83 Commits

Author SHA1 Message Date
Reid Kleckner
5b3b7ed35d [InstCombine] Add a flag to disable LowerDbgDeclare
Summary:
This should improve optimized debug info for address-taken variables at
the cost of inaccurate debug info in some situations.

We patched this into clang and deployed this change to Chromium
developers, and this significantly improved debuggability of optimized
code. The long-term solution to PR34136 seems more and more like it's
going to take a while, so I would like to commit this change under a
flag so that it can be used as a stop-gap measure.

This flag should really help so for C++ aggregates like std::string and
std::vector, which are typically address-taken, even after inlining, and
cannot be SROA-ed.

Reviewers: aprantl, dblaikie, probinson, dberlin

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D36596

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@313108 91177308-0d34-0410-b5e6-96231b3b80d8
2017-09-13 01:43:25 +00:00
Adrian Prantl
69e607f200 Canonicalize the representation of empty an expression in DIGlobalVariableExpression
This change simplifies code that has to deal with
DIGlobalVariableExpression and mirrors how we treat DIExpressions in
debug info intrinsics. Before this change there were two ways of
representing empty expressions on globals, a nullptr and an empty
!DIExpression().

If someone needs to upgrade out-of-tree testcases:
  perl -pi -e 's/(!DIGlobalVariableExpression\(var: ![0-9]*)\)/\1, expr: !DIExpression())/g' <MYTEST.ll>
will catch 95%.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312144 91177308-0d34-0410-b5e6-96231b3b80d8
2017-08-30 18:06:51 +00:00
Mandeep Singh Grang
89c6743f22 [ADT] Enable reverse iteration for DenseMap
Reviewers: mehdi_amini, dexonsmith, dblaikie, davide, chandlerc, davidxl, echristo, efriedma

Reviewed By: dblaikie

Subscribers: rsmith, mgorny, emaste, llvm-commits

Differential Revision: https://reviews.llvm.org/D35043

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@311730 91177308-0d34-0410-b5e6-96231b3b80d8
2017-08-24 23:02:48 +00:00
Reid Kleckner
a5b2af0eae Parse and print DIExpressions inline to ease IR and MIR testing
Summary:
Most DIExpressions are empty or very simple. When they are complex, they
tend to be unique, so checking them inline is reasonable.

This also avoids the need for CodeGen passes to append to the
llvm.dbg.mir named md node.

See also PR22780, for making DIExpression not be an MDNode.

Reviewers: aprantl, dexonsmith, dblaikie

Subscribers: qcolombet, javed.absar, eraman, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D37075

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@311594 91177308-0d34-0410-b5e6-96231b3b80d8
2017-08-23 20:31:27 +00:00
Sam Elliott
74a34d9193 Keep Optimization Remark Yaml in NewPM
Summary:
The New Pass Manager infrastructure was forgetting to keep around the optimization remark yaml file that the compiler might have been producing. This meant setting the option to '-' for stdout worked, but setting it to a filename didn't give file output (presumably it was deleted because compilation didn't explicitly keep it). This change just ensures that the file is kept if compilation succeeds.

So far I have updated one of the optimization remark output tests to add a version with the new pass manager. It is my intention for this patch to also include changes to all tests that use `-opt-remark-output=` but I wanted to get the code patch ready for review while I was making all those changes.

Fixes https://bugs.llvm.org/show_bug.cgi?id=33951

Reviewers: anemet, chandlerc

Reviewed By: anemet, chandlerc

Subscribers: javed.absar, chandlerc, fhahn, llvm-commits

Differential Revision: https://reviews.llvm.org/D36906

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@311271 91177308-0d34-0410-b5e6-96231b3b80d8
2017-08-20 01:30:45 +00:00
Adrian Prantl
5d0334a48c Remove the obsolete offset parameter from @llvm.dbg.value
There is no situation where this rarely-used argument cannot be
substituted with a DIExpression and removing it allows us to simplify
the DWARF backend. Note that this patch does not yet remove any of
the newly dead code.

rdar://problem/33580047
Differential Revision: https://reviews.llvm.org/D35951

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@309426 91177308-0d34-0410-b5e6-96231b3b80d8
2017-07-28 20:21:02 +00:00
Adam Nemet
7d3d44a14c Migrate SimplifyLibCalls to new OptimizationRemarkEmitter
Summary:
This changes SimplifyLibCalls to use the new OptimizationRemarkEmitter
API.

