246 Commits

Author SHA1 Message Date
Sanjay Patel
be9ee96926 [X86, AVX] instcombine common cases of vperm2* intrinsics into shuffles
vperm2* intrinsics are just shuffles. 
In a few special cases, they're not even shuffles.

Optimizing intrinsics in InstCombine is better than
handling this in the front-end for at least two reasons:

1. Optimizing custom-written SSE intrinsic code at -O0 makes vector coders
   really angry (and so I have regrets about some patches from last week).

2. Doing mask conversion logic in header files is hard to write and 
   subsequently read.

There are a couple of TODOs in this patch to complete this optimization.

Differential Revision: http://reviews.llvm.org/D8486



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232852 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-20 21:47:56 +00:00
David Majnemer
9c2d178707 InstCombine: Don't fold call bitcast into args if callee is byval
This fixes a bug reported here:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20150309/265341.html

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231948 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-11 18:03:05 +00:00
Mehdi Amini
529919ff31 DataLayout is mandatory, update the API to reflect it with references.
Summary:
Now that the DataLayout is a mandatory part of the module, let's start
cleaning the codebase. This patch is a first attempt at doing that.

This patch is not exactly NFC as for instance some places were passing
a nullptr instead of the DataLayout, possibly just because there was a
default value on the DataLayout argument to many functions in the API.
Even though it is not purely NFC, there is no change in the
validation.

I turned as many pointer to DataLayout to references, this helped
figuring out all the places where a nullptr could come up.

I had initially a local version of this patch broken into over 30
independant, commits but some later commit were cleaning the API and
touching part of the code modified in the previous commits, so it
seemed cleaner without the intermediate state.

Test Plan:

Reviewers: echristo

Subscribers: llvm-commits

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231740 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 02:37:25 +00:00
Hal Finkel
532af6859f [InstCombine/PowerPC] Convert aligned QPX load/store intrinsics into loads/stores
InstCombine has long had logic to convert aligned Altivec load/store intrinsics
into regular loads and stores. This mirrors that functionality for QPX vector
load/store intrinsics.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230660 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-26 18:56:03 +00:00
Ramkumar Ramachandra
0608cec657 InstCombine: propagate deref via new addDereferenceableAttr
The "dereferenceable" attribute cannot be added via .addAttribute(),
since it also expects a size in bytes. AttrBuilder#addAttribute or
AttributeSet#addAttribute is wrapped by classes Function, InvokeInst,
and CallInst. Add corresponding wrappers to
AttrBuilder#addDereferenceableAttr.

Having done this, propagate the dereferenceable attribute via
gc.relocate, adding a test to exercise it. Note that -datalayout is
required during execution over and above -instcombine, because
InstCombine only optionally requires DataLayoutPass.

Differential Revision: http://reviews.llvm.org/D7510

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229265 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-14 19:37:54 +00:00
Chandler Carruth
3e77df419d Revert r228556: InstCombine: propagate nonNull through assume
This commit isn't using the correct context, and is transfoming calls
that are operands to loads rather than calls that are operands to an
icmp feeding into an assume. I've replied on the original review thread
with a very reduced test case and some thoughts on how to rework this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228677 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-10 08:07:32 +00:00
Ramkumar Ramachandra
5439a80dca InstCombine: propagate nonNull through assume
Make assume (load (call|invoke) != null) set nonNull return attribute
for the call and invoke. Also include tests.

Differential Revision: http://reviews.llvm.org/D7107

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228556 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-09 01:13:13 +00:00
Chandler Carruth
884f263eab [PM] Rename InstCombine.h to InstCombineInternal.h in preparation for
creating a non-internal header file for the InstCombine pass.

I thought about calling this InstCombiner.h or in some way more clearly
associating it with the InstCombiner clas that it is primarily defining,
but there are several other utility interfaces defined within this for
InstCombine. If, in the course of refactoring, those end up moving
elsewhere or going away, it might make more sense to make this the
combiner's header alone.

