Commit Graph

49877 Commits

Author SHA1 Message Date
John Brawn d6e0ebea10 [AArch64] Fix SelectionDAG infinite loop for v1i64 SCALAR_TO_VECTOR
A consequence of r347274 is that SCALAR_TO_VECTOR can be converted into
BUILD_VECTOR by SimplifyDemandedBits, but LowerBUILD_VECTOR can turn
BUILD_VECTOR into SCALAR_TO_VECTOR so we get an infinite loop.

Fix this by making LowerBUILD_VECTOR not do this transformation for those
vectors that would get transformed back, i.e. BUILD_VECTOR of a single-element
constant vector. Doing that means we get a DUP, which we then need to recognise
in ISel as a copy.

llvm-svn: 347456
2018-11-22 11:45:23 +00:00
Jonas Paulsson 96782c2c0b [SystemZTTIImpl] Give correct cost values for vector bswap intrinsics.
Implement getIntrinsicInstrCost() and return costs reflecting that bswap can
be done with a vperm per vector register.

Review: Ulrich Weigand
https://reviews.llvm.org/D54789

llvm-svn: 347445
2018-11-22 07:17:29 +00:00
Stefan Pintilie 9d6445d34c [PowerPC][NFC] Split PPCMCCodeEmitter into header and cpp file.
This is further cleanup for PPCMCCodeEmitter. The class had been contained
within the cpp file alone. Now it has been split up between a header file and
a cpp file which allows other classes to make use of the functions in this class
if required.

llvm-svn: 347428
2018-11-21 21:23:50 +00:00
Stefan Pintilie 46e3cd76e2 [PowerPC][NFC] Minor Code Cleaup for PPCMCCodeEmitter.
llvm-svn: 347422
2018-11-21 20:47:59 +00:00
Sanjay Patel cadf62f360 [x86] fix predicate for avoiding vblendv
It only makes sense to produce the logic ops when 1 of the
constants is +0.0. Otherwise, go with vblendv to reduce code.

llvm-svn: 347403
2018-11-21 18:02:50 +00:00
Vladimir Stefanovic 64ad1cf24b [mips][mc] Add basic support for R_MIPS_JALR/R_MICROMIPS_JALR
R_MIPS_JALR/R_MICROMIPS_JALR can now be parsed in .s files and emitted to .o.
They are still not generated with JALR.

Differential revision: https://reviews.llvm.org/D54721

llvm-svn: 347398
2018-11-21 16:38:34 +00:00
Michal Gorny 71e902101d [nios2] Add missing Nios2CodeGen -> Nios2AsmPrinter linkage
Add missing linkage from Nios2CodeGen library to Nios2AsmPrinter
library.  The missing dependency causes shared-lib build to fail with
the following reason:

  lib/Target/Nios2/CMakeFiles/LLVMNios2CodeGen.dir/Nios2AsmPrinter.cpp.o: In function `(anonymous namespace)::Nios2AsmPrinter::PrintAsmMemoryOperand(llvm::MachineInstr const*, unsigned int, unsigned int, char const*, llvm::raw_ostream&)':
  Nios2AsmPrinter.cpp:(.text._ZN12_GLOBAL__N_115Nios2AsmPrinter21PrintAsmMemoryOperandEPKN4llvm12MachineInstrEjjPKcRNS1_11raw_ostreamE+0x2b): undefined reference to `llvm::Nios2InstPrinter::getRegisterName(unsigned int)'
  lib/Target/Nios2/CMakeFiles/LLVMNios2CodeGen.dir/Nios2AsmPrinter.cpp.o: In function `(anonymous namespace)::Nios2AsmPrinter::PrintAsmOperand(llvm::MachineInstr const*, unsigned int, unsigned int, char const*, llvm::raw_ostream&)':
  Nios2AsmPrinter.cpp:(.text._ZN12_GLOBAL__N_115Nios2AsmPrinter15PrintAsmOperandEPKN4llvm12MachineInstrEjjPKcRNS1_11raw_ostreamE+0x97): undefined reference to `llvm::Nios2InstPrinter::getRegisterName(unsigned int)'
  collect2: error: ld returned 1 exit status

Differential Revision: https://reviews.llvm.org/D47810

llvm-svn: 347387
2018-11-21 11:25:01 +00:00
Simon Pilgrim 66bae9aee8 [X86][AVX] Remove BROADCAST if we only need the 0'th element
We don't catch this with target shuffle simplification if the src/dst types are different.