In fact, as SimplifyLibCalls is only ever called via InstCombine,
(as far as I can tell) the OptimizationRemarkEmitter is added there,
and then passed through to SimplifyLibCalls later.

I have avoided changing any remark text.

This closes PR33787

Patch by Sam Elliott!

Reviewers: anemet, davide

Reviewed By: anemet

Subscribers: davide, mehdi_amini, eraman, fhahn, llvm-commits

Differential Revision: https://reviews.llvm.org/D35608

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@309158 91177308-0d34-0410-b5e6-96231b3b80d8
2017-07-26 19:03:18 +00:00
Daniel Berlin
e6be55f220 PredicateInfo: Don't insert conditional info when a conditional branch jumps to the same target regardless of condition
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@305416 91177308-0d34-0410-b5e6-96231b3b80d8
2017-06-14 21:19:52 +00:00
NAKAMURA Takumi
4e7fb91232 Introduce the new feature "abi-breaking-checks" to satisfy -reverse-iterate in llvm/test/Transforms/Util/PredicateInfo/
A few tests in llvm/test/Transforms/Util/PredicateInfo/ are using -reverse-iterate.
The option -reverse-iterate is enabled with +Asserts in usual cases, but it can be turned on/off regardless of LLVM_ENABLE_ASSERTIONS.

I wonder if this were incompatible to https://reviews.llvm.org/D33908 (r304757).

Differential Revision: https://reviews.llvm.org/D33854

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304851 91177308-0d34-0410-b5e6-96231b3b80d8
2017-06-07 00:22:52 +00:00
Mandeep Singh Grang
4fc1ca19cd [PredicateInfo] Enable -reverse-iterate tests only for +Asserts builds
Summary: The flag -reverse-iterate is present only on +Asserts builds.

Reviewers: dberlin, davide, RKSimon, efriedma, chapuni

Reviewed By: efriedma, chapuni

Subscribers: chapuni, llvm-commits

Differential Revision: https://reviews.llvm.org/D33795

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304498 91177308-0d34-0410-b5e6-96231b3b80d8
2017-06-01 23:52:59 +00:00
Mandeep Singh Grang
9cc122269f [PredicateInfo] Fix non-determinism in codegen uncovered by reverse iterating SmallPtrSet
Summary:
Sort OpsToRename before iterating to make iteration order deterministic.

Thanks to Daniel Berlin for the sorting logic.

Reviewers: dberlin, RKSimon, efriedma, davide

Reviewed By: dberlin, davide

Subscribers: sanjoy, davide, llvm-commits

Differential Revision: https://reviews.llvm.org/D33265

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304447 91177308-0d34-0410-b5e6-96231b3b80d8
2017-06-01 18:36:24 +00:00
David Blaikie
f80f771764 PR32288: Describe a bool parameter's DWARF location with a simple register
There's no need (& a bit incorrect) to mask off the high bits of the
register reference when describing a simple bool value.

Reviewers: aprantl

Differential Revision: https://reviews.llvm.org/D31062

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@303117 91177308-0d34-0410-b5e6-96231b3b80d8
2017-05-15 21:34:01 +00:00
Andrew Ng
055a715ed6 [SimplifyLibCalls] Fix infinite loop with fast-math optimization.
One of the fast-math optimizations is to replace calls to standard double
functions with their float equivalents, e.g. exp -> expf. However, this can
cause infinite loops for the following:

  float expf(float val) { return (float) exp((double) val); }

A similar inline declaration exists in the MinGW-w64 math.h header file which
when compiled with -O2/3 and fast-math generates infinite loops.

So this fix checks that the calling function to the standard double function
that is being replaced does not match the float equivalent.

