Commit Graph

24929 Commits

Author SHA1 Message Date
Craig Topper
9b611e436f [SelectionDAG] Add a helper function for creating a boolean constant based on the target's boolean content
Many in SimplifySetCC and FoldSetCC try to create true or false constants. Some of them query getBooleanContents to figure out whether to use all ones or just 1 for true. But many places do not check and just use 1 without ensuring the VT has an i1 scalar type. Note sure if those places only trigger before type legalization so they only see an i1
type?

To cleanup the inconsistency and reduce some duplicated code, this patch adds a getBoolConstant method to SelectionDAG that takes are of querying getBooleanContents and doing the right thing.

Differential Revision: https://reviews.llvm.org/D43037

llvm-svn: 324634
2018-02-08 18:55:14 +00:00
Craig Topper
c19aed963e [DAGCombiner] Fix a couple mistakes from r324311 by really passing the original load to ExtendSetCCUses.
We're passing the binary op that uses the load instead of the load.

Noticed by inspection. Not sure how to test this because this just prevents the introduction of an extend that will later be truncated and will probably be combined out.

llvm-svn: 324568
2018-02-08 06:27:18 +00:00
Craig Topper
9b9d527427 [DAGCombiner] Don't create truncate nodes in (aext (zextload x)) -> (zextload x) and similar folds. NFCI
The truncate is being used to replace other users of of the load, but we checked that the load only has one use so there are no other uses to replace.

llvm-svn: 324567
2018-02-08 06:04:18 +00:00
Francis Visoiu Mistrih
da89d1812a [CodeGen] Print MachineBasicBlock labels using MIR syntax in -debug output
Instead of:

%bb.1: derived from LLVM BB %for.body

print:

bb.1.for.body:

Also use MIR syntax for MBB attributes like "align", "landing-pad", etc.

llvm-svn: 324563
2018-02-08 05:02:00 +00:00
Craig Topper
cbfe41ac2f [DAGCombiner] Avoid creating truncate nodes in (zext (and (load)))->(and (zextload)) fold until we know for sure we're going to need it. NFCI
The truncate is only needed if the load has additional users. It used to get passed to extendSetCCUses so was created early, but that's no longer the case.

llvm-svn: 324562
2018-02-08 04:38:04 +00:00
Craig Topper
bf4ed42606 [DAGCombiner] Rename variable to be slightly better. NFC
We were calling a load LN0 but it came from N0.getOperand(0) so its really more like LN00 if we follow the name used in other places.

llvm-svn: 324561
2018-02-08 04:38:02 +00:00
Momchil Velikov
74906a467c Revert "[DebugInfo] Improvements to representation of enumeration types (PR36168)"
Revert commit r324489, it broke LLDB tests.

llvm-svn: 324511
2018-02-07 20:28:47 +00:00
Nirav Dave
efed656873 [SelectionDAG] More Aggressibly prune nodes in AddChains. NFCI.
Travel all chains paths to first non-tokenfactor node can be
exponential work. Add simple redundency check to avoid this.
Fixes PR36264.

llvm-svn: 324491
2018-02-07 17:12:34 +00:00
Momchil Velikov
c502027efd [DebugInfo] Improvements to representation of enumeration types (PR36168)
This patch is the LLVM part of fixing the issues, described in
https://bugs.llvm.org/show_bug.cgi?id=36168

* The representation of enumerator values in the debug info metadata now
  contains a boolean flag isUnsigned, which determines how the bits of
  the value are interpreted.
* The DW_TAG_enumeration type DIE now always (for DWARF version >= 3)
  includes a DW_AT_type attribute, which refers to the underlying
  integer type, as suggested in DWARFv4 (5.7 Enumeration Type Entries).
* The debug info metadata for enumeration type contains (in flags)
  indication whether this is a C++11 "fixed enum".
* For C++11 enumeration with a fixed underlying type, the DIE also
  includes the DW_AT_enum_class attribute (for DWARF version >= 4).
* Encoding of enumerator constants uses DW_FORM_sdata for signed values
  and DW_FORM_udata for unsigned values, as suggested by DWARFv4 (7.5.4
  Attribute Encodings).

The changes should be backwards compatible:

* the isUnsigned attribute is optional and defaults to false.
* if the underlying type for the enumeration is not available, the
  enumerator values are considered signed.
* the FixedEnum flag defaults to clear.
* the bitcode format for DIEnumerator stores the unsigned flag bit #1 of
  the first record element, so the format does not change and the zero
  previously stored there is consistent with the false default for
  IsUnsigned.

