Commit Graph

8592 Commits

Author SHA1 Message Date
Vedant Kumar 4d7f2b02d6 [SelectionDAG] Consolidate (t|T)ransferDbgValues methods, NFC (reapply)
TransferDbgValues (capital 'T') is wired into ReplaceAllUsesWith, and
transferDbgValues (lowercase 't') is used elsewhere (e.g in Legalize).

Both functions should be doing the exact same thing. This patch
consolidates the logic into one place.

This was reverted in r318455 because some newly introduced asserts,
which I thought were NFC, were firing. I filed PR35338. For now I've
weakened the asserts.

Testing: check-llvm, check-clang, and a stage2 Rel+Deb build of clang

Differential Revision: https://reviews.llvm.org/D40104

llvm-svn: 318498
2017-11-17 01:48:33 +00:00
David Blaikie b3bde2ea50 Fix a bunch more layering of CodeGen headers that are in Target
All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).

llvm-svn: 318490
2017-11-17 01:07:10 +00:00
Craig Topper 242374e219 [X86] Don't remove sign extend of gather/scatter indices during SelectionDAGBuilder.
The sign extend might be from an i16 or i8 type and was inserted by InstCombine to match the pointer width. X86 gather legalization isn't currently detecting this to reinsert a sign extend to make things legal.

It's a bit weird for the SelectionDAGBuilder to do this kind of optimization in the first place. With this removed we can at least lean on InstCombine somewhat to ensure the index is i32 or i64.

I'll work on trying to recover some of the test cases by removing sign extends in the backend when its safe to do so with an understanding of the current legalizer capabilities.

This should fix PR30690.

llvm-svn: 318466
2017-11-16 23:08:57 +00:00
Vedant Kumar 53418797fd Revert "[SelectionDAG] Consolidate (t|T)ransferDbgValues methods, NFC."
This reverts commit r318448. It looks like some of the asserts need to
be weakened.

http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-autoconf/builds/16296

llvm-svn: 318455
2017-11-16 21:08:51 +00:00
Craig Topper b6b61dfb15 [DAGCombiner] Use cast instead of an unchecked dyn_cast.
llvm-svn: 318450
2017-11-16 20:23:12 +00:00
Vedant Kumar 494814d52a [SelectionDAG] Consolidate (t|T)ransferDbgValues methods, NFC.
TransferDbgValues (capital 'T') is wired into ReplaceAllUsesWith, and
transferDbgValues (lowercase 't') is used elsewhere (e.g in Legalize).

Both functions should be doing the exact same thing. This patch
consolidates the logic into one place.

Differential Revision: https://reviews.llvm.org/D40104

llvm-svn: 318448
2017-11-16 19:50:24 +00:00
Yaxun Liu 0844ff2aa7 Fix pointer EVT in SelectionDAGBuilder::visitAlloca
SelectionDAGBuilder::visitAlloca assumes alloca address space is 0, which is
incorrect for triple amdgcn---amdgiz and causes isel failure.

This patch fixes that.

Differential Revision: https://reviews.llvm.org/D40095

llvm-svn: 318392
2017-11-16 12:22:19 +00:00
Sam Parker 43fa5911a1 [DAGCombine] Enable more srl -> load combines
Change the calculation for the desired ValueType for non-sign
extending loads, as in those cases we don't care about the
higher bits. This creates a smaller ExtVT and allows for such
combinations as:
(srl (zextload i16, [addr]), 8) -> (zextload i8, [addr + 1])

Differential Revision: https://reviews.llvm.org/D40034

llvm-svn: 318390
2017-11-16 11:28:26 +00:00
Craig Topper 36e8d66e1a [SelectionDAG] Use report_fatal_error instead of llvm_unreachable in some code that can be reached if targets don't configure things correctly.
For example, this is currently reachable by X86 if you use a masked store intrinsic with a v1iX type.

