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Commit Graph

191 Commits

Author SHA1 Message Date
Duncan P. N. Exon Smith
2090bd958a Verifier: Simplify logic in processCallInst(), NFC
No need for local variables here.

llvm-svn: 232413
2015-03-16 21:05:33 +00:00
Duncan P. N. Exon Smith
edd9e25527 IR: Take advantage of -verify checks for MDExpression
Now that we check `MDExpression` during `-verify` (r232299), make
the `DIExpression` wrapper more strict:

  - remove redundant checks in `DebugInfoVerifier`,
  - overload `get()` to `cast_or_null<MDExpression>` (superseding
    `getRaw()`),
  - stop checking for null in any accessor, and
  - remove `DIExpression::Verify()` entirely in favour of
    `MDExpression::isValid()`.

There is still some logic in this class, mostly to do with high-level
iterators; I'll defer cleaning up those until the rest of the wrappers
are similarly strict.

llvm-svn: 232412
2015-03-16 21:03:55 +00:00
Duncan P. N. Exon Smith
fa1b3de43e Verifier: Remove unnecessary double-checks
Turns out `visitIntrinsicFunctionCall()` descends into all operands
already, so explicitly descending in `visitDbgIntrinsic()` (part of
r232296) isn't useful.

Updating a testcase that doesn't really need `-verify-debug-info` (since
r231082) as confirmation.

llvm-svn: 232408
2015-03-16 20:24:02 +00:00
Duncan P. N. Exon Smith
10d626e5d7 Fix doxygen comments from r232268
llvm-svn: 232388
2015-03-16 17:49:03 +00:00
Duncan P. N. Exon Smith
27ff67c213 DbgIntrinsicInst: Downcast to specialized MDNodes in accessors
Change accessors to downcast to `MDLocalVariable` and `MDExpression`,
now that we have -verify checks in place to confirm that it's safe.

llvm-svn: 232299
2015-03-15 01:23:20 +00:00
Duncan P. N. Exon Smith
9f52f307c2 Verifier: Check debug info intrinsic arguments
Verify that debug info intrinsic arguments are valid.  (These checks
will not recurse through the full debug info graph, so they don't need
to be cordoned of in `DebugInfoVerifier`.)

With those checks in place, changing the `DbgIntrinsicInst` accessors to
downcast to `MDLocalVariable` and `MDExpression` is natural (added isa
specializations in `Metadata.h` to support this).

Added tests to `test/Verifier` for the new -verify checks, and fixed the
debug info in all the in-tree tests.

If you have out-of-tree testcases that have started to fail to -verify,
hopefully the verify checks are helpful.  The most likely problem is
that the expression argument is `!{}` (instead of `!MDExpression()`).

llvm-svn: 232296
2015-03-15 01:21:30 +00:00
Duncan P. N. Exon Smith
b5366a7529 Verifier: Remove unnecessary null check
This is already assumed to be non-null above due to a dyn_cast<>.  Also
remove extraneous braces around statement.

llvm-svn: 232292
2015-03-15 00:50:57 +00:00
Duncan P. N. Exon Smith
9d8b121b0f Verifier: Make the raw_ostream constructor argument required
This was passed inconsistently; seems clearer to make it required anyway.

llvm-svn: 232291
2015-03-15 00:46:57 +00:00
Duncan P. N. Exon Smith
40ea3b1320 IR: Make Metadata::print() reliable and useful
Replumb the `AsmWriter` so that `Metadata::print()` is generally useful.
(Similarly change `Metadata::printAsOperand()`.)

- `SlotTracker` now has a mode where all metadata will be correctly
  numbered when initializing a `Module`.  Normally, `Metadata` only
  referenced from within `Function`s gets numbered when the `Function`
  is incorporated.
- `Metadata::print()` and `Metadata::printAsOperand()` (and
  `Metadata::dump()`) now take an optional `Module` argument.  When
  provided, `SlotTracker` is initialized with the new mode, and the
  numbering will be complete and consistent for all calls to `print()`.
- `Value::print()` uses the new `SlotTracker` mode when printing
  intrinsics with `MDNode` operands, `MetadataAsValue` operands, or the
  bodies of functions.  Thus, metadata numbering will be consistent
  between calls to `Metadata::print()` and `Value::print()`.
- `Metadata::print()` (and `Metadata::dump()`) now print the full
  definition of `MDNode`s:

    !5 = !{!6, !"abc", !7}

  This matches behaviour for `Value::print()`, which includes the name
  of instructions.
- Updated call sites in `Verifier` to call `print()` instead of
  `printAsOperand()`.

