Commit Graph

171 Commits

Author SHA1 Message Date
Teresa Johnson
0060160bcf Restore "[ThinLTO] Use MD5 hash in function index." with fix
This restores commit r260408, along with a fix for a bot failure.

The bot failure was caused by dereferencing a unique_ptr in the same
call instruction parameter list where it was passed via std::move.
Apparently due to luck this was not exposed when I built the compiler
with clang, only with gcc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260442 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-10 21:55:02 +00:00
Teresa Johnson
bc947a0d8d Revert "[ThinLTO] Use MD5 hash in function index." due to bot failure
This reverts commit r260408. Bot failure that I need to investigate.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260412 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-10 19:11:15 +00:00
Teresa Johnson
f38049c501 [ThinLTO] Use MD5 hash in function index.
Summary:
This patch uses the lower 64-bits of the MD5 hash of a function name as
a GUID in the function index, instead of storing function names. Any
local functions are first given a global name by prepending the original
source file name. This is the same naming scheme and GUID used by PGO in
the indexed profile format.

This change has a couple of benefits. The primary benefit is size
reduction in the combined index file, for example 483.xalancbmk's
combined index file was reduced by around 70%. It should also result in
memory savings for the index file in memory, as the in-memory map is
also indexed by the hash instead of the string.

Second, this enables integration with indirect call promotion, since the
indirect call profile targets are recorded using the same global naming
convention and hash. This will enable the function importer to easily
locate function summaries for indirect call profile targets to enable
their import and subsequent promotion.

The original source file name is recorded in the bitcode in a new
module-level record for use in the ThinLTO backend pipeline.

Reviewers: davidxl, joker.eph

Subscribers: llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D17028

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260408 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-10 18:57:54 +00:00
Teresa Johnson
74409a0b8a [ThinLTO] Include linkage type in function summary
Summary:
Adds the linkage type to both the per-module and combined function
summaries, which subsumes the current islocal bit. This will eventually
be used to optimized linkage types based on global summary-based
analysis.

Reviewers: joker.eph

Subscribers: joker.eph, davidxl, llvm-commits

Differential Revision: http://reviews.llvm.org/D16943

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259993 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-06 16:07:35 +00:00
Vaivaswatha Nagaraj
ee7970e77e Add InaccessibleMemOnly and inaccessibleMemOrArgMemOnly attributes
Summary:
This patch introduces two new function attributes 

InaccessibleMemOnly: This attribute indicates that the function may only access memory that is not accessible by the program/IR being compiled. This is a weaker form of ReadNone.
inaccessibleMemOrArgMemOnly: This attribute indicates that the function may only access memory that is either not accessible by the program/IR being compiled, or is pointed to by its pointer arguments. This is a weaker form of  ArgMemOnly

Test cases have been updated. This revision uses this (d001932f3a) as reference.

Reviewers: jmolloy, hfinkel

Subscribers: reames, joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D15499

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255778 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-16 16:16:19 +00:00
Sanjay Patel
a3a48d96c9 add fast-math-flags to 'call' instructions (PR21290)
This patch adds optional fast-math-flags (the same that apply to fmul/fadd/fsub/fdiv/frem/fcmp)
to call instructions in IR. Follow-up patches would use these flags in LibCallSimplifier, add 
support to clang, and extend FMF to the DAG for calls.

Motivating example:

%y = fmul fast float %x, %x
%z = tail call float @sqrtf(float %y)

We'd like to be able to optimize sqrt(x*x) into fabs(x). We do this today using a function-wide
attribute for unsafe-math, but we really want to trigger on the instructions themselves:

%z = tail call fast float @sqrtf(float %y)

because in an LTO build it's possible that calls with fast semantics have been inlined into a
function with non-fast semantics.

The code changes and tests are based on the recent commits that added "notail":
http://reviews.llvm.org/rL252368

and added FMF to fcmp:
http://reviews.llvm.org/rL241901

Differential Revision: http://reviews.llvm.org/D14707



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255555 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-14 21:59:03 +00:00
David Majnemer
868145efb0 [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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255522 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-14 18:34:23 +00:00
David Majnemer
8cec2f2816 [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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255422 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-12 05:38:55 +00:00
Amjad Aboud
7db3980c5f Macro debug info support in LLVM IR
Introduced DIMacro and DIMacroFile debug info metadata in the LLVM IR to support macros.