Naturally, this is a bikeshed to a certain degree, so feel free to lobby
for a different shade of paint if this name just doesn't suit you.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226783 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-22 05:25:13 +00:00
David Majnemer
c070e4e528 InstCombine: Don't strip bitcasts off of callsites marked 'thunk'
The return type of a thunk is meaningless, we just want the arguments
and return value to be forwarded.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226708 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-21 22:32:04 +00:00
Chandler Carruth
67d5257374 [PM] Simplify (ha! ha!) the way that instcombine calls the
SimplifyLibCalls utility by sinking it into the specific call part of
the combiner.

This will avoid us needing to do any contortions to build this object in
a subsequent refactoring I'm doing and seems generally better factored.
We don't need this utility everywhere and it carries no interesting
state so we might as well build it on demand.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226654 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-21 11:23:40 +00:00
David Majnemer
72a9513e92 Analysis: Reformulate WillNotOverflowUnsignedAdd for reusability
WillNotOverflowUnsignedAdd's smarts will live in ValueTracking as
computeOverflowForUnsignedAdd.  It now returns a tri-state result:
never overflows, always overflows and sometimes overflows.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225329 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-07 00:39:50 +00:00
David Majnemer
c8c560867f InstCombine: Just a small tidy-up
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225328 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-07 00:39:42 +00:00
David Majnemer
51e4a66417 InstCombine: Bitcast call arguments from/to pointer/integer type
Try harder to get rid of bitcast'd calls by ptrtoint/inttoptr'ing
arguments and return values when DataLayout says it is safe to do so.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225254 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-06 08:41:31 +00:00
Chandler Carruth
5a9cd4d44e [PM] Split the AssumptionTracker immutable pass into two separate APIs:
a cache of assumptions for a single function, and an immutable pass that
manages those caches.

The motivation for this change is two fold. Immutable analyses are
really hacks around the current pass manager design and don't exist in
the new design. This is usually OK, but it requires that the core logic
of an immutable pass be reasonably partitioned off from the pass logic.
This change does precisely that. As a consequence it also paves the way
for the *many* utility functions that deal in the assumptions to live in
both pass manager worlds by creating an separate non-pass object with
its own independent API that they all rely on. Now, the only bits of the
system that deal with the actual pass mechanics are those that actually
need to deal with the pass mechanics.

Once this separation is made, several simplifications become pretty
obvious in the assumption cache itself. Rather than using a set and
callback value handles, it can just be a vector of weak value handles.
The callers can easily skip the handles that are null, and eventually we
can wrap all of this up behind a filter iterator.

For now, this adds boiler plate to the various passes, but this kind of
boiler plate will end up making it possible to port these passes to the
new pass manager, and so it will end up factored away pretty reasonably.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225131 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-04 12:03:27 +00:00
David Majnemer
5e9c6212a8 InstCombine: Detect when llvm.umul.with.overflow always overflows
We know overflow always occurs if both ~LHSKnownZero * ~RHSKnownZero
and LHSKnownOne * RHSKnownOne overflow.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225077 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-02 07:29:47 +00:00
David Majnemer
25e8e79fab Analysis: Reformulate WillNotOverflowUnsignedMul for reusability
WillNotOverflowUnsignedMul's smarts will live in ValueTracking as
computeOverflowForUnsignedMul.  It now returns a tri-state result:
never overflows, always overflows and sometimes overflows.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225076 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-02 07:29:43 +00:00
Philip Reames
91a083c57f Carry facts about nullness and undef across GC relocation
This change implements four basic optimizations:

    If a relocated value isn't used, it doesn't need to be relocated.
    If the value being relocated is null, relocation doesn't change that. (Technically, this might be collector specific. I don't know of one which it doesn't work for though.)
    If the value being relocated is undef, the relocation is meaningless.
    If the value being relocated was known nonnull, the relocated pointer also isn't null. (Since it points to the same source language object.)

I outlined other planned work in comments.

