Commit Graph

7034 Commits

Author SHA1 Message Date
Pawel Bylica 06407c0320 Fix shl folding in DAG combiner.
Summary: The code responsible for shl folding in the DAGCombiner was assuming incorrectly that all constants are less than 64 bits. This patch simply changes the way values are compared.

Test Plan: A regression test included.

Reviewers: andreadb

Reviewed By: andreadb

Subscribers: andreadb, test, llvm-commits

Differential Revision: http://reviews.llvm.org/D10602

llvm-svn: 240291
2015-06-22 15:58:11 +00:00
Chandler Carruth c3f49eb451 [PM/AA] Hoist the AliasResult enum out of the AliasAnalysis class.
This will allow classes to implement the AA interface without deriving
from the class or referencing an internal enum of some other class as
their return types.

Also, to a pretty fundamental extent, concepts such as 'NoAlias',
'MayAlias', and 'MustAlias' are first class concepts in LLVM and we
aren't saving anything by scoping them heavily.

My mild preference would have been to use a scoped enum, but that
feature is essentially completely broken AFAICT. I'm extremely
disappointed. For example, we cannot through any reasonable[1] means
construct an enum class (or analog) which has scoped names but converts
to a boolean in order to test for the possibility of aliasing.

[1]: Richard Smith came up with a "solution", but it requires class
templates, and lots of boilerplate setting up the enumeration multiple
times. Something like Boost.PP could potentially bundle this up, but
even that would be quite painful and it doesn't seem realistically worth
it. The enum class solution would probably work without the need for
a bool conversion.

Differential Revision: http://reviews.llvm.org/D10495

llvm-svn: 240255
2015-06-22 02:16:51 +00:00
Hans Wennborg 6ed81cbcdb Switch lowering: add heuristic for filling leaf nodes in the weight-balanced binary search tree
Sparse switches with profile info are lowered as weight-balanced BSTs. For
example, if the node weights are {1,1,1,1,1,1000}, the right-most node would
end up in a tree by itself, bringing it closer to the top.

However, a leaf in this BST can contain up to 3 cases, and having a single
case in a leaf node as in the example means the tree might become
unnecessarily high.

This patch adds a heauristic to the pivot selection algorithm that moves more
cases into leaf nodes unless that would lower their rank. It still doesn't
yield the optimal tree in every case, but I believe it's conservatibely correct.

llvm-svn: 240224
2015-06-20 17:14:07 +00:00
Sanjoy Das d200893741 [Statepoint] Remove unnecessary argument from Statepoint::getRelocates
NFC.

llvm-svn: 240198
2015-06-20 00:01:03 +00:00
Alexander Kornienko 70bc5f1398 Fixed/added namespace ending comments using clang-tidy. NFC
The patch is generated using this command:

tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
  -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
  llvm/lib/


Thanks to Eugene Kosov for the original patch!

llvm-svn: 240137
2015-06-19 15:57:42 +00:00
Hans Wennborg 67d492a544 Switch lowering: enable whole-switch jump tables at -O0.
To same compile time, the analysis to find dense case-clusters in switches is
not done at -O0. However, when the whole switch is dense enough, it is easy to
turn it into a jump table, resulting in much faster code with no extra effort.

llvm-svn: 240071
2015-06-18 22:22:30 +00:00
Sanjay Patel 8730ef78f8 fix typo; NFC
llvm-svn: 240022
2015-06-18 15:53:33 +00:00
Sanjay Patel a3f423b4fc remove unnecessary casts; NFC
llvm-svn: 239942
2015-06-17 20:54:46 +00:00
David Majnemer 7fddeccb8b Move the personality function from LandingPadInst to Function
The personality routine currently lives in the LandingPadInst.

This isn't desirable because:
- All LandingPadInsts in the same function must have the same
  personality routine.  This means that each LandingPadInst beyond the
  first has an operand which produces no additional information.

- There is ongoing work to introduce EH IR constructs other than
  LandingPadInst.  Moving the personality routine off of any one
  particular Instruction and onto the parent function seems a lot better
  than have N different places a personality function can sneak onto an
  exceptional function.

