() performs a check that allows it to exit early without
doing a DenseMap lookup. It's a bit neater and marginally more

[Local] Sink salvageDI's early exit into helper functions, NFC

salvageDebugInfo() performs a check that allows it to exit early without
doing a DenseMap lookup. It's a bit neater and marginally more useful to
sink this early exit into the findDbg{Addr,Users,Values} helpers.

llvm-svn: 335642

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Improve ConvertDebugDeclareToDebugValue

Summary:
This is a follow-up to r334830 and r335031.

In the valueCoversEntireFragment check we now also handle
the situation when there is a variable length

Improve ConvertDebugDeclareToDebugValue

Summary:
This is a follow-up to r334830 and r335031.

In the valueCoversEntireFragment check we now also handle
the situation when there is a variable length array (VLA)
involved, and the length of the array has been reduced to
a constant.

The ConvertDebugDeclareToDebugValue functions that are related
to PHI nodes and load instructions now avoid inserting dbg.value
intrinsics when the value does not, for certain, cover the
variable/fragment that should be described.
In r334830 we assumed that the value always covered the entire
var/fragment and we had assertions in the code to show that
assumption. However, those asserts failed when compiling code
with VLAs, so we removed the asserts in r335031. Now when we
know that the valueCoversEntireFragment check can fail also for
PHI/Load instructions we avoid to insert the faulty dbg.value
intrinsic in such situations. Compared to the Store instruction
scenario we simply drop the dbg.value here (as the variable does
not change its value due to PHI/Load, so an earlier dbg.value
describing the variable should still be valid).

Reviewers: aprantl, vsk, efriedma

Reviewed By: aprantl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D48547

llvm-svn: 335580

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[Local] Generalize insertReplacementDbgValues, NFC

This utility should operate on Values, not Instructions. While I'm here,
I've also made it possible to skip emitting replacement dbg.values for
cer

[Local] Generalize insertReplacementDbgValues, NFC

This utility should operate on Values, not Instructions. While I'm here,
I've also made it possible to skip emitting replacement dbg.values for
certain debug users (by having RewriteExpr return nullptr).

llvm-svn: 335152

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[Local] Add a utility to insert replacement dbg.values, NFC

The purpose of this utility is to make it easier for optimizations to
insert replacement dbg.values for instructions they are deleting. Th

[Local] Add a utility to insert replacement dbg.values, NFC

The purpose of this utility is to make it easier for optimizations to
insert replacement dbg.values for instructions they are deleting. This
is useful in situations where salvageDebugInfo is inapplicable, say,
because the new dbg.value cannot refer to an operand of the dying value.

The utility is called insertReplacementDbgValues.

It assumes that the instruction 'From' is going to be deleted, and
inserts replacement dbg.values for each debug user of 'From'. The
newly-inserted dbg.values refer to 'To' instead of 'From'. Each
replacement dbg.value has the same location and variable as the debug
user it replaces, has a DIExpression determined by the result of
'RewriteExpr' applied to an old debug user of 'From', and is placed
before 'InsertBefore'.

This should simplify future patches, like D48331.

llvm-svn: 335144

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Remove valueCoversEntireFragment asserts in ConvertDebugDeclareToDebugValue

This is a fixup for r334830 causing problems in polly-aosp buildbot.

Focus in r334830 was to fix a problem seen with
Conv

Remove valueCoversEntireFragment asserts in ConvertDebugDeclareToDebugValue

This is a fixup for r334830 causing problems in polly-aosp buildbot.

Focus in r334830 was to fix a problem seen with
ConvertDebugDeclareToDebugValue involving store instructions.
It also added some asserts to find out of similar problems
existed for the ConvertDebugDeclareToDebugValue functions
involving load and phi instructions. One of those asserts seems
to blow in the polly-aosp buildbot, so I'll revert the asserts
while debugging.

llvm-svn: 335031

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Re-apply "[DebugInfo] Check size of variable in ConvertDebugDeclareToDebugValue"

This is r334704 (which was reverted in r334732) with a fix for
types like x86_fp80. We need to use getTypeAllocSizeIn

Re-apply "[DebugInfo] Check size of variable in ConvertDebugDeclareToDebugValue"

This is r334704 (which was reverted in r334732) with a fix for
types like x86_fp80. We need to use getTypeAllocSizeInBits and
not getTypeStoreSizeInBits to avoid dropping debug info for
such types.

