Commit Graph

86 Commits

Author SHA1 Message Date
Matt Arsenault
d5684f76e0 GlobalISel: Allow bitcount ops to have different result type
For AMDGPU the result is always 32-bit for 64-bit inputs.

llvm-svn: 352717
2019-01-31 02:09:57 +00:00
Diana Picus
574e0c5e32 [ARM GlobalISel] Support integer division for Thumb2
Support G_SDIV, G_UDIV, G_SREM and G_UREM.

The only significant difference between arm and thumb mode is that we
need to check a different subtarget feature.

llvm-svn: 352346
2019-01-28 10:37:30 +00:00
Diana Picus
8976ad12a9 [ARM GlobalISel] Support shifts for Thumb2
Same as ARM.

On this occasion we split some of the instruction select tests for more
complicated instructions into their own files, so we can reuse them for
ARM and Thumb mode. Likewise for the legalizer tests.

llvm-svn: 352188
2019-01-25 10:48:42 +00:00
Diana Picus
23628c7b05 [ARM GlobalISel] Remove rebase artifact from r351882. NFC
r351882 introduced some superfluous calls to mark G_INTTOPTR and
G_PTRTOINT as legal (looks like a rebase mishap). Remove them.

llvm-svn: 352187
2019-01-25 10:48:35 +00:00
Matt Arsenault
30989e492b GlobalISel: Allow shift amount to be a different type
For AMDGPU the shift amount is never 64-bit, and
this needs to use a 32-bit shift.

X86 uses i8, but seemed to be hacking around this before.

llvm-svn: 351882
2019-01-22 21:42:11 +00:00
Chandler Carruth
2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Diana Picus
6c35a1e5af [ARM GlobalISel] Support G_CONSTANT for Thumb2
All we have to do is mark it as legal.

This allows us to select a lot of new patterns handled by TableGen. This
patch adds tests for them and splits up the existing test file for
binary operators into 2 files, one for arithmetic ops and one for
logical ones.

llvm-svn: 349610
2018-12-19 09:55:10 +00:00
Diana Picus
02c8343c75 [ARM GlobalISel] Thumb2: casts between int and ptr
Mark as legal and add tests. Nothing special to do.

llvm-svn: 349147
2018-12-14 13:45:38 +00:00
Diana Picus
14dc3b2959 [ARM GlobalISel] Allow simple binary ops in Thumb2
Mark G_ADD, G_SUB, G_MUL, G_AND, G_OR and G_XOR as legal for both ARM
and Thumb2.

Extract the legalizer tests for these opcodes into another file.

Add tests for the instruction selector.

llvm-svn: 349142
2018-12-14 11:58:14 +00:00
Diana Picus
99cd644b6c [ARM GlobalISel] Support exts and truncs for Thumb2
Mark G_SEXT, G_ZEXT and G_ANYEXT to 32 bits as legal and add support for
them in the instruction selector. This uses handwritten code again
because the patterns that are generated with TableGen are tuned for what
the DAG combiner would produce and not for simple sext/zext nodes.
Luckily, we only need to update the opcodes to use the Thumb2 variants,
everything else can be reused from ARM.

llvm-svn: 349026
2018-12-13 12:06:54 +00:00
Diana Picus
59720b422a [ARM GlobalISel] Select load/store for Thumb2
Unfortunately we can't use TableGen for this because it doesn't yet
support predicates on the source pattern root. Therefore, add a bit of
handwritten code to the instruction selector to handle the most basic
cases.

Also mark them as legal and extract their legalizer test cases to a new
test file.

llvm-svn: 348920
2018-12-12 10:32:15 +00:00
Diana Picus
1027249ec9 [ARM GlobalISel] Nothing is legal for Thumb
...yet!

A lot of the current code should be shared for arm and thumb mode, but
until we add tests and work out some of the details (e.g. checking the
correct subtarget feature for G_SDIV) it's safer to bail out as early as
possible for thumb targets.