Differential Revision: https://reviews.llvm.org/D31806

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301304 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-25 12:36:14 +00:00
Daniel Berlin
e0f5ddbc01 MemorySSA: Move to Analysis, from Transforms/Utils. It's used as
Analysis, it has Analysis passes, and once NewGVN is made an Analysis,
this removes the cross dependency from Analysis to Transform/Utils.
NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299980 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-11 20:06:36 +00:00
Matt Arsenault
bdbe8280f2 Add address space mangling to lifetime intrinsics
In preparation for allowing allocas to have non-0 addrspace.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299876 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-10 20:18:21 +00:00
Daniel Berlin
13d8288f8e MemorySSA: Make lifetime starts defs for mustaliased pointers
Summary:
While we don't want them aliasing with other pointers, there seems to
be no point in not having them clobber must-aliased'd pointers.

If some day, we split the aliasing and ordering chains, we'd make this
not aliasing but an ordering barrier (IE it doesn't affect it's
memory, but we can't hoist it above it).

Reviewers: hfinkel, george.burgess.iv

Subscribers: Prazek, llvm-commits

Differential Revision: https://reviews.llvm.org/D31865

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299865 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-10 18:46:00 +00:00
Hal Finkel
cfe441c874 [MemorySSA] Fix use of pointsToConstantMemory in isUseTriviallyOptimizableToLiveOnEntry
In isUseTriviallyOptimizableToLiveOnEntry, pointsToConstantMemory needs to be
called on the load's pointer operand, not on the result of the load (which
might not even be a pointer).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299823 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-09 12:57:50 +00:00
Piotr Padlewski
f580f444f6 [MSSA] Small test fix
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299235 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-31 17:39:07 +00:00
Adrian Prantl
70eccef966 Teach stripNonLineTableDebugInfo() to remap DILocations in !llvm.loop nodes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299107 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-30 20:10:56 +00:00
Daniel Berlin
4ddfe6915d PredicateInfo: Support switch statements
Summary:
Depends on D29606 and D29682

Makes us pass GVN's edge.ll (we also will pass a few other testcases
they just need cleaning up).

Thoughts on the Predicate* hiearchy of classes especially welcome :)
(it's not clear to me how best to organize it, and currently, the getBlock* seems ... uglier than maybe wasting a field somewhere or something).

Reviewers: davide

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29747

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@295889 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-22 22:20:58 +00:00
Daniel Berlin
33e17b4040 PredicateInfo: Clean up predicate info a little, using insertion
helpers, and fixing support for the renaming the comparison.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@295581 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-18 23:06:38 +00:00
Daniel Berlin
8697d189a9 PredicateInfo: Handle critical edges
Summary:
This adds support for placing predicateinfo such that it affects critical edges.

This fixes the issues mentioned by Nuno on the mailing list.

Depends on D29519

Reviewers: davide, nlopes

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29606

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294921 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-12 22:12:20 +00:00
Daniel Berlin
94f2e5a1f1 Add PredicateInfo utility and printing pass
Summary:
This patch adds a utility to build extended SSA (see "ABCD: eliminating
array bounds checks on demand"), and an intrinsic to support it. This
is then used to get functionality equivalent to propagateEquality in
GVN, in NewGVN (without having to replace instructions as we go). It
would work similarly in SCCP or other passes. This has been talked
about a few times, so i built a real implementation and tried to
productionize it.

Copies are inserted for operands used in assumes and conditional
branches that are based on comparisons (see below for more)

Every use affected by the predicate is renamed to the appropriate
intrinsic result.

E.g.
%cmp = icmp eq i32 %x, 50
br i1 %cmp, label %true, label %false
true:
ret i32 %x
false:
ret i32 1

will become

%cmp = icmp eq i32, %x, 50
br i1 %cmp, label %true, label %false
true:
; Has predicate info
; branch predicate info { TrueEdge: 1 Comparison: %cmp = icmp eq i32 %x, 50 }
%x.0 = call @llvm.ssa_copy.i32(i32 %x)
ret i32 %x.0
false:
ret i23 1

(you can use -print-predicateinfo to get an annotated-with-predicateinfo dump)

This enables us to easily determine what operations are affected by a
given predicate, and how operations affected by a chain of
predicates.