Original commit msg:
> Summary:
> Do not convert a DbgDeclare to DbgValue if the store
> instruction only refer to a fragment of the variable
> described by the DbgDeclare.
>
> Problem was seen when for example having an alloca for an
> array or struct, and there were stores to individual elements.
> In the past we inserted a DbgValue intrinsics for each store,
> just as if the store wrote the whole variable.
>
> When handling store instructions we insert a DbgValue that
> indicates that the variable is "undefined", as we do not know
> which part of the variable that is updated by the store.
>
> When ConvertDebugDeclareToDebugValue is used with a load/phi
> instruction we assert that the referenced value is large enough
> to cover the whole variable. Afaict this should be true for all
> scenarios where those methods are used on trunk. If the assert
> blows in the future I guess we could simply skip to insert a
> dbg.value instruction.
>
> In the future I think we should examine which part of the variable
> that is accessed, and add a DbgValue instrinsic with an appropriate
> DW_OP_LLVM_fragment expression.
>
> Reviewers: dblaikie, aprantl, rnk
>
> Reviewed By: aprantl
>
> Subscribers: JDevlieghere, llvm-commits
>
> Tags: #debug-info
>
> Differential Revision: https://reviews.llvm.org/D48024

llvm-svn: 334830

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Revert rL334704: "[DebugInfo] Check size of variable in ConvertDebugDeclareToDebugValue"

This reverts commit r334704.

Buildbots detected an assertion in "test tsan in debug compiler-rt build".

llv

Revert rL334704: "[DebugInfo] Check size of variable in ConvertDebugDeclareToDebugValue"

This reverts commit r334704.

Buildbots detected an assertion in "test tsan in debug compiler-rt build".

llvm-svn: 334732

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[DebugInfo] Check size of variable in ConvertDebugDeclareToDebugValue

Summary:
Do not convert a DbgDeclare to DbgValue if the store
instruction only refer to a fragment of the variable
described by

[DebugInfo] Check size of variable in ConvertDebugDeclareToDebugValue

Summary:
Do not convert a DbgDeclare to DbgValue if the store
instruction only refer to a fragment of the variable
described by the DbgDeclare.

Problem was seen when for example having an alloca for an
array or struct, and there were stores to individual elements.
In the past we inserted a DbgValue intrinsics for each store,
just as if the store wrote the whole variable.

When handling store instructions we insert a DbgValue that
indicates that the variable is "undefined", as we do not know
which part of the variable that is updated by the store.

When ConvertDebugDeclareToDebugValue is used with a load/phi
instruction we assert that the referenced value is large enough
to cover the whole variable. Afaict this should be true for all
scenarios where those methods are used on trunk. If the assert
blows in the future I guess we could simply skip to insert a
dbg.value instruction.

In the future I think we should examine which part of the variable
that is accessed, and add a DbgValue instrinsic with an appropriate
DW_OP_LLVM_fragment expression.

Reviewers: dblaikie, aprantl, rnk

Reviewed By: aprantl

Subscribers: JDevlieghere, llvm-commits

Tags: #debug-info

Differential Revision: https://reviews.llvm.org/D48024

llvm-svn: 334704

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Move Analysis/Utils/Local.h back to Transforms

Review feedback from r328165. Split out just the one function from the
file that's used by Analysis. (As chandlerc pointed out, the original
change onl

Move Analysis/Utils/Local.h back to Transforms

Review feedback from r328165. Split out just the one function from the
file that's used by Analysis. (As chandlerc pointed out, the original
change only moved the header and not the implementation anyway - which
was fine for the one function that was used (since it's a
template/inlined in the header) but not in general)

llvm-svn: 333954

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[LoopInstSimplify] Re-implement the core logic of loop-instsimplify to
be both simpler and substantially more efficient.

Rather than use a hand-rolled iteration technique that isn't quite the
same a

[LoopInstSimplify] Re-implement the core logic of loop-instsimplify to
be both simpler and substantially more efficient.

Rather than use a hand-rolled iteration technique that isn't quite the
same as RPO, use the pre-built RPO loop body traversal utility.

Once visiting the loop body in RPO, we can assert that we visit defs
before uses reliably. When this is the case, the only need to iterate is
when simplifying a def that is used by a PHI node along a back-edge.
With this patch, the first pass over the loop body is just a complete
simplification of every instruction across the loop body. When we
encounter a use of a simplified instruction that stems from a PHI node
in the loop body that has already been visited (due to some cyclic CFG,
potentially the loop itself, or a nested loop, or unstructured control
flow), we recall that specific PHI node for the second iteration.
Nothing else needs to be preserved from iteration to iteration.

On the second and later iterations, only instructions known to have
simplified inputs are considered, each time starting from a set of PHIs
that had simplified inputs along the backedges.

Dead instructions are collected along the way, but deleted in a batch at
the end of each iteration making the iterations themselves substantially
simpler. This uses a new batch API for recursively deleting dead
instructions.