This should have arguably been part of r348347, which allowed Thumb
functions to be handled by the IR Translator.

llvm-svn: 348472
2018-12-06 09:26:14 +00:00
Aditya Nandakumar
f75d4f329c [GISel]: Provide standard interface to observe changes in GISel passes
https://reviews.llvm.org/D54980

This provides a standard API across GISel passes to observe and notify
passes about changes (insertions/deletions/mutations) to MachineInstrs.
This patch also removes the recordInsertion method in MachineIRBuilder
and instead provides method to setObserver.

Reviewed by: vkeles.

llvm-svn: 348406
2018-12-05 20:14:52 +00:00
Diana Picus
0528e2cfb3 [ARM GlobalISel] Support G_CTLZ and G_CTLZ_ZERO_UNDEF
We can now select CLZ via the TableGen'erated code, so support G_CTLZ
and G_CTLZ_ZERO_UNDEF throughout the pipeline for types <= s32.

Legalizer:
If the CLZ instruction is available, use it for both G_CTLZ and
G_CTLZ_ZERO_UNDEF. Otherwise, use a libcall for G_CTLZ_ZERO_UNDEF and
lower G_CTLZ in terms of it.

In order to achieve this we need to add support to the LegalizerHelper
for the legalization of G_CTLZ_ZERO_UNDEF for s32 as a libcall (__clzsi2).

We also need to allow lowering of G_CTLZ in terms of G_CTLZ_ZERO_UNDEF
if that is supported as a libcall, as opposed to just if it is Legal or
Custom. Due to a minor refactoring of the helper function in charge of
this, we will also allow the same behaviour for G_CTTZ and G_CTPOP.
This is not going to be a problem in practice since we don't yet have
support for treating G_CTTZ and G_CTPOP as libcalls (not even in
DAGISel).

Reg bank select:
Map G_CTLZ to GPR. G_CTLZ_ZERO_UNDEF should not make it to this point.

Instruction select:
Nothing to do.

llvm-svn: 347545
2018-11-26 11:07:02 +00:00
Roman Tereshin
667c7581ed [GlobalISel][ARM] LegalizerInfo verifier: Adding LegalizerInfo::verify(...) call and fixing bugs exposed
Reviewers: aemerson, qcolombet

Reviewed By: qcolombet

Differential Revision: https://reviews.llvm.org/D46339

llvm-svn: 333663
2018-05-31 16:16:48 +00:00
Craig Topper
2fa1436206 [IR][CodeGen] Remove dependency on EVT from IR/Function.cpp. Move EVT to CodeGen layer.
Currently EVT is in the IR layer only because of Function.cpp needing a very small piece of the functionality of EVT::getEVTString(). The rest of EVT is used in codegen making CodeGen a better place for it.

The previous code converted a Type* to EVT and then called getEVTString. This was only expected to handle the primitive types from Type*. Since there only a few primitive types, we can just print them as strings directly.

Differential Revision: https://reviews.llvm.org/D45017

llvm-svn: 328806
2018-03-29 17:21:10 +00:00
David Blaikie
36a0f226b1 Fix layering by moving ValueTypes.h from CodeGen to IR
ValueTypes.h is implemented in IR already.

llvm-svn: 328397
2018-03-23 23:58:31 +00:00
Diana Picus
12ed95e3e7 Fix formatting for r323876. NFC
llvm-svn: 323878
2018-01-31 15:16:17 +00:00
Diana Picus
1d4421f6a6 [ARM GlobalISel] Modernize LegalizerInfo. NFCI
Start using the new LegalizerInfo API introduced in r323681.

Keep the old API for opcodes that need Lowering in some circumstances
(G_FNEG and G_UREM/G_SREM).

llvm-svn: 323876
2018-01-31 14:55:07 +00:00
Diana Picus
517531e5a5 [ARM GlobalISel] Legalize G_SITOFP and G_UITOFP
Legal if we have hardware support, libcall otherwise.

Also add supporting code to the legalizer helper for libcalls.

llvm-svn: 323730
2018-01-30 09:15:17 +00:00
Diana Picus
4ed0ee7b5f [ARM GlobalISel] Legalize G_FPTOSI and G_FPTOUI
Legal if we have hardware support for floating point, libcalls
otherwise.