Differential Revision: http://reviews.llvm.org/D6600



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224968 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-29 23:27:30 +00:00
Erik Eckstein
96bd465d6c Strength reduce intrinsics with overflow into regular arithmetic operations if possible.
Some intrinsics, like s/uadd.with.overflow and umul.with.overflow, are already strength reduced.
This change adds other arithmetic intrinsics: s/usub.with.overflow, smul.with.overflow.
It completes the work on PR20194.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224417 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-17 07:29:19 +00:00
Andrea Di Biagio
f27500040b [InstCombine][X86] Improved folding of calls to Intrinsic::x86_sse4a_insertqi.
This patch teaches the instruction combiner how to fold a call to 'insertqi' if
the 'length field' (3rd operand) is set to zero, and if the sum between
field 'length' and 'bit index' (4th operand) is bigger than 64.

From the AMD64 Architecture Programmer's Manual:
1. If the sum of the bit index + length field is greater than 64, then the
   results are undefined;
2. A value of zero in the field length is defined as a length of 64.

This patch improves the existing combining logic for intrinsic 'insertqi'
adding extra checks to address both point 1. and point 2.

Differential Revision: http://reviews.llvm.org/D6583


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224054 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-11 20:44:59 +00:00
Erik Eckstein
1bf1224a06 Refactor creation of overflow result tuples in InstCombineCalls.
Extract the creation of overflow result tuples in a separate function. NFC.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224006 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-11 08:02:30 +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
Philip Reames
d021bb8003 [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





git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223137 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-02 18:50:36 +00:00
Bill Schmidt
fc22bfd921 [PowerPC] Add vec_vsx_ld and vec_vsx_st intrinsics
This patch enables the vec_vsx_ld and vec_vsx_st intrinsics for
PowerPC, which provide programmer access to the lxvd2x, lxvw4x,
stxvd2x, and stxvw4x instructions.

New LLVM intrinsics are provided to represent these four instructions
in IntrinsicsPowerPC.td.  These are patterned after the similar
intrinsics for lvx and stvx (Altivec).  In PPCInstrVSX.td, these
intrinsics are tied to the code gen patterns, with additional patterns
to allow plain vanilla loads and stores to still generate these
instructions.

At -O1 and higher the intrinsics are immediately converted to loads
and stores in InstCombineCalls.cpp.  This will open up more
optimization opportunities while still allowing the correct
instructions to be generated.  (Similar code exists for aligned
Altivec loads and stores.)

The new intrinsics are added to the code that checks for consecutive
loads and stores in PPCISelLowering.cpp, as well as to
PPCTargetLowering::getTgtMemIntrinsic().

There's a new test to verify the correct instructions are generated.
The loads and stores tend to be reordered, so the test just counts
their number.  It runs at -O2, as it's not very effective to test this
at -O0, when many unnecessary loads and stores are generated.

I ended up having to modify vsx-fma-m.ll.  It turns out this test case
is slightly unreliable, but I don't know a good way to prevent
problems with it.  The xvmaddmdp instructions read and write the same
register, which is one of the multiplicands.  Commutativity allows
either to be chosen.  If the FMAs are reordered differently than
expected by the test, the register assignment can be different as a
result.  Hopefully this doesn't change often.

There is a companion patch for Clang.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221767 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 04:19:40 +00:00
Philip Reames
a03cda02ab Canonicalize an assume(load != null) into !nonnull metadata
We currently have two ways of informing the optimizer that the result of a load is never null: metadata and assume. This change converts the second in to the former. This avoids a need to implement optimizations using both forms.

We should probably extend this basic idea to metadata of other forms; in particular, range metadata. We view is that assumes should be considered a "last resort" for when there isn't a more canonical way to represent something.

Reviewed by: Hal
Differential Revision: http://reviews.llvm.org/D5951



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221737 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 23:33:19 +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
3a84a6377c IR: MDNode => Value: Instruction::getMetadata()
Change `Instruction::getMetadata()` to return `Value` as part of
PR21433.

