38528 Commits

Author SHA1 Message Date
Thomas Lively
e657c84fa1 [WebAssembly] Use v128.const instead of splats for constants
We previously used splats instead of v128.const to materialize vector constants
because V8 did not support v128.const. Now that V8 supports v128.const, we can
use v128.const instead. Although this increases code size, it should also
increase performance (or at least require fewer engine-side optimizations), so
it is an appropriate change to make.

Differential Revision: https://reviews.llvm.org/D100716
2021-04-19 12:43:59 -07:00
madhur13490
6a4d9cb7e0 [AMDGPU] Remove error check for indirect calls and add missing queue-ptr
This patch removes -fixed-abi check for indirect calls
and also adds queue-ptr which is required for indirect calls to work.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D100633
2021-04-20 00:35:17 +05:30
Pavel Iliin
2ec16103c6 [AArch64] Peephole rule to remove redundant cmp after cset.
Comparisons to zero or one after cset instructions can be safely
removed in examples like:

cset w9, eq          cset w9, eq
cmp  w9, #1   --->   <removed>
b.ne    .L1          b.ne    .L1

cset w9, eq          cset w9, eq
cmp  w9, #0   --->   <removed>
b.ne    .L1          b.eq    .L1

Peephole optimization to detect suitable cases and get rid of that
comparisons added.

Differential Revision: https://reviews.llvm.org/D98564
2021-04-19 19:58:38 +01:00
Craig Topper
7ed01a420a [RISCV] Pad v4i1/v2i1/v1i1 stores with 0s to make a full byte.
As noted in the FIXME there's a sort of agreement that the any
extra bits stored will be 0.

The generated code is pretty terrible. I was really hoping we
could use a tail undisturbed trick, but tail undisturbed no
longer applies to masked destinations in the current draft
spec.

Fingers crossed that it isn't common to do this. I doubt IR
from clang or the vectorizer would ever create this kind of store.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D100618
2021-04-19 11:05:18 -07:00
Jessica Paquette
65f257a215 [AArch64][GlobalISel] Implement custom legalization for s32 and s64 G_CTPOP
This is a partial port of AArch64TargetLowering::LowerCTPOP.

This custom lowering tries to uses NEON instructions to give a more efficient
CTPOP lowering when possible.

In the non-NEON/noimplicitfloat case, this should use the generic lowering
(see: https://godbolt.org/z/GcaPvWe4x). I think that's worth implementing after
implementing the widening code for s16/s8 though.

Differential Revision: https://reviews.llvm.org/D100399
2021-04-19 10:56:02 -07:00
Jessica Paquette
91bbb914e0 [AArch64][GlobalISel] Regbankselect + select @llvm.aarch64.neon.uaddlv
It turns out we actually import a bunch of selection code for intrinsics. The
imported code checks that the register banks on the G_INTRINSIC instruction
are correct. If so, it goes ahead and selects it.

This adds code to AArch64RegisterBankInfo to allow us to correctly determine
register banks on intrinsics which have known register bank constraints.

For now, this only handles @llvm.aarch64.neon.uaddlv. This is necessary for
porting AArch64TargetLowering::LowerCTPOP.

Also add a utility for getting the intrinsic ID from a G_INTRINSIC instruction.
This seems a little nicer than having to know about how intrinsic instructions
are structured.

Differential Revision: https://reviews.llvm.org/D100398
2021-04-19 10:47:49 -07:00
Jay Foad
ef443390a9 [AMDGPU] Remove MachineDCE after SIFoldOperands
Remove the MachineDCE pass after the first SIFoldOperands pass now
that SIFoldOperands deletes its own dead instructions.

Reapply after fixing dependent change D100188.

Differential Revision: https://reviews.llvm.org/D100189
2021-04-19 12:08:02 +01:00
Fraser Cormack
c9a93c3e01 [RISCV] Lower vector shuffles to vrgather operations
This patch extends the lowering of RVV fixed-length vector shuffles to
avoid the default stack expansion and instead lower to vrgather
instructions.

For "permute"-style shuffles where one vector is swizzled, we can lower
to one vrgather. For shuffles involving two vector operands, we lower to
one unmasked vrgather (or splat, where appropriate) followed by a masked
vrgather which blends in the second half.