Also add the necessary support for libcalls in the legalizer helper.

llvm-svn: 323726
2018-01-30 07:54:52 +00:00
Daniel Sanders
08464524c3 [ARM][GISel] PR35965 Constrain RegClasses of nested instructions built from Dst Pattern
Summary:
Apparently, we missed on constraining register classes of VReg-operands of all the instructions
built from a destination pattern but the root (top-level) one. The issue exposed itself
while selecting G_FPTOSI for armv7: the corresponding pattern generates VTOSIZS wrapped
into COPY_TO_REGCLASS, so top-level COPY_TO_REGCLASS gets properly constrained,
while nested VTOSIZS (or rather its destination virtual register to be exact) does not.

Fixing this by issuing GIR_ConstrainSelectedInstOperands for every nested GIR_BuildMI.

https://bugs.llvm.org/show_bug.cgi?id=35965
rdar://problem/36886530

Patch by Roman Tereshin

Reviewers: dsanders, qcolombet, rovka, bogner, aditya_nandakumar, volkan

Reviewed By: dsanders, qcolombet, rovka

Subscribers: aemerson, javed.absar, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D42565

llvm-svn: 323692
2018-01-29 21:09:12 +00:00
Daniel Sanders
9ade5592d9 [globalisel] Make LegalizerInfo::LegalizeAction available outside of LegalizerInfo. NFC
Summary:
The improvements to the LegalizerInfo discussed in D42244 require that
LegalizerInfo::LegalizeAction be available for use in other classes. As such,
it needs to be moved out of LegalizerInfo. This has been done separately to the
next patch to minimize the noise in that patch.

llvm-svn: 323669
2018-01-29 17:37:29 +00:00
Diana Picus
01bcfd2112 [ARM GlobalISel] Rename local variable. NFC
llvm-svn: 322667
2018-01-17 15:25:37 +00:00
Diana Picus
65ed364fac [ARM GlobalISel] Legalize G_FPEXT and G_FPTRUNC
Mark G_FPEXT and G_FPTRUNC as legal or libcall, depending on hardware
support, but only for conversions between float and double.

Also add the necessary boilerplate so that the LegalizerHelper can
introduce the required libcalls. This also works only for float and
double, but isn't too difficult to extend when the need arises.

llvm-svn: 322651
2018-01-17 13:34:10 +00:00
Diana Picus
e74243d473 [ARM GlobalISel] Legalize G_FMA
For hard float with VFP4, it is legal. Otherwise, we use libcalls.

This needs a bit of support in the LegalizerHelper for soft float
because we didn't handle G_FMA libcalls yet. The support is trivial, as
the only difference between G_FMA and other libcalls that we already
handle is that it has 3 input operands rather than just 2.

llvm-svn: 322366
2018-01-12 11:30:45 +00:00
Diana Picus
f949a0abac [ARM GlobalISel] Legalize G_FNEG for s32 and s64
For hard float, it is legal.

For soft float, we need to lower to 0 - x first, and then we can use the
libcall for G_FSUB. This is undoing some of the canonicalization
performed by the IRTranslator (which introduces G_FNEG when it sees a
0 - x). Ideally, that canonicalization would be performed by a
pre-legalizer pass that would allow targets to opt out of this behaviour
rather than dance around it in the legalizer.

llvm-svn: 322168
2018-01-10 10:45:34 +00:00
Diana Picus
8f14886630 [ARM GlobalISel] Legalize s32/s64 G_FCONSTANT
Legal for hard float.
Change to G_CONSTANT for soft float (but preserve the binary
representation).

llvm-svn: 322164
2018-01-10 10:01:49 +00:00
Diana Picus
734a5e8912 [ARM GlobalISel] Legalize G_CONSTANT for scalars > 32 bits
Make G_CONSTANT narrow for any scalars larger than 32 bits.

llvm-svn: 322162
2018-01-10 09:32:01 +00:00
Diana Picus
c768bbe2e7 [ARM GlobalISel] Legalize scalar G_PHI
Mark G_PHI as Legal for s32 and p0, and also for s64 if we have hard
float. Widen any smaller types.

llvm-svn: 321795
2018-01-04 13:09:14 +00:00
Diana Picus
28a6d0e639 [ARM GlobalISel] Support G_INTTOPTR and G_PTRTOINT for s32
Mark conversions between pointers and 32-bit scalars as legal, map them
to the GPR and select to a simple COPY.