llvm-svn: 347386
2018-11-21 11:00:09 +00:00
Craig Topper e9b4001a82 [X86] In getScalarMaskingNode, replace scalar_to_vector with a bitcast to v8i1 and an extract_subvector to convert i8 to v1i1.
The bitcast can be nicely merged with any i8 loads that exist for argument passing in 32 mode for example.

llvm-svn: 347380
2018-11-21 07:01:22 +00:00
Nemanja Ivanovic 5cf902ccd4 [PowerPC] Do not use vectors to codegen bswap with Altivec turned off
We have efficient codegen on P9 for lowering bswap that involves moving
the value into a vector reg and moving it back. However, the check under
which we custom lowered it did not adequately reflect the actual requirements.
It required only that the subtarget be an implementation of ISA 3.0 since all
compliant implementations have to provide the vector instructions.
However, the kernel builds have a valid use case for -mno-altivec -mcpu=pwr9
(i.e. don't emit vector code, don't have to save vector regs for context
switch). So we should require the correct features for this lowering.
Fixes https://bugs.llvm.org/show_bug.cgi?id=39334

llvm-svn: 347376
2018-11-21 02:53:50 +00:00
Craig Topper 27a5896fe8 [X86] Correct 256 vpmovzx/vpmovsx isel patterns to check HasAVX2 instead of HasAVX to prevent fast-isel from using them incorrectly.
These are AVX2 instructions, but have been incorrectly marked in tablegen for a while. This wasn't a problem until r346784 switched the patterns to use target independent ISD opcodes. This made the patterns visible to fast isel.

Fixes PR39733

llvm-svn: 347375
2018-11-21 01:39:38 +00:00
Craig Topper aa52ee2770 [X86] Emit a PACKUS instead of a VECTOR_SHUFFLE from LowerTRUNCATE for v16i16->v16i8.
We can't guarantee that demanded bits passing through the vector shuffle won't cause the AND in front of this to be removed. This would prevent the PACKUS from being matched during shuffle lowering.

Unfortunately, this adds a packuswb to one of the vector-reduce-mul.ll tests since we were removing the shuffle via SimplifyDemandedVectorElts. We appear to have similar issues with vpmovwb on the same test case on other targets.

llvm-svn: 347361
2018-11-20 22:57:48 +00:00
Craig Topper 24b346da42 [X86] Emit a single shuffle for the v16i8->v4i32 step of a SIGN_EXTEND_VECTOR_INREG lowering on pre-sse4.1 targets.
Previously we emitted to separate shuffles, one for unpcklbw and one for unpcklwd. Instead emit a single shuffle equivalent to both of the original shuffles. Shuffle lowering seems able to handle it. This avoids a bitcast between the two shuffles which seems helpful to DAG combine.

Remove the custom type legalization for v8i8->v8i32. I had put that in to avoid some almost duplicate punpcklbw instructions I was seeing, but this lowering change seems to fix that. It also fixes some duplicate shuffles seen in vector-sext.ll

llvm-svn: 347348
2018-11-20 21:21:52 +00:00
Sam Clegg 4791a668f5 [WebAssembly] WebAssemblyLowerEmscriptenEHSjLj: use getter/setter for accessing tempRet0
Rather than assuming that `tempRet0` exists in linear memory only assume
the getter/setter functions exist.  This avoids conflicting with
binaryen which declares a wasm global for this purpose and defines it's
own getter and setter for that.

The other advantage of doing things this way is that it leaving
it up to the linker/finalizer to decide how to actually store this
temporary.  As it happens binaryen uses a wasm global which is more
appropriate since it is thread safe.

This also allows us to change the way this is stored in the future
(memory, TLS memory, wasm global) without modifying LLVM.

This is part of a 4 part change:
LLVM: https://reviews.llvm.org/D53240
fastcomp: https://github.com/kripken/emscripten-fastcomp/pull/237
emscripten: https://github.com/kripken/emscripten/pull/7358
binaryen: https://github.com/WebAssembly/binaryen/pull/1709

Differential Revision: https://reviews.llvm.org/D53240

llvm-svn: 347340
2018-11-20 19:25:07 +00:00
Jinsong Ji 9a0ed20072 [PowerPC] Add Itineraries for STWU/STWUX etc
When doing some instruction scheduling work, we noticed some missing itineraries.