Reviewers: davide, sanjoy

Subscribers: mgorny, llvm-commits, Prazek

Differential Revision: https://reviews.llvm.org/D29519

Update for review comments

Fix a bug Nuno noticed where we are giving information about and/or on edges where the info is not useful and easy to use wrong

Update for review comments

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294351 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-07 21:10:46 +00:00
Peter Collingbourne
6db6348785 IR: Consider two DISubprograms to be odr-equal if they have the same template parameters.
In ValueMapper we create new operands for MDNodes and
rely on MDNode::replaceWithUniqued to create a new MDNode
with the specified operands. However this doesn't always
actually happen correctly for DISubprograms because when we
uniquify the new node, we only odr-compare it with existing nodes
(MDNodeSubsetEqualImpl<DISubprogram>::isDeclarationOfODRMember). Although
the TemplateParameters field can refer to a distinct DICompileUnit via
DITemplateTypeParameter::type -> DICompositeType::scope -> DISubprogram::unit,
it is not currently included in the odr comparison. As a result, we can end
up getting our original DISubprogram back, which means we will have a cloned
module referring to the DICompileUnit in the original module, which causes
a verification error.

The fix I implemented was to consider TemplateParameters to be one of the
odr-equal properties. But I'm a little uncomfortable with this. In general it
seems unsound to rely on distinct MDNodes never being reachable from nodes
which we only check odr-equality of. My only long term suggestion would be
to separate odr-uniquing from full uniquing.

Differential Revision: https://reviews.llvm.org/D29240

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294240 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-06 21:23:03 +00:00
Piotr Padlewski
d0675bd5cb [MemorySSA] Add new tests for invariant.groups
Summary:
Next round of extra tests for MSSA.
I have a prototype invariant.group handling implementation
that fixes all the FIXMEs, and I think it will be
easier to see what is the difference if I firstly
post this, and then only fix fixits.

Reviewers: george.burgess.iv, dberlin

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29022

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292797 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-23 16:38:10 +00:00
Benjamin Kramer
84d682db0f Fix some broken CHECK lines.
The colon is important.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292761 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-22 20:28:56 +00:00
Piotr Padlewski
9228080c77 [MemorySSA] Remove deprecated comment from test
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292733 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-21 22:14:02 +00:00
Piotr Padlewski
1fbffa18ae [MemorySSA] Fix invariant.group test and add new
Summary:
This test had a bug: !llvm.invariant.group instead
of !invariant.group.

Also add some new test for future development.
All tests passes, when MSSA will support invariant.group
only the lines with FIXIT should be changed.

Reviewers: dberlin, george.burgess.iv

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D28969

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292730 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-21 21:56:56 +00:00
Bryant Wong
f7285121c8 [AliasAnalysis] Teach BasicAA about memcpy.
Differential Revision: https://reviews.llvm.org/D27034

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290526 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-25 22:42:27 +00:00
Adrian Prantl
c271bc0481 Renumber testcase metadata nodes after r290153.
This patch renumbers the metadata nodes in debug info testcases after
https://reviews.llvm.org/D26769. This is a separate patch because it
causes so much churn. This was implemented with a python script that
pipes the testcases through llvm-as - | llvm-dis - and then goes
through the original and new output side-by side to insert all
comments at a close-enough location.

Differential Revision: https://reviews.llvm.org/D27765

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290292 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-22 00:45:21 +00:00
Adrian Prantl
7b500b4bdf [IR] Remove the DIExpression field from DIGlobalVariable.
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.

Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:

(1) The DIGlobalVariable should describe the source level variable,
    not how to get to its location.

(2) It makes it unsafe/hard to update the expressions when we call
    replaceExpression on the DIGLobalVariable.

(3) It makes it impossible to represent a global variable that is in
    more than one location (e.g., a variable with multiple
    DW_OP_LLVM_fragment-s).  We also moved away from attaching the
    DIExpression to DILocalVariable for the same reasons.

This reapplies r289902 with additional testcase upgrades and a change
to the Bitcode record for DIGlobalVariable, that makes upgrading the
old format unambiguous also for variables without DIExpressions.