On occasion, when it's not possible to create a legal BUILD_VECTOR for
the indices, we use vrgatherei16 instructions with 16-bit index types.

For 8-bit element vectors where we may have indices over 255, we have a
fairly blunt fallback to the stack expansion to avoid custom-splitting
of the vector types.

To enable the selection of masked vrgather instructions, this patch
extends the various RISCVISD::VRGATHER nodes to take a passthru operand.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D100549
2021-04-19 11:13:13 +01:00
David Sherwood
83f5fa519e [CodeGen] Improve code generation for clamping of constant indices with scalable vectors
When trying to clamp a constant index into a scalable vector we can
test if the index is less than the minimum number of elements in the
vector. If so, we can simply return the index because we know it is
guaranteed to fit inside the vector.

Differential Revision: https://reviews.llvm.org/D100639
2021-04-19 08:34:17 +01:00
Serguei Katkov
9f33943ee0 [GreedyRA ORE] Add stats for copy of virtual registers.
Greedy RA adds copies of virtual registers when splitting live interval.
This stat might be useful.

Reviewers: reames, MatzeB, anemet, thegameg
Reviewed By: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D100017
2021-04-19 12:43:44 +07:00
Serguei Katkov
61d22f2e4e [Greedy RA] Add a check to MachineVerifier
If Virtual Register is alive in landing pad its def must be
before the call causing the exception or it should be statepoint instruction itself and
in this case def actually means the relocation of gc pointer and is alive in
landing pad.

The test shows the triggering this check for an option under development
use-registers-for-gc-values-in-landing-pad which is off by default until
it is functionally correct.

Reviewers: reames, void, jyknight, nickdesaulniers, efriedma, arsenm, rnk
Reviewed By: rnk
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D100525
2021-04-19 12:31:18 +07:00
Nemanja Ivanovic
ff769dd111 [PowerPC] Minor improvement for insert_vector_elt codegen
For v2f64, all VSX subtargets can insert an element with a single
XXPERMDI.
2021-04-16 18:52:37 -05:00
Philip Reames
f549176ad9 [funcattrs] Add the maximal set of implied attributes to definitions
Have funcattrs expand all implied attributes into the IR. This expands the infrastructure from D100400, but for definitions not declarations this time.

Somewhat subtly, this mostly isn't semantic. Because the accessors did the inference, any client which used the accessor was already getting the stronger result. Clients that directly checked presence of attributes (there are some), will see a stronger result now.

The old behavior can end up quite confusing for two reasons:
* Without this change, we have situations where function-attrs appears to fail when inferring an attribute (as seen by a human reading IR), but that consuming code will see that it should have been implied. As a human trying to sanity check test results and study IR for optimization possibilities, this is exceeding error prone and confusing. (I'll note that I wasted several hours recently because of this.)
* We can have transforms which trigger without the IR appearing (on inspection) to meet the preconditions. This change doesn't prevent this from happening (as the accessors still involve multiple checks), but it should make it less frequent.

I'd argue in favor of deleting the extra checks out of the accessors after this lands, but I want that in it's own review as a) it's purely stylistic, and b) I already know there's some disagreement.

Once this lands, I'm also going to do a cleanup change which will delete some now redundant duplicate predicates in the inference code, but again, that deserves to be a change of it's own.

Differential Revision: https://reviews.llvm.org/D100226
2021-04-16 14:22:19 -07:00
Thomas Lively
5c729750a6 [WebAssembly] Remove saturating fp-to-int target intrinsics
Use the target-independent @llvm.fptosi and @llvm.fptoui intrinsics instead.
This includes removing the instrinsics for i32x4.trunc_sat_zero_f64x2_{s,u},
which are now represented in IR as a saturating truncation to a v2i32 followed by
a concatenation with a zero vector.

Differential Revision: https://reviews.llvm.org/D100596
2021-04-16 12:11:20 -07:00
Malhar Jajoo
093f1828e5 [ARM] Prevent phi-node-elimination from generating copy above t2WhileLoopStartLR
This patch prevents phi-node-elimination from generating a COPY
operation for the register defined by t2WhileLoopStartLR, as it is a
terminator that defines a value.