Before we switch to machine scheduler, those missing itineraries might not have impact to actually scheduling, 
because we can still get same latency due to default values.

With machine scheduler, however, itineraries will have impact to scheduling.
eg: NumMicroOps will default to be 0 if there is NO itineraries for specific instruction class.
And most of the instruction class with itineraries will have NumMicroOps default to 1.

This will has impact on the count of RetiredMOps, affects the Pending/Available Queue, 
then causing different scheduling or suboptimal scheduling further.

This patch is for STWU/STWUX (IIC_LdStStoreUpd ) for P8.

Since there are already multiple IIC for store update, this patch also merge
IIC_LdStSTDU/IIC_LdStStoreUpd to IIC_LdStSTU
IIC_LdStSTDUX to IIC_LdStSTUX

and we add a new testcase in https://reviews.llvm.org/D54699 to show the difference.

Differential Revision: https://reviews.llvm.org/D54700

llvm-svn: 347311
2018-11-20 15:11:42 +00:00
Simon Pilgrim c9cc6cca42 Fix MSVC 'truncation of constant value' warning. NFCI.
llvm-svn: 347308
2018-11-20 14:29:40 +00:00
Simon Pilgrim ee8b96f253 [X86][SSE] Add computeKnownBits/ComputeNumSignBits support for PACKSS/PACKUS instructions.
Pull out getPackDemandedElts demanded elts remapping helper from computeKnownBitsForTargetNode and use in computeKnownBits/ComputeNumSignBits.

llvm-svn: 347303
2018-11-20 13:23:37 +00:00
Simon Pilgrim ed7e2fda18 [X86][SSE] XFormVExtractWithShuffleIntoLoad - getVectorShuffle won't accept SM_SentinelZero
Noticed while working on improving demanded elts target shuffle shuffle combining

llvm-svn: 347302
2018-11-20 12:17:50 +00:00
Simon Pilgrim a6fb85ffa7 [X86][SSE] Lower immediately to PACKUS instead of VECTOR_SHUFFLE.
As discussed on rL347240, this avoids some regressions on D54679 and also helps some combines to kick in a bit earlier.

llvm-svn: 347300
2018-11-20 11:46:37 +00:00
Simon Pilgrim 7198506ba8 [X86][SSE] Add SimplifyDemandedVectorElts support for PACKSS/PACKUS instructions.
As discussed on rL347240.

llvm-svn: 347299
2018-11-20 11:09:46 +00:00
Craig Topper 17fa42a69b [X86] Preserve undef information when creating a punpckl/hbw from a v16i8 where all the even or odd elements are undef.
Previously if V2 was unused we ended up using V1 for both inputs as part of the code that follows the new code. By using lowerVectorShuffleWithUNPCK we keep the undef nature of V2 in the output.

As near as I can tell this makes v16i8 behavior consistent with every other VT now.

This does mean that we give the register allocator freedom to fill in random registers now and create false dependencies. But like I said we're already doing that for other types.

llvm-svn: 347296
2018-11-20 09:04:01 +00:00
Craig Topper b06d1aa3a1 [X86] Add custom type legalization for v8i8->v8i32 sign extend pre-SSE4.1
This helps with a future patch and makes us less reliant on DAG combine merging shuffles.

llvm-svn: 347295
2018-11-20 09:03:58 +00:00
Craig Topper c733c7bf94 [X86] Replace more calls to getZeroVector with regular getConstant.
getZeroVector produces a specifically canonicalized zero vector, but we can just let DAG legalization take care of it.

The test changes are because MULH lowering happens later than it should and this change gave us the opportunity to constant fold away a multiply during a DAG combine before the build_vector got legalized with a bitcast.

llvm-svn: 347290
2018-11-20 06:54:01 +00:00
Nemanja Ivanovic 9b393909e2 [PowerPC] Don't combine to bswap store on 1-byte truncating store
Turns out that there was no check for a store that truncates down
to a single byte when combining a (store (bswap...)) into a byte-swapping
store. This patch just adds that check.