Update most callers to use `Instruction::getMDNode()`, which wraps the
result in a `cast_or_null<MDNode>`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221024 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-01 00:10:31 +00:00
Frederic Riss
648728d4e4 Assert that ValueHandleBase::ValueIsRAUWd doesn't change the tracked Value type.
This invariant is enforced in Value::replaceAllUsesWith, thus it seems
logical to apply it also to ValueHandles. This commit fixes InstCombine
to not trigger the assertion during the removal of constant bitcasts in
call instructions.

Differential Revision: http://reviews.llvm.org/D5828

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220468 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-23 04:08:42 +00:00
Matt Arsenault
252134602f Add minnum / maxnum intrinsics
These are named following the IEEE-754 names for these
functions, rather than the libm fmin / fmax to avoid
possible ambiguities. Some languages may implement something
resembling fmin / fmax which return NaN if either operand is
to propagate errors. These implement the IEEE-754 semantics
of returning the other operand if either is a NaN representing
missing data.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220341 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-21 23:00:20 +00:00
Hal Finkel
bda7a45f8e [InstCombine] Simplify the logic from r219067 using ValueTracking
Joerg suggested on IRC that I look at generalizing the logic from r219067 to
handle more general redundancies (like removing an assume(x > 3) dominated by
an assume(x > 5)). The way to do this would be to ask ValueTracking to
determine the value of the i1 argument. It turns out that ValueTracking is not
very good at this right now (although it does get the trivial redundancy case)
because it does not understand ICmps. Nevertheless, the resulting code in
InstCombine is simpler than r219067, so we might as well do it now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219070 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-05 00:53:02 +00:00
Hal Finkel
a5fda70c13 [InstCombine] Remove redundant @llvm.assume intrinsics
For any @llvm.assume intrinsic, if there is another which dominates it and uses
the same condition, then it is redundant and can be removed. While this does
not alter the semantics of the @llvm.assume intrinsics, it makes subsequent
handling more efficient (and the resulting IR easier to read).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219067 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-04 21:27:06 +00:00
Hal Finkel
851b04c920 Make use of @llvm.assume in ValueTracking (computeKnownBits, etc.)
This change, which allows @llvm.assume to be used from within computeKnownBits
(and other associated functions in ValueTracking), adds some (optional)
parameters to computeKnownBits and friends. These functions now (optionally)
take a "context" instruction pointer, an AssumptionTracker pointer, and also a
DomTree pointer, and most of the changes are just to pass this new information
when it is easily available from InstSimplify, InstCombine, etc.

As explained below, the significant conceptual change is that known properties
of a value might depend on the control-flow location of the use (because we
care that the @llvm.assume dominates the use because assumptions have
control-flow dependencies). This means that, when we ask if bits are known in a
value, we might get different answers for different uses.

The significant changes are all in ValueTracking. Two main changes: First, as
with the rest of the code, new parameters need to be passed around. To make
this easier, I grouped them into a structure, and I made internal static
versions of the relevant functions that take this structure as a parameter. The
new code does as you might expect, it looks for @llvm.assume calls that make
use of the value we're trying to learn something about (often indirectly),
attempts to pattern match that expression, and uses the result if successful.
By making use of the AssumptionTracker, the process of finding @llvm.assume
calls is not expensive.

Part of the structure being passed around inside ValueTracking is a set of
already-considered @llvm.assume calls. This is to prevent a query using, for
example, the assume(a == b), to recurse on itself. The context and DT params
are used to find applicable assumptions. An assumption needs to dominate the
context instruction, or come after it deterministically. In this latter case we
only handle the specific case where both the assumption and the context
instruction are in the same block, and we need to exclude assumptions from
being used to simplify their own ephemeral values (those which contribute only
to the assumption) because otherwise the assumption would prove its feeding
comparison trivial and would be removed.