This happens because of the presence of phi-nodes in the loop body (the
Preheader of which is the block containing the t2WhileLoopStartLR). If
this is not done, the COPY is generated above/before the terminator
(t2WhileLoopStartLR here), and since it uses the value defined by
t2WhileLoopStartLR, MachineVerifier throws a 'use before define' error.

This essentially adds on to the change in differential D91887/D97729.

Differential Revision: https://reviews.llvm.org/D100376
2021-04-16 16:45:07 +01:00
Nigel Perks
23f8993f32 Restore lit feature object-emission. Omit DebugInfo/Generic on XCore.
D73568 removed the lit feature object-emission, because it was introduced for a
target which did not support the integrated assembler, and that target no longer
required the feature. XCore still does not support the integrated assembler,
so a build with XCore as the default target fails tests requiring
object-emission. This issue was not publicly visible because there was not a
buildbot for XCore as the default target. We fixed the failures downstream. We
now have builder clang-xcore-ubuntu-20-x64 on the staging buildmaster, which
shows the failures. We would like to make upstream build green.

Omit DebugInfo/Generic on XCore to avoid annotating 70 separate files.

Differential Revision: https://reviews.llvm.org/D98508
2021-04-16 13:02:14 +01:00
Caroline Concatto
394eb91854 [NFC][AArch64][SVE] Move select-sve.ll tests to sve-select.ll
This patch merges the two select tests: select-sve.ll and sve-select.ll into
sve-select.ll as they are both testing SELECT instruction
2021-04-16 11:59:53 +01:00
David Green
00a6045473 [ARM] Combine sub 0, csinc X, Y, CC -> csinv -X, Y, CC
Combine sub 0, csinc X, Y, CC to csinv -X, Y, CC providing that the
negation of X is cheap, currently just handling constants. This comes up
during the splat of an i1 to a predicate, where we now generate csetm,
as opposed to cset; rsb.

Differential Revision: https://reviews.llvm.org/D99940
2021-04-16 11:52:31 +01:00
Fraser Cormack
ec0f7c6923 [RISCV] Rerun stack test through update_llc_test_checks.py
Adjusts formatting of comments only. Just to reduce diffs in future
patches.
2021-04-16 11:08:58 +01:00
Nick Desaulniers
bb7016f8f5 [Aarch64] handle "o" inline asm memory constraints
This Linux kernel is making use of this inline asm constraint which is
causing an ICE.

PR49956

Link: https://github.com/ClangBuiltLinux/linux/issues/1348

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D100412
2021-04-15 23:36:21 -07:00
Jim Lin
2893570e86 [RISCV] Don't emit save-restore call if function is a interrupt handler
It has to save all caller-saved registers before a call in the handler.
So don't emit a call that save/restore registers.

Reviewed By: simoncook, luismarques, asb

Differential Revision: https://reviews.llvm.org/D100532
2021-04-16 12:54:47 +08:00
Momchil Velikov
f9d932e673 [clang][AArch64] Correctly align HFA arguments when passed on the stack
When we pass a AArch64 Homogeneous Floating-Point
Aggregate (HFA) argument with increased alignment
requirements, for example

    struct S {
      __attribute__ ((__aligned__(16))) double v[4];
    };

Clang uses `[4 x double]` for the parameter, which is passed
on the stack at alignment 8, whereas it should be at
alignment 16, following Rule C.4 in
AAPCS (https://github.com/ARM-software/abi-aa/blob/master/aapcs64/aapcs64.rst#642parameter-passing-rules)

Currently we don't have a way to express in LLVM IR the
alignment requirements of the function arguments. The align
attribute is applicable to pointers only, and only for some
special ways of passing arguments (e..g byval). When
implementing AAPCS32/AAPCS64, clang resorts to dubious hacks
of coercing to types, which naturally have the needed
alignment. We don't have enough types to cover all the
cases, though.

This patch introduces a new use of the stackalign attribute
to control stack slot alignment, when and if an argument is
passed in memory.

The attribute align is left as an optimizer hint - it still
applies to pointer types only and pertains to the content of
the pointer, whereas the alignment of the pointer itself is
determined by the stackalign attribute.

For byval arguments, the stackalign attribute assumes the
role, previously perfomed by align, falling back to align if
stackalign` is absent.

On the clang side, when passing arguments using the "direct"
style (cf. `ABIArgInfo::Kind`), now we can optionally
specify an alignment, which is emitted as the new
`stackalign` attribute.