All this, so that `Verifier` can print out useful failure messages that
involve `Metadata` for PR22777.

Note that `Metadata::printAsOperand()` previously took an optional
`bool` and `Module` operand.  The former was cargo-culted from
`Value::printAsOperand()` and wasn't doing anything useful.  The latter
didn't give consistent results (without the new `SlotTracker` mode).

llvm-svn: 232275
2015-03-14 20:19:36 +00:00
Duncan P. N. Exon Smith
2a90990ab0 Recover the ability to 'b CheckFailed' after r231577
Given that the stated purpose of `CheckFailed()` is to provide a nice
spot for a breakpoint, it'd be nice not to have to use a regex to break
on it.  Recover the ability to simply use `b CheckFailed` by
specializing the message-only version, and by changing the variadic
version to call into the message-only version.

llvm-svn: 232268
2015-03-14 16:47:37 +00:00
Owen Anderson
09cf5bf820 Fix an infinite recursion in the verifier caused by calling isSized on a recursive type.
llvm-svn: 232143
2015-03-13 06:41:26 +00:00
Owen Anderson
018886831b Fix another verifier crash where a GC intrinsic would look at the internals of another intrinsic in order to verify itself.
This causes a crash if the referenced intrinsic was malformed.  In this case, we
would already have reported an error on the referenced intrinsic, but then
crashed on the second one when it tried to introspect the first without
error checking.

llvm-svn: 231910
2015-03-11 06:57:30 +00:00
Owen Anderson
b10fb77aca Fix an issue in the verifier where we could try to read information out of a malformed statepoint intrinsic.
In this situation we would always have already flagged an error on the statepoint intrinsic,
but then we carry on to parse other, related GC intrinsics, and could end up crashing during that
verification when they try to access data from the malformed statepoint.

llvm-svn: 231759
2015-03-10 05:58:21 +00:00
David Blaikie
350b9cbf65 Simplify expressions involving boolean constants with clang-tidy
Patch by Richard (legalize at xmission dot com).

Differential Revision: http://reviews.llvm.org/D8154

llvm-svn: 231617
2015-03-09 01:57:13 +00:00
Benjamin Kramer
c2404156f7 Make the assertion macros in Verifier and Linter truly variadic.
NFC.

llvm-svn: 231577
2015-03-07 21:15:40 +00:00
Reid Kleckner
0cb21beeab Remove accidental errs() call in Verifier
llvm-svn: 231391
2015-03-05 19:05:25 +00:00
Reid Kleckner
d0e0d012a0 Replace llvm.frameallocate with llvm.frameescape
Turns out it's pretty straightforward and simplifies the implementation.

Reviewers: andrew.w.kaylor

Differential Revision: http://reviews.llvm.org/D8051

llvm-svn: 231386
2015-03-05 18:26:34 +00:00
Owen Anderson
eaf4cde743 Teach the verifier to enforce that the alignment argument of memory intrinsics must be a power of 2.
llvm-svn: 230941
2015-03-02 09:35:06 +00:00
David Majnemer
c4bcdfa1bc Verifier: Unused comdats might not have a corresponding GV
This fixes PR22646.

llvm-svn: 230051
2015-02-20 19:58:48 +00:00
Igor Laevsky
bd5ab1e4f1 Implement invoke statepoint verification.
Differential Revision: http://reviews.llvm.org/D7366

llvm-svn: 229840
2015-02-19 11:28:47 +00:00
Benjamin Kramer
21bee91af5 Prefer SmallVector::append/insert over push_back loops.
Same functionality, but hoists the vector growth out of the loop.

llvm-svn: 229500
2015-02-17 15:29:18 +00:00
David Majnemer
9580d6a824 Verifier: Diagnose module flags which have null ID operands
llvm-svn: 229361
2015-02-16 08:14:22 +00:00
Duncan P. N. Exon Smith
94f67658e0 IR: Add MDExpression::ExprOperand
Port `DIExpression::Operand` over to `MDExpression::ExprOperand`.  The
logic is needed directly in `MDExpression` to support printing in
assembly.