llvm-svn: 321356
2017-12-22 13:05:51 +00:00
Diana Picus
68773859c8 [ARM GlobalISel] Support pointer constants
Pointer constants are pretty rare, since we usually represent them as
integer constants and then cast to pointer. One notable exception is the
null pointer constant, which is represented directly as a G_CONSTANT 0
with pointer type. Mark it as legal and make sure it is selected like
any other integer constant.

llvm-svn: 321354
2017-12-22 11:09:18 +00:00
Diana Picus
8ee540c01a [ARM GlobalISel] Fix G_(UN)MERGE_VALUES handling after r319524
r319524 has made more G_MERGE_VALUES/G_UNMERGE_VALUES pairs legal than
are supported by the rest of the pipeline. Restrict that to only the
cases that we can currently handle: packing 32-bit values into 64-bit
ones, when we have hardware FP.

llvm-svn: 320980
2017-12-18 13:22:28 +00:00
Matthias Braun
f1caa2833f MachineFunction: Return reference from getFunction(); NFC
The Function can never be nullptr so we can return a reference.

llvm-svn: 320884
2017-12-15 22:22:58 +00:00
Volkan Keles
a32ff00b00 GlobalISel: Enable the legalization of G_MERGE_VALUES and G_UNMERGE_VALUES
Summary: LegalizerInfo assumes all G_MERGE_VALUES and G_UNMERGE_VALUES instructions are legal, so it is not possible to legalize vector operations on illegal vector types. This patch fixes the problem by removing the related check and adding default actions for G_MERGE_VALUES and G_UNMERGE_VALUES.

Reviewers: qcolombet, ab, dsanders, aditya_nandakumar, t.p.northover, kristof.beyls

Reviewed By: dsanders

Subscribers: rovka, javed.absar, igorb, llvm-commits

Differential Revision: https://reviews.llvm.org/D39823

llvm-svn: 319524
2017-12-01 08:19:10 +00:00
Diana Picus
c01f7f131b [ARM GlobalISel] Support G_FDIV for s32 and s64
TableGen already generates code for selecting a G_FDIV, so we only need
to add a test.

For the legalizer and reg bank select, we do the same thing as for the
other floating point binary operations: either mark as legal if we have
a FP unit or lower to a libcall, and map to the floating point
registers.

llvm-svn: 318915
2017-11-23 13:26:07 +00:00
Diana Picus
9faa09b21e [ARM GlobalISel] Support G_FMUL for s32 and s64
TableGen already generates code for selecting a G_FMUL, so we only need
to add a test for that part.

For the legalizer and reg bank select, we do the same thing as the other
floating point binary operators: either mark as legal if we have a FP
unit or lower to a libcall, and map to the floating point registers.

llvm-svn: 318910
2017-11-23 12:44:20 +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
Kristof Beyls
af9814a1fc [GlobalISel] Enable legalizing non-power-of-2 sized types.
This changes the interface of how targets describe how to legalize, see
the below description.

1. Interface for targets to describe how to legalize.

In GlobalISel, the API in the LegalizerInfo class is the main interface
for targets to specify which types are legal for which operations, and
what to do to turn illegal type/operation combinations into legal ones.

For each operation the type sizes that can be legalized without having
to change the size of the type are specified with a call to setAction.
This isn't different to how GlobalISel worked before. For example, for a
target that supports 32 and 64 bit adds natively:

  for (auto Ty : {s32, s64})
    setAction({G_ADD, 0, s32}, Legal);

or for a target that needs a library call for a 32 bit division:

  setAction({G_SDIV, s32}, Libcall);

The main conceptual change to the LegalizerInfo API, is in specifying
how to legalize the type sizes for which a change of size is needed. For
example, in the above example, how to specify how all types from i1 to
i8388607 (apart from s32 and s64 which are legal) need to be legalized
and expressed in terms of operations on the available legal sizes
(again, i32 and i64 in this case). Before, the implementation only
allowed specifying power-of-2-sized types (e.g. setAction({G_ADD, 0,
s128}, NarrowScalar).  A worse limitation was that if you'd wanted to
specify how to legalize all the sized types as allowed by the LLVM-IR
LangRef, i1 to i8388607, you'd have to call setAction 8388607-3 times
and probably would need a lot of memory to store all of these
specifications.