Differential Revision: http://reviews.llvm.org/D10429

llvm-svn: 239940
2015-06-17 20:52:32 +00:00
Sanjay Patel dcaa53791c fix typos in comments; NFC
llvm-svn: 239916
2015-06-17 16:34:48 +00:00
Chandler Carruth ac80dc7532 [PM/AA] Remove the Location typedef from the AliasAnalysis class now
that it is its own entity in the form of MemoryLocation, and update all
the callers.

This is an entirely mechanical change. References to "Location" within
AA subclases become "MemoryLocation", and elsewhere
"AliasAnalysis::Location" becomes "MemoryLocation". Hope that helps
out-of-tree folks update.

llvm-svn: 239885
2015-06-17 07:18:54 +00:00
Sanjay Patel 0fcc53f6d6 rename variables; NFC
...because I see 'StoreBW' and read it as 'store bandwidth'

llvm-svn: 239850
2015-06-16 20:47:19 +00:00
Sanjay Patel bb385ed454 extract some code into a helper function for MergeConsecutiveStores(); NFCI
llvm-svn: 239847
2015-06-16 20:05:00 +00:00
Sanjay Patel f134048b1d propagate IR-level fast-math-flags to DAG nodes, disabled by default
This is an updated version of the patch that was checked in at:
http://reviews.llvm.org/rL237046

but subsequently reverted because it exposed a bug in the DAG Combiner:
http://reviews.llvm.org/D9893

This time, there's an enablement flag ("EnableFMFInDAG") around the code in
SelectionDAGBuilder where we copy the set of FP optimization flags from IR
instructions to DAG nodes. So, in theory, there should be no functional change
from this patch as-is, but it will allow testing with the added functionality
to proceed via "-enable-fmf-dag" passed to llc.

This patch adds the minimum plumbing necessary to use IR-level
fast-math-flags (FMF) in the backend without actually using
them for anything yet. This is a follow-on to:
http://reviews.llvm.org/rL235997

Differential Revision: http://reviews.llvm.org/D10403

llvm-svn: 239828
2015-06-16 16:25:43 +00:00
Matt Arsenault ed891b5561 Revert "Revert "Fix merges of non-zero vector stores""
Reapply r239539. Don't assume the collected number of
stores is the same vector size. Just take the first N
stores to fill the vector.

llvm-svn: 239825
2015-06-16 15:51:48 +00:00
Simon Pilgrim d3f6427446 [DAGCombiner] Added BSWAP(BSWAP(x)) -> x combine pattern.
llvm-svn: 239682
2015-06-13 16:25:12 +00:00
Simon Pilgrim 2c35e7a264 [SelectionDAG] Added assertions + UNDEF handling for BSWAP node creation.
llvm-svn: 239679
2015-06-13 15:23:58 +00:00
Simon Pilgrim 011381d48b [DAGCombiner] Added BSWAP vector constant folding support.
llvm-svn: 239675
2015-06-13 14:08:15 +00:00
Simon Pilgrim 096cccd01a Stripped trailing whitespace. NFC.
llvm-svn: 239674
2015-06-13 12:57:36 +00:00
Reid Kleckner 2691c59e97 Revert "Fix merges of non-zero vector stores"
This reverts commit r239539.

It was causing SDAG assertions while building freetype.

llvm-svn: 239543
2015-06-11 17:25:24 +00:00
Matt Arsenault e23a063dc3 Fix merges of non-zero vector stores
Now actually stores the non-zero constant instead of 0.
I somehow forgot to include this part of r238108.

The test change was just an independent instruction order swap,
so just add another check line to satisfy CHECK-NEXT.

llvm-svn: 239539
2015-06-11 16:03:52 +00:00
Igor Laevsky 346ff628f7 [StatepointLowering] Reuse stack slots across basic blocks
During statepoint lowering we can sometimes avoid spilling of the value if we know that it was already spilled for previous statepoint.
We were doing this by checking if incoming statepoint value was lowered into load from stack slot. This was working only in boundaries of one basic block.

But instead of looking at the lowered node we can look directly at the llvm-ir value and if it was gc.relocate (or some simple modification of it) look up stack slot for it's derived pointer and reuse stack slot from it. This allows us to look across basic block boundaries.