Fixes https://bugs.llvm.org/show_bug.cgi?id=39478.

llvm-svn: 347288
2018-11-20 04:42:31 +00:00
Craig Topper 808d0dd689 [X86] Rename combineVSZext->combineExtendVectorInreg. NFC
Now that we no longer have target specific vector extend nodes let's make the function name match the nodes we do use.

llvm-svn: 347268
2018-11-19 22:18:47 +00:00
Konstantin Zhuravlyov 700b1ef54d AMDGPU: Fix V_FMA_F16 selection on GFX9
GFX9 should select opsel version.

Differential Revision: https://reviews.llvm.org/D54545

llvm-svn: 347265
2018-11-19 21:10:16 +00:00
Stanislav Mekhanoshin 8bafbae889 [AMDGPU] Restored selection of scalar_to_vector (v2x16)
This works if DAG combiner is enabled, but without combining
we cannot select scalar_to_vector of <2 x half> and <2 x i16>.

Differential Revision: https://reviews.llvm.org/D54718

llvm-svn: 347259
2018-11-19 19:58:13 +00:00
Craig Topper a5e0380c30 [X86][CostModel] Don't lookup intrinsic cost tables if the intrinsic isn't one we care about
We're seeing some issues internally where we sent some intrinsics into the cost model that the getTypeLegalizationCost call fails on, but X86 specific tables don't care about. Our base class implementation takes care of them. We'd just like X86 backend to ignore them.

This patch makes sure the switch returned something X86 cares about and skips the table lookups and type legalization call if not. Probably more efficient too since we don't go scanning the tables for every intrinsic we could possibly see.

Differential Revision: https://reviews.llvm.org/D54711

llvm-svn: 347248
2018-11-19 18:57:31 +00:00
Simon Pilgrim c4861ab170 [X86][SSE] Remove unnecessary bit-and in pshufb vector ctlz (PR39703)
SSE PSHUFB vector ctlz lowering works at the i4 nibble level. As detailed in PR39703, we were masking the lower nibble off but we only actually use it in the case where the upper nibble is known to be zero, making it safe to remove the mask and save an instruction.

Differential Revision: https://reviews.llvm.org/D54707

llvm-svn: 347242
2018-11-19 18:40:59 +00:00
Craig Topper 311bbcd535 [X86] Attempt to improve v32i8/v64i8 multiply lowering by applying the v16i8 non-avx2 algorithm to each 128-bit lane.
Previously we split the vectors in half to allow the two halves to be any extended then concatenated the results back together.

This patch instead instead extends the v16i8 sse algorithm to extend half of each 128-bit lane using punpcklbw/punpckhbw. Multiplies all the low half lanes and high half lanes together in separate operations. Then merges the half lane results back together using packuswb.

Unfortunately, some of the cases in vector-reduce-mul.ll regress because we aren't narrowing the vector width of the multiplies as we reduce. The splitting was somewhat making up for that before by causing halves to be discarded after the split.

Differential Revision: https://reviews.llvm.org/D54668

llvm-svn: 347240
2018-11-19 18:32:53 +00:00
Fangrui Song d83a5526d5 [AMDGPU] Fix -Wunused-variable
llvm-svn: 347234
2018-11-19 17:54:27 +00:00
Stanislav Mekhanoshin 054f8101f1 [AMDGPU] Convert insert_vector_elt into set of selects
This allows to avoid scratch use or indirect VGPR addressing for
small vectors.

Differential Revision: https://reviews.llvm.org/D54606

llvm-svn: 347231
2018-11-19 17:39:20 +00:00
Wouter van Oortmerssen 49482f824a [WebAssembly] replaced .param/.result by .functype
Summary:
This makes it easier/cleaner to generate a single signature from
this directive. Also:
- Adds the symbol name, such that we don't depend on the location
  of this directive anymore.
- Actually constructs the signature in the assembler, and make the
  assembler own it.
- Refactor the use of MVT vs ValType in the streamer and assembler
  to require less conversions overall.
- Changed 700 or so tests to use it.

Reviewers: sbc100, dschuff

Subscribers: jgravelle-google, eraman, aheejin, sunfish, jfb, llvm-commits

Differential Revision: https://reviews.llvm.org/D54652

llvm-svn: 347228
2018-11-19 17:10:36 +00:00
David Stuttard be3d7ba9fb [AMDGPU] Derive GCNSubtarget from MF to get overridden target features
Summary:
AMDGPUAsmPrinter has a getSTI function that derives a GCNSubtarget from the
TM. However, this means that overridden target features are not detected and can
result in incorrect behaviour.