Instead, the legalization actions that need to change the size of the
type are specified now using a "SizeChangeStrategy".  For example:

   setLegalizeScalarToDifferentSizeStrategy(
       G_ADD, 0, widenToLargerAndNarrowToLargest);

This example indicates that for type sizes for which there is a larger
size that can be legalized towards, do it by Widening the size.
For example, G_ADD on s17 will be legalized by first doing WidenScalar
to make it s32, after which it's legal.
The "NarrowToLargest" indicates what to do if there is no larger size
that can be legalized towards. E.g. G_ADD on s92 will be legalized by
doing NarrowScalar to s64.

Another example, taken from the ARM backend is:
   for (unsigned Op : {G_SDIV, G_UDIV}) {
     setLegalizeScalarToDifferentSizeStrategy(Op, 0,
         widenToLargerTypesUnsupportedOtherwise);
     if (ST.hasDivideInARMMode())
       setAction({Op, s32}, Legal);
     else
       setAction({Op, s32}, Libcall);
   }

For this example, G_SDIV on s8, on a target without a divide
instruction, would be legalized by first doing action (WidenScalar,
s32), followed by (Libcall, s32).

The same principle is also followed for when the number of vector lanes
on vector data types need to be changed, e.g.:

   setAction({G_ADD, LLT::vector(8, 8)}, LegalizerInfo::Legal);
   setAction({G_ADD, LLT::vector(16, 8)}, LegalizerInfo::Legal);
   setAction({G_ADD, LLT::vector(4, 16)}, LegalizerInfo::Legal);
   setAction({G_ADD, LLT::vector(8, 16)}, LegalizerInfo::Legal);
   setAction({G_ADD, LLT::vector(2, 32)}, LegalizerInfo::Legal);
   setAction({G_ADD, LLT::vector(4, 32)}, LegalizerInfo::Legal);
   setLegalizeVectorElementToDifferentSizeStrategy(
       G_ADD, 0, widenToLargerTypesUnsupportedOtherwise);

As currently implemented here, vector types are legalized by first
making the vector element size legal, followed by then making the number
of lanes legal. The strategy to follow in the first step is set by a
call to setLegalizeVectorElementToDifferentSizeStrategy, see example
above.  The strategy followed in the second step
"moreToWiderTypesAndLessToWidest" (see code for its definition),
indicating that vectors are widened to more elements so they map to
natively supported vector widths, or when there isn't a legal wider
vector, split the vector to map it to the widest vector supported.

Therefore, for the above specification, some example legalizations are:
  * getAction({G_ADD, LLT::vector(3, 3)})
    returns {WidenScalar, LLT::vector(3, 8)}
  * getAction({G_ADD, LLT::vector(3, 8)})
    then returns {MoreElements, LLT::vector(8, 8)}
  * getAction({G_ADD, LLT::vector(20, 8)})
    returns {FewerElements, LLT::vector(16, 8)}


2. Key implementation aspects.

How to legalize a specific (operation, type index, size) tuple is
represented by mapping intervals of integers representing a range of
size types to an action to take, e.g.:

       setScalarAction({G_ADD, LLT:scalar(1)},
                       {{1, WidenScalar},  // bit sizes [ 1, 31[
                        {32, Legal},       // bit sizes [32, 33[
                        {33, WidenScalar}, // bit sizes [33, 64[
                        {64, Legal},       // bit sizes [64, 65[
                        {65, NarrowScalar} // bit sizes [65, +inf[
                       });

Please note that most of the code to do the actual lowering of
non-power-of-2 sized types is currently missing, this is just trying to
make it possible for targets to specify what is legal, and how non-legal
types should be legalized.  Probably quite a bit of further work is
needed in the actual legalizing and the other passes in GlobalISel to
support non-power-of-2 sized types.

I hope the documentation in LegalizerInfo.h and the examples provided in the
various {Target}LegalizerInfo.cpp and LegalizerInfoTest.cpp explains well
enough how this is meant to be used.

