Commit Graph

74 Commits

Author SHA1 Message Date
Matt Arsenault 3922392969 AMDGPU: Correct behavior of f16 buffer loads
Don't assume format loads for f16. Also fixes support for targets
without i16.

llvm-svn: 367879
2019-08-05 15:59:07 +00:00
Matt Arsenault 0e0a1c80fb AMDGPU: Correct behavior of f16/i16 non-format store intrinsics
This was switching to use a format store for a non-format store for
f16 types. Also fixes i16/f16 stores on targets without legal f16.

The corresponding loads also need to be fixed.

llvm-svn: 367872
2019-08-05 14:57:59 +00:00
Nicolai Haehnle e204786b6c AMDGPU: add missing llvm.amdgcn.{raw,struct}.buffer.atomic.{inc,dec}
Summary:
Wrapping increment/decrement. These aren't exposed by many APIs...

Change-Id: I1df25c7889de5a5ba76468ad8e8a2597efa9af6c

Reviewers: arsenm, tpr, dstuttard

Subscribers: kzhuravl, jvesely, wdng, yaxunl, t-tye, jfb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65283

llvm-svn: 367821
2019-08-05 09:36:06 +00:00
Matt Arsenault e6ce48422c AMDGPU: Start redefining atomic PatFrags
Start migrating to a form that will be compatible with the global isel
emitter. Also should fix some overly lax checks on the memory type,
which allowed mis-selecting some illegal atomics.

llvm-svn: 367506
2019-08-01 03:25:52 +00:00
Matt Arsenault 70e20c0f08 AMDGPU: Correct FP atomic patterns
These need to use an fadd, not an add. Also make the noret part clear
in the name.

llvm-svn: 367505
2019-08-01 03:22:40 +00:00
Matt Arsenault 2d10407719 AMDGPU/GlobalISel: Fix selection of private stores
llvm-svn: 366249
2019-07-16 19:27:44 +00:00
Matt Arsenault c6fd5abecc AMDGPU: Redefine load PatFrags
Rewrite PatFrags using the new PatFrag address space matching in
tablegen. These will now work with both SelectionDAG and GlobalISel.

llvm-svn: 366234
2019-07-16 17:38:50 +00:00
Matt Arsenault 1739b700b1 AMDGPU: Avoid code predicates for extload PatFrags
Use the MemoryVT field. This will be necessary for tablegen to
automatically handle patterns for GlobalISel.

Doesn't handle the d16 lo/hi patterns. Those are a special case since
it involvess the custom node type.

llvm-svn: 366168
2019-07-16 02:46:05 +00:00
Matt Arsenault b082f1055b AMDGPU: Use standalone MUBUF load patterns
We already do this for the flat and DS instructions, although it is
certainly uglier and more verbose.

This will allow using separate pattern definitions for extload and
zextload. Currently we get away with using a single PatFrag with
custom predicate code to check if the extension type is a zextload or
anyextload. The generic mechanism the global isel emitter understands
treats these as mutually exclusive. I was considering making the
pattern emitter accept zextload or sextload extensions for anyextload
patterns, but in global isel, the different extending loads have
distinct opcodes, and there is currently no mechanism for an opcode
matcher to try multiple (and there probably is very little need for
one beyond this case).

llvm-svn: 366132
2019-07-15 21:41:44 +00:00
Stanislav Mekhanoshin e93279fd1b [AMDGPU] gfx908 atomic fadd and atomic pk_fadd
Differential Revision: https://reviews.llvm.org/D64435

llvm-svn: 365717
2019-07-11 00:10:17 +00:00
Matt Arsenault 224d8cd987 AMDGPU: Remove mubuf specific PatFrags
These are identical to the *_global PatFrag, and will only create more
work to get the GlobalISel importer to handle them.

llvm-svn: 365350
2019-07-08 16:53:53 +00:00
Stanislav Mekhanoshin bdf7f81b89 [AMDGPU] hazard recognizer for fp atomic to s_denorm_mode
This requires 3 wait states unless there is a wait or VALU in
between.

