774 Commits

Author SHA1 Message Date
Teresa Johnson
2d9da4dc50 [ThinLTO] Ensure function summary output order is stable
Iterate over the function list instead of a DenseMap of Function pointers
when emitting the function summary into the module.

This fixes PR26419.

llvm-svn: 259398
2016-02-01 20:16:35 +00:00
Akira Hatanaka
4f472a8867 [llvm-bcanalyzer] Dump bitcode wrapper header
This patch enables llvm-bcanalyzer to print the bitcode wrapper header
if the file has one, which is needed to test the changes made in
r258627 (bitcode-wrapper-header-armv7m.ll is the test case for r258627).

Differential Revision: http://reviews.llvm.org/D16642

llvm-svn: 259162
2016-01-29 05:55:09 +00:00
Akira Hatanaka
1235d280d8 [Bitcode] Insert the darwin wrapper at the beginning of a file when the
target is macho.

It looks like the check for macho was accidentally dropped in r132959.

I don't have a test case, but I'll add one if anyone knows how this can
be tested.

llvm-svn: 258627
2016-01-23 16:02:10 +00:00
Chris Ray
b541a3488f NFC Test Commit whitespace change in a comment
Changed whitespace so comments line up.

llvm-svn: 258151
2016-01-19 18:01:20 +00:00
Justin Bogner
a43eacbf9e Bitcode: Fix reading and writing of ConstantDataVectors of halfs
In r254991 I allowed ConstantDataVectors to contain elements of
HalfTy, but I missed updating the bitcode reader and writer to handle
this, so now we crash if we try to emit bitcode on programs that have
constant vectors of half.

This fixes the issue and adds test coverage for reading and writing
constant sequences in bitcode.

llvm-svn: 256982
2016-01-06 22:31:32 +00:00
Vaivaswatha Nagaraj
fb3f4907c0 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

llvm-svn: 255778
2015-12-16 16:16:19 +00:00
Sanjay Patel
fa54acedd1 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

llvm-svn: 255555
2015-12-14 21:59:03 +00:00
David Majnemer
bbfc7219ef [IR] Remove terminatepad
It turns out that terminatepad gives little benefit over a cleanuppad
which calls the termination function.  This is not sufficient to
implement fully generic filters but MSVC doesn't support them which
makes terminatepad a little over-designed.

Depends on D15478.

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

llvm-svn: 255522
2015-12-14 18:34:23 +00:00
David Majnemer
8a1c45d6e8 [IR] Reformulate LLVM's EH funclet IR
While we have successfully implemented a funclet-oriented EH scheme on
top of LLVM IR, our scheme has some notable deficiencies:
- catchendpad and cleanupendpad are necessary in the current design
  but they are difficult to explain to others, even to seasoned LLVM
  experts.
- catchendpad and cleanupendpad are optimization barriers.  They cannot
  be split and force all potentially throwing call-sites to be invokes.
  This has a noticable effect on the quality of our code generation.
- catchpad, while similar in some aspects to invoke, is fairly awkward.
  It is unsplittable, starts a funclet, and has control flow to other
  funclets.
- The nesting relationship between funclets is currently a property of
  control flow edges.  Because of this, we are forced to carefully
  analyze the flow graph to see if there might potentially exist illegal
  nesting among funclets.  While we have logic to clone funclets when
  they are illegally nested, it would be nicer if we had a
  representation which forbade them upfront.

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

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

Reviewers: rnk, JosephTremoulet, andrew.w.kaylor

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

llvm-svn: 255422
2015-12-12 05:38:55 +00:00
Amjad Aboud
a9bcf16ebc 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

llvm-svn: 255245
2015-12-10 12:56:35 +00:00
Teresa Johnson
d4d3dfd8ef [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

llvm-svn: 253668
2015-11-20 14:51:27 +00:00
Teresa Johnson
12545075f0 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

llvm-svn: 253154
2015-11-15 02:00:09 +00:00
Sanjay Patel
225d65f1e6 use range-based for loop; NFCI
llvm-svn: 253048
2015-11-13 16:21:23 +00:00
Sanjoy Das
b9ca6dcc6b [OperandBundles] Identify operand bundles with both their names and IDs
No code uses this functionality yet.  This change just exposes
information / structure that was already present.

llvm-svn: 252644
2015-11-10 20:13:15 +00:00
Akira Hatanaka
97cb397132 [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

llvm-svn: 252395
2015-11-07 02:48:49 +00:00
Sanjoy Das
54c3ca694a [OperandBundles] Rename accessor, NFC
Rename getOperandBundle to getOperandBundleAt since that's more obvious.

