Commit Graph

477 Commits

Author SHA1 Message Date
Duncan P. N. Exon Smith
fb7514fccb IR: Allow 16-bits for column info
Raise the limit for column information from 8 bits to 16 bits.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226291 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-16 17:33:08 +00:00
Duncan P. N. Exon Smith
3b0fe4ec0a AsmParser/Bitcode: Add support for MDLocation
This adds assembly and bitcode support for `MDLocation`.  The assembly
side is rather big, since this is the first `MDNode` subclass (that
isn't `MDTuple`).  Part of PR21433.

(If you're wondering where the mountains of testcase updates are, we
don't need them until I update `DILocation` and `DebugLoc` to actually
use this class.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225830 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 21:10:44 +00:00
Duncan P. N. Exon Smith
0c51e0a826 AsmParser: Use subclass API instead of MDNode wrappers, NFC
Use subclass API instead of the wrappers in `MDNode` in the assembly
parser.  This will make the code easier to follow once we have multiple
subclasses.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225711 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 22:27:39 +00:00
Duncan P. N. Exon Smith
e390a8e7ab AsmParser: Factor duplicated code into ParseMDNode(), NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225710 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 22:26:48 +00:00
Duncan P. N. Exon Smith
9e9479148f AsmParser: Reorder ParseMetadata() logic, NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225709 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 22:24:50 +00:00
Duncan P. N. Exon Smith
9460ae45a6 AsmParser: Simplify ParseMDTuple(), NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225708 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 22:23:04 +00:00
Duncan P. N. Exon Smith
9e8d3bc46a AsmParser: ParseMDNode() => ParseMDTuple(), NFC
This isn't parsing arbitrary subclasses of `MDNode`, just `MDTuple`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225702 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 21:23:11 +00:00
Duncan P. N. Exon Smith
023f8e4be7 AsmParser: Remove unused version of ParseMDNodeID()
Merge the two versions of `ParseMDNodeID()` now that no one needs
special forward references.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225699 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 21:14:38 +00:00
Duncan P. N. Exon Smith
d0517feb77 AsmParser: Use normal references for metadata attachments, NFC
Remove special parsing logic for metadata attachments.  Now that
`DebugLoc` is stored normally (since the metadata/value split), we don't
need this special forward referencing logic.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225698 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 21:13:09 +00:00
Duncan P. N. Exon Smith
ae9e15f914 IR: Split GenericMDNode into MDTuple and UniquableMDNode
Split `GenericMDNode` into two classes (with more descriptive names).

  - `UniquableMDNode` will be a common subclass for `MDNode`s that are
    sometimes uniqued like constants, and sometimes 'distinct'.

    This class gets the (short-lived) RAUW support and related API.

  - `MDTuple` is the basic tuple that has always been returned by
    `MDNode::get()`.  This is as opposed to more specific nodes to be
    added soon, which have additional fields, custom assembly syntax,
    and extra semantics.

    This class gets the hash-related logic, since other sublcasses of
    `UniquableMDNode` may need to hash based on other fields.

To keep this diff from getting too big, I've added casts to `MDTuple`
that won't really scale as new subclasses of `UniquableMDNode` are
added, but I'll clean those up incrementally.

(No functionality change intended.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225682 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 20:09:34 +00:00
Duncan P. N. Exon Smith
f416d72973 IR: Add 'distinct' MDNodes to bitcode and assembly
Propagate whether `MDNode`s are 'distinct' through the other types of IR
(assembly and bitcode).  This adds the `distinct` keyword to assembly.

Currently, no one actually calls `MDNode::getDistinct()`, so these nodes
only get created for:

  - self-references, which are never uniqued, and
  - nodes whose operands are replaced that hit a uniquing collision.

The concept of distinct nodes is still not quite first-class, since
distinct-ness doesn't yet survive across `MapMetadata()`.

Part of PR22111.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225474 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-08 22:38:29 +00:00
Rafael Espindola
f907a26bc2 Change the .ll syntax for comdats and add a syntactic sugar.
In order to make comdats always explicit in the IR, we decided to make
the syntax a bit more compact for the case of a GlobalObject in a
comdat with the same name.

Just dropping the $name causes problems for

@foo = globabl i32 0, comdat
$bar = comdat ...

and

declare void @foo() comdat
$bar = comdat ...