Differential Revision: https://reviews.llvm.org/D63619

llvm-svn: 364074
2019-06-21 16:30:14 +00:00
Stanislav Mekhanoshin a6322941ff [AMDGPU] gfx1010 VMEM and SMEM implementation
Differential Revision: https://reviews.llvm.org/D61330

llvm-svn: 359621
2019-04-30 22:08:23 +00:00
Stanislav Mekhanoshin 5182302a37 [AMDGPU] Sort out and rename multiple CI/VI predicates
Differential Revision: https://reviews.llvm.org/D60346

llvm-svn: 357835
2019-04-06 09:20:48 +00:00
Stanislav Mekhanoshin 7895c03232 [AMDGPU] predicate and feature refactoring
We have done some predicate and feature refactoring lately but
did not upstream it. This is to sync.

Differential revision: https://reviews.llvm.org/D60292

llvm-svn: 357791
2019-04-05 18:24:34 +00:00
Tim Renouf 677387d8dc [AMDGPU] Implemented dwordx3 variants of buffer/tbuffer load/store intrinsics
Now we have vec3 MVTs, this commit implements dwordx3 variants of the
buffer intrinsics.

On gfx6, a dwordx3 buffer load intrinsic is implemented as a dwordx4
instruction, and a dwordx3 buffer store intrinsic is not supported.
We need to support the dwordx3 load intrinsic because it is generated by
subtarget-unaware code in InstCombine.

Differential Revision: https://reviews.llvm.org/D58904

Change-Id: I016729d8557b98a52f529638ae97c340a5922a4e
llvm-svn: 356755
2019-03-22 14:58:02 +00:00
Tim Renouf 361b5b2193 [AMDGPU] Support for v3i32/v3f32
Added support for dwordx3 for most load/store types, but not DS, and not
intrinsics yet.

SI (gfx6) does not have dwordx3 instructions, so they are not enabled
there.

Some of this patch is from Matt Arsenault, also of AMD.

Differential Revision: https://reviews.llvm.org/D58902

Change-Id: I913ef54f1433a7149da8d72f4af54dbb13436bd9
llvm-svn: 356659
2019-03-21 12:01:21 +00:00
Ryan Taylor 00e063ab92 [AMDGPU] Add buffer/load 8/16 bit overloaded intrinsics
Summary:
Add buffer store/load 8/16 overloaded intrinsics for buffer, raw_buffer and struct_buffer

Change-Id: I166a29f071b2ff4e4683fb0392564b1f223ac61d

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59265

llvm-svn: 356465
2019-03-19 16:07:00 +00:00
Matt Arsenault e8c03a2511 AMDGPU: Move d16 load matching to preprocess step
When matching half of the build_vector to a load, there could still be
a hidden dependency on the other half of the build_vector the pattern
wouldn't detect. If there was an additional chain dependency on the
other value, a cycle could be introduced.

I don't think a tablegen pattern is capable of matching the necessary
conditions, so move this into PreprocessISelDAG. Check isPredecessorOf
for the other value to avoid a cycle. This has a warning that it's
expensive, so this should probably be moved into an MI pass eventually
that will have more freedom to reorder instructions to help match
this. That is currently complicated by the lack of a computeKnownBits
type mechanism for the selected function.

llvm-svn: 355731
2019-03-08 20:58:11 +00:00
Ryan Taylor 67f36903ae [AMDGPU] Add support for 64 bit buffer atomic artihmetic instructions
Summary:
This adds support for 64 bit buffer atomic arithmetic instructions but does not include
cmpswap as that depends on a fix to the way the register pairs are handled

Change-Id: Ib207ea65fb69487ccad5066ea647ae8ddfe2ce61

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58918

llvm-svn: 355520
2019-03-06 17:02:06 +00:00
Konstantin Zhuravlyov 9a278bf6b5 Revert "AMDGPU/NFC: Cleanup subtarget predicates"
It breaks one of our downstream merges, so revert it
temporarily while investigating failures downstream

llvm-svn: 354700
2019-02-22 23:21:06 +00:00
Konstantin Zhuravlyov c2650178a1 AMDGPU/NFC: Cleanup subtarget predicates
Differential Revision: https://reviews.llvm.org/D58522

llvm-svn: 354620
2019-02-21 20:43:43 +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
Neil Henning 76504a4c5e [AMDGPU] Extend the SI Load/Store optimizer to combine more things.
I've extended the load/store optimizer to be able to produce dwordx3
loads and stores, This change allows many more load/stores to be combined,
and results in much more optimal code for our hardware.

