Commit Graph

82 Commits

Author SHA1 Message Date
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
02a8d1bcfd IR: Stop printing 'metadata' in Metadata::print()
Stop printing `metadata` in `Metadata::print()` and
`Metadata::printAsOperand()`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224327 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-16 07:40:31 +00:00
Duncan P. N. Exon Smith
2ebd1efc08 IR: Make MDNode::dump() useful by adding addresses
It's horrible to inspect `MDNode`s in a debugger.  All of their operands
that are `MDNode`s get dumped as `<badref>`, since we can't assign
metadata slots in the context of a `Metadata::dump()`.  (Why not?  Why
not assign numbers lazily?  Because then each time you called `dump()`,
a given `MDNode` could have a different lazily assigned number.)

Fortunately, the C memory model gives us perfectly good identifiers for
`MDNode`.  Add pointer addresses to the dumps, transforming this:

    (lldb) e N->dump()
    !{i32 662302, i32 26, <badref>, null}

    (lldb) e ((MDNode*)N->getOperand(2))->dump()
    !{i32 4, !"foo"}

into:

    (lldb) e N->dump()
    !{i32 662302, i32 26, <0x100706ee0>, null}

    (lldb) e ((MDNode*)0x100706ee0)->dump()
    !{i32 4, !"foo"}

and this:

    (lldb) e N->dump()
    0x101200248 = !{<badref>, <badref>, <badref>, <badref>, <badref>}

    (lldb) e N->getOperand(0)
    (const llvm::MDOperand) $0 = {
      MD = 0x00000001012004e0
    }
    (lldb) e N->getOperand(1)
    (const llvm::MDOperand) $1 = {
      MD = 0x00000001012004e0
    }
    (lldb) e N->getOperand(2)
    (const llvm::MDOperand) $2 = {
      MD = 0x0000000101200058
    }
    (lldb) e N->getOperand(3)
    (const llvm::MDOperand) $3 = {
      MD = 0x00000001012004e0
    }
    (lldb) e N->getOperand(4)
    (const llvm::MDOperand) $4 = {
      MD = 0x0000000101200058
    }
    (lldb) e ((MDNode*)0x00000001012004e0)->dump()
    !{}

    (lldb) e ((MDNode*)0x0000000101200058)->dump()
    !{null}

into:

    (lldb) e N->dump()
    !{<0x1012004e0>, <0x1012004e0>, <0x101200058>, <0x1012004e0>, <0x101200058>}

    (lldb) e ((MDNode*)0x1012004e0)->dump()
    !{}

    (lldb) e ((MDNode*)0x101200058)->dump()
    !{null}

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224325 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-16 07:09:37 +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
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
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
Duncan P. N. Exon Smith
5bf8ade9d0 Revert "IR: MDNode => Value"
Instead, we're going to separate metadata from the Value hierarchy.  See
PR21532.

This reverts commit r221375.
This reverts commit r221373.
This reverts commit r221359.
This reverts commit r221167.
This reverts commit r221027.
This reverts commit r221024.
This reverts commit r221023.
This reverts commit r220995.
This reverts commit r220994.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221711 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 21:30:22 +00:00
Duncan P. N. Exon Smith
ee6433511d IR: MDNode => Value: AsmWriter SlotTracker API
Change `SlotTracker::CreateMetadataSlot()` and
`SlotTracker::getMetadataSlot()` to use `Value` instead of `MDNode`.
Part of PR21433.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221373 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-05 17:56:28 +00:00
Duncan P. N. Exon Smith
b2187ede9e IR: MDNode => Value: Instruction::getAllMetadata()
Change `Instruction::getAllMetadata()` to modify a vector of `Value`
instead of `MDNode` and update call sites.  This is part of PR21433.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221027 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-01 00:26:42 +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
Duncan P. N. Exon Smith
83902832de Revert "Revert "DI: Fold constant arguments into a single MDString""
This reverts commit r218918, effectively reapplying r218914 after fixing
an Ocaml bindings test and an Asan crash.  The root cause of the latter
was a tightened-up check in `DILexicalBlock::Verify()`, so I'll file a
PR to investigate who requires the loose check (and why).

Original commit message follows.

--

This patch addresses the first stage of PR17891 by folding constant
arguments together into a single MDString.  Integers are stringified and
a `\0` character is used as a separator.

Part of PR17891.