So the syntax is changed to

@g1 = globabl i32 0, comdat($c1)
@g2 = globabl i32 0, comdat

and

declare void @foo() comdat($c1)
declare void @foo() comdat

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225302 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-06 22:55:16 +00:00
Duncan P. N. Exon Smith
1ef70ff39b IR: Make metadata typeless in assembly
Now that `Metadata` is typeless, reflect that in the assembly.  These
are the matching assembly changes for the metadata/value split in
r223802.

  - Only use the `metadata` type when referencing metadata from a call
    intrinsic -- i.e., only when it's used as a `Value`.

  - Stop pretending that `ValueAsMetadata` is wrapped in an `MDNode`
    when referencing it from call intrinsics.

So, assembly like this:

    define @foo(i32 %v) {
      call void @llvm.foo(metadata !{i32 %v}, metadata !0)
      call void @llvm.foo(metadata !{i32 7}, metadata !0)
      call void @llvm.foo(metadata !1, metadata !0)
      call void @llvm.foo(metadata !3, metadata !0)
      call void @llvm.foo(metadata !{metadata !3}, metadata !0)
      ret void, !bar !2
    }
    !0 = metadata !{metadata !2}
    !1 = metadata !{i32* @global}
    !2 = metadata !{metadata !3}
    !3 = metadata !{}

turns into this:

    define @foo(i32 %v) {
      call void @llvm.foo(metadata i32 %v, metadata !0)
      call void @llvm.foo(metadata i32 7, metadata !0)
      call void @llvm.foo(metadata i32* @global, metadata !0)
      call void @llvm.foo(metadata !3, metadata !0)
      call void @llvm.foo(metadata !{!3}, metadata !0)
      ret void, !bar !2
    }
    !0 = !{!2}
    !1 = !{i32* @global}
    !2 = !{!3}
    !3 = !{}

I wrote an upgrade script that handled almost all of the tests in llvm
and many of the tests in cfe (even handling many `CHECK` lines).  I've
attached it (or will attach it in a moment if you're speedy) to PR21532
to help everyone update their out-of-tree testcases.

This is part of PR21532.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224257 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-15 19:07:53 +00:00
David Majnemer
054eb6cba6 AsmParser: Don't crash on an ill-formed MDNodeVector
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224056 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-11 20:51:54 +00:00
David Majnemer
ff3fa3dc00 AsmParser: Don't crash on an ill-formed MDNodeVector
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224053 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-11 20:44:09 +00:00
Duncan P. N. Exon Smith
dad20b2ae2 IR: Split Metadata from Value
Split `Metadata` away from the `Value` class hierarchy, as part of
PR21532.  Assembly and bitcode changes are in the wings, but this is the
bulk of the change for the IR C++ API.

I have a follow-up patch prepared for `clang`.  If this breaks other
sub-projects, I apologize in advance :(.  Help me compile it on Darwin
I'll try to fix it.  FWIW, the errors should be easy to fix, so it may
be simpler to just fix it yourself.

This breaks the build for all metadata-related code that's out-of-tree.
Rest assured the transition is mechanical and the compiler should catch
almost all of the problems.

Here's a quick guide for updating your code:

  - `Metadata` is the root of a class hierarchy with three main classes:
    `MDNode`, `MDString`, and `ValueAsMetadata`.  It is distinct from
    the `Value` class hierarchy.  It is typeless -- i.e., instances do
    *not* have a `Type`.

  - `MDNode`'s operands are all `Metadata *` (instead of `Value *`).

  - `TrackingVH<MDNode>` and `WeakVH` referring to metadata can be
    replaced with `TrackingMDNodeRef` and `TrackingMDRef`, respectively.

    If you're referring solely to resolved `MDNode`s -- post graph
    construction -- just use `MDNode*`.

  - `MDNode` (and the rest of `Metadata`) have only limited support for
    `replaceAllUsesWith()`.

    As long as an `MDNode` is pointing at a forward declaration -- the
    result of `MDNode::getTemporary()` -- it maintains a side map of its
    uses and can RAUW itself.  Once the forward declarations are fully
    resolved RAUW support is dropped on the ground.  This means that
    uniquing collisions on changing operands cause nodes to become
    "distinct".  (This already happened fairly commonly, whenever an
    operand went to null.)

    If you're constructing complex (non self-reference) `MDNode` cycles,
    you need to call `MDNode::resolveCycles()` on each node (or on a
    top-level node that somehow references all of the nodes).  Also,
    don't do that.  Metadata cycles (and the RAUW machinery needed to
    construct them) are expensive.