Differential Revision: https://reviews.llvm.org/D42734

llvm-svn: 324489
2018-02-07 16:46:33 +00:00
Clement Courbet
10003e31f4 [MergeICmps] Re-commit rL324317 "Enable the MergeICmps Pass by default."
With fixes from rL324341.

Original commit message:

[MergeICmps] Enable the MergeICmps Pass by default.

Summary: Now that PR33325 is fixed, this should always improve the generated code.

Reviewers: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D42793

llvm-svn: 324465
2018-02-07 09:58:55 +00:00
Eugene Leviant
25347ea895 [LegalizeDAG] Truncate condition operand of ISD::SELECT
Differential revision: https://reviews.llvm.org/D42737

llvm-svn: 324447
2018-02-07 05:38:29 +00:00
Craig Topper
58ecffd857 [DAGCombiner][AMDGPU][X86] Turn cttz/ctlz into cttz_zero_undef/ctlz_zero_undef if we can prove the input is never zero
X86 currently has a late DAG combine after cttz/ctlz are turned into BSR+BSF+CMOV to detect this and remove the CMOV. But we should be able to do this much earlier and avoid creating the cmov all together.

For the changed AMDGPU test case it appears that previously the i8 cttz was type legalized to i16 which introduced an OR with 256 in order to limit the result to 8 on the widened type. At this point the result is known to never be zero, but nothing checked that. Then operation legalization is told to promote all i16 cttz to i32. This introduces an extend and a truncate and another OR with 65536 to limit the result to 16. With the DAG combiner change we are able to prevent the creation of the second OR since the opcode will have been changed to cttz_zero_undef after the first OR. I the lack of the OR caused the instruction to change to v_ffbl_b32_sdwa

Differential Revision: https://reviews.llvm.org/D42985

llvm-svn: 324427
2018-02-06 23:54:37 +00:00
Adrian Prantl
8c59921ca3 Add DWARF for discriminated unions
n Rust, an enum that carries data in the variants is, essentially, a
discriminated union. Furthermore, the Rust compiler will perform
space optimizations on such enums in some situations. Previously,
DWARF for these constructs was emitted using a hack (a magic field
name); but this approach stopped working when more space optimizations
were added in https://github.com/rust-lang/rust/pull/45225.

This patch changes LLVM to allow discriminated unions to be
represented in DWARF. It adds createDiscriminatedUnionType and
createDiscriminatedMemberType to DIBuilder and then arranges for this
to be emitted using DWARF's DW_TAG_variant_part and DW_TAG_variant.

Note that DWARF requires that a discriminated union be represented as
a structure with a variant part. However, as Rust only needs to emit
pure discriminated unions, this is what I chose to expose on
DIBuilder.

Patch by Tom Tromey!

Differential Revision: https://reviews.llvm.org/D42082

llvm-svn: 324426
2018-02-06 23:45:59 +00:00
Eli Friedman
98f8bba283 [LivePhysRegs] Fix handling of return instructions.
See D42509 for the original version of this.

Basically, there are two significant changes to behavior here:

- addLiveOuts always adds all pristine registers (even if a block has
no successors).
- addLiveOuts and addLiveOutsNoPristines always add all callee-saved
registers for return blocks (including conditional return blocks).

I cleaned up the functions a bit to make it clear these properties hold.

Differential Revision: https://reviews.llvm.org/D42655

llvm-svn: 324422
2018-02-06 23:00:17 +00:00
Andrew Kaylor
c41499865b Add SelectionDAGDumper support for strict FP nodes
Patch by Kevin P. Neal

llvm-svn: 324416
2018-02-06 22:28:15 +00:00
Adrian Prantl
c929f7ad42 Fix a crash when emitting DIEs for variable-length arrays
VLAs may refer to a previous DIE to express the DW_AT_count of their
type. Clang generates an artificial "vla_expr" variable for this. If
this DIE hasn't been created yet LLVM asserts. This patch fixes this
by sorting the local variables so that dependencies come before they
are needed. It also replaces the linear scan in DWARFFile with a
std::map, which can be faster.