Differential Revision: http://reviews.llvm.org/D10251

llvm-svn: 239472
2015-06-10 12:31:53 +00:00
Reid Kleckner f12c030f48 [WinEH] Add 32-bit SEH state table emission prototype
This gets all the handler info through to the asm printer and we can
look at the .xdata tables now. I've convinced one small catch-all test
case to work, but other than that, it would be a stretch to say this is
functional.

The state numbering algorithm avoids doing any scope reconstruction as
we do for C++ to simplify the implementation.

llvm-svn: 239433
2015-06-09 21:42:19 +00:00
Matt Arsenault 705eb8f6b1 Implement computeKnownBits for min/max nodes
llvm-svn: 239378
2015-06-09 00:52:41 +00:00
Simon Pilgrim 4791f6d89b [DAGCombiner] Added CTLZ vector constant folding support.
llvm-svn: 239305
2015-06-08 16:19:00 +00:00
Simon Pilgrim c789e1d57b [DAGCombiner] Added CTTZ vector constant folding support.
llvm-svn: 239293
2015-06-08 09:57:09 +00:00
Simon Pilgrim 68cd237f57 [DAGCombiner] Added CTPOP vector constant folding support.
Added tests to the existing SSE/AVX test files.

llvm-svn: 239252
2015-06-07 15:37:14 +00:00
Fiona Glaser 666e352440 DAGCombiner: don't duplicate (fmul x, c) in visitFNEG if fneg is free
For targets with a free fneg, this fold is always a net loss if it
ends up duplicating the multiply, so definitely avoid it.

This might be true for some targets without a free fneg too, but
I'll leave that for future investigation.

llvm-svn: 239167
2015-06-05 17:52:34 +00:00
Andrea Di Biagio eb33134ce7 Simplify code; NFC.
Also, moved test cases from CodeGen/X86/fold-buildvector-bug.ll into
CodeGen/X86/buildvec-insertvec.ll and regenerated CHECK lines using
update_llc_test_checks.py.

llvm-svn: 239142
2015-06-05 10:29:55 +00:00
Swaroop Sridhar 70d18df18f Statepoint: Fix handling of Far Immediate calls
gc.statepoint intrinsics with a far immediate call target 
were lowered incorrectly as pc-rel32 calls.

This change fixes the problem, and generates an indirect call 
via a scratch register.

For example: 

Intrinsic:
  %safepoint_token = call i32 (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* inttoptr (i64 140727162896504 to void ()*), i32 0, i32 0, i32 0, i32 0)

Old Incorrect Lowering:
  callq 140727162896504

New Correct Lowering:
  movabsq $140727162896504, %rax 
  callq *%rax

In lowerCallFromStatepoint(), the callee-target was modified and 
represented as a "TargetConstant" node, rather than a "Constant" node.
Undoing this modification enabled LowerCall() to generate the 
correct CALL instruction.

llvm-svn: 239114
2015-06-04 23:03:21 +00:00
Benjamin Kramer ff0fb6936b [SDAG switch lowering] Fix switch case -> or merging for 0 and INT_MIN
The big/small ordering here is based on signed values so SmallValue will
be INT_MIN and BigValue 0. This shouldn't be a problem but the code
assumed that BigValue always had more bits set than SmallValue.

We used to just miss the transformation, but a recent refactoring of
mine turned this into an assertion failure.

llvm-svn: 239105
2015-06-04 22:05:51 +00:00
Sergey Dmitrouk 3160d02b5b Erase constant dbgloc on reuse in PHI node
Basic block selection involves checking successor BBs for PHI nodes
that depend on the current BB.  In case such BBs are found, the value
being selected is a constant and such constant already exists in
current BB, it's value is reused.

This might lead to wrong locations in some situations, especially if
same constant value ends up being materialized twice in two different
ways, which discards that sharing and leaves us with wrong debug
location in the successor BB.

In code this involves the following sequence of calls:

 SelectionDAGBuilder::HandlePHINodesInSuccessorBlocks ->
 SelectionDAGBuilder::CopyValueToVirtualRegister ->
 SelectionDAGBuilder::getNonRegisterValue

llvm-svn: 239089
2015-06-04 20:48:40 +00:00
Andrea Di Biagio 9ac8a6b13d [DAGCombiner] Fix wrong folding of a build_vector into a blend with zero.
Method 'visitBUILD_VECTOR' in the DAGCombiner knows how to combine a
build_vector of a bunch of extract_vector_elt nodes and constant zero nodes
into a shuffle blend with a zero vector.