<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290153 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-20 02:09:43 +00:00
Adrian Prantl
096faa974a Revert "[IR] Remove the DIExpression field from DIGlobalVariable."
This reverts commit 289920 (again).
I forgot to implement a Bitcode upgrade for the case where a DIGlobalVariable
has not DIExpression. Unfortunately it is not possible to safely upgrade
these variables without adding a flag to the bitcode record indicating which
version they are.
My plan of record is to roll the planned follow-up patch that adds a
unit: field to DIGlobalVariable into this patch before recomitting.
This way we only need one Bitcode upgrade for both changes (with a
version flag in the bitcode record to safely distinguish the record
formats).

Sorry for the churn!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289982 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-16 19:39:01 +00:00
Adrian Prantl
eb38a2a075 [IR] Remove the DIExpression field from DIGlobalVariable.
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.

Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:

(1) The DIGlobalVariable should describe the source level variable,
    not how to get to its location.

(2) It makes it unsafe/hard to update the expressions when we call
    replaceExpression on the DIGLobalVariable.

(3) It makes it impossible to represent a global variable that is in
    more than one location (e.g., a variable with multiple
    DW_OP_LLVM_fragment-s).  We also moved away from attaching the
    DIExpression to DILocalVariable for the same reasons.

This reapplies r289902 with additional testcase upgrades.

<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289920 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-16 04:25:54 +00:00
Adrian Prantl
7766e56d48 Revert "[IR] Remove the DIExpression field from DIGlobalVariable."
This reverts commit 289902 while investigating bot berakage.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289906 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-16 01:00:30 +00:00
Adrian Prantl
1b11b0778e [IR] Remove the DIExpression field from DIGlobalVariable.
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.

Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:

(1) The DIGlobalVariable should describe the source level variable,
    not how to get to its location.

(2) It makes it unsafe/hard to update the expressions when we call
    replaceExpression on the DIGLobalVariable.

(3) It makes it impossible to represent a global variable that is in
    more than one location (e.g., a variable with multiple
    DW_OP_LLVM_fragment-s).  We also moved away from attaching the
    DIExpression to DILocalVariable for the same reasons.

<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289902 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-16 00:36:43 +00:00
Sanjoy Das
a942d77488 [Verifier] Add verification for TBAA metadata
Summary:
This change adds some verification in the IR verifier around struct path
TBAA metadata.

Other than some basic sanity checks (e.g. we get constant integers where
we expect constant integers), this checks:

 - That by the time an struct access tuple `(base-type, offset)` is
   "reduced" to a scalar base type, the offset is `0`.  For instance, in
   C++ you can't start from, say `("struct-a", 16)`, and end up with
   `("int", 4)` -- by the time the base type is `"int"`, the offset
   better be zero.  In particular, a variant of this invariant is needed
   for `llvm::getMostGenericTBAA` to be correct.

 - That there are no cycles in a struct path.

 - That struct type nodes have their offsets listed in an ascending
   order.

 - That when generating the struct access path, you eventually reach the
   access type listed in the tbaa tag node.

Reviewers: dexonsmith, chandlerc, reames, mehdi_amini, manmanren

Subscribers: mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D26438

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289402 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-11 20:07:15 +00:00
Adrian Prantl
460dd60c1a [DIExpression] Introduce a dedicated DW_OP_LLVM_fragment operation
so we can stop using DW_OP_bit_piece with the wrong semantics.

The entire back story can be found here:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20161114/405934.html

The gist is that in LLVM we've been misinterpreting DW_OP_bit_piece's
offset field to mean the offset into the source variable rather than
the offset into the location at the top the DWARF expression stack. In
order to be able to fix this in a subsequent patch, this patch
introduces a dedicated DW_OP_LLVM_fragment operation with the
semantics that we used to apply to DW_OP_bit_piece, which is what we
actually need while inside of LLVM. This patch is complete with a
bitcode upgrade for expressions using the old format. It does not yet
fix the DWARF backend to use DW_OP_bit_piece correctly.

Implementation note: We discussed several options for implementing
this, including reserving a dedicated field in DIExpression for the
fragment size and offset, but using an custom operator at the end of
the expression works just fine and is more efficient because we then
only pay for it when we need it.