Differential Revision: https://reviews.llvm.org/D42940

llvm-svn: 324412
2018-02-06 22:17:45 +00:00
Sanjay Patel
87ce2fd82d [TargetLowering] use local variable to reduce duplication; NFCI
llvm-svn: 324401
2018-02-06 21:09:42 +00:00
Sanjay Patel
e96a9014ab [TargetLowering] use local variables to reduce duplication; NFCI
llvm-svn: 324397
2018-02-06 20:49:28 +00:00
Nirav Dave
27721e8617 [DAG, X86] Improve Dependency analysis when doing multi-node
Instruction Selection

Cleanup cycle/validity checks in ISel (IsLegalToFold,
HandleMergeInputChains) and X86 (isFusableLoadOpStore). Now do a full
search for cycles / dependencies pruning the search when topological
property of NodeId allows.

As part of this propogate the NodeId-based cutoffs to narrow
hasPreprocessorHelper searches.

Reviewers: craig.topper, bogner

Subscribers: llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D41293

llvm-svn: 324359
2018-02-06 16:14:29 +00:00
Alexander Ivchenko
6805004cb1 Fix unused variable warning in release mode. NFC.
llvm-svn: 324330
2018-02-06 09:53:02 +00:00
Clement Courbet
333be329c4 Revert "[MergeICmps] Enable the MergeICmps Pass by default."
Breaks clang-ppc64be-linux-multistage buildbot.

This reverts commit 515bab711f308c2e8299c49dd8c84ea6a2e0b60e.

llvm-svn: 324319
2018-02-06 08:40:18 +00:00
Clement Courbet
7d09780fa2 [MergeICmps] Enable the MergeICmps Pass by default.
Summary: Now that PR33325 is fixed, this should always improve the generated code.

Reviewers: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D42793

llvm-svn: 324317
2018-02-06 07:20:33 +00:00
Craig Topper
ee1f34eb9a [DAGCombiner] Pass the original load to ExtendSetCCUses not the turncate.
Summary:
This method is trying to use the truncate node to find which SETCC operand should be replaced directly with the extended load.

This used to work correctly because all uses of the original load were replaced by the truncate before this function was called. So this was used to effectively bypass the truncate and find the load under it.

All but one of the callers now call this before the truncate has replaced the laod so the setcc doesn't yet use the truncate. To account for this we should pass the original load instead.

I changed the order of that one caller to make this work there too.

I don't have a test case because this is probably hidden by later DAG combines causing the extend and truncate to cancel out. I assume this way is a little more efficient and matches what was originally intended.

Reviewers: RKSimon, spatel, niravd

Reviewed By: niravd

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D42878

llvm-svn: 324311
2018-02-06 03:23:27 +00:00
Francis Visoiu Mistrih
1c55aefd1e [PEI][NFC] Move StackSize opt-remark code next to -warn-stack code
This allows us to make sure we're always having the same sizes in both
remarks and warnings.

llvm-svn: 324283
2018-02-05 22:46:54 +00:00
Krzysztof Parzyszek
fee3f419ae [SDAG] Legalize all CondCodes by inverting them and/or swapping operands
Differential Revision: https://reviews.llvm.org/D42788

llvm-svn: 324274
2018-02-05 21:27:16 +00:00
Craig Topper
fc5bd023dd [DAGCombiner] When folding fold (sext/zext (and/or/xor (sextload/zextload x), cst)) -> (and/or/xor (sextload/zextload x), (sext/zext cst)) make sure we check the legality of the full extended load.
Summary:
If the load is already an extended load we should be using the memory VT for the legality check, not just the VT of the current extension.

I don't have a test case, just noticed it while investigating some load extension improvements.

Reviewers: RKSimon, spatel, niravd

Reviewed By: niravd

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D42783

llvm-svn: 324181
2018-02-03 23:00:31 +00:00
Simon Pilgrim
4df6499f10 [SelectionDAG] Don't use simple VT in generic shuffle code
Better to assume that any value type may be commuted, not just MVTs.

No test case right now, but discovered while investigating possible shuffle combines.

llvm-svn: 324179
2018-02-03 21:34:42 +00:00
Aditya Nandakumar
58eb183128 [GISel][NFC]: Move RegisterBankInfo::getSizeInBits into TargetRegisterInfo.
llvm-svn: 324125
2018-02-02 19:42:07 +00:00
Jonas Paulsson
422dfbf7cc [SelectionDAG] Consider endianness in scalarizeVectorStore().
When handling vectors with non byte-sized elements, reverse the order of the
elements in the built integer if the target is Big-Endian.