Patch by Momchil Velikov and Lucas Prates.

Differential Revision: https://reviews.llvm.org/D98794
2021-04-15 22:58:14 +01:00
Krzysztof Parzyszek
280678122d [Hexagon] Avoid infinite loops in type legalization when lowering SETCC
Only widen SETCC if the operands can be widened. Not checking that caused
infinite widen-split loops in legalization.
2021-04-15 13:34:37 -05:00
Stelios Ioannou
bf147c4653 [LSR] Fix for pre-indexed generated constant offset
This patch changed the isLegalUse check to ensure that
LSRInstance::GenerateConstantOffsetsImpl generates an
offset that results in a legal addressing mode and
formula. The check is changed to look similar to the
assert check used for illegal formulas.

Differential Revision: https://reviews.llvm.org/D100383

Change-Id: Iffb9e32d59df96b8f072c00f6c339108159a009a
2021-04-15 16:44:42 +01:00
Sebastian Neubauer
7842e1725e [AMDGPU] Fix large return values with amdgpu_gfx
Returning in memory is not supported, so fall back to sret.
Also, extend i1 and i16 to i32. Otherwise, they would be passed through
memory.

Differential Revision: https://reviews.llvm.org/D100543
2021-04-15 14:57:56 +02:00
Simon Pilgrim
9d57a77b81 [X86] combineCMP - fold cmpEQ/NE(TRUNC(X),0) -> cmpEQ/NE(X,0)
If we are truncating from a i32 source before comparing the result against zero, then see if we can directly compare the source value against zero.

If the upper (truncated) bits are known to be zero then we can compare against that, hopefully increasing the chances of us folding the compare into a EFLAG result of the source's operation.

Fixes PR49028.

Differential Revision: https://reviews.llvm.org/D100491
2021-04-15 13:55:51 +01:00
Bradley Smith
22c017f0f9 [AArch64][NEON] Match (or (and -a b) (and (a+1) b)) => bit select
With this patch vbslq_f32(vnegq_s32(a), b, c) lowers to a BIT instruction.

Co-authored-by: Paul Walker <paul.walker@arm.com>

Differential Revision: https://reviews.llvm.org/D100304
2021-04-15 13:52:47 +01:00
Jun Ma
7e1422c1e4 [DAGCombiner] Fold step_vector with add/mul/shl
This patch implements some DAG combines for STEP_VECTOR:
add step_vector(C1), step_vector(C2) -> step_vector(C1+C2)
add (add X step_vector(C1)), step_vector(C2) -> add X step_vector(C1+C2)
mul step_vector(C1), C2 -> step_vector(C1*C2)
shl step_vector(C1), C2 -> step_vector(C1<<C2)

TestPlan: check-llvm

Differential Revision: https://reviews.llvm.org/D100088
2021-04-15 18:06:35 +08:00
Fraser Cormack
eae0ac3a1f [RISCV] Pre-commit vector shuffle test cases
This codegen will be improved by future patches.
2021-04-15 10:31:13 +01:00
Martin Storsjö
5144f730a8 [AArch64] Fix windows vararg functions with floats in the fixed args
On Windows, float arguments are normally passed in float registers
in the calling convention for regular functions. For variable
argument functions, floats are passed in integer registers. This
already was done correctly since many years.

However, the surprising bit was that floats among the fixed arguments
also are supposed to be passed in integer registers, contrary to regular
functions. (This also seems to be the behaviour on ARM though, both
on Windows, but also on e.g. hardfloat linux.)

In the calling convention, don't promote shorter floats to f64, but
convert them to integers of the same length. (Floats passed as part of
the actual variable arguments are promoted to double already on the
C/Clang level; the LLVM vararg calling convention doesn't do any
extra promotion of f32 to f64 - this matches how it works on X86 too.)

Technically, this is an ABI break compared to older LLVM versions,
but it fixes compatibility with the official platform ABI. (In practice,
floats among the fixed arguments in variable argument functions is
a pretty rare construct.)

Differential Revision: https://reviews.llvm.org/D100365
2021-04-15 11:02:14 +03:00
hsmahesha
4973b0c4e7 [AMDGPU] Disable forceful inline of non-kernel functions which use LDS.
Now since LDS uses within non-kernel functions are being handled in the
pass - LowerModuleLDS, we *NO* need to *forcefully* inline non-kernel
functions just because they use LDS. Do forceful inlining only when the
pass - LowerModuleLDS is not enabled. It is enabled by default.

