Commit Graph

1643 Commits

Author SHA1 Message Date
Craig Topper cdfc3cbcb5 [SelectionDAG] Use various APInt methods to reduce temporary APInt creation
This patch uses various APInt methods to reduce the number of temporary APInts. These were all found while working through converting SelectionDAG's computeKnownBits to also use the KnownBits struct recently added to the ValueTracking version.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301618 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-28 04:57:59 +00:00
Craig Topper a7fa95c0e5 [APInt] Use inplace shift methods where possible. NFCI
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301612 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-28 03:36:24 +00:00
Craig Topper 58c7fe69d0 [ValueTracking] Introduce a KnownBits struct to wrap the two APInts for computeKnownBits
This patch introduces a new KnownBits struct that wraps the two APInt used by computeKnownBits. This allows us to treat them as more of a unit.

Initially I've just altered the signatures of computeKnownBits and InstCombine's simplifyDemandedBits to pass a KnownBits reference instead of two separate APInt references. I'll do similar to the SelectionDAG version of computeKnownBits/simplifyDemandedBits as a separate patch.

I've added a constructor that allows initializing both APInts to the same bit width with a starting value of 0. This reduces the repeated pattern of initializing both APInts. Once place default constructed the APInts so I added a default constructor for those cases.

Going forward I would like to add more methods that will work on the pairs. For example trunc, zext, and sext occur on both APInts together in several places. We should probably add a clear method that can be used to clear both pieces. Maybe a method to check for conflicting information. A method to return (Zero|One) so we don't write it out everywhere. Maybe a method for (Zero|One).isAllOnesValue() to determine if all bits are known. I'm sure there are many other methods we can come up with.

Differential Revision: https://reviews.llvm.org/D32376

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301432 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-26 16:39:58 +00:00
Sanjay Patel 0f75548f9f [DAG] add FIXME comments for splat detection; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301403 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-26 13:27:57 +00:00
Sanjay Patel 2b2adc9567 [DAG] fix formatting of isConstantSplat(); NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301366 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-25 23:33:28 +00:00
Simon Pilgrim 5c072c6410 [SelectionDAG] Recognise splat vector isKnownToBeAPowerOfTwo one/sign bit shift cases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301303 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-25 12:29:07 +00:00
Renato Golin d907744fff Revert "[APInt] Fix a few places that use APInt::getRawData to operate within the normal API."
This reverts commit r301105, 4, 3 and 1, as a follow up of the previous
revert, which broke even more bots.

For reference:
Revert "[APInt] Use operator<<= where possible. NFC"
Revert "[APInt] Use operator<<= instead of shl where possible. NFC"
Revert "[APInt] Use ashInPlace where possible."

PR32754.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301111 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-23 12:15:30 +00:00
Craig Topper e3ba850127 [APInt] Use operator<<= where possible. NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301104 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-23 05:43:02 +00:00
Craig Topper 1ea7b69466 [APInt] Use ashInPlace where possible.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301101 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-23 03:45:59 +00:00
Benjamin Kramer 4b3567dbfc [Recycler] Add asan/msan annotations.
This enables use after free and uninit memory checking for memory
returned by a recycler. SelectionDAG currently relies on the opcode of a
free'd node being ISD::DELETED_NODE, so poke a hole in the asan poison
for SDNode opcodes. This means that we won't find some issues, but only
in SDag.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300868 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-20 18:29:37 +00:00
Yaxun Liu 1baa360f32 CodeGen: Let frame index value type match alloca addr space
Recently alloca address space has been added to data layout. Due to this
change, pointer returned by alloca may have different size as pointer in
address space 0.

However, currently the value type of frame index is assumed to be of the
same size as pointer in address space 0.

This patch fixes that.

Most targets assume alloca returning pointer in address space 0, which
is the default alloca address space. Therefore it is NFC for them.

AMDGCN target with amdgiz environment requires this change since it
assumes alloca returning pointer to addr space 5 and its size is 32,
which is different from the size of pointer in addr space 0 which is 64.

Differential Revision: https://reviews.llvm.org/D32021


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300864 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-20 18:15:34 +00:00
Craig Topper 54f0462d2b [APInt] Rename getSignBit to getSignMask
getSignBit is a static function that creates an APInt with only the sign bit set. getSignMask seems like a better name to convey its functionality. In fact several places use it and then store in an APInt named SignMask.

