Commit Graph

4881 Commits

Author SHA1 Message Date
Hal Finkel
b41c7e59a7 [StackMaps] Mark in CallLoweringInfo when lowering a patchpoint
While, generally speaking, the process of lowering arguments for a patchpoint
is the same as lowering a regular indirect call, on some targets it may not be
exactly the same. Targets may not, for example, want to add additional register
dependencies that apply only to making cross-DSO calls through linker stubs,
may not want to load additional registers out of function descriptors, and may
not want to add additional side-effect-causing instructions that cannot be
removed later with the call itself being generated.

The PowerPC target will use this in a future commit (for all of the reasons
stated above).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225806 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 17:48:04 +00:00
Reid Kleckner
d8f69a7201 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225752 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 01:51:34 +00:00
Reid Kleckner
221a7075cf 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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225746 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 00:48:10 +00:00
Adrian Prantl
df545e8d6c Make DwarfExpression store the AsmPrinter instead of the TargetMachine.
NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225731 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 23:36:56 +00:00
Lang Hames
4c553e0367 Recommit r224935 with a fix for the ObjC++/AArch64 bug that that revision
introduced.

A test case for the bug was already committed in r225385.

Patch by Rafael Espindola.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225534 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-09 18:55:42 +00:00
Ahmed Bougacha
a84b573c98 [CodeGen] Add MVT::isValid to replace manual validity checks. NFC.
Now that we have MVT::FIRST_VALUETYPE (r225362), we can provide a method
checking that the MVT is valid, that is, it's in
  [FIRST_VALUETYPE, LAST_VALUETYPE[.
This commit also uses it in a few asserts, that would previously accept
invalid MVTs, such as the default constructed -1.  In that case,
the code following those asserts would do an out-of-bounds array access.
Using MVT::isValid, those assertions fail as expected when passed
invalid MVTs.
It feels clunky to have such a validity checking function, but it's
at least better than the alternative of broken manual checks.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225411 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-07 22:47:46 +00:00
Ahmed Bougacha
c83d4c6a1b [CodeGen] Add iterator_range for the MVT::SimpleValueType enum.
This commit adds a simple iterator over that enum, and a few
functions to create iterator ranges over the most common types.

Differential Revision: http://reviews.llvm.org/D6537


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225387 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-07 21:15:38 +00:00
Philip Reames
28fa9e1e9f Introduce an example statepoint GC strategy
This change includes the most basic possible GCStrategy for a GC which is using the statepoint lowering code. At the moment, this GCStrategy doesn't really do much - aside from actually generate correct stackmaps that is - but I went ahead and added a few extra correctness checks as proof of concept. It's mostly here to provide documentation on how to do one, and to provide a point for various optimization legality hooks I'd like to add going forward. (For context, see the TODOs in InstCombine around gc.relocate.)

Most of the validation logic added here as proof of concept will soon move in to the Verifier.  That move is dependent on http://reviews.llvm.org/D6811

There was discussion in the review thread about addrspace(1) being reserved for something.  I'm going to follow up on a seperate llvmdev thread.  If needed, I'll update all the code at once.

Note that I am deliberately not making a GCStrategy required to use gc.statepoints with this change. I want to give folks out of tree - including myself - a chance to migrate. In a week or two, I'll make having a GCStrategy be required for gc.statepoints. To this end, I added the gc tag to one of the test cases but not others.

Differential Revision: http://reviews.llvm.org/D6808



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225365 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-07 19:07:50 +00:00
Ahmed Bougacha
c694182380 [CodeGen] Add MVT::FIRST_VALUETYPE to avoid explicit 0. NFC.
Many places reference MVT::LAST_VALUETYPE when iterating over all
valid MVTs, but they usually start with 0.
With FIRST_VALUETYPE, we can avoid explicit constants when we really
should be using MVT::SimpleValueType.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225362 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-07 18:39:00 +00:00
Jonas Paulsson
18a7c886c0 New method SDep::isNormalMemoryOrBarrier() in ScheduleDAGInstrs.cpp.
Used to iterate over previously added memory dependencies in
adjustChainDeps() and iterateChainSucc().

