Commit Graph

6676 Commits

Author SHA1 Message Date
Alexander Kornienko 8c0809c7f8 Replace size method call of containers to empty method where appropriate
This patch was generated by a clang tidy checker that is being open sourced.
The documentation of that checker is the following:

/// The emptiness of a container should be checked using the empty method
/// instead of the size method. It is not guaranteed that size is a
/// constant-time function, and it is generally more efficient and also shows
/// clearer intent to use empty. Furthermore some containers may implement the
/// empty method but not implement the size method. Using empty whenever
/// possible makes it easier to switch to another container in the future.

Patch by Gábor Horváth!

llvm-svn: 226161
2015-01-15 11:41:30 +00:00
Chandler Carruth b98f63dbdb [PM] Separate the TargetLibraryInfo object from the immutable pass.
The pass is really just a means of accessing a cached instance of the
TargetLibraryInfo object, and this way we can re-use that object for the
new pass manager as its result.

Lots of delta, but nothing interesting happening here. This is the
common pattern that is developing to allow analyses to live in both the
old and new pass manager -- a wrapper pass in the old pass manager
emulates the separation intrinsic to the new pass manager between the
result and pass for analyses.

llvm-svn: 226157
2015-01-15 10:41:28 +00:00
Chandler Carruth 62d4215baa [PM] Move TargetLibraryInfo into the Analysis library.
While the term "Target" is in the name, it doesn't really have to do
with the LLVM Target library -- this isn't an abstraction which LLVM
targets generally need to implement or extend. It has much more to do
with modeling the various runtime libraries on different OSes and with
different runtime environments. The "target" in this sense is the more
general sense of a target of cross compilation.

This is in preparation for porting this analysis to the new pass
manager.

No functionality changed, and updates inbound for Clang and Polly.

llvm-svn: 226078
2015-01-15 02:16:27 +00:00
Reid Kleckner 9b5eaf0d5a Emit the Itanium LSDA for unknown EH personalities on Win64
This fixes lots of generic CodeGen tests that use __gcc_personality_v0.
This suggests that using ExceptionHandling::MSVC was a mistake, and we
should instead classify each function by personality function. This
would, for example, allow us to LTO a binary containing uses of SEH and
Itanium EH.

llvm-svn: 226019
2015-01-14 18:50:10 +00:00
Reid Kleckner b57c1dc0f7 Remove dead code for llvm.eh.selector in the old EH model
llvm-svn: 226018
2015-01-14 18:49:39 +00:00
Chandler Carruth d9903888d9 [cleanup] Re-sort all the #include lines in LLVM using
utils/sort_includes.py.

I clearly haven't done this in a while, so more changed than usual. This
even uncovered a missing include from the InstrProf library that I've
added. No functionality changed here, just mechanical cleanup of the
include order.

llvm-svn: 225974
2015-01-14 11:23:27 +00:00
Mehdi Amini d8976b8ed3 SelectionDAG: add a -filter-view-dags option to llc
This option takes the name of the basic block you want to visualize
with -view-*-dags

Differential Revision: http://reviews.llvm.org/D6948

llvm-svn: 225953
2015-01-14 06:03:18 +00:00
Mehdi Amini 648eff1695 DAG Combiner: Fold SelectCC When Cond is UNDEF
In case folding a node end up with a NaN as operand for the select, 
the folding of the condition of the selectcc node returns "UNDEF".

Differential Revision: http://reviews.llvm.org/D6889

llvm-svn: 225952
2015-01-14 05:45:24 +00:00
Matt Arsenault bd22342322 Implement new way of expanding extloads.
Now that the source and destination types can be specified,
allow doing an expansion that doesn't use an EXTLOAD of the
result type. Try to do a legal extload to an intermediate type
and extend that if possible.

This generalizes the special case custom lowering of extloads
R600 has been using to work around this problem.

This also happens to fix a bug that would incorrectly use more
aligned loads than should be used.

llvm-svn: 225925
2015-01-14 01:35:17 +00:00
Hal Finkel 665026838b Adjust ScheduleDAGSDNodes::RegDefIter for patchpoints
PATCHPOINT is a strange pseudo-instruction. Depending on how it is used, and
whether or not the AnyReg calling convention is being used, it might or might
not define a value. However, its TableGen definition says that it defines one
value, and so when it doesn't, the code in ScheduleDAGSDNodes::RegDefIter
becomes confused and the code that uses the RegDefIter will try to get the
register class of the MVT::Other type associated with the PATCHPOINT's chain
result (under certain circumstances).