Differential Revision: https://reviews.llvm.org/D32108



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300856 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-20 16:56:25 +00:00
Amara Emerson 780f89d961 [MVT][SVE] Scalable vector MVTs (1/3)
This patch adds a few helper functions to obtain new vector
value types based on existing ones without needing to care
about whether they are scalable or not.

I've confined their use to a few common locations right now,
and targets that don't have scalable vectors should never
need to care about these.

Patch by Graham Hunter.

Differential Revision: https://reviews.llvm.org/D32017



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300838 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-20 13:08:17 +00:00
Galina Kistanova 6b92d164d6 Temporarily revert r299221 to fix nondeterminism in ThinLTO builder.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300783 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-19 23:16:14 +00:00
Craig Topper 3bebc1eb2e [APInt] Cast calls to add/sub/mul overflow methods to void if only their overflow bool out param is used.
This is preparation for a clang change to improve the [[nodiscard]] warning to not be ignored on methods that return a class marked [[nodiscard]] that are defined in the class itself. See D32207.

We should consider adding wrapper methods to APInt that return the overflow flag directly and discard the APInt result. This would eliminate the void casts and the need to create a bool before the call to pass to the out param.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300758 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-19 21:09:45 +00:00
Craig Topper df22034939 [APInt] Use lshrInPlace to replace lshr where possible
This patch uses lshrInPlace to replace code where the object that lshr is called on is being overwritten with the result.

This adds an lshrInPlace(const APInt &) version as well.

Differential Revision: https://reviews.llvm.org/D32155




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300566 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-18 17:14:21 +00:00
Jonas Paulsson ff14b9ebc7 [SelectionDAG] NFC patch removing a redundant check.
Since the BUILD_VECTOR has already been checked by
isBuildVectorOfConstantSDNodes() in SelectionDAG::getNode() for a
SIGN_EXTEND_INREG, it can be assumed that Op is always either undef or a
ConstantSDNode, and Ops.size() will always equal VT.getVectorNumElements().

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299647 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-06 13:00:37 +00:00
Jonas Paulsson 4a035b600a [DAGCombiner] Don't make a BUILD_VECTOR with operands of illegal type.
When DAGCombiner visits a SIGN_EXTEND_INREG of a BUILD_VECTOR with
constant operands, a new BUILD_VECTOR node will be created transformed
constants.

Llvm-stress found a case where the new BUILD_VECTOR had constant operands
of an illegal type, because the (legal) element type is in fact not a legal
scalar type.

This patch changes this so that the new BUILD_VECTOR has the same operand
type as the old one.

Review: Eli Friedman, Nirav Dave
https://bugs.llvm.org//show_bug.cgi?id=32422

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299540 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-05 13:45:37 +00:00
Simon Pilgrim 40593e05da [DAGCombiner] Add ComputeNumSignBits vector demanded elements support to ASHR and INSERT_VECTOR_ELT
Followup to D31311

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299221 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-31 14:21:50 +00:00
Simon Pilgrim 9fc191fd45 [DAGCombiner] Add vector demanded elements support to ComputeNumSignBits
Currently ComputeNumSignBits returns the minimum number of sign bits for all elements of vector data, when we may only be interested in one/some of the elements.

This patch adds a DemandedElts argument that allows us to specify the elements we actually care about. The original ComputeNumSignBits implementation calls with a DemandedElts demanding all elements to match current behaviour. Scalar types set this to 1.

I've only added support for BUILD_VECTOR and EXTRACT_VECTOR_ELT so far, all others will default to demanding all elements but can be updated in due course.

Followup to D25691.

Differential Revision: https://reviews.llvm.org/D31311

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299219 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-31 13:54:09 +00:00
Simon Pilgrim 07898901df [DAGCombiner] Add vector demanded elements support to computeKnownBitsForTargetNode
Follow up to D25691, this sets up the plumbing necessary to support vector demanded elements support in known bits calculations in target nodes.

Differential Revision: https://reviews.llvm.org/D31249

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299201 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-31 11:24:16 +00:00
Ahmed Bougacha 04dea7e088 [CodeGen] Pass SDAG an ORE, and replace FastISel stats with remarks.
In the long-term, we want to replace statistics with something
finer-grained that lets us gather per-function data.
Remarks are that replacement.