Reviewed By: JonChesterfield

Differential Revision: https://reviews.llvm.org/D100481
2021-04-15 09:12:56 +05:30
Philip Reames
dd985551c2 Reapply "[InferAttributes] Materialize all infered attributes for declaration"" and follow on patches.
This reverts commit ab98f2c7129a52e216fd7e088b964cf4af27b0f2 and 98eea392cdbcdb7360e58b46e9329573f092cd96.

It includes a fix for the clang test which triggered the revert.  I failed to notice this one because there was another AMDGPU llvm test with a similiar name and the exact same text in the error message.  Odd.  Since only one build bot reported the clang test, I didn't notice that one.
2021-04-14 16:38:07 -07:00
Nico Weber
98eea392cd Revert "Fix buildbots after 61a85da"
This reverts commit c609d533634416fc701939d39bf1e43f293e84dc.
61a85da was reverted in ab98f2c7
2021-04-14 18:47:46 -04:00
Philip Reames
c609d53363 Fix buildbots after 61a85da 2021-04-14 15:16:05 -07:00
Thomas Lively
6a18cc23ef [WebAssembly] Codegen for i64x2.extend_{low,high}_i32x4_{s,u}
Removes the builtins and intrinsics used to opt in to using these instructions
and replaces them with normal ISel patterns now that they are no longer
prototypes.

Differential Revision: https://reviews.llvm.org/D100402
2021-04-14 13:43:09 -07:00
Thomas Lively
af7925b4dd [WebAssembly] Codegen for f64x2.convert_low_i32x4_{s,u}
Add a custom DAG combine and ISD opcode for detecting patterns like

  (uint_to_fp (extract_subvector ...))

before the extract_subvector is expanded to ensure that they will ultimately
lower to f64x2.convert_low_i32x4_{s,u} instructions. Since these instructions
are no longer prototypes and can now be produced via standard IR, this commit
also removes the target intrinsics and builtins that had been used to prototype
the instructions.

Differential Revision: https://reviews.llvm.org/D100425
2021-04-14 10:42:45 -07:00
Thomas Lively
af7ab81ce3 [WebAssembly] Use standard intrinsics for f32x4 and f64x2 ops
Now that these instructions are no longer prototypes, we do not need to be
careful about keeping them opt-in and can use the standard LLVM infrastructure
for them. This commit removes the bespoke intrinsics we were using to represent
these operations in favor of the corresponding target-independent intrinsics.
The clang builtins are preserved because there is no standard way to easily
represent these operations in C/C++.

For consistency with the scalar codegen in the Wasm backend, the intrinsic used
to represent {f32x4,f64x2}.nearest is @llvm.nearbyint even though
@llvm.roundeven better captures the semantics of the underlying Wasm
instruction. Replacing our use of @llvm.nearbyint with use of @llvm.roundeven is
left to a potential future patch.

Differential Revision: https://reviews.llvm.org/D100411
2021-04-14 09:19:27 -07:00
Simon Pilgrim
c4c9e4d6df [X86] Add PR49028 test case 2021-04-14 15:55:21 +01:00
hsmahesha
e3070db0f7 [AMDGPU] Rename "LDS lowering" pass name.
Rename the name of "LDS lowering" pass from `amdgpu-disable-lower-module-lds` to
`amdgpu-enable-lower-module-lds` as later is consistent and reads better.

Reviewed By: JonChesterfield

Differential Revision: https://reviews.llvm.org/D100441
2021-04-14 20:19:53 +05:30
Simon Pilgrim
4fbe761572 [X86][SSE] canonicalizeShuffleWithBinOps - check for more combos of merge-able binary shuffles.
In the fold SHUFFLE(BINOP(X,Y),BINOP(Z,W)) -> BINOP(SHUFFLE(X,Z),SHUFFLE(Y,W)), check if both X/Z AND Y/W have at least one merge-able shuffle in which case the total number of shuffle should still fall.