SystemZ tests updated.

Review: Eli Friedman, Ulrich Weigand.
https://reviews.llvm.org/D42786

llvm-svn: 324063
2018-02-02 08:48:02 +00:00
Jonas Paulsson
ad089fe46e [SelectionDAG] Add an assert in getNode() for EXTRACT_VECTOR_ELT.
When getNode() is called to create an EXTRACT_VECTOR_ELT, assert that
the result VT is at least as wide as the vector element type.

Review: Eli Friedman
llvm-svn: 324061
2018-02-02 08:21:53 +00:00
Amara Emerson
98af4664e0 Fix debug spelling in ResetMachineFunction pass.
llvm-svn: 324048
2018-02-02 01:49:59 +00:00
Matthias Braun
ca0abaebfb SplitKit: Fix liveness recomputation in some remat cases.
Example situation:
```
BB0:
  %0 = ...
  use %0
  ; ...
  condjump BB1
  jmp BB2

BB1:
  %0 = ...   ; rematerialized def from above (from earlier split step)
  jmp BB2

BB2:
  ; ...
  use %0
```

%0 will have a live interval with 3 value numbers (for the BB0, BB1 and
BB2 parts). Now SplitKit tries and succeeds in rematerializing the value
number in BB2 (This only works because it is a secondary split so
SplitKit is can trace this back to a single original def).

We need to recompute all live ranges affected by a value number that we
rematerialize. The case that we missed before is that when the value
that is rematerialized is at a join (Phi VNI) then we also have to
recompute liveness for the predecessor VNIs.

rdar://35699130

Differential Revision: https://reviews.llvm.org/D42667

llvm-svn: 324039
2018-02-02 00:08:19 +00:00
Amara Emerson
4d19655a56 [GlobalISel][Legalizer] Relax a legalization loop detecting assert.
Legalizing vectors may keep the element type the same but change the number of
elements, the assert didn't take this into account.

llvm-svn: 324028
2018-02-01 23:10:57 +00:00
Craig Topper
a5944aade1 [DAGCombiner] When folding (insert_subvector undef, (bitcast (extract_subvector N1, Idx)), Idx) -> (bitcast N1) make sure that N1 has the same total size as the original output
We were only checking the element count, but not the total width. This could cause illegal bitcasts to be created if for example the output was 512-bits, but N1 is 256 bits, and the extraction size was 128-bits.

Fixes PR36199

Differential Revision: https://reviews.llvm.org/D42809

llvm-svn: 324002
2018-02-01 20:48:50 +00:00
Amara Emerson
cbc02c71a4 [GlobalISel] Fix assert failure when legalizing non-power-2 loads.
Until we support extending loads properly we're going to fall back for these.
We already handle stores in the same way, so this is just being consistent.

llvm-svn: 324001
2018-02-01 20:47:03 +00:00
Brock Wyma
4536c1f569 [CodeView] Class record member counts should include base classes and ...
Increment the field list member count for base classes and virtual base
classes.

Differential Revision: https://reviews.llvm.org/D41874

llvm-svn: 324000
2018-02-01 20:37:38 +00:00
Geoff Berry
94503c7bc3 [MachineCopyPropagation] Extend pass to do COPY source forwarding
Summary:
This change extends MachineCopyPropagation to do COPY source forwarding
and adds an additional run of the pass to the default pass pipeline just
after register allocation.

This version of this patch uses the newly added
MachineOperand::isRenamable bit to avoid forwarding registers is such a
way as to violate constraints that aren't captured in the
Machine IR (e.g. ABI or ISA constraints).

This change is a continuation of the work started in D30751.

Reviewers: qcolombet, javed.absar, MatzeB, jonpa, tstellar

Subscribers: tpr, mgorny, mcrosier, nhaehnle, nemanjai, jyknight, hfinkel, arsenm, inouehrs, eraman, sdardis, guyblank, fedor.sergeev, aheejin, dschuff, jfb, myatsina, llvm-commits

Differential Revision: https://reviews.llvm.org/D41835

llvm-svn: 323991
2018-02-01 18:54:01 +00:00
Sanjay Patel
657e5d8d41 [DAGCombiner] filter out denorm inputs when calculating sqrt estimate (PR34994)
As shown in the example in PR34994:
https://bugs.llvm.org/show_bug.cgi?id=34994
...we can return a very wrong answer (inf instead of 0.0) for square root when 
using a reciprocal square root estimate instruction.