Note: I've attached my testcases upgrade scripts to the PR.  If I've
just broken your out-of-tree testcases, they might help.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219010 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-03 20:01:09 +00:00
Duncan P. N. Exon Smith
32e192aeb3 Revert "DI: Fold constant arguments into a single MDString"
This reverts commit r218914 while I investigate some bots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218918 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-02 22:15:31 +00:00
Duncan P. N. Exon Smith
0917b70630 DI: Fold constant arguments into a single MDString
This patch addresses the first stage of PR17891 by folding constant
arguments together into a single MDString.  Integers are stringified and
a `\0` character is used as a separator.

Part of PR17891.

Note: I've attached my testcases upgrade scripts to the PR.  If I've
just broken your out-of-tree testcases, they might help.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218914 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-02 21:56:57 +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
Justin Bogner
2925be515b IR: Print a newline when dumping Types
Type::dump() doesn't print a newline, which makes for a poor
experience in a debugger. This looks like it was an ommission
considering Value::dump() two lines above, so I've changed Type to add
a newline as well.

Of the two in-tree callers, one added a newline anyway, and I've
updated the other one to use Type::print instead.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215421 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-12 03:24:59 +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
David Majnemer
c1a6d65d21 IR: Aliases don't belong to an explicit comdat
Aliases inherit their comdat from their aliasee, they don't have an
explicit comdat.

This fixes PR20279.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212732 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-10 16:26:10 +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
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
Richard Trieu
f31ecd3927 Removing an "if (!this)" check from two print methods. The condition will
never be true in a well-defined context.  The checking for null pointers
has been moved into the caller logic so it does not rely on undefined behavior.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210497 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-09 22:53:16 +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
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
Rafael Espindola
27c076ae40 Fix most of PR10367.
This patch changes the design of GlobalAlias so that it doesn't take a
ConstantExpr anymore. It now points directly to a GlobalObject, but its type is
independent of the aliasee type.

To avoid changing all alias related tests in this patches, I kept the common
syntax

@foo = alias i32* @bar

to mean the same as now. The cases that used to use cast now use the more
general syntax

@foo = alias i16, i32* @bar.

Note that GlobalAlias now behaves a bit more like GlobalVariable. We
know that its type is always a pointer, so we omit the '*'.

For the bitcode, a nice surprise is that we were writing both identical types
already, so the format change is minimal. Auto upgrade is handled by looking
through the casts and no new fields are needed for now. New bitcode will
simply have different types for Alias and Aliasee.

One last interesting point in the patch is that replaceAllUsesWith becomes
smart enough to avoid putting a ConstantExpr in the aliasee. This seems better
than checking and updating every caller.

A followup patch will delete getAliasedGlobal now that it is redundant. Another
patch will add support for an explicit offset.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209007 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-16 19:35:39 +00:00
Reid Kleckner
d30c11edde Revert "[ms-cxxabi] Add a new calling convention that swaps 'this' and 'sret'"
This reverts commit r200561.

This calling convention was an attempt to match the MSVC C++ ABI for
methods that return structures by value.  This solution didn't scale,
because it would have required splitting every CC available on Windows
into two: one for methods and one for free functions.

Now that we can put sret on the second arg (r208453), and Clang does
that (r208458), revert this hack.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208459 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-09 22:56:42 +00:00
Nick Lewycky
e584911870 printCustom is only used in PseudoSourceValue, remove it from Value.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208383 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-09 00:49:03 +00:00
Reid Kleckner
710c1a449d Add 'musttail' marker to call instructions
This is similar to the 'tail' marker, except that it guarantees that
tail call optimization will occur.  It also comes with convervative IR
verification rules that ensure that tail call optimization is possible.

Reviewers: nicholas

Differential Revision: http://llvm-reviews.chandlerc.com/D3240

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207143 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-24 20:14:34 +00:00
Rafael Espindola
8b9fe76c0c Remove AssemblyAnnotationWriter from NamedMDNode::print.
No functionality change, this parameter was always set to nullptr.

Patch by Robert Matusewicz!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206972 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-23 12:23:05 +00:00
Nick Lewycky
d63390cba1 Break PseudoSourceValue out of the Value hierarchy. It is now the root of its own tree containing FixedStackPseudoSourceValue (which you can use isa/dyn_cast on) and MipsCallEntry (which you can't). Anything that needs to use either a PseudoSourceValue* and Value* is strongly encouraged to use a MachinePointerInfo instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206255 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-15 07:22:52 +00:00
Craig Topper
ec0f0bc6af [C++11] More 'nullptr' conversion or in some cases just using a boolean check instead of comparing to nullptr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205831 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-09 06:08:46 +00:00
David Blaikie
ec37734d3c Remove unused parameter
Also update a few null pointers in this function to be consistent with
new null pointers being added.