Create an ORE instance in SelectionDAGISel, and pass it to
SelectionDAG.

SelectionDAG was used so that we can emit remarks from all
SelectionDAG-related code, including TargetLowering and DAGCombiner.
This isn't used in the current patch but Adam tells me he's interested
for the fp-contract combines.

Use the ORE instance to emit FastISel failures as remarks (instead of
the mix of dbgs() dumps and statistics that we currently have).

Eventually, we want to have an API that tells us whether remarks are
enabled (http://llvm.org/PR32352) so that we don't emit expensive
remarks (in this case, dumping IR) when it's not needed.  For now, use
'isEnabled' as a crude replacement.

This does mean that the replacement for '-fast-isel-verbose' is now
'-pass-remarks-missed=isel'.  Additionally, clang users also need to
enable remark diagnostics, using '-Rpass-missed=isel'.

This also removes '-fast-isel-verbose2': there are no static statistics
that we want to only enable in asserts builds, so we can always use
the remarks regardless of the build type.

Differential Revision: https://reviews.llvm.org/D31405

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299093 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-30 17:49:58 +00:00
Sanjay Patel bdb8cec802 [DAG] fix formatting; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298950 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-28 22:25:25 +00:00
Simon Pilgrim a31a2f7e7b Apply clang-format as commented in D31311. NFCI.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298751 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-24 23:47:41 +00:00
Simon Pilgrim 33e1fb27fd Fix constant folding of fp2int to large integers
We make the assumption in most of our constant folding code that a fp2int will target an integer of 128-bits or less, calling the APFloat::convertToInteger with only uint64_t[2] of raw bits for the result.

Fuzz testing (PR24662) showed that we don't handle other cases at all, resulting in stack overflows and all sorts of crashes.

This patch uses the APSInt version of APFloat::convertToInteger instead to better handle such cases.

Differential Revision: https://reviews.llvm.org/D31074

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298226 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-19 16:50:25 +00:00
Nirav Dave 11fdc7845a Make library calls sensitive to regparm module flag (Fixes PR3997).
Reviewers: mkuper, rnk

Subscribers: mehdi_amini, jyknight, aemerson, llvm-commits, rengolin

Differential Revision: https://reviews.llvm.org/D27050

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298179 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-18 00:44:07 +00:00
Eli Friedman 87552d6290 [SelectionDAG] Remove redundant stores more aggressively.
Handle TokenFactors more aggressively in
SDValue::reachesChainWithoutSideEffects.  This isn't really a
very effective change anymore because of other changes to
chain handling, but it's a cheap check, and the expanded
comments are still useful.

It might be possible to loosen the hasOneUse() requirement with a
deeper analysis, but a naive implementation of that check would be
expensive.

Differential Revision: https://reviews.llvm.org/D29845




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298156 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-17 22:15:50 +00:00
Simon Pilgrim 20afc5b611 [SelectionDAG] Add SelectionDAG.computeKnownBits test support for ISD::ABS
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298108 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-17 17:45:36 +00:00
Craig Topper 01c2f41249 [CodeGen] Use APInt::setLowBits/setHighBits/setBitsFrom in more places
This patch replaces ORs with getHighBits/getLowBits etc. with setLowBits/setHighBits/setBitsFrom.

In a few of the places we weren't ORing, but the KnownZero/KnownOne vectors were already initialized to zero. We exploit this in most places already there were just some that were inconsistent.

Differential Revision: https://reviews.llvm.org/D30965




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297860 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-15 16:53:53 +00:00
Simon Pilgrim a1d8ce502d [SelectionDAG] Support BUILD_VECTOR implicit truncation in SelectionDAG::ComputeNumSignBits (PR32273)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297852 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-15 16:22:24 +00:00
Nuno Lopes 13c7e8f75d fix gcc -Wmisleading-indentation [NFC]
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297816 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-15 09:33:33 +00:00
Simon Pilgrim e35265b998 [SelectionDAG] Add a signed integer absolute ISD node
Reduced version of D26357 - based on the discussion on llvm-dev about canonicalization of UMIN/UMAX/SMIN/SMAX as well as ABS I've reduced that patch to just the ABS ISD node (with x86/sse support) to improve basic combines and lowering.