Differential Revision: http://reviews.llvm.org/D14687

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255245 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-10 12:56:35 +00:00
Teresa Johnson
086ed798ff [ThinLTO] Add MODULE_CODE_METADATA_VALUES record
Summary:
This is split out from the ThinLTO metadata mapping patch
http://reviews.llvm.org/D14752.

To avoid needing to parse the module level metadata during function
importing, a new module-level record is added which holds the
number of module-level metadata values. This is required because
metadata value ids are assigned implicitly during parsing, and the
function-level metadata ids start after the module-level metadata ids.

I made a change to this version of the code compared to D14752
in order to add more consistent and thorough assertion checking of the
new record value. We now unconditionally use the record value to
initialize the MDValueList size, and handle it the same in parseMetadata
for all module level metadata cases (lazy loading or not).

Reviewers: dexonsmith, joker.eph

Subscribers: davidxl, llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D14825

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253668 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-20 14:51:27 +00:00
Teresa Johnson
778af35f66 Use a different block id for block of metadata kind records
Summary:
There are currently two blocks with the METADATA_BLOCK id at module
scope. The first has the module-level metadata values (consisting of
some combination of METADATA_* record codes except for METADATA_KIND).
The second consists only of METADATA_KIND records. The latter is used
only in the METADATA_ATTACHMENT block within function blocks (for
metadata attached to instructions).

For ThinLTO we want to delay the parsing of module level metadata
until all functions have been imported from that module (there is some
bookkeeping used to suture it up when we read it during a post-pass).
However, we do need the METADATA_KIND records when parsing the function
body during importing, since those kinds are used as described above.

To simplify identification and parsing of just the block containing
the metadata kinds, use a different block id (METADATA_KIND_BLOCK_ID).
Support older bitcode without the new block id as well.

Reviewers: dexonsmith, joker.eph

Subscribers: davidxl, llvm-commits

Differential Revision: http://reviews.llvm.org/D14654

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253154 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-15 02:00:09 +00:00
Akira Hatanaka
2ff41cea41 [Bitcode] Add enums for call instruction markers and flags. NFC.
This commit adds enums in LLVMBitCodes.h to improve readability and
maintainability. This is a follow-up to r252368 which was discussed
here:

http://reviews.llvm.org/D12923


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252395 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-07 02:48:49 +00:00
James Molloy
d001932f3a Add a new attribute: norecurse
This attribute allows the compiler to assume that the function never recurses into itself, either directly or indirectly (transitively). This can be used among other things to demote global variables to locals.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252282 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-06 10:32:53 +00:00
Sanjay Patel
15216161aa fix typo; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252096 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-04 23:21:13 +00:00
Mehdi Amini
b738d340fa Add an (optional) identification block in the bitcode
Processing bitcode from a different LLVM version can lead to
unexpected behavior. The LLVM project guarantees autoupdating
bitcode from a previous minor revision for the same major, but
can't make any promise when reading bitcode generated from a
either a non-released LLVM, a vendor toolchain, or a "future"
LLVM release. This patch aims at being more user-friendly and
allows a bitcode produce to emit an optional block at the
beginning of the bitcode that will contains an opaque string
intended to describe the bitcode producer information. The
bitcode reader will dump this information alongside any error it
reports.

The optional block also includes an "epoch" number, monotonically
increasing when incompatible changes are made to the bitcode. The
reader will reject bitcode whose epoch is different from the one
expected.

Differential Revision: http://reviews.llvm.org/D13666

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251325 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-26 18:37:00 +00:00
Teresa Johnson
b97baa5fe5 Support for function summary index bitcode sections and files.
Summary:
The bitcode format is described in this document:
  https://drive.google.com/file/d/0B036uwnWM6RWdnBLakxmeDdOeXc/view
For more info on ThinLTO see:
  https://sites.google.com/site/llvmthinlto

The first customer is ThinLTO, however the data structures are designed
and named more generally based on prior feedback. There are a few
comments regarding how certain interfaces are used by ThinLTO, and the
options added here to gold currently have ThinLTO-specific names as the
behavior they provoke is currently ThinLTO-specific.

This patch includes support for generating per-module function indexes,
the combined index file via the gold plugin, and several tests
(more are included with the associated clang patch D11908).