  - An `MDNode` can only refer to a `Constant` through a bridge called
    `ConstantAsMetadata` (one of the subclasses of `ValueAsMetadata`).

    As a side effect, accessing an operand of an `MDNode` that is known
    to be, e.g., `ConstantInt`, takes three steps: first, cast from
    `Metadata` to `ConstantAsMetadata`; second, extract the `Constant`;
    third, cast down to `ConstantInt`.

    The eventual goal is to introduce `MDInt`/`MDFloat`/etc. and have
    metadata schema owners transition away from using `Constant`s when
    the type isn't important (and they don't care about referring to
    `GlobalValue`s).

    In the meantime, I've added transitional API to the `mdconst`
    namespace that matches semantics with the old code, in order to
    avoid adding the error-prone three-step equivalent to every call
    site.  If your old code was:

        MDNode *N = foo();
        bar(isa             <ConstantInt>(N->getOperand(0)));
        baz(cast            <ConstantInt>(N->getOperand(1)));
        bak(cast_or_null    <ConstantInt>(N->getOperand(2)));
        bat(dyn_cast        <ConstantInt>(N->getOperand(3)));
        bay(dyn_cast_or_null<ConstantInt>(N->getOperand(4)));

    you can trivially match its semantics with:

        MDNode *N = foo();
        bar(mdconst::hasa               <ConstantInt>(N->getOperand(0)));
        baz(mdconst::extract            <ConstantInt>(N->getOperand(1)));
        bak(mdconst::extract_or_null    <ConstantInt>(N->getOperand(2)));
        bat(mdconst::dyn_extract        <ConstantInt>(N->getOperand(3)));
        bay(mdconst::dyn_extract_or_null<ConstantInt>(N->getOperand(4)));

    and when you transition your metadata schema to `MDInt`:

        MDNode *N = foo();
        bar(isa             <MDInt>(N->getOperand(0)));
        baz(cast            <MDInt>(N->getOperand(1)));
        bak(cast_or_null    <MDInt>(N->getOperand(2)));
        bat(dyn_cast        <MDInt>(N->getOperand(3)));
        bay(dyn_cast_or_null<MDInt>(N->getOperand(4)));

  - A `CallInst` -- specifically, intrinsic instructions -- can refer to
    metadata through a bridge called `MetadataAsValue`.  This is a
    subclass of `Value` where `getType()->isMetadataTy()`.

    `MetadataAsValue` is the *only* class that can legally refer to a
    `LocalAsMetadata`, which is a bridged form of non-`Constant` values
    like `Argument` and `Instruction`.  It can also refer to any other
    `Metadata` subclass.

(I'll break all your testcases in a follow-up commit, when I propagate
this change to assembly.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223802 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-09 18:38:53 +00:00
David Majnemer
db7b69e3a6 AsmParser: Don't crash on malformed attribute groups
This fixes PR21785.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223801 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-09 18:33:57 +00:00
David Majnemer
2959baffd2 Reland r223754
The commit is identical except a reference to `GV' should have been to
`GVal'.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223756 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-09 05:56:09 +00:00
David Majnemer
ebddbe8ba6 Revert "AsmParser: Reject invalid mismatch between forward ref and def"
This reverts commit r223754.  I've upset the buildbots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223755 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-09 05:50:11 +00:00
David Majnemer
82258b45e4 AsmParser: Reject invalid mismatch between forward ref and def
Don't assume that the forward referenced entity was of the same
global-kind as the new entity.

This fixes PR21779.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223754 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-09 05:43:56 +00:00
Duncan P. N. Exon Smith
a77df65a84 IR: Add missing tests for function-local metadata
Add assembly and bitcode tests that I neglected to add in r223564 (IR:
Disallow complicated function-local metadata) and r223574 (IR: Disallow
function-local metadata attachments).

Found a couple of bugs:

  - The error message for function-local attachments gave the wrong line
    number -- it indicated the next token (typically on the next line)
    instead of the token that started the attachment.  Fixed.

  - Metadata arguments of the form `!{i32 0, i32 %v}` (or with the
    arguments reversed) fired an assertion in `ValueEnumerator` in LLVM
    v3.5, so I suppose this never really worked.  I suppose this was
    "fixed" by r223564.

(Thanks to dblaikie for pointing out my omission.)

Part of PR21532.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223616 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-07 17:56:16 +00:00
Duncan P. N. Exon Smith
09ba28c27c IR: Disallow function-local metadata attachments
Metadata attachments to instructions cannot be function-local.