Patch by Robert Matusewicz!

Differential Revision: http://reviews.llvm.org/D3123

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205682 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-05 23:33:25 +00:00
Benjamin Kramer
571832b930 Make some assertions on constant expressions static.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204011 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-15 18:47:07 +00:00
Rafael Espindola
1f21e0dd0d Remove the linker_private and linker_private_weak linkages.
These linkages were introduced some time ago, but it was never very
clear what exactly their semantics were or what they should be used
for. Some investigation found these uses:

* utf-16 strings in clang.
* non-unnamed_addr strings produced by the sanitizers.

It turns out they were just working around a more fundamental problem.
For some sections a MachO linker needs a symbol in order to split the
section into atoms, and llvm had no idea that was the case. I fixed
that in r201700 and it is now safe to use the private linkage. When
the object ends up in a section that requires symbols, llvm will use a
'l' prefix instead of a 'L' prefix and things just work.

With that, these linkages were already dead, but there was a potential
future user in the objc metadata information. I am still looking at
CGObjcMac.cpp, but at this point I am convinced that linker_private
and linker_private_weak are not what they need.

The objc uses are currently split in

* Regular symbols (no '\01' prefix). LLVM already directly provides
whatever semantics they need.
* Uses of a private name (start with "\01L" or "\01l") and private
linkage. We can drop the "\01L" and "\01l" prefixes as soon as llvm
agrees with clang on L being ok or not for a given section. I have two
patches in code review for this.
* Uses of private name and weak linkage.

The last case is the one that one could think would fit one of these
linkages. That is not the case. The semantics are

* the linker will merge these symbol by *name*.
* the linker will hide them in the final DSO.

Given that the merging is done by name, any of the private (or
internal) linkages would be a bad match. They allow llvm to rename the
symbols, and that is really not what we want. From the llvm point of
view, these objects should really be (linkonce|weak)(_odr)?.

For now, just keeping the "\01l" prefix is probably the best for these
symbols. If we one day want to have a more direct support in llvm,
IMHO what we should add is not a linkage, it is just a hidden_symbol
attribute. It would be applicable to multiple linkages. For example,
on weak it would produce the current behavior we have for objc
metadata. On internal, it would be equivalent to private (and we
should then remove private).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203866 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-13 23:18:37 +00:00
Tim Northover
ca396e391e IR: add a second ordering operand to cmpxhg for failure
The syntax for "cmpxchg" should now look something like:

	cmpxchg i32* %addr, i32 42, i32 3 acquire monotonic

where the second ordering argument gives the required semantics in the case
that no exchange takes place. It should be no stronger than the first ordering
constraint and cannot be either "release" or "acq_rel" (since no store will
have taken place).

rdar://problem/15996804

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203559 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-11 10:48:52 +00:00
David Majnemer
39a09d2b7c IR: Change inalloca's grammar a bit
The grammar for LLVM IR is not well specified in any document but seems
to obey the following rules:

 - Attributes which have parenthesized arguments are never preceded by
   commas.  This form of attribute is the only one which ever has
   optional arguments.  However, not all of these attributes support
   optional arguments: 'thread_local' supports an optional argument but
   'addrspace' does not.  Interestingly, 'addrspace' is documented as
   being a "qualifier".  What constitutes a qualifier?  I cannot find a
   definition.

 - Some attributes use a space between the keyword and the value.
   Examples of this form are 'align' and 'section'.  These are always
   preceded by a comma.

 - Otherwise, the attribute has no argument.  These attributes do not
   have a preceding comma.

Sometimes an attribute goes before the instruction, between the
instruction and it's type, or after it's type.  'atomicrmw' has
'volatile' between the instruction and the type while 'call' has 'tail'
preceding the instruction.

With all this in mind, it seems most consistent for 'inalloca' on an
'inalloca' instruction to occur before between the instruction and the
type.  Unlike the current formulation, there would be no preceding
comma.  The combination 'alloca inalloca' doesn't look particularly
appetizing, perhaps a better spelling of 'inalloca' is down the road.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203376 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-09 06:41:58 +00:00
Chandler Carruth
f4ec8bfaec [Layering] Move DebugInfo.h into the IR library where its implementation
already lives.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203046 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-06 00:46:21 +00:00
Chandler Carruth
03e36d752c [Modules] Move CFG.h to the IR library as it defines graph traits over
IR types.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202827 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-04 11:45:46 +00:00
Rafael Espindola
aab87fe0ec Store a DataLayout in Module.
Now that DataLayout is not a pass, store one in Module.