ARM/AArch64, Hexagon, PowerPC and NVPTX all have similar instructions allowing us to make this a generic opcode and move away from the hard coded tablegen patterns which makes it tricky to match more complex patterns.

At the moment this patch doesn't attempt legalization as we only create an ABS node if its legal/custom.

Differential Revision: https://reviews.llvm.org/D29639

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297780 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-14 21:26:58 +00:00
Sanjay Patel bea559baff [DAG] vector div/rem with any zero element in divisor is undef
This is the backend counterpart to:
https://reviews.llvm.org/rL297390
https://reviews.llvm.org/rL297409
and follow-up to:
https://reviews.llvm.org/rL297384

It surprised me that we need to duplicate the check in FoldConstantArithmetic and FoldConstantVectorArithmetic, 
but one or the other doesn't catch all of the test cases. There is an existing code comment about merging those 
someday.

Differential Revision: https://reviews.llvm.org/D30826


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297762 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-14 18:06:28 +00:00
Amaury Sechet ff2afbf7d8 Use setBits in SelectionDAG
Summary: As per title.

Reviewers: RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30836

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297559 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-11 11:24:03 +00:00
Simon Pilgrim 49e0bf23d7 [SelectionDAG] Add support for BUILD_VECTOR to ComputeNumSignBits
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297492 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-10 18:36:46 +00:00
Amaury Sechet 5436744eb4 [SelectionDAG] Make SelectionDAG aware of the known bits in USUBO and SSUBO and SUBC.
Summary:
Depends on D30379

This improves the state of things for the sub class of operation.

Reviewers: jyknight, nemanjai, mkuper, spatel, RKSimon, zvi, bkramer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30436

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297482 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-10 17:26:44 +00:00
Amaury Sechet a29d680671 [SelectionDAG] Make SelectionDAG aware of the known bits in UADDO and SADDO.
Summary: As per title. This is extracted from D29872 and I threw SADDO in.

Reviewers: jyknight, nemanjai, mkuper, spatel, RKSimon, zvi, bkramer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30379

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297479 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-10 17:06:52 +00:00
Simon Pilgrim 943d3e07f8 [APInt] Add APInt::insertBits() method to insert an APInt into a larger APInt
We currently have to insert bits via a temporary variable of the same size as the target with various shift/mask stages, resulting in further temporary variables, all of which require the allocation of memory for large APInts (MaskSizeInBits > 64).

This is another of the compile time issues identified in PR32037 (see also D30265).

This patch adds the APInt::insertBits() helper method which avoids the temporary memory allocation and masks/inserts the raw bits directly into the target.

Differential Revision: https://reviews.llvm.org/D30780

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297458 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-10 13:44:32 +00:00
Sanjay Patel 4f7ea50478 [DAG] recognize div/rem by 0 as undef before trying constant folding
As discussed in the review thread for rL297026, this is actually 2 changes that 
would independently fix all of the test cases in the patch:

1. Return undef in FoldConstantArithmetic for div/rem by 0.
2. Move basic undef simplifications for div/rem (simplifyDivRem()) before 
   foldBinopIntoSelect() as a matter of efficiency.

I will handle the case of vectors with any zero element as a follow-up. That change
is the DAG sibling for D30665 + adding a check of vector elements to FoldConstantVectorArithmetic().

I'm deleting the test for PR30693 because it does not test for the actual bug any more
(dangers of using bugpoint).

Differential Revision:
https://reviews.llvm.org/D30741


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297384 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-09 15:02:25 +00:00
Simon Pilgrim ca6750e3d5 [X86][SSE] Lower 128-bit vectors to SIGN/ZERO_EXTEND_VECTOR_IN_REG ops
As described on PR31712, we miss a variety of legalization combines because we lower these to X86ISD::VSEXT/VZEXT despite them having the same functionality. This patch makes 128-bit (SSE41) SIGN/ZERO_EXTEND_VECTOR_IN_REG ops legal, adds the necessary tablegen plumbing and uses a helper 'getExtendInVec' to decide when to use SIGN/ZERO_EXTEND_VECTOR_IN_REG or VSEXT/VZEXT.

We're missing a couple of shuffle combines that will be added in a future patch for review.

Later patches can then support the AVX2 cases as a mixture of SIGN/ZERO_EXTEND and SIGN/ZERO_EXTEND_VECTOR_IN_REG, and then finally deal with the AVX512 cases.

