Commit Graph

55473 Commits

Author SHA1 Message Date
Cullen Rhodes 49edf9a509 [AArch64][SVE] Add break intrinsics
Summary:
Implements the following intrinsics:

    * @llvm.aarch64.sve.brka
    * @llvm.aarch64.sve.brka.z
    * @llvm.aarch64.sve.brkb
    * @llvm.aarch64.sve.brkb.z
    * @llvm.aarch64.sve.brkn.z
    * @llvm.aarch64.sve.brkpa.z
    * @llvm.aarch64.sve.brkpb.z

Reviewers: sdesmalen, efriedma, dancgr, mgudim, cameron.mcinally, rengolin

Reviewed By: sdesmalen

Subscribers: tschuett, kristof.beyls, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72393
2020-01-17 11:47:08 +00:00
Kerry McLaughlin fe3bb8ec96 [AArch64][SVE] Add ImmArg property to intrinsics with immediates
Summary:
Several SVE intrinsics with immediate arguments (including those
added by D70253 & D70437) do not use the ImmArg property.
This patch adds ImmArg<Op> where required and changes
the appropriate patterns which match the immediates.

Reviewers: efriedma, sdesmalen, andwar, rengolin

Reviewed By: efriedma

Subscribers: tschuett, kristof.beyls, hiraditya, rkruppe, psnobl, cfe-commits, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72612
2020-01-17 10:47:55 +00:00
Craig Topper caee96031d [Transforms][RISCV] Remove a "using namespace llvm" from an include file. Fix a place that became dependent on it.
This include file was created in October and has a "using namespace llvm". This seems to get exposed to other include files and finally onto cpp files. While this somewhat okay for llvm itself, its bad for other projects that use llvm as a library and includes a header file that picks this up. This was found by ISPC which has some class names at gloal scope with the same names as LLVM.

It looks like RISCV accidentally became dependent on this. I fixed it by reordering some includes in the RISCV code, but maybe we want to change the TableGenEmitter to put "namespace llvm {" in the generated file instead? But we probably want to do the simplest thing first so we can merge it to 10.0.

Differential Revision: https://reviews.llvm.org/D72895
2020-01-16 20:50:41 -08:00
Matt Arsenault 117d4f1900 AMDGPU: Add register classes to MUBUF load patterns 2020-01-16 22:00:44 -05:00
Zakk Chen cef838e65f Revert "[RISCV] Support ABI checking with per function target-features"
This reverts commit 7bc58a779a.
It breaks EXPENSIVE_CHECKS on Windows
2020-01-16 18:01:07 -08:00
Jessica Paquette b82d18e1e8 [AArch64][GlobalISel] Change G_FCONSTANTs feeding into stores into G_CONSTANTS
Given the following situation:

x = G_FCONSTANT (something that can't be materialized)
G_STORE x, some_addr

We know that x must be materialized as at least a single mov. However, at the
time of selection, the G_STORE will have been regbankselected to a FPR store.

So, as a result, you'll get an unnecessary fmov into the G_STORE.

Storing a constant value in a GPR and a constant value in a FPR are the same.
So, whenever you see a G_FCONSTANT that feeds into only G_STORES, so might as
well make it a G_CONSTANT.

This adds a target-specific combine which changes G_FCONSTANTs feeding into
G_STOREs into G_CONSTANTs.

Differential Revision: https://reviews.llvm.org/D72814
2020-01-16 15:18:44 -08:00
Derek Schuff 80906d9d16 Revert "[WebAssembly] Track frame registers through VReg and local allocation"
This reverts commit 3a05c3969c.
It breaks under expensive-checks and on Windows
2020-01-16 14:38:00 -08:00
Matt Arsenault 91e758b732 AMDGPU: Move permlane discard vdst_in optimization
This case can be handled as a regular selection pattern, so move it
out of the weird post-isel folding code which doesn't have an exactly
equivalent place in GlobalISel.