SDep::isCtrl() was previously used in these places, that also gave
anti and output edges. The code may be worse if these are followed,
because MisNeedChainEdge() will conservatively return true since a
non-memory instruction has no memory operands, and a false chain dep
will be added. It is also unnecessary since all memory accesses of
interest will be reached by memory dependencies, and there is a budget
limit for the number of edges traversed.

This problem was found on an out-of-tree target with enabled alias
analysis. No test case for an in-tree target has been found.

Reviewed by Hal Finkel.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225351 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-07 13:38:29 +00:00
Lang Hames
84acf09f32 Revert r224935 "Refactor duplicated code. No intended functionality change."
This is affecting the behavior of some ObjC++ / AArch64 test cases on Darwin.
Reverting to get the bots green while I track down the source of the changed
behavior.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225311 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-06 23:04:36 +00:00
Matt Arsenault
fe63e38cb5 Add isNegative helper to ConstantFPSDNode
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225309 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-06 23:00:44 +00:00
Matt Arsenault
628708ed17 Add isInfinity helper to ConstantFPSDNode
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225308 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-06 23:00:43 +00:00
Mehdi Amini
193f586fd2 Use a Factory Method for MachineFunctionInfo Creation
The goal is to allows MachineFunctionInfo to override this create
function to customize the creation.
No change intended in existing backend in this patch.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225292 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-06 20:05:02 +00:00
Frederic Riss
0c36e97b78 Make DIE.h a public CodeGen header.
dsymutil would like to use all the AsmPrinter/MCStreamer infrastructure
to stream out the DWARF. In order to do so, it will reuse the DIE object
and so this header needs to be public.

The interface exposed here has some corners that cannot be used without a
DwarfDebug object, but clients that want to stream Dwarf can just avoid
these.

Differential Revision: http://reviews.llvm.org/D6695

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225208 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-05 21:29:41 +00:00
Peter Collingbourne
d8ae3e1fee x86_64: Fix calls to __morestack under the large code model.
Under the large code model, we cannot assume that __morestack lives within
2^31 bytes of the call site, so we cannot use pc-relative addressing. We
cannot perform the call via a temporary register, as the rax register may
be used to store the static chain, and all other suitable registers may be
either callee-save or used for parameter passing. We cannot use the stack
at this point either because __morestack manipulates the stack directly.

To avoid these issues, perform an indirect call via a read-only memory
location containing the address.

This solution is not perfect, as it assumes that the .rodata section
is laid out within 2^31 bytes of each function body, but this seems to
be sufficient for JIT.

Differential Revision: http://reviews.llvm.org/D6787

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225003 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-30 20:05:19 +00:00
Rafael Espindola
2a1c1c9dea Refactor duplicated code.
No intended functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224935 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-29 15:18:31 +00:00
Matthias Braun
8882414a11 LiveInterval: Introduce createMainRangeFromSubranges().
This function constructs the main liverange by merging all subranges if
subregister liveness tracking is available. This should be slightly
faster to compute instead of performing the liveness calculation again
for the main range. More importantly it avoids cases where the main
liverange would cover positions where no subrange was live. These cases
happened for partial definitions where the actual defined part was dead
and only the undefined parts used later.

The register coalescing requires that every part covered by the main
live range has at least one subrange live.

I also expect this function to become usefull later for places where the
subranges are modified in a way that it is hard to correctly fix the
main liverange in the machine scheduler, we can simply reconstruct it
from subranges then.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224806 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-24 02:11:51 +00:00
Alexey Samsonov
acd25d2481 Fix UBSan bootstrap: don't bind reference to nullptr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224751 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-23 04:15:47 +00:00
Reid Kleckner
34b7fde802 Make musttail more robust for vector types on x86
Previously I tried to plug musttail into the existing vararg lowering
code. That turned out to be a mistake, because non-vararg calls use
significantly different register lowering, even on x86. For example, AVX
vectors are usually passed in registers to normal functions and memory
to vararg functions.  Now musttail uses a completely separate lowering.

Hopefully this can be used as the basis for non-x86 perfect forwarding.