Differential Revision: https://reviews.llvm.org/D54042

llvm-svn: 348937
2018-12-12 16:15:21 +00:00
Matt Arsenault 3ff764a944 AMDGPU: Remove llvm.SI.buffer.load.dword
llvm-svn: 348616
2018-12-07 17:46:20 +00:00
Konstantin Zhuravlyov 7f1959ebb3 AMDGPU/NFC: Split MUBUF_Pseudo_Atomics into RTN/NO_RTN multiclasses
llvm-svn: 346357
2018-11-07 21:21:32 +00:00
Nicolai Haehnle e9b134aa31 AMDGPU: Remove dead TableGen code
Summary: Change-Id: Ic1f2c1d0cf9e90a0baa9fc6bacd0d3c386069fb0

Reviewers: tpr

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

Differential Revision: https://reviews.llvm.org/D53318

Change-Id: Ib4d143c898801e5cf6cb9999a495d62c91ae77fb
llvm-svn: 344691
2018-10-17 12:14:26 +00:00
Matt Arsenault 0da6350dc8 AMDGPU: Remove remnants of old address space mapping
llvm-svn: 341165
2018-08-31 05:49:54 +00:00
Tim Renouf bb5ee41ab4 [AMDGPU] Allow int types for MUBUF vdata
Summary:
Previously the new llvm.amdgcn.raw/struct.buffer.load/store intrinsics
only allowed float types for the data to be loaded or stored, which
sometimes meant the frontend needed to generate a bitcast. In this, the
new intrinsics copied the old buffer intrinsics.

This commit extends the new intrinsics to allow int types as well.

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

Differential Revision: https://reviews.llvm.org/D50315

Change-Id: I8202af2d036455553681dcbb3d7d32ae273f8f85
llvm-svn: 340270
2018-08-21 11:08:12 +00:00
Tim Renouf 4f703f5e11 [AMDGPU] New buffer intrinsics
Summary:
This commit adds new intrinsics
  llvm.amdgcn.raw.buffer.load
  llvm.amdgcn.raw.buffer.load.format
  llvm.amdgcn.raw.buffer.load.format.d16
  llvm.amdgcn.struct.buffer.load
  llvm.amdgcn.struct.buffer.load.format
  llvm.amdgcn.struct.buffer.load.format.d16
  llvm.amdgcn.raw.buffer.store
  llvm.amdgcn.raw.buffer.store.format
  llvm.amdgcn.raw.buffer.store.format.d16
  llvm.amdgcn.struct.buffer.store
  llvm.amdgcn.struct.buffer.store.format
  llvm.amdgcn.struct.buffer.store.format.d16
  llvm.amdgcn.raw.buffer.atomic.*
  llvm.amdgcn.struct.buffer.atomic.*

with the following changes from the llvm.amdgcn.buffer.*
intrinsics:

* there are separate raw and struct versions: raw does not have an
  index arg and sets idxen=0 in the instruction, and struct always sets
  idxen=1 in the instruction even if the index is 0, to allow for the
  fact that gfx9 does bounds checking differently depending on whether
  idxen is set;

* there is a combined cachepolicy arg (glc+slc)

* there are now only two offset args: one for the offset that is
  included in bounds checking and swizzling, to be split between the
  instruction's voffset and immoffset fields, and one for the offset
  that is excluded from bounds checking and swizzling, to go into the
  instruction's soffset field.

The AMDISD::BUFFER_* SD nodes always have an index operand, all three
offset operands, combined cachepolicy operand, and an extra idxen
operand.

The obsolescent llvm.amdgcn.buffer.* intrinsics continue to work.