llvm-svn: 252388
2015-11-07 01:56:04 +00:00
Akira Hatanaka
5cfcce12eb Add 'notail' marker for call instructions.
This marker prevents optimization passes from adding 'tail' or
'musttail' markers to a call. Is is used to prevent tail call
optimization from being performed on the call.

rdar://problem/22667622

Differential Revision: http://reviews.llvm.org/D12923

llvm-svn: 252368
2015-11-06 23:55:38 +00:00
James Molloy
e6f87ca812 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.

llvm-svn: 252282
2015-11-06 10:32:53 +00:00
Peter Collingbourne
d4bff30370 DI: Reverse direction of subprogram -> function edge.
Previously, subprograms contained a metadata reference to the function they
described. Because most clients need to get or set a subprogram for a given
function rather than the other way around, this created unneeded inefficiency.

For example, many passes needed to call the function llvm::makeSubprogramMap()
to build a mapping from functions to subprograms, and the IR linker needed to
fix up function references in a way that caused quadratic complexity in the IR
linking phase of LTO.

This change reverses the direction of the edge by storing the subprogram as
function-level metadata and removing DISubprogram's function field.

Since this is an IR change, a bitcode upgrade has been provided.

Fixes PR23367. An upgrade script for textual IR for out-of-tree clients is
attached to the PR.

Differential Revision: http://reviews.llvm.org/D14265

llvm-svn: 252219
2015-11-05 22:03:56 +00:00
Mehdi Amini
ba19c6eed8 Fix Abbrev emission in WriteIdentificationBlock
This Abbrev was not emitted and basically unused, just leacking there.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 252110
2015-11-05 00:25:03 +00:00
Teresa Johnson
f72278f051 Clang format a few prior patches (NFC)
I had clang formatted my earlier patches using the wrong style.
Reformatted with the LLVM style.

llvm-svn: 251812
2015-11-02 18:02:11 +00:00
Mehdi Amini
5d303285b9 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>
llvm-svn: 251325
2015-10-26 18:37:00 +00:00
Teresa Johnson
3da931f87a Pass FunctionInfoIndex by reference to WriteFunctionSummaryToFile (NFC)
Implemented suggestion by dblakie in review for r250704.

llvm-svn: 250723
2015-10-19 19:06:06 +00:00
Duncan P. N. Exon Smith
584af871cc BitcodeWriter: Stop using implicit ilist iterator conversion, NFC
Now LLVMBitWriter compiles without implicit ilist iterator conversions.

In these cases, the cleanest thing was to switch to range-based for
loops.  Since there wasn't much noise I converted sub-loops and parent
loops as a drive-by.

llvm-svn: 250144
2015-10-13 03:26:19 +00:00
Teresa Johnson
ca6b64ff04 Fix combined function index abbrev (NFC)
Removed an unused abbrev op in the VST_CODE_COMBINED_FNENTRY abbrev.

I noticed while writing/testing an array string dumper for
llvm-bcanalyze that the combined function's VST entry abbrevs contained
an old field that I am not using. Everything was working fine since the
bitcode writer and reader were in sync on how the record fields were
actually being set up and interpreted.

llvm-svn: 249691
2015-10-08 13:52:56 +00:00
Teresa Johnson
403a787e03 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

llvm-svn: 249270
2015-10-04 14:33:43 +00:00
Sanjoy Das
b513a9fa4f [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

llvm-svn: 248551
2015-09-24 23:34:52 +00:00
David Blaikie
6a51dbdb3c [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.

llvm-svn: 247952
2015-09-17 22:18:59 +00:00
Teresa Johnson
ff642b9b84 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

llvm-svn: 247927
2015-09-17 20:12:00 +00:00
Teresa Johnson
2e98d57ad4 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.

llvm-svn: 247898
2015-09-17 16:19:10 +00:00
Teresa Johnson
b77b1f8a0c 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

llvm-svn: 247894
2015-09-17 15:52:30 +00:00
Teresa Johnson
c01e4cbccc Refactor string encoding checks in BitcodeWriter (NFC)
llvm-svn: 247891
2015-09-17 14:37:35 +00:00
Joseph Tremoulet
9ce71f76b9 [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

llvm-svn: 246751
2015-09-03 09:09:43 +00:00
Joseph Tremoulet
8220bcc570 [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

llvm-svn: 245797
2015-08-23 00:26:33 +00:00
David Majnemer
0bc0eef71c [IR] Give catchret an optional 'return value' operand
Some personality routines require funclet exit points to be clearly
marked, this is done by producing a token at the funclet pad and
consuming it at the corresponding ret instruction.  CleanupReturnInst
already had a spot for this operand but CatchReturnInst did not.
Other personality routines don't need to use this which is why it has
been made optional.