Reviewers: dexonsmith, davidxl, joker.eph

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D13107

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249270 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-04 14:33:43 +00:00
Sanjoy Das
f70eb72453 [Bitcode][Asm] Teach LLVM to read and write operand bundles.
Summary:
This also adds the first set of tests for operand bundles.

The optimizer has not been audited to ensure that it does the right
thing with operand bundles.

Depends on D12456.

Reviewers: reames, chandlerc, majnemer, dexonsmith, kmod, JosephTremoulet, rnk, bogner

Subscribers: maksfb, llvm-commits

Differential Revision: http://reviews.llvm.org/D12457

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@248551 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-24 23:34:52 +00:00
Teresa Johnson
c4736349a5 Remove couple of new Bitcode enum vals that snuck in via r247927 (NFC)
These are meant to be part of the follow on patch I am sending for
review shortly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@248023 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-18 19:38:53 +00:00
David Blaikie
5fab6109a3 [opaque pointer types] Add an explicit pointee type to alias records in the IR
Since aliases actually use and verify their explicit type already, no
further invalid testing is required here. The
invalid.test:ALIAS-TYPE-MISMATCH case catches errors due to emitting a
non-pointee type in the new format or a non-pointer type in the old
format.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247952 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-17 22:18:59 +00:00
Teresa Johnson
3011017ecc Restore "Function bitcode index in Value Symbol Table and lazy reading support"
This reverts commit r247898 (which reverted r247894).

Patch fixed to address two issues exposed by buildbots:
- unused variable warning in NDEBUG mode
- std::initializer_list lifetime issue causing test failures

Original Summary:
Support for including the function bitcode indices in the Value Symbol
Table. This requires writing the VST after the function blocks, which in
turn requires a new VST forward declaration record encoding the offset of
the full VST (which is backpatched to contain the offset after the VST
is written).

This patch also enables the lazy function reader to use the new function
indices out of the VST. This support will be used by ThinLTO as well, which
will be in a follow on patch. Backwards compatibility with older bitcode
files is maintained.

A new test is also included.

The bitcode format (used for the lazy reader as well as the upcoming
ThinLTO patches) came out of discussions with Duncan and others and is
described here:
https://drive.google.com/file/d/0B036uwnWM6RWdnBLakxmeDdOeXc/view

Reviewers: dexonsmith, davidxl, joker.eph

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D12536

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247927 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-17 20:12:00 +00:00
Teresa Johnson
c9d578aaf4 Revert "Function bitcode index in Value Symbol Table and lazy reading support"
Temporarily revert to fix some buildbot issues. One is a minor issue
with a variable unused in NDEBUG mode. More concerning are some test
failures on win7 that I need to dig into.

This reverts commit 4e66a74543459832cfd571db42b4543580ae1d1d.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247898 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-17 16:19:10 +00:00
Teresa Johnson
1f05ba2fcb Function bitcode index in Value Symbol Table and lazy reading support
Summary:
Support for including the function bitcode indices in the Value Symbol
Table. This requires writing the VST after the function blocks, which in
turn requires a new VST forward declaration record encoding the offset of
the full VST (which is backpatched to contain the offset after the VST
is written).

This patch also enables the lazy function reader to use the new function
indices out of the VST. This support will be used by ThinLTO as well, which
will be in a follow on patch. Backwards compatibility with older bitcode
files is maintained.

A new test is also included.

The bitcode format (used for the lazy reader as well as the upcoming
ThinLTO patches) came out of discussions with Duncan and others and is
described here:
https://drive.google.com/file/d/0B036uwnWM6RWdnBLakxmeDdOeXc/view

Reviewers: dexonsmith, davidxl, joker.eph

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D12536

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247894 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-17 15:52:30 +00:00
Joseph Tremoulet
226889eb73 [WinEH] Add cleanupendpad instruction
Summary:
Add a `cleanupendpad` instruction, used to mark exceptional exits out of
cleanups (for languages/targets that can abort a cleanup with another
exception).  The `cleanupendpad` instruction is similar to the `catchendpad`
instruction in that it is an EH pad which is the target of unwind edges in
the handler and which itself has an unwind edge to the next EH action.
The `cleanupendpad` instruction, similar to `cleanupret` has a `cleanuppad`
argument indicating which cleanup it exits.  The unwind successors of a
`cleanuppad`'s `cleanupendpad`s must agree with each other and with its
`cleanupret`s.