I think it doesn't make much sense to do this optimization here
though, and it would be more useful in instcombine. There's not really
any new information that will be gained during lowering since these
inputs were known from the beginning.
2020-01-16 17:27:53 -05:00
Derek Schuff 3a05c3969c [WebAssembly] Track frame registers through VReg and local allocation
This change has 2 components:

Target-independent: add a method getDwarfFrameBase to TargetFrameLowering. It
describes how the Dwarf frame base will be encoded.  That can be a register (the
default), the CFA (which replaces NVPTX-specific logic in DwarfCompileUnit), or
a DW_OP_WASM_location descriptr.

WebAssembly: Allow WebAssemblyFunctionInfo::getFrameRegister to return the
correct virtual register instead of FP32/SP32 after WebAssemblyReplacePhysRegs
has run.  Make WebAssemblyExplicitLocals store the local it allocates for the
frame register. Use this local information to implement getDwarfFrameBase

The result is that the DW_AT_frame_base attribute is correctly encoded for each
subprogram, and each param and local variable has a correct DW_AT_location that
uses DW_OP_fbreg to refer to the frame base.

Differential Revision: https://reviews.llvm.org/D71681
2020-01-16 13:51:17 -08:00
Matt Arsenault f5d98543b8 AMDGPU: Remove outdated comment 2020-01-16 14:54:27 -05:00
Matt Arsenault e12b840abf AMDGPU/GlobalISel: Improve lowering of G_SEXT_INREG
Clamping the scalar is much better than lowering with superwide shifts
for types > s64.
2020-01-16 14:29:37 -05:00
Krzysztof Parzyszek 5f65065437 [Hexagon] Update autogeneated intrinsic information in LLVM 2020-01-16 13:11:18 -06:00
Matt Arsenault 0d0fce42b0 GlobalISel: Preserve load/store metadata in IRTranslator
This was dropping the invariant metadata on dead argument loads, so
they weren't deleted.

Atomics still need to be fixed the same way. Also, apparently store
was never preserving dereferencable which should also be fixed.
2020-01-16 13:49:43 -05:00
Krzysztof Parzyszek 8ee2d16896 [Hexagon] Add a target feature to disable compound instructions
This affects the following instructions:
Tag: M4_mpyrr_addr     Syntax: Ry32 = add(Ru32,mpyi(Ry32,Rs32))
Tag: M4_mpyri_addr_u2  Syntax: Rd32 = add(Ru32,mpyi(#u6:2,Rs32))
Tag: M4_mpyri_addr     Syntax: Rd32 = add(Ru32,mpyi(Rs32,#u6))
Tag: M4_mpyri_addi     Syntax: Rd32 = add(#u6,mpyi(Rs32,#U6))
Tag: M4_mpyrr_addi     Syntax: Rd32 = add(#u6,mpyi(Rs32,Rt32))
Tag: S4_addaddi        Syntax: Rd32 = add(Rs32,add(Ru32,#s6))
Tag: S4_subaddi        Syntax: Rd32 = add(Rs32,sub(#s6,Ru32))
Tag: S4_or_andix       Syntax: Rx32 = or(Ru32,and(Rx32,#s10))
Tag: S4_andi_asl_ri    Syntax: Rx32 = and(#u8,asl(Rx32,#U5))
Tag: S4_ori_asl_ri     Syntax: Rx32 = or(#u8,asl(Rx32,#U5))
Tag: S4_addi_asl_ri    Syntax: Rx32 = add(#u8,asl(Rx32,#U5))
Tag: S4_subi_asl_ri    Syntax: Rx32 = sub(#u8,asl(Rx32,#U5))
Tag: S4_andi_lsr_ri    Syntax: Rx32 = and(#u8,lsr(Rx32,#U5))
Tag: S4_ori_lsr_ri     Syntax: Rx32 = or(#u8,lsr(Rx32,#U5))
Tag: S4_addi_lsr_ri    Syntax: Rx32 = add(#u8,lsr(Rx32,#U5))
Tag: S4_subi_lsr_ri    Syntax: Rx32 = sub(#u8,lsr(Rx32,#U5))
2020-01-16 12:37:30 -06:00
stevewan bed7626f04 [PowerPC][AIX] Make PIC the default relocation model for AIX
Summary:
The `llc` tool currently defaults to Static relocation model and generates non-relocatable code for 32-bit Power.
This is not desirable on AIX where we always generate Position Independent Code (PIC). This patch makes PIC the default relocation model for AIX.