This will be covered by the PPC64 PatchPoint test cases once that support is
re-committed.

llvm-svn: 225907
2015-01-14 01:07:03 +00:00
Reid Kleckner 0a57f65514 CodeGen support for x86_64 SEH catch handlers in LLVM
This adds handling for ExceptionHandling::MSVC, used by the
x86_64-pc-windows-msvc triple. It assumes that filter functions have
already been outlined in either the frontend or the backend. Filter
functions are used in place of the landingpad catch clause type info
operands. In catch clause order, the first filter to return true will
catch the exception.

The C specific handler table expects the landing pad to be split into
one block per handler, but LLVM IR uses a single landing pad for all
possible unwind actions. This patch papers over the mismatch by
synthesizing single instruction BBs for every catch clause to fill in
the EH selector that the landing pad block expects.

Missing functionality:
- Accessing data in the parent frame from outlined filters
- Cleanups (from __finally) are unsupported, as they will require
  outlining and parent frame access
- Filter clauses are unsupported, as there's no clear analogue in SEH

In other words, this is the minimal set of changes needed to write IR to
catch arbitrary exceptions and resume normal execution.

Reviewers: majnemer

Differential Revision: http://reviews.llvm.org/D6300

llvm-svn: 225904
2015-01-14 01:05:27 +00:00
Matthias Braun f50ab43214 DAGCombiner: simplify by using condition variables; NFC
llvm-svn: 225836
2015-01-13 22:17:46 +00:00
Matt Arsenault bf0db918b2 R600: Implement getRecipEstimate
This requires a new hook to prevent expanding sqrt in terms
of rsqrt and reciprocal. v_rcp_f32, v_rsq_f32, and v_sqrt_f32 are
all the same rate, so this expansion would just double the number
of instructions and cycles.

llvm-svn: 225828
2015-01-13 20:53:23 +00:00
Hal Finkel 0ad96c818c [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).

llvm-svn: 225806
2015-01-13 17:48:04 +00:00
Olivier Sallenave 325096980b Added TLI hook for isFPExtFree. Some of the FMA combine heuristics are now guarded with that hook.
llvm-svn: 225795
2015-01-13 15:06:36 +00:00
Reid Kleckner 3542ace6ef 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 e9b8931873 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
Matt Arsenault a982e4f82b Combine fcmp + select to fminnum / fmaxnum if no nans and legal
Also require unsafe FP math for no since there isn't a way to
test for signed zeros.

llvm-svn: 225744
2015-01-13 00:43:00 +00:00
Hal Finkel 0ce7f372e5 [DAGCombine] Remainder of fix to r225380 (More FMA folding opportunities)
As pointed out by Aditya (and Owen), when we elide an FP extend to form an FMA,
we need to extend the incoming operands so that the resulting node will really
be legal. This is currently enabled only for PowerPC, and it happens to work
there regardless, but this should fix the functionality for everyone else
should anyone else wish to use it.

llvm-svn: 225492
2015-01-09 01:29:29 +00:00
Hal Finkel 33ead6f901 Partial fix to r225380 (More FMA folding opportunities)
As pointed out by Aditya (and Owen), there are two things wrong with this code.
First, it adds patterns which elide FP extends when forming FMAs, and that might
not be profitable on all targets (it belongs behind the pre-existing
aggressive-FMA-formation flag). This is fixed by this change.

Second, the resulting nodes might have operands of different types (the
extensions need to be re-added). That will be fixed in the follow-up commit.

llvm-svn: 225485
2015-01-09 00:45:54 +00:00
Elena Demikhovsky 285fbd551a Masked Load/Store - fixed a bug in type legalization.
llvm-svn: 225441
2015-01-08 12:29:19 +00:00
Ahmed Bougacha 2b6917b020 [SelectionDAG] Allow targets to specify legality of extloads' result
type (in addition to the memory type).

The *LoadExt* legalization handling used to only have one type, the
memory type.  This forced users to assume that as long as the extload
for the memory type was declared legal, and the result type was legal,
the whole extload was legal.

However, this isn't always the case.  For instance, on X86, with AVX,
this is legal:
    v4i32 load, zext from v4i8
but this isn't:
    v4i64 load, zext from v4i8
Whereas v4i64 is (arguably) legal, even without AVX2.

Note that the same thing was done a while ago for truncstores (r46140),
but I assume no one needed it yet for extloads, so here we go.

Calls to getLoadExtAction were changed to add the value type, found
manually in the surrounding code.

