Commit Graph

308 Commits

Author SHA1 Message Date
Alex Richardson 51e09e1d5a [AMDGPU] Set the default globals address space to 1
This will ensure that passes that add new global variables will create them
in address space 1 once the passes have been updated to no longer default
to the implicit address space zero.
This also changes AutoUpgrade.cpp to add -G1 to the DataLayout if it wasn't
already to present to ensure bitcode backwards compatibility.

Reviewed by: arsenm

Differential Revision: https://reviews.llvm.org/D84345
2020-11-20 15:46:53 +00:00
Michael Liao f375885ab8 [InferAddrSpace] Teach to handle assumed address space.
- In certain cases, a generic pointer could be assumed as a pointer to
  the global memory space or other spaces. With a dedicated target hook
  to query that address space from a given value, infer-address-space
  pass could infer and propagate that to all its users.

Differential Revision: https://reviews.llvm.org/D91121
2020-11-16 17:06:33 -05:00
Carl Ritson 057934a6d7 [AMDGPU] Fix insert of SIPreAllocateWWMRegs in FastRegAlloc
SIPreAllocateWWMRegs was being inserted after RegisterCoalescer
but this pass does not exist during FastAlloc so pre-allocation
pass was never being run.
Insert pre-allocation after TwoAddressInstructionPass instead.

Reviewed By: rampitec

Differential Revision: https://reviews.llvm.org/D90236
2020-10-28 12:15:15 +09:00
Michael Liao 46c3d5cb05 [amdgpu] Add the late codegen preparation pass.
Summary:
- Teach that pass to widen naturally aligned but not DWORD aligned
  sub-DWORD loads.

Reviewers: rampitec, arsenm

Subscribers:

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80364
2020-10-27 14:07:59 -04:00
Carl Ritson 7a880ab388 [AMDGPU] Move WQM Pass after MI Scheduler
Exec mask manipulation inserted by SIWholeQuadMode barriers to
instruction scheduling.  Move the entire pass after the machine
instruction scheduler and make changes so pass is correct for
non-SSA operation.  These changes should leave the pass still
usable pre-scheduler, although tests have be updated to reflect
post-scheduler results.

Reviewed By: nhaehnle

Differential Revision: https://reviews.llvm.org/D88081
2020-10-27 10:25:53 +09:00
Austin Kerbow 37d907899f [HazardRec] Allow inserting multiple wait-states simultaneously
If a target can encode multiple wait-states into a noop allow emitting such
instructions directly.

Reviewed By: rampitec, dmgreen

Differential Revision: https://reviews.llvm.org/D89753
2020-10-20 17:03:47 -07:00
Austin Kerbow 978fbd8268 [AMDGPU] Run hazard recognizer pass later
If instructions were removed in peephole passes after the hazard recognizer was
run it is possible that new hazards could be introduced.

Fixes: SWDEV-253090

Reviewed By: rampitec, arsenm

Differential Revision: https://reviews.llvm.org/D89077
2020-10-16 12:15:51 -07:00
Roman Lebedev 03bd5198b6
[OldPM] Pass manager: run SROA after (simple) loop unrolling
I have stumbled into this pretty accidentally, when rewriting
some spaghetti-like code into something more structured,
which involved using some `std::array<>`s. And to my surprise,
the `alloca`s remained, causing about `+160%` perf regression.

https://llvm-compile-time-tracker.com/compare.php?from=bb6f4d32aac3eecb51909f4facc625219307ee68&to=d563e66f40f9d4d145cb2050e41cb961e2b37785&stat=instructions
suggests that this has geomean compile-time cost of `+0.08%`.

Note that D68593 / cecc0d27ad
already did this chage for NewPM, but left OldPM in a pessimized state.

This fixes [[ https://bugs.llvm.org/show_bug.cgi?id=40011 | PR40011 ]], [[ https://bugs.llvm.org/show_bug.cgi?id=42794 | PR42794 ]] and probably some other reports.

Reviewed By: nikic, xbolva00

Differential Revision: https://reviews.llvm.org/D87972
2020-10-04 11:53:50 +03:00
Jay Foad c799f873cb [AMDGPU] Don't cluster stores
Clustering loads has caching benefits, but as far as I know there is no
advantage to clustering stores on any AMDGPU subtargets.

The disadvantage is that it tends to increase register pressure and
restricts scheduling freedom.

Differential Revision: https://reviews.llvm.org/D85530
2020-09-14 13:40:17 +01:00
Amara Emerson e5784ef8f6 [GlobalISel] Enable usage of BranchProbabilityInfo in IRTranslator.
We weren't using this before, so none of the MachineFunction CFG edges had the
branch probability information added. As a result, block placement later in the
pipeline was flying blind.

This is enabled only with optimizations enabled like SelectionDAG.