This is part of PR21532.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223574 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-06 02:29:44 +00:00
Duncan P. N. Exon Smith
30596886ed IR: Disallow complicated function-local metadata
Disallow complex types of function-local metadata.  The only valid
function-local metadata is an `MDNode` whose sole argument is a
non-metadata function-local value.

Part of PR21532.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223564 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-06 01:26:49 +00:00
Peter Collingbourne
bb660fc192 Prologue support
Patch by Ben Gamari!

This redefines the `prefix` attribute introduced previously and
introduces a `prologue` attribute.  There are a two primary usecases
that these attributes aim to serve,

  1. Function prologue sigils

  2. Function hot-patching: Enable the user to insert `nop` operations
     at the beginning of the function which can later be safely replaced
     with a call to some instrumentation facility

  3. Runtime metadata: Allow a compiler to insert data for use by the
     runtime during execution. GHC is one example of a compiler that
     needs this functionality for its tables-next-to-code functionality.

Previously `prefix` served cases (1) and (2) quite well by allowing the user
to introduce arbitrary data at the entrypoint but before the function
body. Case (3), however, was poorly handled by this approach as it
required that prefix data was valid executable code.

Here we redefine the notion of prefix data to instead be data which
occurs immediately before the function entrypoint (i.e. the symbol
address). Since prefix data now occurs before the function entrypoint,
there is no need for the data to be valid code.

The previous notion of prefix data now goes under the name "prologue
data" to emphasize its duality with the function epilogue.

The intention here is to handle cases (1) and (2) with prologue data and
case (3) with prefix data.

References
----------

This idea arose out of discussions[1] with Reid Kleckner in response to a
proposal to introduce the notion of symbol offsets to enable handling of
case (3).

[1] http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-May/073235.html

Test Plan: testsuite

Differential Revision: http://reviews.llvm.org/D6454

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223189 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-03 02:08:38 +00:00
Reid Kleckner
03c735b42c Parse 'ghccc' in .ll files as the GHC convention (cc 10)
Previously we just used "cc 10" in the .ll files, but that isn't very
human readable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223076 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-01 21:04:44 +00:00
David Blaikie
5401ba7099 Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool>
This is to be consistent with StringSet and ultimately with the standard
library's associative container insert function.

This lead to updating SmallSet::insert to return pair<iterator, bool>,
and then to update SmallPtrSet::insert to return pair<iterator, bool>,
and then to update all the existing users of those functions...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222334 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-19 07:49:26 +00:00
Reid Kleckner
d5de327da0 X86: Implement the vectorcall calling convention
This is a Microsoft calling convention that supports both x86 and x86_64
subtargets. It passes vector and floating point arguments in XMM0-XMM5,
and passes them indirectly once they are consumed.

Homogenous vector aggregates of up to four elements can be passed in
sequential vector registers, but this part is not implemented in LLVM
and will be handled in Clang.

On 32-bit x86, it is similar to fastcall in that it uses ecx:edx as
integer register parameters and is callee cleanup. On x86_64, it
delegates to the normal win64 calling convention.

Reviewers: majnemer

Differential Revision: http://reviews.llvm.org/D5943

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220745 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-28 01:29:26 +00:00
Alexey Samsonov
5e4558e5a8 Make CallingConv::ID an alias of "unsigned".
Summary:
Make CallingConv::ID a plain unsigned instead of enum with a
fixed set of valus. LLVM IR allows arbitraty calling conventions (you are
free to write cc12345), and loading them as enum is an undefined
behavior. This was reported by UBSan.

Test Plan: llvm regression test suite

Reviewers: nicholas

Reviewed By: nicholas

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5248

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217529 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-10 18:00:17 +00:00
Robin Morisset
217b38e19a Fix typos in comments, NFC
Summary: Just fixing comments, no functional change.

Test Plan: N/A

Reviewers: jfb

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D5130

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216784 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-29 21:53:01 +00:00
Reid Kleckner
44b3a0b411 Declare that musttail calls in variadic functions forward the ellipsis
Summary:
There is no functionality change here except in the way we assemble and
dump musttail calls in variadic functions. There's really no need to
separate out the bits for musttail and "is forwarding varargs" on call
instructions. A musttail call by definition has to forward the ellipsis
or it would fail verification.

Reviewers: chandlerc, nlewycky

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D4892

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216423 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-26 00:33:28 +00:00
Duncan P. N. Exon Smith
7838818ad7 IR: Implement uselistorder assembly directives
Implement `uselistorder` and `uselistorder_bb` assembly directives,
which allow the use-list order to be recovered when round-tripping to
assembly.