Helps with instruction count regressions we saw while fixing PR48823
2021-04-14 15:24:41 +01:00
Pablo Barrio
cca40aa8d8 [AArch64][v8.5A] Add BTI to all function starts
The existing BTI placement pass avoids inserting "BTI c" when the
function has local linkage and is only directly called. However,
even in this case, there is a (small) chance that the linker later
adds a hunk with an indirect call to the function, e.g. if the
function is placed in a separate section and moved far away from
its callers. Make sure to add BTI for these functions too.

Differential Revision: https://reviews.llvm.org/D99417
2021-04-14 15:24:01 +01:00
Sebastian Neubauer
929edd4375 [AMDGPU] Mark scavenged SGPR as used
Otherwise it reuses the same register for storing the stack slot
offset if the stack slot offset is big.

Differential Revision: https://reviews.llvm.org/D100461
2021-04-14 14:55:01 +02:00
Zarko Todorovski
6b7838b68c [AIX] Allow safe for 32bit P8 VSX pattern matching
Pull some of the safe for 32bit pattern matching for Pwr8 and above.

Reviewed By: nemanjai

Differential Revision: https://reviews.llvm.org/D97909
2021-04-14 08:12:48 -04:00
Tim Northover
6401b78ab3 SDAG: constant fold bf16 -> i16 casts
This direction is particularly useful because i16 constants are much more
likely to be legal than bf16.
2021-04-14 11:27:46 +01:00
Simon Pilgrim
73737fe990 [X86] Fold cmpeq/ne(trunc(x),0) --> cmpeq/ne(x,0)
Relax the fold from rGbaadbe04bf75 to compare any op, not just logic ops, now that the movmsk regressions have been handled.
2021-04-14 11:02:02 +01:00
Simon Pilgrim
62af2af85d [X86] Regenerate PR32284.ll test case prefixes. NFC.
Use X64 for 64-bit targets and X86 for 32-bit targets
2021-04-14 11:02:01 +01:00
Serguei Katkov
cf0d3477aa [GreedyRA ORE] Separate Folder Reloads and Zero Cost Folder Reloads
Patchpoint instructions have operands which is actually zero cost
(or the same as register) to use the value from the stack.
In terms of statistic it makes same to separate them.

Move from computation instructions related to stack spill/reload to
number of stack slot referenced.

Reviewers: reames, MatzeB, anemet, thegameg
Reviewed By: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D100016
2021-04-14 14:25:28 +07:00
Serguei Katkov
02265ed7ad [Live Intervals] Teach Greedy RA to recognize special case live-through
Statepoint instruction has a deopt section which is actually live-through the call.
Currently this is handled by special post pass after RA - fixup-statepoint-caller-saved.

This change teaches Greedy RA that if segment of live interval is ended with statepoint
instruction and its reg is used in deopt bundle then this live interval interferes regmask of this statepoint
and as a result caller-saved register cannot be assigned to this live interval.

Reviewers: reames, dantrushin
Reviewed By: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D100296
2021-04-14 13:26:49 +07:00
Wang, Pengfei
a3b52a9d13 [X86][AMX] Refactor for PostRA ldtilecfg pass.
This is a follow up of D99010. We didn't consider the live range of shape registers when hoist ldtilecfg. There maybe risks, e.g. we happen to insert it to an invalid range of some registers and get unexpected error.

This patch fixes this problem by storing the value to corresponding stack place of ldtilecfg after all its definition immediately.

This patch also fix a problem in previous code: If we don't have a ldtilecfg which dominates all AMX instructions, we cannot initialize shapes for other ldtilecfg.

There're still some optimization points left. E.g. eliminate unused mov instructions, break the def-use dependency before RA etc.

Reviewed By: LuoYuanke, xiangzhangllvm

Differential Revision: https://reviews.llvm.org/D99966
2021-04-14 10:08:23 +08:00
ShihPo Hung
d5e962f1f2 [RISCV] Implement COPY for Zvlsseg registers
When copying Zvlsseg register tuples, we split the COPY to NF whole register moves
as below:

  $v10m2_v12m2 = COPY $v4m2_v6m2 # NF = 2
=>
  $v10m2 = PseudoVMV2R_V $v4m2
  $v12m2 = PseudoVMV2R_V $v6m2

This patch copies forwardCopyWillClobberTuple from AArch64 to check
register overlapping.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D100280
2021-04-13 18:55:51 -07:00