Differential Revision: https://reviews.llvm.org/D86824
2020-09-09 14:31:12 -07:00
Michael Liao 1f4e7463b5 [amdgpu] Run SROA after loop unrolling.
Summary: - There are promotable `alloca`s after loop unrolling.

Reviewers: rampitec, arsenm

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D84252
2020-09-01 16:09:56 -04:00
Craig Topper aab90384a3 [Attributes] Add a method to check if an Attribute has AttrKind None. Use instead of hasAttribute(Attribute::None)
There's a special case in hasAttribute for None when pImpl is null. If pImpl is not null we dispatch to pImpl->hasAttribute which will always return false for Attribute::None.

So if we just want to check for None its sufficient to just check that pImpl is null. Which can even be done inline.

This patch adds a helper for that case which I hope will speed up our getSubtargetImpl implementations.

Differential Revision: https://reviews.llvm.org/D86744
2020-08-28 13:23:45 -07:00
Matt Arsenault 79298a5067 AMDGPU: Remove SIFixupVectorISel pass
This was only used for matching the saddr addressing mode of global
instructions, but this was not implemented correctly. The instruction
definitions aren't even correct, and are defined as using a 64-bit
VGPR component. Eliminate this pass to enable correcting the
instruction definitions. A new matching implementation can work in
GlobalISel or relying on DAG divergence information for the base
address.
2020-08-15 12:11:51 -04:00
Matt Arsenault 57bd64ff84 Support addrspacecast initializers with isNoopAddrSpaceCast
Moves isNoopAddrSpaceCast to the TargetMachine. It logically belongs
with the DataLayout.
2020-07-31 10:42:43 -04:00
Christudasan Devadasan d7a05698ef [AMDGPU] Move LowerSwitch pass to CodeGenPrepare.
It is possible that LowerSwitch pass leaves certain blocks
unreachable from the entry. If not removed, these dead blocks
can cause undefined behavior in the subsequent passes.
It caused a crash in the AMDGPU backend after the instruction
selection when a PHI node has its incoming values coming from
these unreachable blocks.

In the AMDGPU pass flow, the last invocation of UnreachableBlockElim
precedes where LowerSwitch is currently placed and eventually
missed out on the opportunity to get these blocks eliminated.
This patch ensures that LowerSwitch pass get inserted earlier
to make use of the existing unreachable block elimination pass.

Reviewed By: sameerds, arsenm

Differential Revision: https://reviews.llvm.org/D83584
2020-07-11 16:33:38 +05:30
Carl Ritson a3daa3f75a [AMDGPU] Unify early PS termination blocks
Generate a single early exit block out-of-line and branch to this
if all lanes are killed. This avoids branching if lanes are active.

Reviewed By: nhaehnle

Differential Revision: https://reviews.llvm.org/D82641
2020-07-03 09:58:05 +09:00
Jay Foad def2e4c47f [AMDGPU] Simplify GCNPassConfig::addOptimizedRegAlloc. NFC. 2020-06-17 15:56:15 +01:00
Sameer Sahasrabuddhe d8f651d3e8 [AMDGPU] Enable structurizer workarounds by default
Reviewed By: nhaehnle

Differential Revision: https://reviews.llvm.org/D81211
2020-06-09 13:14:15 +05:30
Stanislav Mekhanoshin 689e616ed0 [AMDGPU] Promote alloca to vector in opt
Promote alloca to vector before SROA and loop unroll. If we manage
to eliminate allocas before unroll we may choose to unroll less.

Differential Revision: https://reviews.llvm.org/D80386
2020-05-21 13:49:51 -07:00
Jay Foad 42a5560503 [AMDGPU] New SIInsertHardClauses pass
Enable clausing of memory loads on gfx10 by adding a new pass to insert
the s_clause instructions that mark the start of each hard clause.

Differential Revision: https://reviews.llvm.org/D79792
2020-05-14 18:54:49 +01:00
Carl Ritson e3ffe7269b [AMDGPU] Cluster shader exports
Summary:
Add DAG scheduling mutation to cluster export instructions.
This avoids unnecessary waitcnts being added when computation
ends up interspersed with exports.

Reviewers: foad, arsenm, rampitec, nhaehnle

Reviewed By: foad

Subscribers: kzhuravl, jvesely, wdng, mgorny, yaxunl, dstuttard, tpr, t-tye, hiraditya, kerbowa, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79481
2020-05-07 19:05:38 +09:00
alex-t 5b898bddff [AMDGPU] Enable carry out ADD/SUB operations divergence driven instruction selection.
Summary: This change enables all kind of carry out ISD opcodes to be selected according to the node divergence.