Differential Revision: https://reviews.llvm.org/D27361
rdar://problem/29335809

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288683 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-05 18:04:47 +00:00
Mandeep Singh Grang
21e956f318 [MemorySSA] Fix unit tests broken by D26704
Summary:
D26704 fixed the non-determinism in codegen by sorting basic blocks before
iteration so as to have a defined iteration order. As a result we need to fix
the names (numbers) of the temporaries in the following unit tests:
  test/Transforms/Util/MemorySSA/multi-edges.ll
  test/Transforms/Util/MemorySSA/multiple-backedges-hal.ll

Reviewers: dberlin, david2050, mgrang

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D26926

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@287575 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-21 20:39:08 +00:00
Mandeep Singh Grang
d8c5ecbd82 [MemorySSA] Fix for non-determinism in codegen
This patch fixes the non-determinism caused due to iterating SmallPtrSet's
which was uncovered due to the experimental "reverse iteration order " patch:
https://reviews.llvm.org/D26718

The following unit tests failed because of the undefined order of iteration.
LLVM :: Transforms/Util/MemorySSA/cyclicphi.ll
LLVM :: Transforms/Util/MemorySSA/many-dom-backedge.ll
LLVM :: Transforms/Util/MemorySSA/many-doms.ll
LLVM :: Transforms/Util/MemorySSA/phi-translation.ll

Reviewers: dberlin, mgrang

Subscribers: dberlin, llvm-commits, david2050

Differential Revision: https://reviews.llvm.org/D26704

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@287563 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-21 19:33:02 +00:00
Michael Ilseman
5bd98bf7d6 Add -strip-nonlinetable-debuginfo capability
This adds a new function to DebugInfo.cpp that takes an llvm::Module
as input and removes all debug info metadata that is not directly
needed for line tables, thus effectively stripping all type and
variable information from the module.

The primary motivation for this feature was the bitcode work flow
(cf. http://lists.llvm.org/pipermail/llvm-dev/2016-June/100643.html
for more background). This is not wired up yet, but will be in
subsequent patches.  For testing, the new functionality is exposed to
opt with a -strip-nonlinetable-debuginfo option.

The secondary use-case (and one that works right now!) is as a
reduction pass in bugpoint. I added two new bugpoint options
(-disable-strip-debuginfo and -disable-strip-debug-types) to control
the new features. By default it will first attempt to remove all debug
information, then only the type info, and then proceed to hack at any
remaining MDNodes.

Thanks to Adrian Prantl for stewarding this patch!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285094 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-25 18:44:13 +00:00
Anna Thomas
79f85df65a [StripGCRelocates] New pass to remove gc.relocates added by RS4GC
Summary:
Utility pass to remove gc.relocates created by rewrite statepoints for GC.
With respect to safepoint verification, the IR generated would be incorrect, and cannot run
as such.

This would be a single transformation on the final optimized IR.
The benefit of the pass is for easy analysis when the IRs are 'polluted' by too
many gc.relocates.
Added tests.

test run: All RS4GC tests with -verify option. Local downstream tests on large
IR files. This also works when the pointer being gc.relocated is another
gc.relocate.

Reviewers: sanjoy, reames

Subscribers: beanz, mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D25096

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284855 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-21 18:43:16 +00:00
Rong Xu
fe89a6bcf0 Conditionally eliminate library calls where the result value is not used
Summary:
This pass shrink-wraps a condition to some library calls where the call
result is not used. For example:
   sqrt(val);
 is transformed to
   if (val < 0)
     sqrt(val);
Even if the result of library call is not being used, the compiler cannot
safely delete the call because the function can set errno on error
conditions.
Note in many functions, the error condition solely depends on the incoming
parameter. In this optimization, we can generate the condition can lead to
the errno to shrink-wrap the call. Since the chances of hitting the error
condition is low, the runtime call is effectively eliminated.

These partially dead calls are usually results of C++ abstraction penalty
exposed by inlining. This optimization hits 108 times in 19 C/C++ programs
in SPEC2006.