Subscribers: arsenm, kzhuravl, wdng, nhaehnle, yaxunl, dstuttard, t-tye, jfb, llvm-commits

Differential Revision: https://reviews.llvm.org/D50306

Change-Id: If897ea7dc34fcbf4d5496e98cc99a934f62fc205
llvm-svn: 340269
2018-08-21 11:07:10 +00:00
Tim Renouf 35484c9d50 [AMDGPU] New tbuffer intrinsics
Summary:
This commit adds new intrinsics
  llvm.amdgcn.raw.tbuffer.load
  llvm.amdgcn.struct.tbuffer.load
  llvm.amdgcn.raw.tbuffer.store
  llvm.amdgcn.struct.tbuffer.store

with the following changes from the llvm.amdgcn.tbuffer.* intrinsics:

* there are separate raw and struct versions: raw does not have an index
  arg and sets idxen=0 in the instruction, and struct always sets
  idxen=1 in the instruction even if the index is 0, to allow for the
  fact that gfx9 does bounds checking differently depending on whether
  idxen is set;

* there is a combined format arg (dfmt+nfmt)

* there is a combined cachepolicy arg (glc+slc)

* there are now only two offset args: one for the offset that is
  included in bounds checking and swizzling, to be split between the
  instruction's voffset and immoffset fields, and one for the offset
  that is excluded from bounds checking and swizzling, to go into the
  instruction's soffset field.

The AMDISD::TBUFFER_* SD nodes always have an index operand, all three
offset operands, combined format operand, combined cachepolicy operand,
and an extra idxen operand.

The tbuffer pseudo- and real instructions now also have a combined
format operand.

The obsolescent llvm.amdgcn.tbuffer.* and llvm.SI.tbuffer.store
intrinsics continue to work.

V2: Separate raw and struct intrinsics.
V3: Moved extract_glc and extract_slc defs to a more sensible place.
V4: Rebased on D49995.
V5: Only two separate offset args instead of three.
V6: Pseudo- and real instructions have joint format operand.
V7: Restored optionality of dfmt and nfmt in assembler.
V8: Addressed minor review comments.

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

Differential Revision: https://reviews.llvm.org/D49026

Change-Id: If22ad77e349fac3a5d2f72dda53c010377d470d4
llvm-svn: 340268
2018-08-21 11:06:05 +00:00
Nicolai Haehnle f267431901 AMDGPU: Turn D16 for MIMG instructions into a regular operand
Summary:
This allows us to reduce the number of different machine instruction
opcodes, which reduces the table sizes and helps flatten the TableGen
multiclass hierarchies.

We can do this because for each hardware MIMG opcode, we have a full set
of IMAGE_xxx_Vn_Vm machine instructions for all required sizes of vdata
and vaddr registers. Instead of having separate D16 machine instructions,
a packed D16 instructions loading e.g. 4 components can simply use the
same V2 opcode variant that non-D16 instructions use.

We still require a TSFlag for D16 buffer instructions, because the
D16-ness of buffer instructions is part of the opcode. Renaming the flag
should help avoid future confusion.

The one non-obvious code change is that for gather4 instructions, the
disassembler can no longer automatically decide whether to use a V2 or
a V4 variant. The existing logic which choose the correct variant for
other MIMG instruction is extended to cover gather4 as well.

As a bonus, some of the assembler error messages are now more helpful
(e.g., complaining about a wrong data size instead of a non-existing
instruction).

While we're at it, delete a whole bunch of dead legacy TableGen code.