Reviewers: daltenty, hubert.reinterpretcast, DiggerLin, Xiangling_L, sfertile

Reviewed By: hubert.reinterpretcast

Subscribers: mgorny, wuzish, nemanjai, hiraditya, kbarton, jsji, shchenz, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72479
2020-01-16 13:07:36 -05:00
Matt Arsenault 4ca1ad85b7 AMDGPU/GlobalISel: Don't handle legacy buffer intrinsic 2020-01-16 11:31:12 -05:00
Matt Arsenault 9b2f3532c7 AMDGPU/GlobalISel: Select DS GWS intrinsics 2020-01-16 11:25:10 -05:00
Jay Foad 63f73545dd [GlobalISel] Pass MachineOperands into MachineIRBuilder helper methods
Reviewers: arsenm, aditya_nandakumar, aemerson

Subscribers: wdng, rovka, hiraditya, volkan, Petar.Avramovic, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72849
2020-01-16 16:04:21 +00:00
Sam Parker 760b175109 [ARM][LowOverheadLoops] Update liveness info
Recommitting e93e0d413f after reverting due to test failures, which
will hopefully now be fixed. Original commit message:

After expanding the pseudo instructions, update the liveness info.
We do this in a post-order traversal of the loop, including its
exit blocks and preheader(s).

Differential Revision: https://reviews.llvm.org/D72131
2020-01-16 15:44:25 +00:00
Anna Welker c24cf97960 [ARM][MVE] Enable extending gathers
Enables the masked gather pass to
create extending masked gathers.

Differential Revision: https://reviews.llvm.org/D72451
2020-01-16 15:24:54 +00:00
Kazushi (Jam) Marukawa 773ae62ff8 [VE] i64 arguments, return values and constants
Summary: Support for i64 arguments (in register), return values and constants along with tests.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D72776
2020-01-16 10:09:50 +01:00
Liu, Chen3 8fdafb7dce Insert wait instruction after X87 instructions which could raise
float-point exception.

This patch also modify some mayRaiseFPException flag which set in D68854.

Differential Revision: https://reviews.llvm.org/D72750
2020-01-16 12:12:51 +08:00
Matt Arsenault c378e52cb9 Set some fast math attributes in setFunctionAttributes
This will provide a more consistent view to codegen for these
attributes. The current system is somewhat awkward, and the fields in
TargetOptions are reset based on the command line flag if the
attribute isn't set. By forcing these attributes with the flag, there
can never be an inconsistency in the behavior if code directly
inspects the attribute on the function without considering the command
line flags.
2020-01-15 22:23:18 -05:00
Craig Topper e445447921 [X86] When handling i64->f32 sint_to_fp on 32-bit targets only bitcast to f64 if sse2 is enabled.
The code is trying to copy the i64 value to an xmm register to
use a 64-bit store so that the 64-bit fild can benefit from
store forwarding.

But this trick only works if f64 is going to be stored in an
XMM register. If we only have SSE1 then only float is in xmm
register. So this trick just causes 2 stores i32 stores, an f64
load into the x87, an f64 from x87, and a 64-bit fild. So we end
up with an extra stack temporary and still didn't get store forwarding.

We might be able to use v2f32 here instead, but I didn't check. I
just wanted the code to make sense.

Found by inspection as I continue to stare too hard at our
int_to_fp conversions.
2020-01-15 18:26:28 -08:00
Matt Arsenault 711a17afaf AMDGPU/GlobalISel: Select exp with patterns
This does produce slightly different code. Now a unique IMPLICIT_DEF
is emitted for each of the implicit_def operands, rather than reusing
the same one.
2020-01-15 18:33:15 -05:00
Matt Arsenault eef92f25cc AMDGPU: Remove custom node for exports
I'm mildly worried about potentially reordering exp/exp_done with
IntrWriteMem on the intrinsic.