Reviewers: rampitec, arsenm, vpykhtin

Reviewed By: rampitec

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D78091
2020-05-04 16:42:25 +03:00
Sameer Sahasrabuddhe 8c11bc0cd0 Introduce fix-irreducible pass
An irreducible SCC is one which has multiple "header" blocks, i.e., blocks
with control-flow edges incident from outside the SCC. This pass converts an
irreducible SCC into a natural loop by introducing a single new header
block and redirecting all the edges on the original headers to this
new block.

This is a useful workaround for a limitation in the structurizer
which, which produces incorrect control flow in the presence of
irreducible regions. The AMDGPU backend provides an option to
enable this pass before the structurizer, which may eventually be
enabled by default.

Reviewed By: nhaehnle

Differential Revision: https://reviews.llvm.org/D77198

This restores commit 2ada8e2525.

Originally reverted with commit 44e09b59b8.
2020-04-15 15:05:51 +05:30
Sameer Sahasrabuddhe 44e09b59b8 Revert "Introduce fix-irreducible pass"
This reverts commit 2ada8e2525.

Buildbots produced compilation errors which I was not able to quickly
reproduce locally. Need more time to investigate.
2020-04-15 12:19:50 +05:30
Sameer Sahasrabuddhe 2ada8e2525 Introduce fix-irreducible pass
An irreducible SCC is one which has multiple "header" blocks, i.e., blocks
with control-flow edges incident from outside the SCC. This pass converts an
irreducible SCC into a natural loop by introducing a single new header
block and redirecting all the edges on the original headers to this
new block.

This is a useful workaround for a limitation in the structurizer
which, which produces incorrect control flow in the presence of
irreducible regions. The AMDGPU backend provides an option to
enable this pass before the structurizer, which may eventually be
enabled by default.

Reviewed By: nhaehnle

Differential Revision: https://reviews.llvm.org/D77198
2020-04-15 11:29:19 +05:30
Jay Foad 4970a1deca [AMDGPU] Remove outdated comment 2020-04-09 10:36:00 +01:00
Matt Arsenault 0aa0d70067 MIR: Use Register 2020-04-08 22:07:26 -04:00
Konstantin Pyzhov 72e8754916 [AMDGPU] Disable 'Skip Uniform Regions' optimization by default for AMDGPU.
Reviewers: sameerds, dstuttard

Differential Revision: https://reviews.llvm.org/D77228
2020-04-06 09:05:58 -04:00
Konstantin Pyzhov 51dc028314 Revert e1730cfeb3 2020-04-06 05:56:11 -04:00
Konstantin Pyzhov e1730cfeb3 [AMDGPU] Disable 'Skip Uniform Regions' optimization by default for AMDGPU.
Reviewers: sameerds, dstuttard

Differential Revision: https://reviews.llvm.org/D77228
2020-04-06 05:10:37 -04:00
Sameer Sahasrabuddhe 3cbbded68c Introduce unify-loop-exits pass.
For each natural loop with multiple exit blocks, this pass creates a
new block N such that all exiting blocks now branch to N, and then
control flow is redistributed to all the original exit blocks.

The bulk of the tranformation is a new function introduced in
BasicBlockUtils that an redirect control flow from a set of incoming
blocks to a set of outgoing blocks via a common "hub".

This is a useful workaround for a limitation in the structurizer which
incorrectly orders blocks when processing a nest of loops. This pass
bypasses that issue by ensuring that each natural loop is recognized
as a separate region. Since the structurizer is a region pass, it no
longer sees a nest of loops in a single region, and instead processes
each "level" in the nesting as a separate region.

The AMDGPU backend provides a new option to enable this pass before
the structurizer, which may eventually be enabled by default.

Reviewers: madhur13490, arsenm, nhaehnle

Reviewed By: nhaehnle

Differential Revision: https://reviews.llvm.org/D75865
2020-03-30 13:23:56 -04:00
Matt Arsenault 348735b723 AMDGPU: Stop setting attributes based on TargetOptions
Having arbitrary passes looking at the TargetOptions is pretty
messy. This was also disregarding if a function already had an
explicit attribute setting on it. opt/llc now add the attributes to
functions that don't specify the attribute. clang and lld do not call
the function to do this, which they maybe should.

This was also treating unsafe-fp-math as implying the others, and
setting the other attributes based on it. This is not done anywhere
else, and I'm not sure is correct based on the current description of
the option bit.

Effectively reverts 1d8cf2be89
2020-03-27 13:13:43 -07:00
Stanislav Mekhanoshin 6e00e3fcb0 [AMDGPU] Preserve original symbol during attribute propagation
AMDGPUPropagateAttributes can swap names while cloning a function.
Only do it if original symbol was not externally visible.

Differential Revision: https://reviews.llvm.org/D76789
2020-03-25 15:26:30 -07:00
cdevadas ce984129ea [AMDGPU] Add SIPreEmitPeephole pass.
This pass can handle all the optimization
opportunities found just before code emission.
Presently it includes the handling of vcc branch
optimization that was handled earlier in SIInsertSkips.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D76712
2020-03-25 15:35:35 +00:00
Ram Nalamothu 24698e526f Implement wave32 DWARF register mapping
Implement the DWARF register mapping described in llvm/docs/AMDGPUUsage.rst.