Since the C API expects to be able to get a char* to the datalayout description,
we have to keep a std::string somewhere. This patch keeps it in Module and also
uses it to represent modules without a DataLayout.

Once DataLayout is mandatory, we should probably move the string to DataLayout
itself since it won't be necessary anymore to represent the special case of a
module without a DataLayout.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202190 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-25 20:01:08 +00:00
Reid Kleckner
65c98b9da4 [ms-cxxabi] Add a new calling convention that swaps 'this' and 'sret'
MSVC always places the 'this' parameter for a method first.  The
implicit 'sret' pointer for methods always comes second.  We already
implement this for __thiscall by putting sret parameters on the stack,
but __cdecl methods require putting both parameters on the stack in
opposite order.

Using a special calling convention allows frontends to keep the sret
parameter first, which avoids breaking lots of assumptions in LLVM and
Clang.

Fixes PR15768 with the corresponding change in Clang.

Reviewers: ributzka, majnemer

Differential Revision: http://llvm-reviews.chandlerc.com/D2663

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200561 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-31 17:41:22 +00:00
Reid Kleckner
1d1670227b Fix llvm-dis to print the inalloca bit on allocas.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200059 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 01:24:06 +00:00
Juergen Ributzka
ceaf829339 Add two new calling conventions for runtime calls
This patch adds two new target-independent calling conventions for runtime
calls - PreserveMost and PreserveAll.
The target-specific implementation for X86-64 is defined as following:
  - Arguments are passed as for the default C calling convention
  - The same applies for the return value(s)
  - PreserveMost preserves all GPRs - except R11
  - PreserveAll preserves all GPRs and all XMMs/YMMs - except R11

Reviewed by Lang and Philip

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199508 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-17 19:47:03 +00:00
Nico Rieck
38f68c5a2e Decouple dllexport/dllimport from linkage
Representing dllexport/dllimport as distinct linkage types prevents using
these attributes on templates and inline functions.

Instead of introducing further mixed linkage types to include linkonce and
weak ODR, the old import/export linkage types are replaced with a new
separate visibility-like specifier:

  define available_externally dllimport void @f() {}
  @Var = dllexport global i32 1, align 4

Linkage for dllexported globals and functions is now equal to their linkage
without dllexport. Imported globals and functions must be either
declarations with external linkage, or definitions with
AvailableExternallyLinkage.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199218 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-14 15:22:47 +00:00
Nico Rieck
55463f4ec1 Revert "Decouple dllexport/dllimport from linkage"
Revert this for now until I fix an issue in Clang with it.

This reverts commit r199204.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199207 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-14 12:38:32 +00:00
Nico Rieck
bce07a0c3b Decouple dllexport/dllimport from linkage
Representing dllexport/dllimport as distinct linkage types prevents using
these attributes on templates and inline functions.

Instead of introducing further mixed linkage types to include linkonce and
weak ODR, the old import/export linkage types are replaced with a new
separate visibility-like specifier:

  define available_externally dllimport void @f() {}
  @Var = dllexport global i32 1, align 4

Linkage for dllexported globals and functions is now equal to their linkage
without dllexport. Imported globals and functions must be either
declarations with external linkage, or definitions with
AvailableExternallyLinkage.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199204 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-14 11:55:03 +00:00
Chandler Carruth
8a5351f0f5 [PM] Rename the IR printing pass header to a more generic and correct
name to match the source file which I got earlier. Update the include
sites. Also modernize the comments in the header to use the more
recommended doxygen style.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199041 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-12 11:10:32 +00:00
Chandler Carruth
560e3955c3 Put the functionality for printing a value to a raw_ostream as an
operand into the Value interface just like the core print method is.
That gives a more conistent organization to the IR printing interfaces
-- they are all attached to the IR objects themselves. Also, update all
the users.

This removes the 'Writer.h' header which contained only a single function
declaration.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198836 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-09 02:29:41 +00:00
Chandler Carruth
bc65a8d518 Move the LLVM IR asm writer header files into the IR directory, as they
are part of the core IR library in order to support dumping and other
basic functionality.

Rename the 'Assembly' include directory to 'AsmParser' to match the
library name and the only functionality left their -- printing has been
in the core IR library for quite some time.

Update all of the #includes to match.

All of this started because I wanted to have the layering in good shape
before I started adding support for printing LLVM IR using the new pass
infrastructure, and commandline support for the new pass infrastructure.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198688 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-07 12:34:26 +00:00