Using a fatal error seems like a better user experience if someone were to encounter this on a release build. There are several other similar places that have been converted from unreachable to fatal error previously.

llvm-svn: 318379
2017-11-16 06:02:03 +00:00
Yaxun Liu 4d9a4d7ac8 Fix APInt bit size in processDbgDeclares
processDbgDeclares assumes pointer size is the same for different addr spaces.
It uses pointer size for addr space 0 for all pointers, which causes assertion
in stripAndAccumulateInBoundsConstantOffsets for amdgcn---amdgiz since
pointer in addr space 5 has different size than in addr space 0.

This patch fixes that.

Differential Revision: https://reviews.llvm.org/D40085

llvm-svn: 318370
2017-11-16 02:54:49 +00:00
Rong Xu e4572c6b73 [CodeGen] Fix the branch probability assertion in r318202
Due to integer precision, we might have numerator greater than denominator in
the branch probability scaling. Add a check to prevent this from happening.

llvm-svn: 318353
2017-11-16 00:14:05 +00:00
Rong Xu 3573d8da36 [CodeGen] Peel off the dominant case in switch statement in lowering
This patch peels off the top case in switch statement into a branch if the
probability exceeds a threshold. This will help the branch prediction and
avoids the extra compares when lowering into chain of branches.

Differential Revision: http://reviews.llvm.org/D39262

llvm-svn: 318202
2017-11-14 21:44:09 +00:00
Yaxun Liu 0b2f73fd84 CodeGen: Fix TargetLowering::LowerCallTo for sret value type
TargetLowering::LowerCallTo assumes that sret value type corresponds to a
pointer in default address space, which is incorrect, since sret value type
should correspond to a pointer in alloca address space, which may not
be the default address space. This causes assertion for amdgcn target
in amdgiz environment.

This patch fixes that.

Differential Revision: https://reviews.llvm.org/D39996

llvm-svn: 318167
2017-11-14 18:46:52 +00:00
Adrian Prantl 73d0e94e82 Fix an assertion in SelectionDAG::transferDbgValues()
when transferring debug info describing the lower bits of an extended SDNode.

rdar://problem/35504722

llvm-svn: 318086
2017-11-13 21:24:54 +00:00
Craig Topper bdb8db4589 [SelectionDAG] Make getUniformBase in SelectionDAGBuilder fail if any of the middle GEP indices are non-constant.
This is a fix for a bug in r317947. We were supposed to check that all the indices are are constant 0, but instead we're only make sure that indices that are constant are 0. Non-constant indices are being ignored.

llvm-svn: 317950
2017-11-10 23:36:56 +00:00
Craig Topper ffd48e3c27 [SelectionDAG] Teach SelectionDAGBuilder's getUniformBase for gather/scatter handling to accept GEPs with more than 2 operands if the middle operands are all 0s
Currently we can only get a uniform base from a simple GEP with 2 operands. This causes us to miss address folding opportunities for simple global array accesses as the test case shows.

This patch adds support for larger GEPs if the other indices are 0 since those don't require any additional computations to be inserted.

We may also want to handle constant splats of zero here, but I'm leaving that for future work when I have a real world example.

Differential Revision: https://reviews.llvm.org/D39911

llvm-svn: 317947
2017-11-10 22:50:50 +00:00
Amaury Sechet 3f0f650f49 [DAGcombine] Do not replace truncate node by itself when doing constant folding, this trigger needless extra rounds of combine for nothing. NFC
llvm-svn: 317926
2017-11-10 20:59:53 +00:00
Jatin Bhateja aaa5944ad4 [WebAssembly] Fix stack offsets of return values from call lowering.
Summary: Fixes PR35220

Reviewers: vadimcn, alexcrichton

Reviewed By: alexcrichton

Subscribers: pepyakin, alexcrichton, jfb, dschuff, sbc100, jgravelle-google, llvm-commits, aheejin

Differential Revision: https://reviews.llvm.org/D39866

llvm-svn: 317895
2017-11-10 16:26:04 +00:00
Adrian Prantl 1c8c544946 Preserve debug info when DAG-combinging (zext (truncate x)) -> (and x, mask).
rdar://problem/27139077

llvm-svn: 317825
2017-11-09 19:50:20 +00:00
Dan Gohman 2c74fe977d Add an @llvm.sideeffect intrinsic
This patch implements Chandler's idea [0] for supporting languages that
require support for infinite loops with side effects, such as Rust, providing
part of a solution to bug 965 [1].