Reviewers: majnemer

Differential Revision: http://reviews.llvm.org/D6156

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224745 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-22 23:58:37 +00:00
Peter Collingbourne
9caa5bdec0 CodeGen: do not attempt to invalidate virtual registers for zero-sized phis.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224615 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-19 20:50:07 +00:00
Matthias Braun
b82636bb80 LiveIntervalAnalysis: Cleanup computeDeadValues
- This also fixes a bug introduced in r223880 where values were not
  correctly marked as Dead anymore.
- Cleanup computeDeadValues(): split up SubRange code variant, simplify
  arguments.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224538 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-18 19:58:52 +00:00
Eric Christopher
c559ba7251 Add a new string member to the TargetOptions struct for the name
of the abi we should be using. For targets that don't use the
option there's no change, otherwise this allows external users
to set the ABI via string and avoid some of the -backend-option
pain in clang.

Use this option to move the ABI for the ARM port from the
Subtarget to the TargetMachine and update the testcases
accordingly since it's no longer valid to set via -mattr.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224492 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-18 02:20:58 +00:00
Toma Tabacu
3fea427a63 [mips] Set GCC-compatible MIPS asssembler options before inline asm blocks.
Summary:
When generating MIPS assembly, LLVM always overrides the default assembler options by emitting the '.set noreorder', '.set nomacro' and '.set noat' directives,
while GCC uses the default options if an assembly-level function contains inline assembly code.

This becomes a problem when the code generated by LLVM is interleaved with inline assembly which assumes GCC-like assembler options (from Linux, for example).

This patch fixes these conflicts by setting the appropriate assembler options at the beginning of an inline asm block and popping them at the end.

Reviewers: dsanders

Reviewed By: dsanders

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D6637

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224425 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-17 10:56:16 +00:00
Matt Arsenault
8b5b0f5ee5 Move lowerConstant to AsmPrinter
This was a static function before, and NVPTX duplicated it
because it wasn't exposed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224354 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-16 19:16:14 +00:00
Michael Ilseman
9ecdca9115 Silence more static analyzer warnings.
Add in definedness checks for shift operators, null checks when
pointers are assumed by the code to be non-null, and explicit
unreachables.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224255 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-15 18:48:43 +00:00
Philip Reames
b7dfa31ac8 Comment and minor code cleanup for GCStrategy (NFC)
Updating comments to reflect the current state of the world after my recent changes to ownership structure and generally better describe what a GCStrategy is and how it works.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224086 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-12 00:49:03 +00:00
Matthias Braun
5b17297b3d [CodeGen] Add print and verify pass after each MachineFunctionPass by default
Previously print+verify passes were added in a very unsystematic way, which is
annoying when debugging as you miss intermediate steps and allows bugs to stay
unnotice when no verification is performed.

To make this change practical I added the possibility to explicitely disable
verification. I used this option on all places where no verification was
performed previously (because alot of places actually don't pass the
MachineVerifier).
In the long term these problems should be fixed properly and verification
enabled after each pass. I'll enable some more verification in subsequent
commits.

This is the 2nd attempt at this after realizing that PassManager::add() may
actually delete the pass.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224059 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-11 21:26:47 +00:00
Rafael Espindola
428923cfe2 This reverts commit r224043 and r224042.
check-llvm was failing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224045 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-11 20:03:57 +00:00
Matthias Braun
71f56c4aac [CodeGen] Add print and verify pass after each MachineFunctionPass by default
Previously print+verify passes were added in a very unsystematic way, which is
annoying when debugging as you miss intermediate steps and allows bugs to stay
unnotice when no verification is performed.

To make this change practical I added the possibility to explicitely disable
verification. I used this option on all places where no verification was
performed previously (because alot of places actually don't pass the
MachineVerifier).
In the long term these problems should be fixed properly and verification
enabled after each pass. I'll enable some more verification in subsequent
commits.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224042 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-11 19:42:05 +00:00
Matthias Braun
9173c775e3 [CodeGen] Let MachineVerifierPass own its banner string
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224041 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-11 19:41:51 +00:00
Philip Reames
5e62b8471d GCStrategy should not own GCFunctionInfo
This change moves the ownership and access of GCFunctionInfo (the object which describes the safepoints associated with a safepoint under GCRoot) to GCModuleInfo. Previously, this was owned by GCStrategy which was in turned owned by GCModuleInfo. This made GCStrategy module specific which is 'surprising' given it's name and other purposes.