Reviewers: hfinkel, mehdi_amini, davidxl

Subscribers: modocache, mgorny, mehdi_amini, xur, llvm-commits, beanz

Differential Revision: https://reviews.llvm.org/D24414

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284542 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-18 21:36:27 +00:00
Michael Ilseman
33fe838cad Revert "Add -strip-nonlinetable-debuginfo capability"
This reverts commit r283473.

Reverted until review is completed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283478 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-06 18:30:26 +00:00
Michael Ilseman
bda4e020b8 Add -strip-nonlinetable-debuginfo capability
This adds a new function to DebugInfo.cpp that takes an llvm::Module
as input and removes all debug info metadata that is not directly
needed for line tables, thus effectively stripping all type and
variable information from the module.

The primary motivation for this feature was the bitcode work flow
(cf. http://lists.llvm.org/pipermail/llvm-dev/2016-June/100643.html
for more background). This is not wired up yet, but will be in
subsequent patches.  For testing, the new functionality is exposed to
opt with a -strip-nonlinetable-debuginfo option.

The secondary use-case (and one that works right now!) is as a
reduction pass in bugpoint. I added two new bugpoint options
(-disable-strip-debuginfo and -disable-strip-debug-types) to control
the new features. By default it will first attempt to remove all debug
information, then only the type info, and then proceed to hack at any
remaining MDNodes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283473 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-06 17:58:38 +00:00
Daniel Berlin
a50e80efdf Remove pruning of phi nodes in MemorySSA - it makes updating harder
Reviewers: george.burgess.iv

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D24923

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282419 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-26 17:22:54 +00:00
Hans Wennborg
a613eb13a3 Revert r281895 "Add @llvm.dbg.value entries for the phi node created by -mem2reg"
(And follow-up r281964.)

It caused PR30468.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282077 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-21 15:55:53 +00:00
Keith Walker
383922dd5b Add @llvm.dbg.value entries for the phi node created by -mem2reg
When phi nodes are created in the -mem2reg phase, the @llvm.dbg.declare
entries are converted to @llvm.dbg.value entries at the place where the
store instructions existed. However no entry is created to describe
the resulting value of the phi node.

The effect of this is especially noticeable in for loops which have a
constant for the intial value; the loop control variable's location
would be described as the intial constant value in the loop body once
the -mem2reg optimization phase was run.

This change adds the creation of the @llvm.dbg.value entries to describe
variables whose location is the result of a phi node created in -mem2reg.

Also when the phi node is finally lowered to a machine instruction it
is important that the lowered "load" instruction is placed before the
associated DEBUG_VALUE entry describing the value loaded.

Differential Revision: https://reviews.llvm.org/D23715


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281895 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-19 09:49:30 +00:00
Daniel Berlin
cd3dcaa09e [MSSA] Fix PR28880 by fixing use optimizer's lower bound tracking behavior.
Summary:
In the use optimizer, we need to keep of whether the lower bound still
dominates us or else we may decide a lower bound is still valid when it
is not due to intervening pushes/pops.  Fixes PR28880 (and probably a
bunch of other things).

Reviewers: george.burgess.iv

Subscribers: MatzeB, llvm-commits, sebpop

Differential Revision: https://reviews.llvm.org/D23237

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277978 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-08 04:44:53 +00:00
George Burgess IV
cd112f0139 [MSSA] Add special handling for invariant/constant loads.
This is a follow-up to r277637. It teaches MemorySSA that invariant
loads (and loads of provably constant memory) are always liveOnEntry.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277640 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-03 19:57:02 +00:00
George Burgess IV
94c82b281d [MSSA] Add logic for special handling of atomics/volatiles.
This patch makes MemorySSA recognize atomic/volatile loads, and makes
MSSA treat said loads specially. This allows us to be a bit more
aggressive in some cases.

Administrative note: Revision was LGTM'ed by reames in person.
Additionally, this doesn't include the `invariant.load` recognition in
the differential revision, because I feel it's better to commit that
separately. Will commit soon.

Differential Revision: https://reviews.llvm.org/D16875


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277637 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-03 19:39:54 +00:00