This drops the need for LLT::{half,double}...Size().


Differential Revision: https://reviews.llvm.org/D30529

llvm-svn: 317560
2017-11-07 10:34:34 +00:00
Javed Absar
5cde1ccb29 [GlobalISel|ARM] : Allow legalizing G_FSUB
Adding support for VSUB.
Reviewed by: @rovka
Differential Revision: https://reviews.llvm.org/D39261

llvm-svn: 316902
2017-10-30 13:51:56 +00:00
Diana Picus
2c95730450 [ARM] GlobalISel: Mark shifts as legal for s32
The new legalize combiner introduces shifts all over the place, so we
should support them sooner rather than later.

llvm-svn: 315064
2017-10-06 14:30:05 +00:00
Quentin Colombet
250e050a50 [GlobalISel] Make GlobalISel a non-optional library.
With this change, the GlobalISel library gets always built. In
particular, this is not possible to opt GlobalISel out of the build
using the LLVM_BUILD_GLOBAL_ISEL variable any more.

llvm-svn: 309990
2017-08-03 21:52:25 +00:00
Diana Picus
b1fd784936 [ARM] GlobalISel: Mark G_GLOBAL_VALUE as legal
llvm-svn: 309090
2017-07-26 09:25:15 +00:00
Diana Picus
da25d5b8b0 [ARM] GlobalISel: Support G_(S|U)REM for s8 and s16
Widen to s32, and then do whatever Lowering/Custom/Libcall action the
subtarget wants.

llvm-svn: 308285
2017-07-18 10:07:01 +00:00
Diana Picus
87a7067983 [ARM] GlobalISel: Support G_BRCOND
Insert a TSTri to set the flags and a Bcc to branch based on their
values. This is a bit inefficient in the (common) cases where the
condition for the branch comes from a compare right before the branch,
since we set the flags both as part of the compare lowering and as part
of the branch lowering. We're going to live with that until we settle on
a principled way to handle this kind of situation, which occurs with
other patterns as well (combines might be the way forward here).

llvm-svn: 308009
2017-07-14 09:46:06 +00:00
Diana Picus
443135c6eb [ARM] GlobalISel: Fix oversight in G_FCMP legalization
We used to forget to erase the original instruction when replacing a
G_FCMP true/false. Fix this bug and make sure the tests check for it.

llvm-svn: 307639
2017-07-11 09:43:51 +00:00
Diana Picus
b57bba8316 [ARM] GlobalISel: Legalize s64 G_FCMP
Same as the s32 version, for both hard and soft float.

llvm-svn: 307633
2017-07-11 08:50:01 +00:00
Diana Picus
d0104eaae8 [ARM] GlobalISel: Legalize G_FCMP for s32
This covers both hard and soft float.

Hard float is easy, since it's just Legal.

Soft float is more involved, because there are several different ways to
handle it based on the predicate: one and ueq need not only one, but two
libcalls to get a result. Furthermore, we have large differences between
the values returned by the AEABI and GNU functions.

AEABI functions return a nice 1 or 0 representing true and respectively
false. GNU functions generally return a value that needs to be compared
against 0 (e.g. for ogt, the value returned by the libcall is > 0 for
true).  We could introduce redundant comparisons for AEABI as well, but
they don't seem easy to remove afterwards, so we do different processing
based on whether or not the result really needs to be compared against
something (and just truncate if it doesn't).

llvm-svn: 307243
2017-07-06 09:09:33 +00:00
Diana Picus
cd460c89c4 [ARM] GlobalISel: Widen s1, s8, s16 G_CONSTANT
Get the legalizer to widen small constants.

llvm-svn: 307239
2017-07-06 08:04:16 +00:00
Diana Picus
fc1675eb16 [GlobalISel] Refactor Legalizer helpers for libcalls
We used to have a helper that replaced an instruction with a libcall.
That turns out to be too aggressive, since sometimes we need to replace
the instruction with at least two libcalls. Therefore, change our
existing helper to only create the libcall and leave the instruction
removal as a separate step. Also rename the helper accordingly.

llvm-svn: 307149
2017-07-05 12:57:24 +00:00