Differential Revision: https://reviews.llvm.org/D30549

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296985 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-05 09:57:20 +00:00
Simon Pilgrim 74b3a7ad26 Use APInt::setBits instead of OR'ing in a separate APInt::getBitsSet call
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296886 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-03 17:03:52 +00:00
Amaury Sechet a50f957a61 [DAGCombiner] mulhi + 1 never overflow.
Summary:
This can be used to optimize large multiplications after legalization.

Depends on D29565

Reviewers: mkuper, spatel, RKSimon, zvi, bkramer, aaboud, craig.topper

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29587

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296711 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-01 23:44:17 +00:00
Simon Pilgrim ada0a4f5b0 [DAGCombine] Allow vector constant folding of any value type before type legalization
The patch comes in 2 parts:

1 - it makes use of the SelectionDAG::NewNodesMustHaveLegalTypes flag to tell when it can safely constant fold illegal types.

2 - it correctly resets SelectionDAG::NewNodesMustHaveLegalTypes at the start of each call to SelectionDAGISel::CodeGenAndEmitDAG so all the pre-legalization stages can make use of it - not just the first basic block that gets handled.

Fix for PR30760

Differential Revision: https://reviews.llvm.org/D29568

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294749 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-10 14:37:25 +00:00
Amaury Sechet 6f12c47b49 Add ADDC to SelectionDAG::computeKnownBits and ComputeNumSignBits.
Summary: As per title.

Reviewers: bkramer, sunfish, lattner, RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29521

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294188 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-06 14:59:06 +00:00
Amaury Sechet ffd1e5a54c [DAGCombiner] Make DAGCombiner smarter about overflow
Summary: Leverage it to transform addc into add.

Reviewers: mkuper, spatel, RKSimon, zvi

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29524

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294187 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-06 14:54:49 +00:00
Simon Pilgrim 0aca40051b [X86][SSE] Combine shuffle nodes with multiple uses if all the users are being combined.
Currently we only combine shuffle nodes if they have a single user to prevent us from causing code bloat by splitting the shuffles into several different combines.

We don't take into account that in some cases we will already have combined all the users during recursively calling up the shuffle tree.

This patch keeps a list of all the shuffle nodes that have been combined so far and permits combining of further shuffle nodes if all its users are in that list.

Differential Revision: https://reviews.llvm.org/D29399

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294183 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-06 13:44:45 +00:00
Matt Arsenault 430953ebc8 DAG: Constant fold fp16_to_fp/fp16_to_fp
This fixes emitting conversions of constants on targets
without legal f16 that need to use these for legalization.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293499 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-30 16:57:41 +00:00
Craig Topper 544a997a27 [SelectionDAG] Make SDNode::getConstantOperandVal an inline method.
It's operation already exists manually in many places without using the method.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293421 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-29 06:08:02 +00:00
Craig Topper 8a3705cb10 [SelectionDAG] Teach getNode to simplify a couple easy cases of EXTRACT_SUBVECTOR
Summary:
This teaches getNode to simplify extracting from Undef. This is similar to what is done for EXTRACT_VECTOR_ELT. It also adds support for extracting from CONCAT_VECTOR when we can reuse one of the inputs to the concat. These seem like simple non-target specific optimizations.

For X86 we currently handle undef in extractSubvector, but not all EXTRACT_SUBVECTOR creations go through there.

Ultimately, my motivation here is to simplify extractSubvector and remove custom lowering for EXTRACT_SUBVECTOR since we don't do anything but handle undef and BUILD_VECTOR optimizations, but those should be DAG combines.

Reviewers: RKSimon, delena

Reviewed By: RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29000

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292876 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-24 02:36:59 +00:00
Simon Pilgrim 64f91a5757 [SelectionDAG] Improve knownbits handling of UMIN/UMAX (PR31293)
This patch improves the knownbits logic for unsigned integer min/max opcodes.

For UMIN we know that the result will have the maximum of the inputs' known leading zero bits in the result, similarly for UMAX the maximum of the inputs' leading one bits.

This is particularly useful for simplifying clamping patterns,. e.g. as SSE doesn't have a uitofp instruction we want to use sitofp instead where possible and for that we need to confirm that the top bit is not set.

Differential Revision: https://reviews.llvm.org/D28853

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292528 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-19 22:41:22 +00:00