This is the bulk of PR20515.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216025 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 21:30:15 +00:00
Duncan P. N. Exon Smith
165897841b LLParser: Handle BlockAddresses on-the-fly
Previously all `blockaddress()` constants were treated as forward
references.  They were resolved twice:  once at the end of the function
in question, and again at the end of the module.  Furthermore, if the
same blockaddress was referenced N times, the parser created N distinct
`GlobalVariable`s (one for each reference).

Instead, resolve all block addresses at the beginning of the function,
creating the standard `BasicBlock` forward references used for all other
basic block references.  After the function, all references can be
resolved immediately.  To check for the condition of parsing block
addresses from within the same function, I created a reference to the
current per-function-state in `BlockAddressPFS`.

Also, create only one forward-reference per basic block.  Because
forward references to block addresses are rare, the data structure here
shouldn't matter.  If somehow it does someday, this can be pretty easily
changed to a `DenseMap<std::pair<ValID, ValID>, GV>`.

This is part of PR20515.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215952 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 00:13:19 +00:00
Duncan P. N. Exon Smith
b72118fb52 Remove dead code in condition
Whether or not it's appropriate, labels have been first-class types
since r51511.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214908 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-05 18:22:58 +00:00
Rafael Espindola
d57120551f Use "weak alias" instead of "alias weak"
Before this patch we had

@a = weak global ...
but
@b = alias weak ...

The patch changes aliases to look more like global variables.

Looking at some really old code suggests that the reason was that the old
bison based parser had a reduction for alias linkages and another one for
global variable linkages. Putting the alias first avoided the reduce/reduce
conflict.

The days of the old .ll parser are long gone. The new one parses just "linkage"
and a later check is responsible for deciding if a linkage is valid in a
given context.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214355 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-30 22:51:54 +00:00
Saleem Abdulrasool
e2c63ff3c9 AsmParser: remove deprecated LLIR support
linker_private and linker_private_weak were deprecated in 3.5.  Remove support
for them now that the 3.5 branch has been created.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213777 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-23 18:09:31 +00:00
Hal Finkel
11af4b49b2 Add a dereferenceable attribute
This attribute indicates that the parameter or return pointer is
dereferenceable. Practically speaking, loads from such a pointer within the
associated byte range are safe to speculatively execute. Such pointer
parameters are common in source languages (C++ references, for example).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213385 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-18 15:51:28 +00:00
David Majnemer
c8a1169c93 IR: Add COMDATs to the IR
This new IR facility allows us to represent the object-file semantic of
a COMDAT group.

COMDATs allow us to tie together sections and make the inclusion of one
dependent on another. This is required to implement features like MS
ABI VFTables and optimizing away certain kinds of initialization in C++.

This functionality is only representable in COFF and ELF, Mach-O has no
similar mechanism.

Differential Revision: http://reviews.llvm.org/D4178

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211920 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-27 18:19:56 +00:00
Alp Toker
8dd8d5c2b2 Revert "Introduce a string_ostream string builder facilty"
Temporarily back out commits r211749, r211752 and r211754.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211814 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-26 22:52:05 +00:00
Alp Toker
2559070422 Introduce a string_ostream string builder facilty
string_ostream is a safe and efficient string builder that combines opaque
stack storage with a built-in ostream interface.

small_string_ostream<bytes> additionally permits an explicit stack storage size
other than the default 128 bytes to be provided. Beyond that, storage is
transferred to the heap.

This convenient class can be used in most places an
std::string+raw_string_ostream pair or SmallString<>+raw_svector_ostream pair
would previously have been used, in order to guarantee consistent access
without byte truncation.

The patch also converts much of LLVM to use the new facility. These changes
include several probable bug fixes for truncated output, a programming error
that's no longer possible with the new interface.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211749 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-26 00:00:48 +00:00
Eli Bendersky
bb167336b3 Rename loop unrolling and loop vectorizer metadata to have a common prefix.
[LLVM part]

These patches rename the loop unrolling and loop vectorizer metadata
such that they have a common 'llvm.loop.' prefix.  Metadata name
changes:

llvm.vectorizer.* => llvm.loop.vectorizer.*
llvm.loopunroll.* => llvm.loop.unroll.*

This was a suggestion from an earlier review
(http://reviews.llvm.org/D4090) which added the loop unrolling
metadata. 