Specifically, it adds an `llvm.sideeffect()` intrinsic, which has no actual
effect, but which appears to optimization passes to have obscure side effects,
such that they don't optimize away loops containing it. It also teaches
several optimization passes to ignore this intrinsic, so that it doesn't
significantly impact optimization in most cases.

As discussed on llvm-dev [2], this patch is the first of two major parts.
The second part, to change LLVM's semantics to have defined behavior
on infinite loops by default, with a function attribute for opting into
potential-undefined-behavior, will be implemented and posted for review in
a separate patch.

[0] http://lists.llvm.org/pipermail/llvm-dev/2015-July/088103.html
[1] https://bugs.llvm.org/show_bug.cgi?id=965
[2] http://lists.llvm.org/pipermail/llvm-dev/2017-October/118632.html

Differential Revision: https://reviews.llvm.org/D38336

llvm-svn: 317729
2017-11-08 21:59:51 +00:00
Adrian Prantl 93faeecd8f Handle inlined variables in SelectionDAGBuilder::EmitFuncArgumentDbgValue().
In 2010 a commit with no testcase and no further explanation
explicitly disabled the handling of inlined variables in
EmitFuncArgumentDbgValue(). I don't think there is a good reason for
this any more and re-enabling this adds debug locations for variables
associated with an LLVM function argument in functions that are
inlined into the first basic block. The only downside of doing this is
that we may insert a DBG_VALUE before the inlined scope, but (1) this
could be filtered out later, and (2) LiveDebugValues will not
propagate it into subsequent basic blocks if they don't dominate the
variable's lexical scope, so this seems like a small price to pay.

rdar://problem/26228128

llvm-svn: 317702
2017-11-08 18:27:13 +00:00
Matt Arsenault f6ee94c1c6 DAG: Add computeKnownBitsForFrameIndex
Some of the AMDGPU stack addressing modes require knowing the sign
bit is zero. We used to accomplish this by custom lowering
frame indexes, and then putting an AssertZext around a
TargetFrameIndex. This required specifically looking for
the AssextZext + frame index pattern which was moderately
disgusting. The same could probably be accomplished
with a target specific node, but would still
require special handling of frame indexes.

llvm-svn: 317671
2017-11-08 08:52:31 +00:00
David Blaikie 3f833edc7c Target/TargetInstrInfo.h -> CodeGen/TargetInstrInfo.h to match layering
This header includes CodeGen headers, and is not, itself, included by
any Target headers, so move it into CodeGen to match the layering of its
implementation.

llvm-svn: 317647
2017-11-08 01:01:31 +00:00
Craig Topper 41bf240726 [SelectionDAG] Fix typo in comment. NFC
llvm-svn: 317588
2017-11-07 16:32:31 +00:00
Adrian Prantl 25a09dd408 Make DIExpression::createFragmentExpression() return an Optional.
We can't safely split arithmetic into multiple fragments because we
can't express carry-over between fragments.

llvm-svn: 317534
2017-11-07 00:45:34 +00:00
Sanjay Patel 629c411538 [IR] redefine 'UnsafeAlgebra' / 'reassoc' fast-math-flags and add 'trans' fast-math-flag
As discussed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2016-November/107104.html
and again more recently:
http://lists.llvm.org/pipermail/llvm-dev/2017-October/118118.html

...this is a step in cleaning up our fast-math-flags implementation in IR to better match
the capabilities of both clang's user-visible flags and the backend's flags for SDNode.