This commit adds the plumbing and the logic for a simple masked-bit propagation
(just enough to write a regression test). Future commits add more patterns
(and, correspondingly, more regression tests).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217342 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-07 18:57:58 +00:00
Hal Finkel
3666e7f4c1 Add an Assumption-Tracking Pass
This adds an immutable pass, AssumptionTracker, which keeps a cache of
@llvm.assume call instructions within a module. It uses callback value handles
to keep stale functions and intrinsics out of the map, and it relies on any
code that creates new @llvm.assume calls to notify it of the new instructions.
The benefit is that code needing to find @llvm.assume intrinsics can do so
directly, without scanning the function, thus allowing the cost of @llvm.assume
handling to be negligible when none are present.

The current design is intended to be lightweight. We don't keep track of
anything until we need a list of assumptions in some function. The first time
this happens, we scan the function. After that, we add/remove @llvm.assume
calls from the cache in response to registration calls and ValueHandle
callbacks.

There are no new direct test cases for this pass, but because it calls it
validation function upon module finalization, we'll pick up detectable
inconsistencies from the other tests that touch @llvm.assume calls.

This pass will be used by follow-up commits that make use of @llvm.assume.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217334 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-07 12:44:26 +00:00
Craig Topper
3512034554 Simplify creation of a bunch of ArrayRefs by using None, makeArrayRef or just letting them be implicitly created.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216525 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-27 05:25:25 +00:00
Hal Finkel
5cb8ab5b5a Canonicalization for @llvm.assume
Adds simple logical canonicalization of assumption intrinsics to instcombine,
currently:
 - invariant(a && b) -> invariant(a); invariant(b)
 - invariant(!(a || b)) -> invariant(!a); invariant(!b)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213977 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-25 21:45:17 +00:00
Benjamin Kramer
9c1df9164c InstCombine: Strength reduce sadd.with.overflow into a regular nsw add if we can prove that it cannot overflow.
PR20194

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212331 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-04 10:22:21 +00:00
Matt Arsenault
d9b35435b8 R600/SI: Add intrinsics for various math instructions.
These will be used for custom lowering and for library
implementations of various math functions, so it's useful
to expose these as builtins.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211247 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-19 01:19:19 +00:00
Bill Schmidt
542fdf5fba [PPC64LE] Correct vperm -> shuffle transform for little endian
As discussed in cfe commit r210279, the correct little-endian
semantics for the vec_perm Altivec interfaces are implemented by
reversing the order of the input vectors and complementing the permute
control vector.  This converts the desired permute from little endian
element order into the big endian element order that the underlying
PowerPC vperm instruction uses.  This is represented with a
ppc_altivec_vperm intrinsic function.

The instruction combining pass contains code to convert a
ppc_altivec_vperm intrinsic into a vector shuffle operation when the
intrinsic has a permute control vector (mask) that is a constant.
However, the vector shuffle operation assumes that vector elements are
in natural order for their endianness, so for little endian code we
will get the wrong result with the existing transformation.

This patch reverses the semantic change to vec_perm that was performed
in altivec.h by once again swapping the input operands and
complementing the permute control vector, returning the element
ordering to little endian.

The correctness of this code is tested by the new perm.c test added in
a previous patch, and by other tests in the test suite that fail
without this patch.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210282 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-05 19:46:04 +00:00
Filipe Cabecinhas
078862e67f Post-commit fixes for r209643
Detected by Daniel Jasper, Ilia Filippov, and Andrea Di Biagio
Fixed the argument order to select (the mask semantics to blendv* are the
inverse of select) and fixed the tests
Added parenthesis to the assert condition
Ran clang-format

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209667 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-27 16:54:33 +00:00
Daniel Jasper
ae85c73d4a Fix bad assert.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209648 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-27 09:55:37 +00:00
Filipe Cabecinhas
c5f611404c Convert some X86 blendv* intrinsics into IR.
Summary:
Implemented an InstCombine transformation that takes a blendv* intrinsic
call and translates it into an IR select, if the mask is constant.

This will eventually get lowered into blends with immediates if possible,
or pblendvb (with an option to further optimize if we can transform the
pblendvb into a blend+immediate instruction, depending on the selector).
It will also enable optimizations by the IR passes, which give up on
sight of the intrinsic.