Requires hacking out the illegal type on SI, so manually select that
case during lowering.
2020-01-15 18:33:15 -05:00
Mircea Trofin 5466597fee [NFC] Refactor InlineResult for readability
Summary:
InlineResult is used both in APIs assessing whether a call site is
inlinable (e.g. llvm::isInlineViable) as well as in the function
inlining utility (llvm::InlineFunction). It means slightly different
things (can/should inlining happen, vs did it happen), and the
implicit casting may introduce ambiguity (casting from 'false' in
InlineFunction will default a message about hight costs,
which is incorrect here).

The change renames the type to a more generic name, and disables
implicit constructors.

Reviewers: eraman, davidxl

Reviewed By: davidxl

Subscribers: kerbowa, arsenm, jvesely, nhaehnle, eraman, hiraditya, haicheng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72744
2020-01-15 13:34:20 -08:00
Amara Emerson 2e39ea726e Revert "Revert rG6078f2fedcac5797ac39ee5ef3fd7a35ef1202d5 - "[AArch64][GlobalISel]: Support @llvm.{return,frame}address selection.""
The original change wasn't constraining the operand regclasses which broke EXPENSIVE_CHECKS.
2020-01-15 10:13:11 -08:00
Mark Murray da9d57d2c2 [ARM][MVE][Intrinsics] Add VMINAQ, VMINNMAQ, VMAXAQ, VMAXNMAQ intrinsics.
Summary: Add VMINAQ, VMINNMAQ, VMAXAQ, VMAXNMAQ intrinsics and unit tests.

Reviewers: simon_tatham, miyuki, dmgreen

Subscribers: kristof.beyls, hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D72761
2020-01-15 17:20:15 +00:00
Matt Arsenault 936483fb7d GlobalISel: Implement lower for G_BITCAST
Bitcast only really applies between scalars and vectors. Implement as
an unmerge and remerge. The test needs to tolerate failure since one
of the unmerges currently fails to legalize.
2020-01-15 08:58:58 -05:00
Matt Arsenault bd7658a212 AMDGPU: Partially directly select llvm.amdgcn.interp.p1.f16
The 16 bank LDS case is complicated due to using multiple
instructions. If I attempt to write a pattern for it, the generated
selector incorrectly places the copy to m0 after the first
instruction, so that needs to be separately addressed.

Also fix not gluing the copy to m0 to the second operation in the
second half of the 16 bank lowering.
2020-01-15 08:58:58 -05:00
Nemanja Ivanovic 9c64f04df8 [PowerPC] Legalize saturating vector add/sub
These intrinsics and the corresponding ISD nodes were recently added. PPC has
instructions that do this for vectors. Legalize them and add patterns to emit
the satuarting instructions.

Differential revision: https://reviews.llvm.org/D71940
2020-01-15 07:00:38 -06:00
Simon Pilgrim e26a78e708 Revert rG6078f2fedcac5797ac39ee5ef3fd7a35ef1202d5 - "[AArch64][GlobalISel]: Support @llvm.{return,frame}address selection."
These intrinsics expand to a variable number of instructions so just like in
ISelLowering.cpp we use custom code to deal with them.

Committing Tim's original patch.

Differential Revision: https://reviews.llvm.org/D65656
----
Breaks EXPENSIVE_CHECKS builds.
2020-01-15 12:37:37 +00:00
Zakk Chen 7bc58a779a [RISCV] Support ABI checking with per function target-features
if users don't specific -mattr, the default target-feature come
from IR attribute.