However, method 'visitBUILD_VECTOR' forgot that a floating point
build_vector may contain negative zero as well as positive zero.

Example:

define <2 x double> @example(<2 x double> %A) {
entry:
  %0 = extractelement <2 x double> %A, i32 0
  %1 = insertelement <2 x double> undef, double %0, i32 0
  %2 = insertelement <2 x double> %1, double -0.0, i32 1
  ret <2 x double> %2
}

Before this patch, llc (with -mattr=+sse4.1) wrongly generated
  movq   %xmm0, %xmm0  # xmm0 = xmm0[0],zero

So, the sign bit of the negative zero was effectively lost.

This patch fixes the problem by adding explicit checks for positive zero.

With this patch, llc produces the following code for the example above:
  movhpd .LCPI0_0(%rip), %xmm0

where .LCPI0_0 referes to a 'double -0'.

llvm-svn: 239070
2015-06-04 19:15:01 +00:00
Benjamin Kramer 185579bf0c [SDag switch lowering] Simplify code a bit. No functional change intended.
llvm-svn: 239056
2015-06-04 17:07:59 +00:00
Matt Arsenault ca519dc28b Pass address space to isLegalAddressingMode in DAGCombiner
No test because I don't know of a target that makes use
of address spaces and indexed load / store.

llvm-svn: 239051
2015-06-04 16:17:34 +00:00
Hans Wennborg d922915685 Switch lowering: fix assert in buildBitTests (PR23738)
When checking (High - Low + 1).sle(BitWidth), BitWidth would be truncated
to the size of the left-hand side. In the case of this PR, the left-hand
side was i4, so BitWidth=64 got truncated to 0 and the assert failed.

llvm-svn: 239048
2015-06-04 15:55:00 +00:00
James Molloy 37593732a4 Don't create a MIN/MAX node if the underlying compare has more than one use.
If the compare in a select pattern has another use then it can't be removed, so we'd just
be creating repeated code if we created a min/max node.

Spotted by Matt Arsenault!

llvm-svn: 239037
2015-06-04 13:48:23 +00:00
Sanjoy Das 513aadecac [SelectionDAG] Fix PR23603.
Summary:
LLVM's MI level notion of invariant_load is different from LLVM's IR
level notion of invariant_load with respect to dereferenceability.  The
IR notion of invariant_load only guarantees that all *non-faulting*
invariant loads result in the same value.  The MI notion of invariant
load guarantees that the load can be legally moved to any location
within its containing function.  The MI notion of invariant_load is
stronger than the IR notion of invariant_load -- an MI invariant_load is
an IR invariant_load + a guarantee that the location being loaded from
is dereferenceable throughout the function's lifetime.

Reviewers: hfinkel, reames

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D10075

llvm-svn: 238881
2015-06-02 22:33:30 +00:00
Chandler Carruth 502b23a7a9 [sdag] Add the helper I most want to the DAG -- building a bitcast
around a value using its existing SDLoc.

Start using this in just one function to save omg lines of code.

llvm-svn: 238638
2015-05-30 04:14:10 +00:00
Jim Grosbach 13760bd152 MC: Clean up MCExpr naming. NFC.
llvm-svn: 238634
2015-05-30 01:25:56 +00:00
Fiona Glaser b82e33106b SelectionDAG: fix logic for promoting shift types
r238503 fixed the problem of too-small shift types by promoting them
during legalization, but the correct solution is to promote only the
operands that actually demand promotion.

This fixes a crash on an out-of-tree target caused by trying to
promote an operand that can't be promoted.

llvm-svn: 238632
2015-05-29 23:37:22 +00:00
Benjamin Kramer f5e2fc474d Replace push_back(Constructor(foo)) with emplace_back(foo) for non-trivial types
If the type isn't trivially moveable emplace can skip a potentially
expensive move. It also saves a couple of characters.