There's a few more changes needed, but we're getting towards the point we can reuse GCStrategy for gc.statepoint as well.

p.s. The style of this code ends up being a mess. I was trying to move code around without otherwise changing much. Once I get the ownership structure rearranged, I will go through and fixup spacing, naming, comments etc.

Differential Revision: http://reviews.llvm.org/D6587



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223994 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-11 01:47:23 +00:00
Matthias Braun
1bfcc2d56f LiveInterval: Use range based for loops for subregister ranges.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223991 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-11 00:59:06 +00:00
Matthias Braun
218d20a48b LiveInterval: Use more range based for loops for value numbers and segments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223978 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-10 23:07:54 +00:00
Matthias Braun
7b54b4de26 LiveIntervalUnion: Allow specification of liverange when unifying/extracting.
This allows it to add subregister ranges into the union.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223890 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-10 01:12:59 +00:00
Matthias Braun
08c7b086a9 RegisterCoalescer: Preserve subregister liveranges.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223888 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-10 01:12:52 +00:00
Matthias Braun
f2f0589b02 LiveInterval: Add removeEmptySubRanges().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223887 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-10 01:12:40 +00:00
Matthias Braun
6e616d2e97 LiveIntervalAnalysis: Add subregister aware variants pruneValue().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223886 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-10 01:12:36 +00:00
Matthias Braun
c080fce9d5 LiveInterval: Introduce LiveQuery accessor for dead or live out values.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223885 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-10 01:12:33 +00:00
Matthias Braun
7fbeb8d1b9 Add a flag to enable/disable subregister liveness.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223884 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-10 01:12:30 +00:00
Matthias Braun
4402447964 LiveIntervalAnalysis: Adapt repairIntervalsInRange() to subregister liveness.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223883 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-10 01:12:26 +00:00
Matthias Braun
e59399c28c LiveIntervalAnalysis: Update SubRanges in shrinkToUses().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223880 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-10 01:12:18 +00:00
Matthias Braun
6cdf1d9a8f LiveIntervalAnalysis: Make computeDeadValues() private.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223879 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-10 01:12:15 +00:00
Matthias Braun
01ddf04b63 LiveInterval: Add support to track liveness of subregisters.
This code adds the required data structures. Algorithms to compute it follow.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223877 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-10 01:12:10 +00:00
Matthias Braun
5874714ac3 LiveInterval: Add a 'covers' operation to LiveRange.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223876 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-10 01:12:06 +00:00
Matthias Braun
fd9bbbb541 LiveInterval: Add const version of LiveRange::advanceTo().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223875 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-10 01:12:02 +00:00
Philip Reames
f8225ab80f Extend some comments around GCModuleInfo, GCFunctionInfo, & GCStrategy
Nothing particularly interesting here, just documenting the way the code currently works before I start changing it...



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223866 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-10 00:30:11 +00:00
Philip Reames
3490d23337 Remove the Module pointer from GCStrategy and GCMetadataPrinter
In the current implementation, GCStrategy is a part of the ownership structure for the gc metadata which describes a Module. It also contains a reference to the module in question. As a result, GCStrategy instances are essentially Module specific.

I plan to transition away from this design. Instead, a GCStrategy will be owned by the LLVMContext. It will be a lightweight policy object which contains no information about the Modules or Functions involved, but can be easily reached given a Function.

The first step in this transition is to remove the direct Module reference from GCStrategy. This also requires removing the single user of this reference, the GCMetadataPrinter hierarchy. In theory, this will allow the lifetime of the printers to be scoped to the LLVMContext as well, but in practice, I'm not actually changing that. (Yet?)

An alternate design would have been to move the direct Module reference into the GCMetadataPrinter and change the keying of the owning maps to explicitly key off both GCStrategy and Module. I'm open to doing it that way instead, but didn't see much value in preserving the per Module association for GCMetadataPrinters.

The next change in this sequence will be to start unwinding the intertwined ownership between GCStrategy, GCModuleInfo, and GCFunctionInfo.

Differential Revision: http://reviews.llvm.org/D6566



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223859 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-09 23:57:54 +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
Elena Demikhovsky
73ae1df82c 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



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223348 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-04 09:40:44 +00:00