llvm-svn: 229002
2015-02-13 01:07:46 +00:00
David Majnemer
87fa2583a6 Verifier: Check for null operands in !llvm.module.flags
llvm-svn: 228818
2015-02-11 09:13:06 +00:00
David Majnemer
5434ded6b2 Verifier: Make sure !llvm.ident's operand isn't null
llvm-svn: 228815
2015-02-11 08:23:20 +00:00
Duncan P. N. Exon Smith
30c159ddd4 Verifier: reuse getInlinedAt() result, NFC
llvm-svn: 228655
2015-02-10 02:25:18 +00:00
Duncan P. N. Exon Smith
ad09354db9 Verifier: Check for valid tags in debug nodes
Check that specialized `DebugNode`s have valid `DW_TAG`s.

llvm-svn: 228649
2015-02-10 01:40:40 +00:00
Duncan P. N. Exon Smith
c23fcf30e5 Verifier: Add simple checks for MDLocation
llvm-svn: 228647
2015-02-10 01:32:56 +00:00
Duncan P. N. Exon Smith
006fe0ff8b Verifier: Create stubs for specialized metadata nodes
llvm-svn: 228645
2015-02-10 01:09:50 +00:00
Duncan P. N. Exon Smith
b936a0417b Verifier: Const-qualify Metadata, NFC
llvm-svn: 228609
2015-02-09 21:30:05 +00:00
Elena Demikhovsky
40c204cf7d Masked Gather and Scatter Intrinsics.
Gather and Scatter are new introduced intrinsics, comming after recently implemented masked load and store.
This is the first patch for Gather and Scatter intrinsics. It includes only the syntax, parsing and verification.

Gather and Scatter intrinsics allow to perform multiple memory accesses (read/write) in one vector instruction.
The intrinsics are not target specific and will have the following syntax:
Gather:
declare <16 x i32> @llvm.masked.gather.v16i32(<16 x i32*> <vector of ptrs>, i32 <alignment>, <16 x i1> <mask>, <16 x i32> <passthru>)
declare <8 x float> @llvm.masked.gather.v8f32(<8 x float*><vector of ptrs>, i32 <alignment>, <8 x i1> <mask>, <8 x float><passthru>)

Scatter:
declare void @llvm.masked.scatter.v8i32(<8 x i32><vector value to be stored> , <8 x i32*><vector of ptrs> , i32 <alignment>, <8 x i1> <mask>)
declare void @llvm.masked.scatter.v16i32(<16 x i32> <vector value to be stored> , <16 x i32*> <vector of ptrs>, i32 <alignment>, <16 x i1><mask> )

Vector of ptrs - a set of source/destination addresses, to load/store the value. 
Mask - switches on/off vector lanes to prevent memory access for switched-off lanes
vector of ptrs, value and mask should have the same vector width.

These are code examples where gather / scatter should be used and will allow function vectorization
;void foo1(int * restrict A, int * restrict B, int * restrict C) {
; for (int i=0; i<SIZE; i++) {
; A[i] = B[C[i]];
; }
;}

;void foo3(int * restrict A, int * restrict B) {
; for (int i=0; i<SIZE; i++) {
; A[B[i]] = i+5;
; }
;}

Tests will come in the following patches, with CodeGen and Vectorizer.

http://reviews.llvm.org/D7433

llvm-svn: 228521
2015-02-08 08:27:19 +00:00
Philip Reames
c3e8c2ec68 Use ImmutableCallSite for statepoint verification.
Patch by: Igor Laevsky

"This change generalizes statepoint verification to use ImmutableCallSite instead of CallInst. This will allow to easily implement invoke statepoint verification (in a following change)."

Differential Revision: http://reviews.llvm.org/D7308

llvm-svn: 228064
2015-02-03 23:18:47 +00:00
Philip Reames
00867a9645 Factor out statepoint verification into separate function. (NFC)
Patch by: Igor Laevsky

"Simple refactoring. This is done in preparation to support verification of invokable statepoints."

Differential Revision: http://reviews.llvm.org/D7276

llvm-svn: 227640
2015-01-30 23:28:05 +00:00
Ramkumar Ramachandra
550e92d3f7 Intrinsics: introduce llvm_any_ty aka ValueType Any
Specifically, gc.result benefits from this greatly. Instead of:

gc.result.int.*
gc.result.float.*
gc.result.ptr.*
...

We now have a gc.result.* that can specialize to literally any type.