Update WinEHPrepare (and docs/tests) to accomodate `cleanupendpad`.

Reviewers: rnk, andrew.w.kaylor, majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D12433

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246751 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-03 09:09:43 +00:00
Joseph Tremoulet
d4a765f88a [WinEH] Require token linkage in EH pad/ret signatures
Summary:
WinEHPrepare is going to require that cleanuppad and catchpad produce values
of token type which are consumed by any cleanupret or catchret exiting the
pad.  This change updates the signatures of those operators to require/enforce
that the type produced by the pads is token type and that the rets have an
appropriate argument.

The catchpad argument of a `CatchReturnInst` must be a `CatchPadInst` (and
similarly for `CleanupReturnInst`/`CleanupPadInst`).  To accommodate that
restriction, this change adds a notion of an operator constraint to both
LLParser and BitcodeReader, allowing appropriate sentinels to be constructed
for forward references and appropriate error messages to be emitted for
illegal inputs.

Also add a verifier rule (noted in LangRef) that a catchpad with a catchpad
predecessor must have no other predecessors; this ensures that WinEHPrepare
will see the expected linear relationship between sibling catches on the
same try.

Lastly, remove some superfluous/vestigial casts from instruction operand
setters operating on BasicBlocks.

Reviewers: rnk, majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D12108

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245797 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-23 00:26:33 +00:00
David Majnemer
2dacece9e2 [IR] Add token types
This introduces the basic functionality to support "token types".
The motivation stems from the need to perform operations on a Value
whose provenance cannot be obscured.

There are several applications for such a type but my immediate
motivation stems from WinEH.  Our personality routine enforces a
single-entry - single-exit regime for cleanups.  After several rounds of
optimizations, we may be left with a terminator whose "cleanup-entry
block" is not entirely clear because control flow has merged two
cleanups together.  We have experimented with using labels as operands
inside of instructions which are not terminators to indicate where we
came from but found that LLVM does not expect such exotic uses of
BasicBlocks.

Instead, we can use this new type to clearly associate the "entry point"
and "exit point" of our cleanup.  This is done by having the cleanuppad
yield a Token and consuming it at the cleanupret.
The token type makes it impossible to obscure or otherwise hide the
Value, making it trivial to track the relationship between the two
points.

What is the burden to the optimizer?  Well, it turns out we have already
paid down this cost by accepting that there are certain calls that we
are not permitted to duplicate, optimizations have to watch out for
such instructions anyway.  There are additional places in the optimizer
that we will probably have to update but early examination has given me
the impression that this will not be heroic.

Differential Revision: http://reviews.llvm.org/D11861

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245029 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-14 05:09:07 +00:00
David Majnemer
4a45f0871a New EH representation for MSVC compatibility
This introduces new instructions neccessary to implement MSVC-compatible
exception handling support.  Most of the middle-end and none of the
back-end haven't been audited or updated to take them into account.

Differential Revision: http://reviews.llvm.org/D11097

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243766 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-31 17:58:14 +00:00
Bob Wilson
b25dcfd104 Reserve some constant values for the Swift calling convention.
Swift has a custom calling convention that also requires some new flags
on arguments and one new attribute on alloca instructions. This patch
does not include the implementation of that calling convention - that
will be provided as part of the open-source release of Swift; this only
reserves the bitcode constant values so that they are not used for
other purposes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243379 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-28 04:05:45 +00:00
Igor Laevsky
6690dbffe0 Add argmemonly attribute.
This change adds new attribute called "argmemonly". Function marked with this attribute can only access memory through it's argument pointers. This attribute directly corresponds to the "OnlyAccessesArgumentPointees" ModRef behaviour in alias analysis.

Differential Revision: http://reviews.llvm.org/D10398



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241979 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-11 10:30:36 +00:00
David Majnemer
eddf9e2057 Revert the new EH instructions
This reverts commits r241888-r241891, I didn't mean to commit them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241893 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-10 07:15:17 +00:00
David Majnemer
751c4be705 New EH representation for MSVC compatibility
Summary:
This introduces new instructions neccessary to implement MSVC-compatible
exception handling support.  Most of the middle-end and none of the
back-end haven't been audited or updated to take them into account.