Both the transformation and the lowering of its result to asm got shiny
new tests.

The transformation is a bit convoluted because of blendvp[sd]'s
definition:

Its mask is a floating point value! This forces us to convert it and get
the highest bit. I suppose this happened because the mask has type
__m128 in Intel's intrinsic and v4sf (for blendps) in gcc's builtin.

I will send an email to llvm-dev to discuss if we want to change this or
not.

Reviewers: grosbach, delena, nadav

Differential Revision: http://reviews.llvm.org/D3859

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209643 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-27 03:42:20 +00:00
Tim Northover
29f94c7201 AArch64/ARM64: move ARM64 into AArch64's place
This commit starts with a "git mv ARM64 AArch64" and continues out
from there, renaming the C++ classes, intrinsics, and other
target-local objects for consistency.

"ARM64" test directories are also moved, and tests that began their
life in ARM64 use an arm64 triple, those from AArch64 use an aarch64
triple. Both should be equivalent though.

This finishes the AArch64 merge, and everyone should feel free to
continue committing as normal now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209577 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-24 12:50:23 +00:00
Jay Foad
6b543713a2 Rename ComputeMaskedBits to computeKnownBits. "Masked" has been
inappropriate since it lost its Mask parameter in r154011.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208811 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-14 21:14:37 +00:00
Rafael Espindola
2259a26a5d Also handle ConstantAggregateZero when optimizing vpermilvar*.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207582 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-29 22:20:40 +00:00
Rafael Espindola
8263bafd17 Remove tabs.
Sorry, new machine and I forgot to change the editor setting.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207578 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-29 21:02:37 +00:00
Rafael Espindola
984f2fc09e Two fixes to the vpermilvar optimization.
The instcomine logic to handle vpermilvar's pd and 256 variants was incorrect.
The _256 variants have indexes into the individual 128 bit lanes and in all
cases it also has to mask out unused bits.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207577 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-29 20:41:54 +00:00
Andrea Di Biagio
96db9b8ed8 [InstCombine][X86] Teach how to fold calls to SSE2/AVX2 packed logical shift
right intrinsics.

A packed logical shift right with a shift count bigger than or equal to the
element size always produces a zero vector. In all other cases, it can be
safely replaced by a 'lshr' instruction.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207299 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-26 01:03:22 +00:00
Craig Topper
8d7221ccf5 [C++] Use 'nullptr'. Transforms edition.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207196 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 05:29:35 +00:00
Michael J. Spencer
96363d5001 [InstCombine][x86] Constant fold psll intrinsics.
This excludes avx512 as I don't have hardware to verify. It excludes _dq
variants because they are represented in the IR as <{2,4} x i64> when it's
actually a byte shift of the entire i{128,265}.

This also excludes _dq_bs as they aren't at all supported by the backend.
There are also no corresponding instructions in the ISA. I have no idea why
they exist...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207058 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-24 00:58:18 +00:00
Filipe Cabecinhas
cd9f6b870e Optimize some special cases for SSE4a insertqi
Summary:
Since the upper 64 bits of the destination register are undefined when
performing this operation, we can substitute it and let the optimizer
figure out that only a copy is needed.

Also added range merging, if an instruction copies a range that can be
merged with a previous copied range.

Added test cases for both optimizations.

Reviewers: grosbach, nadav

CC: llvm-commits

Differential Revision: http://reviews.llvm.org/D3357

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207055 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-24 00:38:14 +00:00
Chandler Carruth
7962dbdc65 [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE
definition below all of the header #include lines, lib/Transforms/...
edition.

This one is tricky for two reasons. We again have a couple of passes
that define something else before the includes as well. I've sunk their
name macros with the DEBUG_TYPE.

Also, InstCombine contains headers that need DEBUG_TYPE, so now those
headers #define and #undef DEBUG_TYPE around their code, leaving them
well formed modular headers. Fixing these headers was a large motivation
for all of these changes, as "leaky" macros of this form are hard on the
modules implementation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206844 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-22 02:55:47 +00:00