Differential Revision: http://reviews.llvm.org/D7020

llvm-svn: 226857
2015-01-22 20:14:38 +00:00
Adrian Prantl
42d17b28f3 Make DIExpression::Verify() stricter by checking that the number of
elements and the ordering is sane and cleanup the accessors.

llvm-svn: 226627
2015-01-21 00:59:20 +00:00
Ramkumar Ramachandra
78c0138d51 [GC] Verify-pass void vararg functions in gc.statepoint
With the appropriate Verifier changes, exactracting the result out of a
statepoint wrapping a vararg function crashes. However, a void vararg
function works fine: commit this first step.

Differential Revision: http://reviews.llvm.org/D7071

llvm-svn: 226599
2015-01-20 19:42:46 +00:00
Duncan P. N. Exon Smith
0341a8121b IR: Remove MDNodeFwdDecl
Remove `MDNodeFwdDecl` (as promised in r226481).  Aside from API
changes, there's no real functionality change here.
`MDNode::getTemporary()` now forwards to `MDTuple::getTemporary()`,
which returns a tuple with `isTemporary()` equal to true.

The main point is that we can now add temporaries of other `MDNode`
subclasses, needed for PR22235 (I introduced `MDNodeFwdDecl` in the
first place because I didn't recognize this need, and thought they were
only needed to handle forward references).

A few things left out of (or highlighted by) this commit:

  - I've had to remove the (few) uses of `std::unique_ptr<>` to deal
    with temporaries, since the destructor is no longer public.
    `getTemporary()` should probably return the equivalent of
    `std::unique_ptr<T, MDNode::deleteTemporary>`.
  - `MDLocation::getTemporary()` doesn't exist yet (worse, it actually
    does exist, but does the wrong thing: `MDNode::getTemporary()` is
    inherited and returns an `MDTuple`).
  - `MDNode` now only has one subclass, `UniquableMDNode`, and the
    distinction between them is actually somewhat confusing.

I'll fix those up next.

llvm-svn: 226501
2015-01-19 20:36:39 +00:00
Ramkumar Ramachandra
f8622411fe Standardize {pred,succ,use,user}_empty()
The functions {pred,succ,use,user}_{begin,end} exist, but many users
have to check *_begin() with *_end() by hand to determine if the
BasicBlock or User is empty. Fix this with a standard *_empty(),
demonstrating a few usecases.

llvm-svn: 225760
2015-01-13 03:46:47 +00:00
Reid Kleckner
033ced7470 Rename llvm.recoverframeallocation to llvm.framerecover
This name is less descriptive, but it sort of puts things in the
'llvm.frame...' namespace, relating it to frameallocate and
frameaddress. It also avoids using "allocate" and "allocation" together.

llvm-svn: 225752
2015-01-13 01:51:34 +00:00
Reid Kleckner
002e480f22 Add the llvm.frameallocate and llvm.recoverframeallocation intrinsics
These intrinsics allow multiple functions to share a single stack
allocation from one function's call frame. The function with the
allocation may only perform one allocation, and it must be in the entry
block.

Functions accessing the allocation call llvm.recoverframeallocation with
the function whose frame they are accessing and a frame pointer from an
active call frame of that function.

These intrinsics are very difficult to inline correctly, so the
intention is that they be introduced rarely, or at least very late
during EH preparation.

Reviewers: echristo, andrew.w.kaylor

Differential Revision: http://reviews.llvm.org/D6493

llvm-svn: 225746
2015-01-13 00:48:10 +00:00
Philip Reames
2ad347b060 [GC] improve testing around gc.relocate and fix a test
Patch by: Ramkumar Ramachandra <artagnon@gmail.com>

"This patch started out as an exploration of gc.relocate, and an attempt
to write a simple test in call-lowering. I then noticed that the
arguments of gc.relocate were not checked fully, so I went in and fixed
a few things. Finally, the most important outcome of this patch is that
my new error handling code caught a bug in a callsite in
stackmap-format."

Differential Revision: http://reviews.llvm.org/D6824

llvm-svn: 225412
2015-01-07 22:48:01 +00:00
Chandler Carruth
2a8b1d4992 [PM] Switch the new pass manager to use a reference-based API for IR
units.

This was debated back and forth a bunch, but using references is now
clearly cleaner. Of all the code written using pointers thus far, in
only one place did it really make more sense to have a pointer. In most
cases, this just removes immediate dereferencing from the code. I think
it is much better to get errors on null IR units earlier, potentially
at compile time, than to delay it.