Here, I've conditionalized the filtering out of denorms based on the function 
having "denormal-fp-math"="ieee" in its attributes. The other options for this 
attribute are 'preserve-sign' and 'positive-zero'.

So we don't generate this extra code by default with just '-ffast-math' (because 
then there's no denormal attribute string at all), but it works if you specify 
'-ffast-math -fdenormal-fp-math=ieee' from clang. 

As noted in the review, there may be other problems in clang that affect the 
results depending on platform (Linux x86 at least), but this should allow 
creating the desired codegen.

Differential Revision: https://reviews.llvm.org/D42323

llvm-svn: 323981
2018-02-01 16:57:18 +00:00
Nirav Dave
18f7f60e17 [SelectionDAG] Fix UpdateChains handling of TokenFactors
Summary:
In Instruction Selection UpdateChains replaces all matched Nodes'
chain references including interior token factors and deletes them.
This may allow nodes which depend on these interior nodes but are not
part of the set of matched nodes to be left with a dangling dependence.
Avoid this by doing the replacement for matched non-TokenFactor nodes.

Fixes PR36164.

Reviewers: jonpa, RKSimon, bogner

Subscribers: llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D42754

llvm-svn: 323977
2018-02-01 16:11:59 +00:00
Dean Michael Berris
cdca0730be [XRay][compiler-rt+llvm] Update XRay register stashing semantics
Summary:
This change expands the amount of registers stashed by the entry and
`__xray_CustomEvent` trampolines.

We've found that since the `__xray_CustomEvent` trampoline calls can show up in
situations where the scratch registers are being used, and since we don't
typically want to affect the code-gen around the disabled
`__xray_customevent(...)` intrinsic calls, that we need to save and restore the
state of even the scratch registers in the handling of these custom events.

Reviewers: pcc, pelikan, dblaikie, eizan, kpw, echristo, chandlerc

Reviewed By: echristo

Subscribers: chandlerc, echristo, hiraditya, davide, dblaikie, llvm-commits

Differential Revision: https://reviews.llvm.org/D40894

llvm-svn: 323940
2018-02-01 02:21:54 +00:00
Matt Arsenault
df0f25070c DAG: Fix not truncating when promoting bswap/bitreverse
These need to convert back to the original type, like any
other promotion.

llvm-svn: 323932
2018-01-31 23:54:16 +00:00
Puyan Lotfi
43e94b15ea Followup on Proposal to move MIR physical register namespace to '$' sigil.
Discussed here:

http://lists.llvm.org/pipermail/llvm-dev/2018-January/120320.html

In preparation for adding support for named vregs we are changing the sigil for
physical registers in MIR to '$' from '%'. This will prevent name clashes of
named physical register with named vregs.

llvm-svn: 323922
2018-01-31 22:04:26 +00:00
Geoff Berry
82203c4149 [MachineOutliner] Freeze registers in new functions
Summary:
Call MRI.freezeReservedRegs() on functions created during outlining so
that calls to isReserved() by the verifier called after this pass won't
assert.

Reviewers: MatzeB, qcolombet, paquette

Subscribers: mcrosier, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D42749

llvm-svn: 323905
2018-01-31 20:15:16 +00:00
Daniel Neilson
be58a220e9 [CodeGenPrepare] Improve source and dest alignments of memory intrinsics independently
Summary:
  This change is part of step five in the series of changes to remove alignment argument from
memcpy/memmove/memset in favour of alignment attributes. In particular, this changes the
CodeGenPrepare pass to be more aggressive in improving the source and destination alignments
of memcpy/memmove/memset by exploiting our new ability to record independent alignments
for each argument.

Steps:
Step 1) Remove alignment parameter and create alignment parameter attributes for
memcpy/memmove/memset. ( rL322965, rC322964, rL322963 )
Step 2) Expand the IRBuilder API to allow creation of memcpy/memmove with differing
source and dest alignments. ( rL323597 )
Step 3) Update Clang to use the new IRBuilder API. ( rC323617 )
Step 4) Update Polly to use the new IRBuilder API. ( rL323618 )
Step 5) Update LLVM passes that create memcpy/memmove calls to use the new IRBuilder API,
and those that use use MemIntrinsicInst::[get|set]Alignment() to use [get|set]DestAlignment()
and [get|set]SourceAlignment() instead. ( rL323886 )
Step 6) Remove the single-alignment IRBuilder API for memcpy/memmove, and the
MemIntrinsicInst::[get|set]Alignment() methods.