Change-Id: I89b02c2841c06f95e662541433e597f5d4553978

Reviewers: arsenm, rampitec, kzhuravl, artem.tamazov, dp, rtaylor

Subscribers: wdng, yaxunl, dstuttard, tpr, t-tye, llvm-commits

Differential Revision: https://reviews.llvm.org/D47434

llvm-svn: 335222
2018-06-21 13:36:01 +00:00
Matt Arsenault 02dc7e19e2 AMDGPU: Make v4i16/v4f16 legal
Some image loads return these, and it's awkward working
around them not being legal.

llvm-svn: 334835
2018-06-15 15:15:46 +00:00
Dmitry Preobrazhensky ffbee7acdc [AMDGPU][MC][GFX8][GFX9] Allow LDS direct reads for BUFFER_LOAD_DWORDX2/X3/X4
See bug 37653: https://bugs.llvm.org/show_bug.cgi?id=37653

Reviewers: artem.tamazov, arsenm

Differential Revision: https://reviews.llvm.org/D47885

llvm-svn: 334609
2018-06-13 15:32:46 +00:00
Nicolai Haehnle 59198ed040 AMDGPU: Make various NamedOperands upper case
Summary:
Avoid name clashes with the corresponding bit fields in the instruction
encoding.

Change-Id: Id1644e703e976e78f7af93788d9f44cb48c3251f

Reviewers: arsenm, rampitec, kzhuravl

Subscribers: wdng, yaxunl, dstuttard, tpr, t-tye, llvm-commits

Differential Revision: https://reviews.llvm.org/D47433

llvm-svn: 333905
2018-06-04 14:45:20 +00:00
Nicolai Haehnle 01d261f18d TableGen: Streamline the semantics of NAME
Summary:
The new rules are straightforward. The main rules to keep in mind
are:

1. NAME is an implicit template argument of class and multiclass,
   and will be substituted by the name of the instantiating def/defm.

2. The name of a def/defm in a multiclass must contain a reference
   to NAME. If such a reference is not present, it is automatically
   prepended.

And for some additional subtleties, consider these:

3. defm with no name generates a unique name but has no special
   behavior otherwise.

4. def with no name generates an anonymous record, whose name is
   unique but undefined. In particular, the name won't contain a
   reference to NAME.

Keeping rules 1&2 in mind should allow a predictable behavior of
name resolution that is simple to follow.

The old "rules" were rather surprising: sometimes (but not always),
NAME would correspond to the name of the toplevel defm. They were
also plain bonkers when you pushed them to their limits, as the old
version of the TableGen test case shows.

Having NAME correspond to the name of the toplevel defm introduces
"spooky action at a distance" and breaks composability:
refactoring the upper layers of a hierarchy of nested multiclass
instantiations can cause unexpected breakage by changing the value
of NAME at a lower level of the hierarchy. The new rules don't
suffer from this problem.

Some existing .td files have to be adjusted because they ended up
depending on the details of the old implementation.

Change-Id: I694095231565b30f563e6fd0417b41ee01a12589

Reviewers: tra, simon_tatham, craig.topper, MartinO, arsenm, javed.absar

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D47430

llvm-svn: 333900
2018-06-04 14:26:05 +00:00
Matt Arsenault 1349a04ef5 AMDGPU: Make v2i16/v2f16 legal on VI
This usually results in better code. Fixes using
inline asm with short2, and also fixes having a different
ABI for function parameters between VI and gfx9.

Partially cleans up the mess used for lowering of the d16
operations. Making v4f16 legal will help clean this up more,
but this requires additional work.

llvm-svn: 332953
2018-05-22 06:32:10 +00:00
Konstantin Zhuravlyov c2c2eb7d01 AMDGPU: Add D16 instructions preserve unused bits feature
- Predicate D16 patterns on this new feature
- Added this new feature to gfx900/2/4

Differential Revision: https://reviews.llvm.org/D46366

llvm-svn: 331551
2018-05-04 20:06:57 +00:00
Dmitry Preobrazhensky 523872ea59 [AMDGPU][MC] Enabled instruction TBUFFER_LOAD_FORMAT_XYZ for SI/CI
See bug 36958: https://bugs.llvm.org/show_bug.cgi?id=36958

Differential Revision: https://reviews.llvm.org/D45099

Reviewers: artem.tamazov, arsenm, timcorringham
llvm-svn: 329197
2018-04-04 13:54:55 +00:00
Dmitry Preobrazhensky a917e88585 [AMDGPU][MC][GFX9] Added buffer_*_format_d16_hi_x
See bug 36835: https://bugs.llvm.org/show_bug.cgi?id=36835