Most notably, the legacy pass manager uses references for its routines
and so as more and more code works with both, the use of pointers was
likely to become really annoying. I noticed this when I ported the
domtree analysis over and wrote the entire thing with references only to
have it fail to compile. =/ It seemed better to switch now than to
delay. We can, of course, revisit this is we learn that references are
really problematic in the API.

llvm-svn: 225145
2015-01-05 02:47:05 +00:00
Elena Demikhovsky
4a153fb55a Masked Load/Store - Changed the order of parameters in intrinsics.
No functional changes.
The documentation is coming.

llvm-svn: 224829
2014-12-25 07:49:20 +00:00
Rafael Espindola
0e63c2a0a5 Use CastInst::castIsValid to simplify the verifier.
Also delete a dead member variable.

llvm-svn: 224356
2014-12-16 19:29:29 +00:00
Duncan P. N. Exon Smith
3d57886267 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.)

llvm-svn: 223802
2014-12-09 18:38:53 +00:00
Elena Demikhovsky
befed29343 Masked Load / Store Intrinsics - the CodeGen part.
I'm recommiting the codegen part of the patch.
The vectorizer part will be send to review again.

Masked Vector Load and Store Intrinsics.
Introduced new target-independent intrinsics in order to support masked vector loads and stores. The loop vectorizer optimizes loops containing conditional memory accesses by generating these intrinsics for existing targets AVX2 and AVX-512. The vectorizer asks the target about availability of masked vector loads and stores.
Added SDNodes for masked operations and lowering patterns for X86 code generator.
Examples:
<16 x i32> @llvm.masked.load.v16i32(i8* %addr, <16 x i32> %passthru, i32 4 /* align */, <16 x i1> %mask)
declare void @llvm.masked.store.v8f64(i8* %addr, <8 x double> %value, i32 4, <8 x i1> %mask)

Scalarizer for other targets (not AVX2/AVX-512) will be done in a separate patch.

http://reviews.llvm.org/D6191

llvm-svn: 223348
2014-12-04 09:40:44 +00:00
Philip Reames
868c243a1a A few more checks for gc.statepoints in the Verifier
This is simply a grab bag of unrelated checks:
- A statepoint call can't be marked readonly or readnone
- We don't currently support inline asm or varadic target functions.  Both could be supported, but don't currently work.
- I forgot to check that the number of call arguments actually matched the wrapped callee in my previous change.  Included here.

llvm-svn: 223322
2014-12-04 00:01:48 +00:00
Philip Reames
ed16aae7df Strength Verifier checks around the types involved in a statepoint
Add checks that the types in a gc.statepoint sequence match the wrapper callee and that relocating a pointer doesn't change it's type.

llvm-svn: 223275
2014-12-03 22:23:24 +00:00
Philip Reames
00e65093bc Make the Verifier more strict about gc.statepoints
The recently added documentation for statepoints claimed that we checked the parameters of the various intrinsics for validity.  This patch adds the code to actually do so.  I also removed a couple of redundant checks for conditions which are checked elsewhere in the Verifier and simplified the logic using the helper functions from Statepoint.h.

llvm-svn: 223259
2014-12-03 19:53:15 +00:00
Philip Reames
cbcf6ea7d6 [Statepoints 1/4] Statepoint infrastructure for garbage collection: IR Intrinsics
The statepoint intrinsics are intended to enable precise root tracking through the compiler as to support garbage collectors of all types. The addition of the statepoint intrinsics to LLVM should have no impact on the compilation of any program which does not contain them. There are no side tables created, no extra metadata, and no inhibited optimizations.

A statepoint works by transforming a call site (or safepoint poll site) into an explicit relocation operation. It is the frontend's responsibility (or eventually the safepoint insertion pass we've developed, but that's not part of this patch series) to ensure that any live pointer to a GC object is correctly added to the statepoint and explicitly relocated. The relocated value is just a normal SSA value (as seen by the optimizer), so merges of relocated and unrelocated values are just normal phis. The explicit relocation operation, the fact the statepoint is assumed to clobber all memory, and the optimizers standard semantics ensure that the relocations flow through IR optimizations correctly.

This is the first patch in a small series.  This patch contains only the IR parts; the documentation and backend support will be following separately.  The entire series can be seen as one combined whole in http://reviews.llvm.org/D5683.

Reviewed by: atrick, ributzka

llvm-svn: 223078
2014-12-01 21:18:12 +00:00