Reviewers: lenary, asb

Reviewed By: lenary, asb

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70837
2020-01-15 04:35:01 -08:00
Zakk Chen 3bc2860e92 Revert "[RISCV] Support ABI checking with per function target-features"
This reverts commit 109e4d12ed.
2020-01-15 04:32:57 -08:00
Simon Pilgrim 7b15865225 Fix "pointer is null" static analyzer warning. NFCI.
Use cast<> instead of dyn_cast<> since the pointer is always dereferenced and cast<> will perform the null assertion for us.
2020-01-15 12:18:11 +00:00
Benjamin Kramer 06cfcdcca7 [AArch64][SVE] Fold variable into assert to silence unused variable warnings in Release builds 2020-01-15 12:50:27 +01:00
Cullen Rhodes 93a4dede3a [AArch64][SVE] Add ptest intrinsics
Summary:
Implements the following intrinsics:

    * @llvm.aarch64.sve.ptest.any
    * @llvm.aarch64.sve.ptest.first
    * @llvm.aarch64.sve.ptest.last

Reviewers: sdesmalen, efriedma, dancgr, mgudim, cameron.mcinally, rengolin

Reviewed By: efriedma

Subscribers: tschuett, kristof.beyls, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72398
2020-01-15 11:15:01 +00:00
Zakk Chen 109e4d12ed [RISCV] Support ABI checking with per function target-features
if users don't specific -mattr, the default target-feature come
from IR attribute.
2020-01-15 02:30:43 -08:00
cdevadas 0dc6c249bf [AMDGPU] Invert the handling of skip insertion.
The current implementation of skip insertion (SIInsertSkip) makes it a
mandatory pass required for correctness. Initially, the idea was to
have an optional pass. This patch inserts the s_cbranch_execz upfront
during SILowerControlFlow to skip over the sections of code when no
lanes are active. Later, SIRemoveShortExecBranches removes the skips
for short branches, unless there is a sideeffect and the skip branch is
really necessary.

This new pass will replace the handling of skip insertion in the
existing SIInsertSkip Pass.

Differential revision: https://reviews.llvm.org/D68092
2020-01-15 15:18:16 +05:30
Kazushi (Jam) Marukawa 064859bde7 [VE] Minimal codegen for empty functions
Summary:
This patch implements minimal VE code generation for empty function bodies (no args, no value return).

Contents

* empty function code generation test.
* Minimal function prologue & epilogue emission
* Instruction formats and instruction definitions as far as required for the empty function prologue & epilogue.
* I64 register class definitions.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D72598
2020-01-15 09:55:16 +01:00
Craig Topper be8f217b18 [X86] Don't call LowerUINT_TO_FP_i32 for i32->f80 on 32-bit targets with sse2.
We were performing an emulated i32->f64 in the SSE registers, then
storing that value to memory and doing a extload into the X87
domain.

After this patch we'll now just store the i32 to memory along
with an i32 0. Then do a 64-bit FILD to f80 completely in the X87
unit. This matches what we do without SSE.
2020-01-15 00:43:07 -08:00
Justin Hibbits 36eedfcb3c [PowerPC] Fix powerpcspe subtarget enablement in llvm backend
Summary:
As currently written, -target powerpcspe will enable SPE regardless of
disabling the feature later on in the command line.  Instead, change
this to just set a default CPU to 'e500' instead of a generic CPU.

As part of this, add FeatureSPE to the e500 definition.

Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D72673
2020-01-14 22:07:03 -06:00
Tom Stellard 0dbcb36394 CMake: Make most target symbols hidden by default
Summary:
For builds with LLVM_BUILD_LLVM_DYLIB=ON and BUILD_SHARED_LIBS=OFF
this change makes all symbols in the target specific libraries hidden
by default.

A new macro called LLVM_EXTERNAL_VISIBILITY has been added to mark symbols in these
libraries public, which is mainly needed for the definitions of the
LLVMInitialize* functions.

This patch reduces the number of public symbols in libLLVM.so by about
25%.  This should improve load times for the dynamic library and also
make abi checker tools, like abidiff require less memory when analyzing
libLLVM.so

One side-effect of this change is that for builds with
LLVM_BUILD_LLVM_DYLIB=ON and LLVM_LINK_LLVM_DYLIB=ON some unittests that
access symbols that are no longer public will need to be statically linked.