Reviewers: rnk, JosephTremoulet, reames, nlewycky, rjmccall

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D11041

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241888 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-10 07:00:44 +00:00
Adrian Prantl
717764717b Add a DIModule metadata node to the IR.
It is meant to be used to record modules @imported by the current
compile unit, so a debugger an import the same modules to replicate this
environment before dropping into the expression evaluator.

DIModule is a sibling to DINamespace and behaves quite similarly.
In addition to the name of the module it also records the module
configuration details that are necessary to uniquely identify the module.
This includes the configuration macros (e.g., -DNDEBUG), the include path
where the module.map file is to be found, and the isysroot.

The idea is that the backend will turn this into a DW_TAG_module.

http://reviews.llvm.org/D9614
rdar://problem/20965932

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241017 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-29 23:03:47 +00:00
Alexander Kornienko
cd52a7a381 Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)
Apparently, the style needs to be agreed upon first.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240390 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 09:49:53 +00:00
Alexander Kornienko
cf0db29df2 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!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240137 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-19 15:57:42 +00:00
David Majnemer
cc714e2142 Move the personality function from LandingPadInst to Function
The personality routine currently lives in the LandingPadInst.

This isn't desirable because:
- All LandingPadInsts in the same function must have the same
  personality routine.  This means that each LandingPadInst beyond the
  first has an operand which produces no additional information.

- There is ongoing work to introduce EH IR constructs other than
  LandingPadInst.  Moving the personality routine off of any one
  particular Instruction and onto the parent function seems a lot better
  than have N different places a personality function can sneak onto an
  exceptional function.

Differential Revision: http://reviews.llvm.org/D10429

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239940 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-17 20:52:32 +00:00
Peter Collingbourne
7ffec838a2 Protection against stack-based memory corruption errors using SafeStack
This patch adds the safe stack instrumentation pass to LLVM, which separates
the program stack into a safe stack, which stores return addresses, register
spills, and local variables that are statically verified to be accessed
in a safe way, and the unsafe stack, which stores everything else. Such
separation makes it much harder for an attacker to corrupt objects on the
safe stack, including function pointers stored in spilled registers and
return addresses. You can find more information about the safe stack, as
well as other parts of or control-flow hijack protection technique in our
OSDI paper on code-pointer integrity (http://dslab.epfl.ch/pubs/cpi.pdf)
and our project website (http://levee.epfl.ch).

The overhead of our implementation of the safe stack is very close to zero
(0.01% on the Phoronix benchmarks). This is lower than the overhead of
stack cookies, which are supported by LLVM and are commonly used today,
yet the security guarantees of the safe stack are strictly stronger than
stack cookies. In some cases, the safe stack improves performance due to
better cache locality.

Our current implementation of the safe stack is stable and robust, we
used it to recompile multiple projects on Linux including Chromium, and
we also recompiled the entire FreeBSD user-space system and more than 100
packages. We ran unit tests on the FreeBSD system and many of the packages
and observed no errors caused by the safe stack. The safe stack is also fully
binary compatible with non-instrumented code and can be applied to parts of
a program selectively.

This patch is our implementation of the safe stack on top of LLVM. The
patches make the following changes:

- Add the safestack function attribute, similar to the ssp, sspstrong and
  sspreq attributes.

- Add the SafeStack instrumentation pass that applies the safe stack to all
  functions that have the safestack attribute. This pass moves all unsafe local
  variables to the unsafe stack with a separate stack pointer, whereas all
  safe variables remain on the regular stack that is managed by LLVM as usual.

- Invoke the pass as the last stage before code generation (at the same time
  the existing cookie-based stack protector pass is invoked).

- Add unit tests for the safe stack.

Original patch by Volodymyr Kuznetsov and others at the Dependable Systems
Lab at EPFL; updates and upstreaming by myself.

Differential Revision: http://reviews.llvm.org/D6094

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239761 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-15 21:07:11 +00:00
Owen Anderson
13146c7e3b Add initial support for the convergent attribute.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238264 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-26 23:48:40 +00:00
David Blaikie
974d5d32c8 [opaque pointer type] Encode the pointee type in the bitcode for 'cmpxchg'
As a space optimization, this instruction would just encode the pointer
type of the first operand and use the knowledge that the second and
third operands would be of the pointee type of the first. When typed
pointers go away, this assumption will no longer be available - so
encode the type of the second operand explicitly and rely on that for
the third.