Patch by Mark Heffernan.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211710 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-25 15:41:00 +00:00
Tim Northover
8f2a85e099 IR: add "cmpxchg weak" variant to support permitted failure.
This commit adds a weak variant of the cmpxchg operation, as described
in C++11. A cmpxchg instruction with this modifier is permitted to
fail to store, even if the comparison indicated it should.

As a result, cmpxchg instructions must return a flag indicating
success in addition to their original iN value loaded. Thus, for
uniformity *all* cmpxchg instructions now return "{ iN, i1 }". The
second flag is 1 when the store succeeded.

At the DAG level, a new ATOMIC_CMP_SWAP_WITH_SUCCESS node has been
added as the natural representation for the new cmpxchg instructions.
It is a strong cmpxchg.

By default this gets Expanded to the existing ATOMIC_CMP_SWAP during
Legalization, so existing backends should see no change in behaviour.
If they wish to deal with the enhanced node instead, they can call
setOperationAction on it. Beware: as a node with 2 results, it cannot
be selected from TableGen.

Currently, no use is made of the extra information provided in this
patch. Test updates are almost entirely adapting the input IR to the
new scheme.

Summary for out of tree users:
------------------------------

+ Legacy Bitcode files are upgraded during read.
+ Legacy assembly IR files will be invalid.
+ Front-ends must adapt to different type for "cmpxchg".
+ Backends should be unaffected by default.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210903 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-13 14:24:07 +00:00
Rafael Espindola
6fd1b8ee48 Allow aliases to be unnamed_addr.
Alias with unnamed_addr were in a strange state. It is stored in GlobalValue,
the language reference talks about "unnamed_addr aliases" but the verifier
was rejecting them.

It seems natural to allow unnamed_addr in aliases:

* It is a property of how it is accessed, not of the data itself.
* It is perfectly possible to write code that depends on the address
of an alias.

This patch then makes unname_addr legal for aliases. One side effect is that
the syntax changes for a corner case: In globals, unnamed_addr is now printed
before the address space.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210302 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-06 01:20:28 +00:00
Tom Roeder
5d0f7af3dc Add a new attribute called 'jumptable' that creates jump-instruction tables for functions marked with this attribute.
It includes a pass that rewrites all indirect calls to jumptable functions to pass through these tables.

This also adds backend support for generating the jump-instruction tables on ARM and X86.
Note that since the jumptable attribute creates a second function pointer for a
function, any function marked with jumptable must also be marked with unnamed_addr.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210280 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-05 19:29:43 +00:00
Rafael Espindola
dcac1523c0 Clauses in a landingpad are always Constant. Use a stricter type.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210203 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-04 18:51:31 +00:00
Rafael Espindola
f35a459723 Update comments to match reality.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210125 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-03 20:25:26 +00:00
Rafael Espindola
8c2d2770e2 Fix a small bug in the parsing of anonymous globals.
It was able to parse

hidden dllexport global i32 42

but not

dllexport global i32 42

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210121 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-03 20:07:32 +00:00
Rafael Espindola
85422f7da3 Simplify the parsing of unnamed globals. No functionality changed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210120 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-03 20:00:20 +00:00
Rafael Espindola
b20541c5fb Update comment. This should have been part of r210062.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210119 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-03 19:38:37 +00:00
Rafael Espindola
2d21b25393 Allow alias to point to an arbitrary ConstantExpr.
This  patch changes GlobalAlias to point to an arbitrary ConstantExpr and it is
up to MC (or the system assembler) to decide if that expression is valid or not.

This reduces our ability to diagnose invalid uses and how early we can spot
them, but it also lets us do things like

@test5 = alias inttoptr(i32 sub (i32 ptrtoint (i32* @test2 to i32),
                                 i32 ptrtoint (i32* @bar to i32)) to i32*)

An important implication of this patch is that the notion of aliased global
doesn't exist any more. The alias has to encode the information needed to
access it in its metadata (linkage, visibility, type, etc).

Another consequence to notice is that getSection has to return a "const char *".
It could return a NullTerminatedStringRef if there was such a thing, but when
that was proposed the decision was to just uses "const char*" for that.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210062 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-03 02:41:57 +00:00
Rafael Espindola
665d42accf [pr19844] Add thread local mode to aliases.
This matches gcc's behavior. It also seems natural given that aliases
contain other properties that govern how it is accessed (linkage,
visibility, dll storage).

Clang still has to be updated to expose this feature to C.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209759 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-28 18:15:43 +00:00