Reference
   http://lists.llvm.org/pipermail/llvm-dev/2015-August/089384.html
   http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html

llvm-svn: 323891
2018-01-31 17:24:53 +00:00
Petar Jovanovic
540f4cd10a [DWARF] Allow duplication of tails with CFI instructions
This commit came as a result for revert of patch r317579 (originally
committed as r317100). The patch made CFI instructions duplicable, because
their existence in the epilogue block was affecting the Tail duplication
pass. However, duplicating blocks with CFI instructions was an issue for
compact unwind info on Darwin, which is why the patch was reverted.

This patch allows duplicating tails with CFI instructions, though they are
not duplicable, by copying them 'manually'.


Patch by Djordje Kovacevic.

Differential Revision: https://reviews.llvm.org/D40979

llvm-svn: 323883
2018-01-31 15:57:57 +00:00
Nirav Dave
c3a1e16db1 [DAG] Prevent NodeId pruning of TokenFactors in Instruction Selection.
Summary:
Instruction Selection preserves relative orders of all nodes save
TokenFactors which we treat specially. As a result Node Ids for
TokenFactors may violate the topological ordering and should not be
considered as valid pruning candidates in predecessor search.

Fixes PR35316.

Reviewers: RKSimon, hfinkel

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D42701

llvm-svn: 323880
2018-01-31 15:23:17 +00:00
Florian Hahn
c68428b5dc [MachineCombiner] Add check for optimal pattern order.
In D41587, @mssimpso discovered that the order of some patterns for
AArch64 was sub-optimal. I thought a bit about how we could avoid that
case in the future. I do not think there is a need for evaluating all
patterns for now. But this patch adds an extra (expensive) check, that
evaluates the latencies of all patterns, and ensures that the latency
saved decreases for subsequent patterns.

This catches the sub-optimal order fixed in D41587, but I am not
entirely happy with the check, as it only applies to sub-optimal
patterns seen while building with EXPENSIVE_CHECKS on. It did not
discover any other sub-optimal pattern ordering.

Reviewers: Gerolf, spatel, mssimpso

Reviewed By: Gerolf, mssimpso

Differential Revision: https://reviews.llvm.org/D41766

llvm-svn: 323873
2018-01-31 13:54:30 +00:00
Marina Yatsina
cd5bc4a2cd Take into account the cost of local intervals when selecting split candidate.
When selecting a split candidate for region splitting, the register allocator tries to predict which candidate will have the cheapest spill cost.
Global splitting may cause the creation of local intervals, and they might spill.

This patch makes RA take into account the spill cost of local split intervals in use blocks (we already take into account the spill cost in through blocks).
A flag ("-condsider-local-interval-cost") controls weather we do this advanced cost calculation (it's on by default for X86 target, off for the rest).

Differential Revision: https://reviews.llvm.org/D41585

Change-Id: Icccb8ad2dbf13124f5d97a18c67d95aa6be0d14d
llvm-svn: 323870
2018-01-31 13:31:08 +00:00
Roger Ferrer Ibanez
aea4208720 [ARM] Allow the scheduler to clone a node with glue to avoid a copy CPSR ↔ GPR.
In Thumb 1, with the new ADDCARRY / SUBCARRY the scheduler may need to do
copies CPSR ↔ GPR but not all Thumb1 targets implement them.

The schedule can attempt, before attempting a copy, to clone the instructions
but it does not currently do that for nodes with input glue. In this patch we
introduce a target-hook to let the hook decide if a glued machinenode is still
eligible for copying. In this case these are ARM::tADCS and ARM::tSBCS .

As a follow-up of this change we should actually implement the copies for the
Thumb1 targets that do implement them and restrict the hook to the targets that
can't really do such copy as these clones are not ideal.

This change fixes PR35836.

Differential Revision: https://reviews.llvm.org/D42051

llvm-svn: 323857
2018-01-31 09:23:43 +00:00
Eli Friedman
804d7ab811 Revert r323559 due to EXPENSIVE_CHECKS regression.
I have a fix for the issue (https://reviews.llvm.org/D42655) but
it's taking a while to get reviewed, so reverting in the meantime.

llvm-svn: 323841
2018-01-31 00:40:42 +00:00