Switch to using STM which is a GCNSubtarget derived from the MF (used elsewhere
in the same function).

Change-Id: Ib6328ad667b7fcdc87e9c06344e59859207db9b0

Subscribers: arsenm, kzhuravl, jvesely, wdng, nhaehnle, yaxunl, tpr, t-tye, llvm-commits

Differential Revision: https://reviews.llvm.org/D54301

llvm-svn: 347221
2018-11-19 15:44:20 +00:00
Martin Elshuber fef3036d37 Subject: [PATCH] [CodeGen] Add pass to combine interleaved loads.
This patch defines an interleaved-load-combine pass. The pass searches
for ShuffleVector instructions that represent interleaved loads. Matches are
converted such that they will be captured by the InterleavedAccessPass.

The pass extends LLVMs capabilities to use target specific instruction
selection of interleaved load patterns (e.g.: ld4 on Aarch64
architectures).

Differential Revision: https://reviews.llvm.org/D52653

llvm-svn: 347208
2018-11-19 14:26:10 +00:00
Nicolai Haehnle c548d91419 AMDGPU/InsertWaitcnts: Some more const-correctness
Reviewers: msearles, rampitec, scott.linder, kanarayan

Subscribers: arsenm, kzhuravl, jvesely, wdng, yaxunl, dstuttard, tpr, t-tye, llvm-commits, hakzsam

Differential Revision: https://reviews.llvm.org/D54225

llvm-svn: 347192
2018-11-19 12:03:11 +00:00
Sam Parker e7c42dd7e2 [ARM] Remove trunc sinks in ARM CGP
Truncs are treated as sources if their produce a value of the same
type as the one we currently trying to promote. Truncs used to be
considered as a sink if their operand was the same value type.
    
We now allow smaller types in the search, so we should search through
truncs that produce a smaller value. These truncs can then be
converted to an AND mask.
    
This leaves sinks as being:
  - points where the value in the register is being observed, such as
    an icmp, switch or store.
  - points where value types have to match, such as calls and returns.
  - zext are included to ease the transformation and are generally
    removed later on.
    
During this change, it also became apart from truncating sinks was
broken: if a sink used a source, its type information had already
been lost by the time the truncation happens. So I've changed the
method of caching the type information.

Differential Revision: https://reviews.llvm.org/D54515

llvm-svn: 347191
2018-11-19 11:34:40 +00:00
Anton Korobeynikov 4df19b75c0 [MSP430] Optimize srl/sra in case of A >> (8 + N)
There is no variable-length shifts on MSP430. Therefore
"eat" 8 bits of shift via bswap & ext.

Path by Kristina Bessonova!

Differential Revision: https://reviews.llvm.org/D54623

llvm-svn: 347187
2018-11-19 10:43:02 +00:00
Craig Topper 8b22bcd39f [X86] Use a pcmpgt with 0 instead of psrad 31, to fill elements with the sign bit in v4i32 MULH lowering.
The shift requires a copy to avoid clobbering a register. Comparing with 0 uses an xor to produce 0 that will be overwritten with the compare results. So still requires 2 instructions, but should be one byte shorter since it doesn't need to encode an immediate.

llvm-svn: 347185
2018-11-19 07:22:26 +00:00
Craig Topper 3616891046 [X86] Use compare with 0 to fill an element with sign bits when sign extending to v2i64 pre-sse4.1
Previously we used an arithmetic shift right by 31, but that requires a copy to preserve the input. So we might as well materialize a zero and compare to it since the comparison will overwrite the register that contains the zeros. This should be one byte shorter.

llvm-svn: 347181
2018-11-19 04:33:20 +00:00
Craig Topper 053f1eea96 [X86] Remove most of the SEXTLOAD Custom setOperationAction calls under -x86-experimental-vector-widening-legalization.
Leave just the v4i8->v4i64 and v8i8->v8i64, but only enable them on pre-sse4.1 targets when 64-bit mode is enabled. In those cases we end up creating sext loads that get scalarized to code that looks better than what we get from loading into a vector register and doing a multiple step sign extend using unpacks and shifts.

llvm-svn: 347180
2018-11-19 00:33:16 +00:00
Simon Pilgrim 7f92efa5a9 [X86][SSE] Add SimplifyDemandedVectorElts support for SSE packed i2fp conversions.
llvm-svn: 347177
2018-11-18 22:13:31 +00:00
Craig Topper 0468c860b7 [X86] Add custom type legalization for extending v4i8/v4i16->v4i64.
Pre-SSE4.1 sext_invec for v2i64 is complicated because we don't have a v2i64 sra instruction. So instead we sign extend to i32 using unpack and sra, then copy the elements and do a v4i32 sra to fill with sign bits, then interleave the i32 sign extend and the sign bits. So really we're doing to two sign extends but only using half of the v4i32 intermediate result.