Call sites were found with the ASTMatcher + some semi-automated cleanup.

memberCallExpr(
    argumentCountIs(1), callee(methodDecl(hasName("push_back"))),
    on(hasType(recordDecl(has(namedDecl(hasName("emplace_back")))))),
    hasArgument(0, bindTemporaryExpr(
                       hasType(recordDecl(hasNonTrivialDestructor())),
                       has(constructExpr()))),
    unless(isInTemplateInstantiation()))

No functional change intended.

llvm-svn: 238602
2015-05-29 19:43:39 +00:00
Reid Kleckner fe4d491bd9 [WinEH] Start inserting state number stores for C++ EH
This moves all the state numbering code for C++ EH to WinEHPrepare so
that we can call it from the X86 state numbering IR pass that runs
before isel.

Now we just call the same state numbering machinery and insert a bunch
of stores. It also populates MachineModuleInfo with information about
the current function.

llvm-svn: 238514
2015-05-28 22:00:24 +00:00
David Majnemer 22d2b02706 [SelectionDAG] Scalar shift amounts may require legalization
The shift amount may be too small to cope with promoted left hand side,
make sure to promote it as well.

This fixes PR23664.

llvm-svn: 238503
2015-05-28 21:29:59 +00:00
Jan Vesely 86f2fda623 SelectionDAG: Don't do libcall on div/rem if divrem is custom
v2: TargetLoweringBase:: -> TargetLowering::
    Use Ops array
v3: Explicitly use value 0 for ?DIV
    Remove redundant newline

Differential revision: http://reviews.llvm.org/D7803
reviewer: ab

llvm-svn: 238336
2015-05-27 16:54:09 +00:00
Elena Demikhovsky 1c1391ba24 Added promotion to EXTRACT_SUBVECTOR operand.
I encountered with this case in one of KNL tests for i1 vectors.
v16i1 = EXTRACT_SUBVECTOR v32i1, x

llvm-svn: 238130
2015-05-25 11:33:13 +00:00
Matt Arsenault 65ad1602b0 Add target hook to allow merging stores of nonzero constants
On GPU targets, materializing constants is cheap and stores are
expensive, so only doing this for zero vectors was silly.

Most of the new testcases aren't optimally merged, and are for
later improvements.

llvm-svn: 238108
2015-05-24 00:51:27 +00:00
Duncan P. N. Exon Smith 0c54197d31 SDAG: Give SDDbgValues their own allocator (and reset it)
Previously `SDDbgValue`s used the general allocator that lives for all
of `SelectionDAG`.  Instead, give them their own allocator, and reset it
whenever `SDDbgInfo::clear()` is called, plugging a spiritual leak.

This drops `SelectionDAGBuilder::visitIntrinsicCall()` off of my heap
profile (was at around 2% of `llc` for codegen of `-flto -g`).  Thanks
to Pete Cooper for spotting the problem and suggesting the fix.

llvm-svn: 237998
2015-05-22 05:45:19 +00:00
Duncan P. N. Exon Smith 1f0c1c4f47 SDAG: Cleanup initialization of SDDbgValue, NFC
Cleanup how `SDDbgValue` is initialized, and rearrange the fields to
save two pointers in the struct layout.  No real functionality change
though (and I doubt the memory savings would show up in a profile).

llvm-svn: 237997
2015-05-22 05:35:53 +00:00
Simon Pilgrim e054199354 [X86][SSE] Improve support for 128-bit vector sign extension
This patch improves support for sign extension of the lower lanes of vectors of integers by making use of the SSE41 pmovsx* sign extension instructions where possible, and optimizing the sign extension by shifts on pre-SSE41 targets (avoiding the use of i64 arithmetic shifts which require scalarization).

It converts SIGN_EXTEND nodes to SIGN_EXTEND_VECTOR_INREG where necessary, that more closely matches the pmovsx* instruction than the default approach of using SIGN_EXTEND_INREG which splits the operation (into an ANY_EXTEND lowered to a shuffle followed by shifts) making instruction matching difficult during lowering. Necessary support for SIGN_EXTEND_VECTOR_INREG has been added to the DAGCombiner.

Differential Revision: http://reviews.llvm.org/D9848

llvm-svn: 237885
2015-05-21 10:05:03 +00:00