llvm-svn: 245149
2015-08-15 02:46:08 +00:00
David Majnemer
b611e3f50e [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

llvm-svn: 245029
2015-08-14 05:09:07 +00:00
Yaron Keren
001e2e4228 Rangify for loop, NFC.
llvm-svn: 244434
2015-08-10 07:04:29 +00:00
Duncan P. N. Exon Smith
55ca964e94 DI: Disallow uniquable DICompileUnits
Since r241097, `DIBuilder` has only created distinct `DICompileUnit`s.
The backend is liable to start relying on that (if it hasn't already),
so make uniquable `DICompileUnit`s illegal and automatically upgrade old
bitcode.  This is a nice cleanup, since we can remove an unnecessary
`DenseSet` (and the associated uniquing info) from `LLVMContextImpl`.

Almost all the testcases were updated with this script:

    git grep -e '= !DICompileUnit' -l -- test |
    grep -v test/Bitcode |
    xargs sed -i '' -e 's,= !DICompileUnit,= distinct !DICompileUnit,'

I imagine something similar should work for out-of-tree testcases.

llvm-svn: 243885
2015-08-03 17:26:41 +00:00
Duncan P. N. Exon Smith
ed013cd221 DI: Remove DW_TAG_arg_variable and DW_TAG_auto_variable
Remove the fake `DW_TAG_auto_variable` and `DW_TAG_arg_variable` tags,
using `DW_TAG_variable` in their place Stop exposing the `tag:` field at
all in the assembly format for `DILocalVariable`.

Most of the testcase updates were generated by the following sed script:

    find test/ -name "*.ll" -o -name "*.mir" |
    xargs grep -l 'DILocalVariable' |
    xargs sed -i '' \
      -e 's/tag: DW_TAG_arg_variable, //' \
      -e 's/tag: DW_TAG_auto_variable, //'

There were only a handful of tests in `test/Assembly` that I needed to
update by hand.

(Note: a follow-up could change `DILocalVariable::DILocalVariable()` to
set the tag to `DW_TAG_formal_parameter` instead of `DW_TAG_variable`
(as appropriate), instead of having that logic magically in the backend
in `DbgVariable`.  I've added a FIXME to that effect.)

llvm-svn: 243774
2015-07-31 18:58:39 +00:00
David Majnemer
654e130b6e 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

llvm-svn: 243766
2015-07-31 17:58:14 +00:00
Bob Wilson
043ee65ef3 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.

llvm-svn: 243379
2015-07-28 04:05:45 +00:00
Igor Laevsky
39d662f7ba 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

llvm-svn: 241979
2015-07-11 10:30:36 +00:00
James Molloy
88eb535b2d Add support for fast-math flags to the FCmp instruction.
FCmp behaves a lot like a floating-point binary operator in many ways,
and can benefit from fast-math information. Flags such as nsz and nnan
can affect if this fcmp (in combination with a select) can be treated
as a fminnum/fmaxnum operation.

This adds backwards-compatible bitcode support, IR parsing and writing,
LangRef changes and IRBuilder changes. I'll need to audit InstSimplify
and InstCombine in a followup to find places where flags should be
copied.

llvm-svn: 241901
2015-07-10 12:52:00 +00:00
David Majnemer
db82d2f338 Revert the new EH instructions
This reverts commits r241888-r241891, I didn't mean to commit them.

llvm-svn: 241893
2015-07-10 07:15:17 +00:00
David Majnemer
ae2ffc8a8c 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

llvm-svn: 241888
2015-07-10 07:00:44 +00:00
Adrian Prantl
ab1243fe6c 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

llvm-svn: 241017
2015-06-29 23:03:47 +00:00
Pete Cooper
125ad17fed Use foreach loop over constant operands. NFC.
A number of places had explicit loops over Constant::operands().
Just use foreach loops where possible.

llvm-svn: 240694
2015-06-25 20:51:38 +00:00
Benjamin Kramer
5014f40fa6 [Bitcode] Replace hand-coded little endian handling with Endian.h functions.
No functional change intended.

llvm-svn: 239944
2015-06-17 20:55:30 +00:00
David Majnemer
7fddeccb8b 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

llvm-svn: 239940
2015-06-17 20:52:32 +00:00
Peter Collingbourne
82437bf7a5 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

llvm-svn: 239761
2015-06-15 21:07:11 +00:00