This alsa changes the routine to visit subloops. Because simplification
is fundamentally transitive, we may need to visit the entire loop body,
including subloops, to handle knock-on simplification.

I've added a basic test file that helps demonstrate that all of these
changes work. It includes both straight-forward loops with
simplifications as well as interesting PHI-structures, CFG-structures,
and a nested loop case.

Differential Revision: https://reviews.llvm.org/D47407

llvm-svn: 333461

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Constant fold launder of null and undef

Summary:
This might be useful because clang will add
some barriers for pointer comparisons.

Reviewers: majnemer, dberlin, hfinkel, nlewycky, davide, rsmith,

Constant fold launder of null and undef

Summary:
This might be useful because clang will add
some barriers for pointer comparisons.

Reviewers: majnemer, dberlin, hfinkel, nlewycky, davide, rsmith, amharc,
kuhar

Subscribers: davide, amharc, llvm-commits

Differential Revision: https://reviews.llvm.org/D32423

llvm-svn: 332786

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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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[STLExtras] Add distance() for ranges, pred_size(), and succ_size()

This commit adds a wrapper for std::distance() which works with ranges.
As it would be a common case to write `distance(predecesso

[STLExtras] Add distance() for ranges, pred_size(), and succ_size()

This commit adds a wrapper for std::distance() which works with ranges.
As it would be a common case to write `distance(predecessors(BB))`, this
also introduces `pred_size()` and `succ_size()` helpers to make that
easier to write.

Differential Revision: https://reviews.llvm.org/D46668

llvm-svn: 332057

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[DebugInfo] Add DILabel metadata and intrinsic llvm.dbg.label.

In order to set breakpoints on labels and list source code around
labels, we need collect debug information for labels, i.e., label
nam

[DebugInfo] Add DILabel metadata and intrinsic llvm.dbg.label.

In order to set breakpoints on labels and list source code around
labels, we need collect debug information for labels, i.e., label
name, the function label belong, line number in the file, and the
address label located. In order to keep these information in LLVM
IR and to allow backend to generate debug information correctly.
We create a new kind of metadata for labels, DILabel. The format
of DILabel is

!DILabel(scope: !1, name: "foo", file: !2, line: 3)

We hope to keep debug information as much as possible even the
code is optimized. So, we create a new kind of intrinsic for label
metadata to avoid the metadata is eliminated with basic block.
The intrinsic will keep existing if we keep it from optimized out.
The format of the intrinsic is

llvm.dbg.label(metadata !1)

It has only one argument, that is the DILabel metadata. The
intrinsic will follow the label immediately. Backend could get the
label metadata through the intrinsic's parameter.

We also create DIBuilder API for labels to be used by Frontend.
Frontend could use createLabel() to allocate DILabel objects, and use
insertLabel() to insert llvm.dbg.label intrinsic in LLVM IR.

Differential Revision: https://reviews.llvm.org/D45024

Patch by Hsiangkai Wang.

llvm-svn: 331841

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Fix a bunch of places where operator-> was used directly on the return from dyn_cast.

Inspired by r331508, I did a grep and found these.

Mostly just change from dyn_cast to cast. Some cases also sh

Fix a bunch of places where operator-> was used directly on the return from dyn_cast.

Inspired by r331508, I did a grep and found these.

Mostly just change from dyn_cast to cast. Some cases also showed a dyn_cast result being converted to bool, so those I changed to isa.

llvm-svn: 331577

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Remove \brief commands from doxygen comments.

We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they ar

Remove \brief commands from doxygen comments.

We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46290

llvm-svn: 331272

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Fix a bug in GlobalOpt's handling of DIExpressions.

This patch adds support for fragment expressions
TryToShrinkGlobalToBoolean() which were previously just dropped.

Thanks to Reid Kleckner for pro

Fix a bug in GlobalOpt's handling of DIExpressions.

This patch adds support for fragment expressions
TryToShrinkGlobalToBoolean() which were previously just dropped.

Thanks to Reid Kleckner for providing me a reproducer!

llvm-svn: 331086

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Fix a couple of layering violations in Transforms

Remove #include of Transforms/Scalar.h from Transform/Utils to fix layering.

Transforms depends on Transforms/Utils, not the other way around. So
r

Fix a couple of layering violations in Transforms

Remove #include of Transforms/Scalar.h from Transform/Utils to fix layering.

Transforms depends on Transforms/Utils, not the other way around. So
remove the header and the "createStripGCRelocatesPass" function
declaration (& definition) that is unused and motivated this dependency.

Move Transforms/Utils/Local.h into Analysis because it's used by
Analysis/MemoryBuiltins.cpp.

llvm-svn: 328165

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