When the result is more than 128 bits, default type legalization would prefer to split the destination type all the way down to v2i64 with shuffles followed by v16i8/v8i16->v2i64 sext_inreg operations. This results in more instructions than necessary because we are only utilizing the lower 2 elements of the v4i32 intermediate result. Instead we can custom split a v4i8/v4i16->v4i64 sign_extend. Then we can sign extend v4i8/v4i16->v4i32 invec producing a full v4i32 result. Create the sign bit vector as a v4i32 then split and interleave with the sign bits using an punpackldq and punpackhdq.

llvm-svn: 347176
2018-11-18 21:28:50 +00:00
Simon Pilgrim b31bdbd2e9 [X86][SSE] Add SimplifyDemandedVectorElts support for SSE splat-vector-shifts.
SSE vector shifts only use the bottom 64-bits of the shift amount vector.

llvm-svn: 347173
2018-11-18 20:21:52 +00:00
Craig Topper 11d50948e2 [X86] Disable combineToExtendVectorInReg under -x86-experimental-vector-widening-legalization. Add custom type legalization for extends.
If we widen illegal types instead of promoting, we should be able to rely on the type legalizer to create the vector_inreg operations for us with some caveats.

This patch disables combineToExtendVectorInReg when we are using widening.

I've enabled custom legalization for v8i8->v8i64 extends under avx512f since the type legalizer would want to create a vector_inreg with a v64i8 input type which isn't legal without avx512bw. So we go to v16i8 with custom code using the relaxation of rules we get from D54346.

I've also enable custom legalization of v8i64 and v16i32 operations with with AVX. When the input type is 128 bits, the default splitting legalization would extend first 128->256, then do the a split to two 128 pieces. Extend each half to 256 and then concat the result. The custom legalization I've added instead uses a 128->256 bit vector_inreg extend that only reads the lower 64-bits for the low half of the split. Then shuffles the high 64-bits to the low 64-bits and does another vector_inreg extend.

llvm-svn: 347172
2018-11-18 18:11:25 +00:00
Craig Topper bc8148f7b0 [X86] Lower v16i16->v8i16 truncate using an 'and' with 255, an extract_subvector, and a packuswb instruction.
Summary: This is an improvement over the two pshufbs and punpcklqdq we'd get otherwise.

Reviewers: RKSimon, spatel

Reviewed By: RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D54671

llvm-svn: 347171
2018-11-18 17:59:28 +00:00
Simon Pilgrim ec808cf541 Remove unused variable. NFCI.
llvm-svn: 347169
2018-11-18 17:24:59 +00:00
Simon Pilgrim 50828c75d0 [X86][SSE] Split IsSplatValue into GetSplatValue and IsSplatVector
Refactor towards making this recursive (necessary for PR38243 rotation splat detection).
IsSplatVector returns the original vector source of the splat and the splat index.
GetSplatValue returns the scalar splatted value as an extraction from IsSplatVector.

llvm-svn: 347168
2018-11-18 17:15:06 +00:00
Simon Pilgrim fec9f8657b [X86][SSE] Relax IsSplatValue - remove the 'variable shift' limit on subtracts.
Means we don't use the per-lane-shifts as much when we can cheaply use the older splat-variable-shifts.

llvm-svn: 347162
2018-11-18 15:52:08 +00:00
Simon Pilgrim cc1f5d2407 [X86][SSE] Use raw shuffle mask decode in SimplifyDemandedVectorEltsForTargetNode (PR39549)
We were using the 'normalized' shuffle mask from resolveTargetShuffleInputs, which replaces zero/undef inputs with sentinel values. For SimplifyDemandedVectorElts we need the raw mask so we can correctly demand those 'zero' inputs that got normalized away, this requires an extra bit of logic to locally normalize undef inputs.

llvm-svn: 347158
2018-11-18 13:34:53 +00:00