Differential Revision: https://reviews.llvm.org/D44825

Reviewers: artem.tamazov, arsenm, timcorringham
llvm-svn: 328707
2018-03-28 14:53:13 +00:00
Dmitry Preobrazhensky d98c97b4f9 [AMDGPU][MC][GFX8] Added BUFFER_STORE_LDS_DWORD Instruction
See bug 36558: https://bugs.llvm.org/show_bug.cgi?id=36558

Differential Revision: https://reviews.llvm.org/D43950

Reviewers: artem.tamazov, arsenm
llvm-svn: 327299
2018-03-12 17:29:24 +00:00
Dmitry Preobrazhensky d6e1a9404d [AMDGPU][MC] Added lds support for MUBUF instructions
See bug 28234: https://bugs.llvm.org/show_bug.cgi?id=28234

Differential Revision: https://reviews.llvm.org/D43472

Reviewers: vpykhtin, artem.tamazov, arsenm
llvm-svn: 325676
2018-02-21 13:13:48 +00:00
Changpeng Fang 29fcf883fb AMDGPU/SI: Adjust the encoding family for D16 buffer instructions when the target has UnpackedD16VMem feature.
Reviewers:
  Matt and Brian

Differential Revision:
  https://reviews.llvm.org/D42548

llvm-svn: 323988
2018-02-01 18:41:33 +00:00
Changpeng Fang ba6240cc71 AMDGPU/SI: Fix typos in d16 support patch the buffer intrinsics.
llvm-svn: 322906
2018-01-18 22:57:57 +00:00
Changpeng Fang 44dfa1de3b AMDGPU/SI: Add d16 support for buffer intrinsics.
Differential Revision:
  https://reviews.llvm.org/D38906

Reviewers:
  Matt and Brian.

llvm-svn: 322402
2018-01-12 21:12:19 +00:00
Matt Arsenault e1cd482fda AMDGPU: Select d16 loads into low component of register
llvm-svn: 318005
2017-11-13 00:22:09 +00:00
Marek Olsak 5cec64195c AMDGPU: Lower buffer store and atomic intrinsics manually
Summary:
Without this, SIMemoryLegalizer inserts s_waitcnt vmcnt(0) before every
buffer store and atomic instruction.

Reviewers: arsenm, nhaehnle

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

Differential Revision: https://reviews.llvm.org/D39060

llvm-svn: 317754
2017-11-09 01:52:48 +00:00
Marek Olsak 5914ece6aa AMDGPU: Select s_buffer_load_dword with a non-constant SGPR offset
Summary:
Apps that benefit:
- alien isolation
- bioshock infinite
- civilization: beyond earth
- company of heroes 2
- dirt showdown
- dota 2
- F1 2015
- grid autosport
- hitman
- legend of grimrock
- serious sam 3: bfe
- shadow warrior
- talos principle
- total war: warhammer
- UE4 demos: effects cave, elemental, sun temple

Reviewers: arsenm, nhaehnle

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

Differential Revision: https://reviews.llvm.org/D38914

llvm-svn: 317038
2017-10-31 21:06:42 +00:00
Matt Arsenault 90c7593a75 AMDGPU: Remove global isGCN predicates
These are problematic because they apply to everything,
and can easily clobber whatever more specific predicate
you are trying to add to a function.

Currently instructions use SubtargetPredicate/PredicateControl
to apply this to patterns applied to an instruction definition,
but not to free standing Pats. Add a wrapper around Pat
so the special PredicateControls requirements can be appended
to the final predicate list like how Mips does it.

llvm-svn: 314742
2017-10-03 00:06:41 +00:00
Matt Arsenault b81495dccb AMDGPU: Match load d16 hi instructions
Also starts selecting global loads for constant address
in some cases. Some end up selecting to mubuf still, which
requires investigation.

We still get sub-optimal regalloc and extra waitcnts inserted
due to not really tracking the liveness of the separate register
halves.

llvm-svn: 313716
2017-09-20 05:01:53 +00:00