Calls to setLoadExtAction were mechanically changed, by wrapping the
call in a loop, to match previous behavior.  The loop iterates over
the MVT subrange corresponding to the memory type (FP vectors, etc...).
I also pulled neighboring setTruncStoreActions into some of the loops;
those shouldn't make a difference, as the additional types are illegal.
(e.g., i128->i1 truncstores on PPC.)

No functional change intended.

Differential Revision: http://reviews.llvm.org/D6532

llvm-svn: 225421
2015-01-08 00:51:32 +00:00
Olivier Sallenave 0451532996 More FMA folding opportunities.
llvm-svn: 225380
2015-01-07 20:54:17 +00:00
Olivier Sallenave e64ad7cedd Test commit
llvm-svn: 225368
2015-01-07 19:45:17 +00:00
Philip Reames 4ac17a3026 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

llvm-svn: 225365
2015-01-07 19:07:50 +00:00
Mehdi Amini f3721bf619 SelectionDAGBuilder: move constant initialization out of loop
No semantic change intended.

Reviewers: resistor

Differential Revision: http://reviews.llvm.org/D6834

llvm-svn: 225278
2015-01-06 18:20:04 +00:00
Craig Topper d3c02f177a Replace several 'assert(false' with 'llvm_unreachable' or fold a condition into the assert.
llvm-svn: 225160
2015-01-05 10:15:49 +00:00
Alexey Samsonov 553185ee4b Revert "merge consecutive stores of extracted vector elements"
This reverts commit r224611. This change causes crashes
in X86 DAG->DAG Instruction Selection.

llvm-svn: 225031
2014-12-31 00:40:28 +00:00
Elena Demikhovsky fb81b93e17 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
Mehdi Amini d38920891e Always assert in DAGCombine and not only when -debug is enabled
Right now in DAG Combine check the validity of the returned type 
only when -debug is given on the command line. However usually 
the test cases in the validation does not use -debug. 
An Assert build should always check this.

llvm-svn: 224779
2014-12-23 18:59:02 +00:00
Michael Kuperstein f4536ea6e8 [DagCombine] Improve DAGCombiner BUILD_VECTOR when it has two sources of elements
This partially fixes PR21943.

For AVX, we go from:

vmovq   (%rsi), %xmm0
vmovq   (%rdi), %xmm1
vpermilps       $-27, %xmm1, %xmm2 ## xmm2 = xmm1[1,1,2,3]
vinsertps       $16, %xmm2, %xmm1, %xmm1 ## xmm1 = xmm1[0],xmm2[0],xmm1[2,3]
vinsertps       $32, %xmm0, %xmm1, %xmm1 ## xmm1 = xmm1[0,1],xmm0[0],xmm1[3]
vpermilps       $-27, %xmm0, %xmm0 ## xmm0 = xmm0[1,1,2,3]
vinsertps       $48, %xmm0, %xmm1, %xmm0 ## xmm0 = xmm1[0,1,2],xmm0[0]

To the expected:

vmovq   (%rdi), %xmm0
vmovhpd (%rsi), %xmm0, %xmm0
retq

Fixing this for AVX2 is still open.

Differential Revision: http://reviews.llvm.org/D6749

llvm-svn: 224759
2014-12-23 08:59:45 +00:00
Matt Arsenault 22b4c256e1 Enable (sext x) == C --> x == (trunc C) combine
Extend the existing code which handles this for zext. This makes this
more useful for targets with ZeroOrNegativeOne BooleanContent and
obsoletes a custom combine SI uses for i1 setcc (sext(i1), 0, setne)
since the constant will now be shrunk to i1.

llvm-svn: 224691
2014-12-21 16:48:42 +00:00
Sanjay Patel 0428a5786e merge consecutive stores of extracted vector elements
Add a path to DAGCombiner::MergeConsecutiveStores() 
to combine multiple scalar stores when the store operands
are extracted vector elements. This is a partial fix for
PR21711 ( http://llvm.org/bugs/show_bug.cgi?id=21711 ).

For the new test case, codegen improves from:

   vmovss  %xmm0, (%rdi)
   vextractps      $1, %xmm0, 4(%rdi)
   vextractps      $2, %xmm0, 8(%rdi)
   vextractps      $3, %xmm0, 12(%rdi)
   vextractf128    $1, %ymm0, %xmm0
   vmovss  %xmm0, 16(%rdi)
   vextractps      $1, %xmm0, 20(%rdi)
   vextractps      $2, %xmm0, 24(%rdi)
   vextractps      $3, %xmm0, 28(%rdi)
   vzeroupper
   retq

To:

   vmovups	%ymm0, (%rdi)
   vzeroupper
   retq

Patch reviewed by Nadav Rotem.