As proposed in the above threads, we're replacing the 'UnsafeAlgebra' bit (which had the 
'umbrella' meaning that all flags are set) with a new bit that only applies to algebraic 
reassociation - 'AllowReassoc'.

We're also adding a bit to allow approximations for library functions called 'ApproxFunc' 
(this was initially proposed as 'libm' or similar).

...and we're out of bits. 7 bits ought to be enough for anyone, right? :) FWIW, I did 
look at getting this out of SubclassOptionalData via SubclassData (spacious 16-bits), 
but that's apparently already used for other purposes. Also, I don't think we can just 
add a field to FPMathOperator because Operator is not intended to be instantiated. 
We'll defer movement of FMF to another day.

We keep the 'fast' keyword. I thought about removing that, but seeing IR like this:
%f.fast = fadd reassoc nnan ninf nsz arcp contract afn float %op1, %op2
...made me think we want to keep the shortcut synonym.

Finally, this change is binary incompatible with existing IR as seen in the 
compatibility tests. This statement:
"Newer releases can ignore features from older releases, but they cannot miscompile 
them. For example, if nsw is ever replaced with something else, dropping it would be 
a valid way to upgrade the IR." 
( http://llvm.org/docs/DeveloperPolicy.html#ir-backwards-compatibility )
...provides the flexibility we want to make this change without requiring a new IR 
version. Ie, we're not loosening the FP strictness of existing IR. At worst, we will 
fail to optimize some previously 'fast' code because it's no longer recognized as 
'fast'. This should get fixed as we audit/squash all of the uses of 'isFast()'.

Note: an inter-dependent clang commit to use the new API name should closely follow 
commit.

Differential Revision: https://reviews.llvm.org/D39304

llvm-svn: 317488
2017-11-06 16:27:15 +00:00
David Blaikie 1be62f0327 Move TargetFrameLowering.h to CodeGen where it's implemented
This header already includes a CodeGen header and is implemented in
lib/CodeGen, so move the header there to match.

This fixes a link error with modular codegeneration builds - where a
header and its implementation are circularly dependent and so need to be
in the same library, not split between two like this.

llvm-svn: 317379
2017-11-03 22:32:11 +00:00
Ayman Musa a37d1130d7 [X86] Fix bug in legalize vector types - Split large loads
When splitting a large load to smaller legally-typed loads, the last load should be padded to reach the size of the previous one so a CONCAT_VECTORS node could reunite them again.
The code currently pads the last load to reach the size of the first load (instead of the previous).

Differential Revision: https://reviews.llvm.org/D38495

Change-Id: Ib60b55ed26ce901fabf68108daf52683fbd5013f
llvm-svn: 317206
2017-11-02 13:07:06 +00:00
Simon Pilgrim 687982c181 [SelectionDAG] computeKnownBits - use ashrInPlace on known bits of ISD::SRA input. NFCI.
llvm-svn: 317087
2017-11-01 13:16:48 +00:00
Craig Topper c51aac675d [DAGCombiner] Fix typos in comments. NFC
llvm-svn: 317072
2017-11-01 03:30:52 +00:00
Simon Pilgrim 9cd7abbcff Fix unused variable warnings. NFCI.
llvm-svn: 316964
2017-10-30 22:38:07 +00:00
Simon Pilgrim 80b371361c [SelectionDAG] Tidyup computeKnownBits extension/truncation cases. NFCI.
We don't need to extend/truncate the Known structure before calling computeKnownBits - it will reset at the start of the function.

llvm-svn: 316962
2017-10-30 22:23:57 +00:00
Daniel Neilson f9c7d29c77 Create instruction classes for identifying any atomicity of memory intrinsic. (NFC)
Summary:
For reference, see: http://lists.llvm.org/pipermail/llvm-dev/2017-August/116589.html