Before and after public symbol counts (using gcc 8.2.1, ld.bfd 2.31.1):
nm before/libLLVM-9svn.so | grep ' [A-Zuvw] ' | wc -l
36221
nm after/libLLVM-9svn.so | grep ' [A-Zuvw] ' | wc -l
26278

Reviewers: chandlerc, beanz, mgorny, rnk, hans

Reviewed By: rnk, hans

Subscribers: merge_guards_bot, luismarques, smeenai, ldionne, lenary, s.egerton, pzheng, sameer.abuasal, MaskRay, wuzish, echristo, Jim, hiraditya, michaelplatings, chapuni, jholewinski, arsenm, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, javed.absar, sbc100, jgravelle-google, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, zzheng, edward-jones, mgrang, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, kristina, jsji, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D54439
2020-01-14 19:46:52 -08:00
Philip Reames 1a7398eca2 [BranchAlign] Add master --x86-branches-within-32B-boundaries flag
This flag was originally part of D70157, but was removed as we carved away pieces of the review. Since we have the nop support checked in, and it appears mature(*), I think it's time to add the master flag. For now, it will default to nop padding, but once the prefix padding support lands, we'll update the defaults.

(*) I can now confirm that downstream testing of the changes which have landed to date - nop padding and compiler support for suppressions - is passing all of the functional testing we've thrown at it. There might still be something lurking, but we've gotten enough coverage to be confident of the basic approach.

Note that the new flag can be used either when assembling an .s file, or when using the integrated assembler directly from the compiler. The later will use all of the suppression mechanism and should always generate correct code. We don't yet have assembly syntax for the suppressions, so passing this directly to the assembler w/a raw .s file may result in broken code. Use at your own risk.

Also note that this isn't the wiring for the clang option. I think the most recent review for that is D72227, but I've lost track, so that might be off.

Differential Revision: https://reviews.llvm.org/D72738
2020-01-14 18:17:53 -08:00
Reid Kleckner 40cd26c700 [Win64] Handle FP arguments more gracefully under -mno-sse
Pass small FP values in GPRs or stack memory according the the normal
convention. This is what gcc -mno-sse does on Win64.

I adjusted the conditions under which we emit an error to check if the
argument or return value would be passed in an XMM register when SSE is
disabled. This has a side effect of no longer emitting an error for FP
arguments marked 'inreg' when targetting x86 with SSE disabled. Our
calling convention logic was already assigning it to FP0/FP1, and then
we emitted this error. That seems unnecessary, we can ignore 'inreg' and
compile it without SSE.

Reviewers: jyknight, aemerson

Differential Revision: https://reviews.llvm.org/D70465
2020-01-14 17:19:35 -08:00
Craig Topper 76291e1158 [X86] Drop an unneeded FIXME. NFC
The extload on X87 is free.
2020-01-14 17:05:46 -08:00
Craig Topper 57eb56b839 [X86] Swap the 0 and the fudge factor in the constant pool for the 32-bit mode i64->f32/f64/f80 uint_to_fp algorithm.
This allows us to generate better code for selecting the fixup
to load.

Previously when the sign was set we had to load offset 0. And
when it was clear we had to load offset 4. This required a testl,
setns, zero extend, and finally a mul by 4. By switching the offsets
we can just shift the sign bit into the lsb and multiply it by 4.
2020-01-14 17:05:23 -08:00
Michael Liao 01a4b83154 [codegen,amdgpu] Enhance MIR DIE and re-arrange it for AMDGPU.
Summary:
- `dead-mi-elimination` assumes MIR in the SSA form and cannot be
  arranged after phi elimination or DeSSA. It's enhanced to handle the
  dead register definition by skipping use check on it. Once a register
  def is `dead`, all its uses, if any, should be `undef`.
- Re-arrange the DIE in RA phase for AMDGPU by placing it directly after
  `detect-dead-lanes`.
- Many relevant tests are refined due to different register assignment.

Reviewers: rampitec, qcolombet, sunfish

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72709
2020-01-14 19:26:15 -05:00
Amara Emerson 6078f2fedc [AArch64][GlobalISel]: Support @llvm.{return,frame}address selection.
These intrinsics expand to a variable number of instructions so just like in
ISelLowering.cpp we use custom code to deal with them.

Committing Tim's original patch.

Differential Revision: https://reviews.llvm.org/D65656
2020-01-14 13:41:21 -08:00