Differential Revision: http://reviews.llvm.org/D6698

llvm-svn: 224611
2014-12-19 20:23:41 +00:00
Michael Kuperstein 047b1a0400 [DAGCombine] Slightly improve lowering of BUILD_VECTOR into a shuffle.
This handles the case of a BUILD_VECTOR being constructed out of elements extracted from a vector twice the size of the result vector. Previously this was always scalarized. Now, we try to construct a shuffle node that feeds on extract_subvectors.

This fixes PR15872 and provides a partial fix for PR21711.

Differential Revision: http://reviews.llvm.org/D6678

llvm-svn: 224429
2014-12-17 12:32:17 +00:00
Hans Wennborg 224cb82a39 SelectionDAG switch lowering: use 'unsigned' to count destination popularity
SwitchInst::getNumCases() returns unsinged, so using uint64_t to count cases
seems unnecessary.

Also fix a missing CHECK in the test case.

llvm-svn: 224393
2014-12-16 23:41:59 +00:00
Sanjay Patel 7129c10cae merge consecutive loads that are offset from a base address
SelectionDAG::isConsecutiveLoad() was not detecting consecutive loads
when the first load was offset from a base address. 

This patch recognizes that pattern and subtracts the offset before comparing
the second load to see if it is consecutive.

The codegen change in the new test case improves from:

vmovsd	32(%rdi), %xmm0
vmovsd	48(%rdi), %xmm1 
vmovhpd	56(%rdi), %xmm1, %xmm1
vmovhpd	40(%rdi), %xmm0, %xmm0
vinsertf128	$1, %xmm1, %ymm0, %ymm0

To:

vmovups	32(%rdi), %ymm0

An existing test case is also improved from:

vmovsd	(%rdi), %xmm0
vmovsd	16(%rdi), %xmm1
vmovsd	24(%rdi), %xmm2
vunpcklpd	%xmm2, %xmm0, %xmm0 ## xmm0 = xmm0[0],xmm2[0]
vmovhpd	8(%rdi), %xmm1, %xmm3

To:

vmovsd	(%rdi), %xmm0
vmovsd	16(%rdi), %xmm1
vmovhpd	24(%rdi), %xmm0, %xmm0
vmovhpd	8(%rdi), %xmm1, %xmm1

This patch fixes PR21771 ( http://llvm.org/bugs/show_bug.cgi?id=21771 ).

Differential Revision: http://reviews.llvm.org/D6642

llvm-svn: 224379
2014-12-16 21:57:18 +00:00
Michael Ilseman addddc441f 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.

llvm-svn: 224255
2014-12-15 18:48:43 +00:00
Matt Arsenault 810cb62962 Add target hook for whether it is profitable to reduce load widths
Add an option to disable optimization to shrink truncated larger type
loads to smaller type loads. On SI this prevents using scalar load
instructions in some cases, since there are no scalar extloads.

llvm-svn: 224084
2014-12-12 00:00:24 +00:00
Duncan P. N. Exon Smith 5bf8fef580 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
Owen Anderson 558012a3fc Fix a few instances found in SelectionDAG where we were not handling F16 at parity with F32 and F64.
llvm-svn: 223760
2014-12-09 06:50:39 +00:00
Justin Bogner 61ba2e3996 InstrProf: An intrinsic and lowering for instrumentation based profiling
Introduce the ``llvm.instrprof_increment`` intrinsic and the
``-instrprof`` pass. These provide the infrastructure for writing
counters for profiling, as in clang's ``-fprofile-instr-generate``.

The implementation of the instrprof pass is ported directly out of the
CodeGenPGO classes in clang, and with the followup in clang that rips
that code out to use these new intrinsics this ends up being NFC.

Doing the instrumentation this way opens some doors in terms of
improving the counter performance. For example, this will make it
simple to experiment with alternate lowering strategies, and allows us
to try handling profiling specially in some optimizations if we want
to.

Finally, this drastically simplifies the frontend and puts all of the
lowering logic in one place.

llvm-svn: 223672
2014-12-08 18:02:35 +00:00
Hans Wennborg 08de833c1c SelectionDAG switch lowering: Replace unreachable default with most popular case.
This can significantly reduce the size of the switch, allowing for more
efficient lowering.

I also worked with the idea of exploiting unreachable defaults by
omitting the range check for jump tables, but always ended up with a
non-neglible binary size increase. It might be worth looking into some more.

SimplifyCFG currently does this transformation, but I'm working towards changing
that so we can optimize harder based on unreachable defaults.