This patch fleshes out the instruction class hierarchy with respect to atomic and
non-atomic memory intrinsics. With this change, the relevant part of the class
hierarchy becomes:

IntrinsicInst
  -> MemIntrinsicBase (methods-only class)
    -> MemIntrinsic (non-atomic intrinsics)
      -> MemSetInst
      -> MemTransferInst
        -> MemCpyInst
        -> MemMoveInst
    -> AtomicMemIntrinsic (atomic intrinsics)
      -> AtomicMemSetInst
      -> AtomicMemTransferInst
        -> AtomicMemCpyInst
        -> AtomicMemMoveInst
    -> AnyMemIntrinsic (both atomicities)
      -> AnyMemSetInst
      -> AnyMemTransferInst
        -> AnyMemCpyInst
        -> AnyMemMoveInst

This involves some class renaming:
    ElementUnorderedAtomicMemCpyInst -> AtomicMemCpyInst
    ElementUnorderedAtomicMemMoveInst -> AtomicMemMoveInst
    ElementUnorderedAtomicMemSetInst -> AtomicMemSetInst
A script for doing this renaming in downstream trees is included below.

An example of where the Any* classes should be used in LLVM is when reasoning
about the effects of an instruction (ex: aliasing).

---
Script for renaming AtomicMem* classes:
PREFIXES="[<,([:space:]]"
CLASSES="MemIntrinsic|MemTransferInst|MemSetInst|MemMoveInst|MemCpyInst"
SUFFIXES="[;)>,[:space:]]"

REGEX="(${PREFIXES})ElementUnorderedAtomic(${CLASSES})(${SUFFIXES})"
REGEX2="visitElementUnorderedAtomic(${CLASSES})"

FILES=$( grep -E "(${REGEX}|${REGEX2})" -r . | tr ':' ' ' | awk '{print $1}' | sort | uniq )

SED_SCRIPT="s~${REGEX}~\1Atomic\2\3~g"
SED_SCRIPT2="s~${REGEX2}~visitAtomic\1~g"

for f in $FILES; do
    echo "Processing: $f"
    sed  -i ".bak" -E "${SED_SCRIPT};${SED_SCRIPT2};${EA_SED_SCRIPT};${EA_SED_SCRIPT2}" $f
done

Reviewers: sanjoy, deadalnix, apilipenko, anna, skatkov, mkazantsev

Reviewed By: sanjoy

Subscribers: hfinkel, jholewinski, arsenm, sdardis, nhaehnle, JDevlieghere, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D38419

llvm-svn: 316950
2017-10-30 19:51:48 +00:00
Simon Pilgrim 017f896adb [SelectionDAG] Add VSELECT demanded elts support to computeKnownBits
llvm-svn: 316947
2017-10-30 19:31:08 +00:00
Simon Pilgrim 96a0b9ef54 [SelectionDAG] Add VSELECT support to computeKnownBits
llvm-svn: 316944
2017-10-30 19:08:21 +00:00
Simon Pilgrim 5da11dfd24 [SelectionDAG] Add SELECT demanded elts support to ComputeNumSignBits
llvm-svn: 316933
2017-10-30 17:53:51 +00:00
Simon Pilgrim 601ae238b7 [SelectionDAG] Add SEXT/AND/XOR/Or demanded elts support to ComputeNumSignBits
llvm-svn: 316875
2017-10-29 22:03:37 +00:00
Simon Pilgrim 7613a7b564 [SelectionDAG] Add SRA/SHL demanded elts support to ComputeNumSignBits
Introduce a isConstOrDemandedConstSplat helper function that can recognise a constant splat build vector for at least the demanded elts we care about.

llvm-svn: 316866
2017-10-29 18:19:37 +00:00
Simon Pilgrim b37a24e82f [SelectionDAG] Add support for INSERT_SUBVECTOR to computeKnownBits
llvm-svn: 316847
2017-10-28 22:10:40 +00:00
Simon Pilgrim d09c1ac20f [SelectionDAG] Support 'bit preserving' floating points bitcasts on computeKnownBits/ComputeNumSignBits
For cases where we know the floating point representations match the bitcasted integer equivalent, allow bitcasting to these types.