Test case added to demonstrate the backwards compatibility concern,
which only comes up when the definition of the second operand comes
after the use (hence the weird basic block sequence) - at which point
the type needs to be explicitly encoded in the bitcode and the record
length changes to accommodate this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235966 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-28 04:30:29 +00:00
David Blaikie
5bd65c73d7 [opaque pointer types] Serialize the value type for atomic store instructions
Without pointee types the space optimization of storing only the pointer
type and not the value type won't be viable - so add the extra type
information that would be missing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235475 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-22 04:14:46 +00:00
David Blaikie
5db5cae26f [opaque pointer types] Serialize the value type for store instructions
Without pointee types the space optimization of storing only the pointer
type and not the value type won't be viable - so add the extra type
information that would be missing.

Storeatomic coming soon.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235474 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-22 04:14:42 +00:00
Sanjoy Das
5ff5907996 [IR] Introduce a dereferenceable_or_null(N) attribute.
Summary:
If a pointer is marked as dereferenceable_or_null(N), LLVM assumes it
is either `null` or `dereferenceable(N)` or both.  This change only
introduces the attribute and adds a token test case for the `llvm-as`
/ `llvm-dis`.  It does not hook up other parts of the optimizer to
actually exploit the attribute -- those changes will come later.

For pointers in address space 0, `dereferenceable(N)` is now exactly
equivalent to `dereferenceable_or_null(N)` && `nonnull`.  For other
address spaces, `dereferenceable(N)` is potentially weaker than
`dereferenceable_or_null(N)` && `nonnull` (since we could have a null
`dereferenceable(N)` pointer).

The motivating case for this change is Java (and other managed
languages), where pointers are either `null` or dereferenceable up to
some usually known-at-compile-time constant offset.

Reviewers: rafael, hfinkel

Reviewed By: hfinkel

Subscribers: nicholas, llvm-commits

Differential Revision: http://reviews.llvm.org/D8650

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235132 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-16 20:29:50 +00:00
David Blaikie
6606ad944b [opaque pointer type] Bitcode support for explicit type parameter on GEP.
Like r230414, add bitcode support including backwards compatibility, for
an explicit type parameter to GEP.

At the suggestion of Duncan I tried coalescing the two older bitcodes into a
single new bitcode, though I did hit a wrinkle: I couldn't figure out how to
create an explicit abbreviation for a record with a variable number of
arguments (the indicies to the gep). This means the discriminator between
inbounds and non-inbounds gep is a full variable-length field I believe? Is my
understanding correct? Is there a way to create such an abbreviation? Should I
just use two bitcodes as before?

Reviewers: dexonsmith

Differential Revision: http://reviews.llvm.org/D7736

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230415 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-25 01:08:52 +00:00
Duncan P. N. Exon Smith
1a7dd178f5 Bitcode: Remove confusing '?' from r229004, NFC
The name is always part of the record, it just might be empty.  Remove
the `?` for clarity.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229032 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 02:43:38 +00:00
Duncan P. N. Exon Smith
08ddf256df Bitcode: Add trailing comma to MetadataCodes, NFC
Suggested in the review of r229004, this should simplify diffs
in the future.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229031 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 02:41:36 +00:00
Duncan P. N. Exon Smith
6a390dc584 AsmWriter/Bitcode: MDImportedEntity
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229025 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:46:02 +00:00
Duncan P. N. Exon Smith
3bfa8d00ae AsmWriter/Bitcode: MDObjCProperty
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229024 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:43:22 +00:00
Duncan P. N. Exon Smith
a034e076c2 AsmWriter/Bitcode: MDExpression
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229023 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:42:09 +00:00
Duncan P. N. Exon Smith
a342d827bd AsmWriter/Bitcode: MDLocalVariable
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229022 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:39:44 +00:00
Duncan P. N. Exon Smith
fbc547da81 AsmWriter/Bitcode: MDGlobalVariable
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229020 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:35:40 +00:00
Duncan P. N. Exon Smith
8921bbca59 AsmWriter/Bitcode: MDTemplate{Type,Value}Parameter
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229019 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:34:32 +00:00
Duncan P. N. Exon Smith
7bd3d1d3bd AsmWriter/Bitcode: MDNamespace
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229018 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:32:09 +00:00