This enables generating appropriate DWARF register numbers for wave64 and
wave32 modes.
2020-03-23 10:24:16 -04:00
Scott Linder 60b1967c39 [AMDGPU] Add Scratch Wave Offset to Scratch Buffer Descriptor in entry functions
Add the scratch wave offset to the scratch buffer descriptor (SRSrc) in
the entry function prologue. This allows us to removes the scratch wave
offset register from the calling convention ABI.

As part of this change, allow the use of an inline constant zero for the
SOffset of MUBUF instructions accessing the stack in entry functions
when a frame pointer is not requested/required. Entry functions with
calls still need to set up the calling convention ABI stack pointer
register, and reference it in order to address arguments of called
functions. The ABI stack pointer register remains unswizzled, but is now
wave-relative instead of queue-relative.

Non-entry functions also use an inline constant zero SOffset for
wave-relative scratch access, but continue to use the stack and frame
pointers as before. When the stack or frame pointer is converted to a
swizzled offset it is now scaled directly, as the scratch wave offset no
longer needs to be subtracted first.

Update llvm/docs/AMDGPUUsage.rst to reflect these changes to the calling
convention.

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75138
2020-03-19 15:35:16 -04:00
Scott Linder db099f994b [AMDGPU][NFC] Refactor some uses of unsigned to Register
Tags: #llvm

Differential Revision: https://reviews.llvm.org/D76035
2020-03-19 15:35:16 -04:00
Matt Arsenault 015b640be4 AMDGPU: Add flag to used fixed function ABI
Pass all arguments to every function, rather than only passing the
minimum set of inputs needed for the call graph.
2020-03-13 13:27:05 -07:00
Matt Arsenault fee41517fe AMDGPU/GlobalISel: Introduce post-legalize combiner
The current set of custom combines are only really useful after
legalization, so move them there. There is a lot of overlap in the
boilerplate here, but I think we do want a pretty different set of
combines before and after legalize. I think we will want a lot of
overlap between the post-legalize and a post-regbankselect combiner.
2020-02-24 22:12:12 -05:00
Matt Arsenault 54137bbaaf GlobalISel: Allow running localizer earlier
This required legal and regbankselected MIR for seemingly no
reason. For AMDGPU this wouldn't see legalized G_GLOBAL_VALUEs.
2020-02-17 11:24:06 -08:00
Matt Arsenault 5fdc9851d0 AMDGPU/GlobalISel: Run the localizer pass
While looking at the output on real sized programs, there is a lot of
extra SGPR spilling compared to the DAG path. This seems to largely be
from all constants being SGPRs in the entry block.
2020-02-17 07:38:12 -08:00
Jay Foad e9900b1fbf [AMDGPU] Add one more pass to LLVMInitializeAMDGPUTarget 2020-02-12 11:19:14 +00:00
Matt Arsenault 1024b73ef5 AMDGPU: Split denormal mode tracking bits
Prepare to accurately track the future denormal-fp-math attribute
changes. The way to actually set these separately is not wired in yet.

This is just a mechanical change, and mostly still assumes the input
and output mode match. This should be refined for some cases. For
example, fcanonicalize lowering should use the flushing variant if
either input or output flushing is enabled
2020-02-04 10:44:21 -08:00
Stanislav Mekhanoshin 555d8f4ef5 [AMDGPU] Bundle loads before post-RA scheduler
We are relying on atrificial DAG edges inserted by the
MemOpClusterMutation to keep loads and stores together in the
post-RA scheduler. This does not work all the time since it
allows to schedule a completely independent instruction in the
middle of the cluster.

Removed the DAG mutation and added pass to bundle already
clustered instructions. These bundles are unpacked before the
memory legalizer because it does not work with bundles but also
because it allows to insert waitcounts in the middle of a store
cluster.

Removing artificial edges also allows a more relaxed scheduling.

Differential Revision: https://reviews.llvm.org/D72737
2020-01-24 11:33:38 -08:00
Matt Arsenault a174f0da62 AMDGPU/GlobalISel: Add pre-legalize combiner pass
Just copy the AArch64 pass as-is for now, except for removing the
memcpy handling.
2020-01-22 10:16:39 -05:00
cdevadas e53a9d96e6 Resubmit: [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
2020-01-22 13:18:32 +09:00
Nicolai Hähnle a80291ce10 Revert "[AMDGPU] Invert the handling of skip insertion."
This reverts commit 0dc6c249bf.

The commit is reported to cause a regression in piglit/bin/glsl-vs-loop for
Mesa.
2020-01-21 09:17:25 +01:00
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
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
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