This is especially useful for the X86 floating point compare results which return all/zero bits but as a floating point type.

Differential Revision: https://reviews.llvm.org/D39289

llvm-svn: 316831
2017-10-28 14:27:53 +00:00
Guozhi Wei 7c67009fe5 [DAGCombine] Don't combine sext with extload if sextload is not supported and extload has multi users
In function DAGCombiner::visitSIGN_EXTEND_INREG, sext can be combined with extload even if sextload is not supported by target, then

  if sext is the only user of extload, there is no big difference, no harm no benefit.
  if extload has more than one user, the combined sextload may block extload from combining with other zext, causes extra zext instructions generated. As demonstrated by the attached test case.

This patch add the constraint that when sextload is not supported by target, sext can only be combined with extload if it is the only user of extload.

Differential Revision: https://reviews.llvm.org/D39108

llvm-svn: 316802
2017-10-27 21:54:24 +00:00
Matt Arsenault 878827d93a DAG: Fold fma (fneg x), K, y -> fma x, -K, y
llvm-svn: 316753
2017-10-27 09:06:07 +00:00
Sean Fertile 57d46b8436 Add subclass data to the FoldingSetNode for MemIntrinsicSDNodes.
Not having the subclass data on an MemIntrinsicSDNodes means it was possible
to try to fold 2 nodes with the same operands but differing MMO flags. This
would trip an assertion when trying to refine the alignment between the 2
MachineMemOperands.

Differential Revision: https://reviews.llvm.org/D38898

llvm-svn: 316737
2017-10-27 04:02:51 +00:00
Matt Arsenault 8a752b77a2 DAG: Fix creating select with wrong condition type
This code added in r297930 assumed that it could create
a select with a condition type that is just an integer
bitcast of the selected type. For AMDGPU any vselect is
going to be scalarized (although the vector types are legal),
and all select conditions must be i1 (the same as getSetCCResultType).

This logic doesn't really make sense to me, but there's
never really been a consistent policy in what the select
condition mask type is supposed to be. Try to extend
the logic for skipping the transform for condition types
that aren't setccs. It doesn't seem quite right to me though,
but checking conditions that seem more sensible (like whether the
vselect is going to be expanded) doesn't work since this
seems to depend on that also.

llvm-svn: 316554
2017-10-25 07:14:07 +00:00
Adrian Prantl 2eb7cbf987 Implement salavageDebugInfo functionality for SelectionDAG.
Similar to how llvm::salvagDebugInfo hooks into InstCombine, this adds
a hook that can be invoked before an SDNode that is associated with an
SDDbgValue is erased to capture the effect of the deleted node in a
DIExpression.

The motivating example is an SDDebugValue attached to an ADD operation
that gets folded into a LOAD+OFFSET operation.

rdar://problem/32121503

llvm-svn: 316525
2017-10-24 22:55:12 +00:00
Adrian Prantl 4569cedf16 Use range-based for loop. NFC
llvm-svn: 316496
2017-10-24 20:38:00 +00:00
Adrian Prantl 1a043aefc4 Use range-based-for. NFC
llvm-svn: 316485
2017-10-24 19:32:59 +00:00
Adrian Prantl 93a3777b7d Doxygenify comments.
llvm-svn: 316466
2017-10-24 17:23:40 +00:00
Simon Pilgrim 1bc62f03a5 [SelectionDAG] Add VSELECT support to ComputeNumSignBits
llvm-svn: 316457
2017-10-24 16:38:38 +00:00
George Burgess IV 7887238c7c Fix buildbot breakage
SP is only used in an assert. Caused by r316374.

llvm-svn: 316377
2017-10-23 21:08:02 +00:00