Differential Revision: http://reviews.llvm.org/D6510

llvm-svn: 223566
2014-12-06 01:28:50 +00:00
Simon Pilgrim be24ab367b [InstCombine] Minor optimization for bswap with binary ops
Added instcombine optimizations for BSWAP with AND/OR/XOR ops:

OP( BSWAP(x), BSWAP(y) ) -> BSWAP( OP(x, y) )
OP( BSWAP(x), CONSTANT ) -> BSWAP( OP(x, BSWAP(CONSTANT) ) )

Since its just a one liner, I've also added BSWAP to the DAGCombiner equivalent as well:

fold (OP (bswap x), (bswap y)) -> (bswap (OP x, y))

Refactored bswap-fold tests to use FileCheck instead of just checking that the bswaps had gone.

Differential Revision: http://reviews.llvm.org/D6407

llvm-svn: 223349
2014-12-04 09:44:01 +00:00
Elena Demikhovsky f1de34b84d 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
Hal Finkel bbdee93638 [PowerPC] Implement readcyclecounter for PPC32
We've long supported readcyclecounter on PPC64, but it is easier there (the
read of the 64-bit time-base register can be accomplished via a single
instruction). This now provides an implementation for PPC32 as well. On PPC32,
the time-base register is still 64 bits, but can only be read 32 bits at a time
via two separate SPRs. The ISA manual explains how to do this properly (it
involves re-reading the upper bits and looping if the counter has wrapped while
being read).

This requires PPC to implement a custom integer splitting legalization for the
READCYCLECOUNTER node, turning it into a target-specific SDAG node, which then
gets turned into a pseudo-instruction, which is then expanded to the necessary
sequence (which has three SPR reads, the comparison and the branch).

Thanks to Paul Hargrove for pointing out to me that this was still unimplemented.

llvm-svn: 223161
2014-12-02 22:01:00 +00:00
Philip Reames 72fbe7a6f0 Restructure some assertion checking based on post commit feedback by Aaron and Tom.
llvm-svn: 223150
2014-12-02 21:01:48 +00:00
Philip Reames f814a511da Appease a build bot complaining about an unused variable that's used in an assertion.
llvm-svn: 223142
2014-12-02 19:28:57 +00:00
Philip Reames 1a1bdb22bf [Statepoints 3/4] Statepoint infrastructure for garbage collection: SelectionDAGBuilder
This is the third patch in a small series.  It contains the CodeGen support for lowering the gc.statepoint intrinsic sequences (223078) to the STATEPOINT pseudo machine instruction (223085).  The change also includes the set of helper routines and classes for working with gc.statepoints, gc.relocates, and gc.results since the lowering code uses them.  

With this change, gc.statepoints should be functionally complete.  The documentation will follow in the fourth change, and there will likely be some cleanup changes, but interested parties can start experimenting now.

I'm not particularly happy with the amount of code or complexity involved with the lowering step, but at least it's fairly well isolated.  The statepoint lowering code is split into it's own files and anyone not working on the statepoint support itself should be able to ignore it.  

During the lowering process, we currently spill aggressively to stack. This is not entirely ideal (and we have plans to do better), but it's functional, relatively straight forward, and matches closely the implementations of the patchpoint intrinsics.  Most of the complexity comes from trying to keep relocated copies of values in the same stack slots across statepoints.  Doing so avoids the insertion of pointless load and store instructions to reshuffle the stack.  The current implementation isn't as effective as I'd like, but it is functional and 'good enough' for many common use cases.  

In the long term, I'd like to figure out how to integrate the statepoint lowering with the register allocator.  In principal, we shouldn't need to eagerly spill at all.  The register allocator should do any spilling required and the statepoint should simply record that fact.  Depending on how challenging that turns out to be, we may invest in a smarter global stack slot assignment mechanism as a stop gap measure.  

Reviewed by: atrick, ributzka

llvm-svn: 223137
2014-12-02 18:50:36 +00:00
Hans Wennborg 5bef5b522b Revert r223049, r223050 and r223051 while investigating test failures.
I didn't foresee affecting the Clang test suite :/

llvm-svn: 223054
2014-12-01 17:36:43 +00:00
Hans Wennborg 1571336fb2 SelectionDAG switch lowering: Replace unreachable default with most popular case.
This can significantly reduce the size of the switch, allowing for more
efficient lowering.

I also worked with the idea of exploiting unreachable defaults by
omitting the range check for jump tables, but always ended up with a
non-neglible binary size increase. It might be worth looking into some more.

llvm-svn: 223049
2014-12-01 17:08:32 +00:00