This change incorporates an effort by Connor Abbot to change how we deal
with WWM operations potentially trashing valid values in inactive lanes.
Previously, the SIFixWWMLiveness pass would work out which registers
were being trashed within WWM regions, and ensure that the register
allocator did not have any values it was depending on resident in those
registers if the WWM section would trash them. This worked perfectly
well, but would cause sometimes severe register pressure when the WWM
section resided before divergent control flow (or at least that is where
I mostly observed it).
This fix instead runs through the WWM sections and pre allocates some
registers for WWM. It then reserves these registers so that the register
allocator cannot use them. This results in a significant register
saving on some WWM shaders I'm working with (130 -> 104 VGPRs, with just
this change!).
Differential Revision: https://reviews.llvm.org/D59295
llvm-svn: 357400
Since this can be set with s_setreg*, it should not be a subtarget
property. Set a default based on the calling convention, and Introduce
a new amdgpu-dx10-clamp attribute to override this if desired.
Also introduce a new amdgpu-ieee attribute to match.
The values need to match to allow inlining. I think it is OK for the
caller's dx10-clamp attribute to override the callee, but there
doesn't appear to be the infrastructure to do this currently without
definining the attribute in the generic Attributes.td.
Eventually the calling convention lowering will need to insert a mode
switch somewhere for these.
llvm-svn: 357302
Summary:
Nodes that have no uses are eventually pruned when they are selected
from the worklist. Record nodes newly added to the worklist or DAG and
perform pruning after every combine attempt.
Reviewers: efriedma, RKSimon, craig.topper, spatel, jyknight
Reviewed By: jyknight
Subscribers: jdoerfert, jyknight, nemanjai, jvesely, nhaehnle, javed.absar, hiraditya, jsji, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58070
llvm-svn: 357283
The register index can only really be an SGPR. Lie that a VGPR index
is legal, and then rewrite the instruction in a waterfall loop to
handle the index.
llvm-svn: 357235
Summary:
Add tests for selection across basic block boundary:
* one test containing a buffer load, where part of the offset
computation is placed in the predecessor of the load
* similar test, but containing two buffer loads and shared
computations
Please note that the behaviour being tested will be updated in
a subsequent commit.
This commit was extracted from https://reviews.llvm.org/D59535.
Reviewers: RKSimon
Reviewed By: RKSimon
Subscribers: jvesely, nhaehnle, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59690
llvm-svn: 357149
When lowering a load or store for TypeWidenVector, the type legalizer
would use a single load or store if the associated integer type was legal
or promoted. E.g. it loads a v4i8 as an i32 if i32 is legal/promotable.
(See https://reviews.llvm.org/rL236528 for reference.)
This applies that behaviour to vector types. If the vector type is
TypePromoteInteger, the element type is going to be TypePromoteInteger
as well, which will lead to have a single promoting load rather than N
individual promoting loads. For instance, if we have a v3i1, we would
now have a load of v4i1 instead of 3 loads of i1.
Patch by Guillaume Marques. Thanks!
Differential Revision: https://reviews.llvm.org/D56201
llvm-svn: 357120
If there were only dbg_values in the block, recede would hit the
beginning of the block and try to use thet dbg_value as a real
instruction.
llvm-svn: 357105
The artifact combiners push instructions which have been marked for deletion
onto an list for the legalizer to deal with on return. However, for trunc(ext)
combines the combiner routine recursively calls itself. When it does this the
dead instructions list may not be empty, and the other combiners don't expect
to be dealing with essentially invalid MIR (multiple vreg defs etc).
This change fixes it by ensuring that the dead instructions are processed on
entry into tryCombineInstruction.
As a result, this fix exposed a few places in tests where G_TRUNC instructions
were not being deleted even though they were dead.
Differential Revision: https://reviews.llvm.org/D59892
llvm-svn: 357101
This reapplies r356149, using the correct overload of findUnusedReg
which passes the current iterator.
This worked most of the time, because the scavenger iterator was moved
at the end of the frame index loop in PEI. This would fail if the
spill was the first instruction. This was further hidden by the fact
that the scavenger wasn't passed in for normal frame index
elimination.
llvm-svn: 357098
This patch removes an overly conservative check that would prevent
simplifying copies when the value we were tracking would go through
several subregister indices.
Indeed, the intend of this check was to not track values whenever
we have to compose subregister, but actually what the check was
doing was bailing anytime we see a second subreg, even if that
second subreg would actually be the new source of truth (as opposed
to a part of that subreg).
Differential Revision: https://reviews.llvm.org/D59891
llvm-svn: 357095
Also includes one example of how this transform is unsound. This isn't
verifying the copies are used in the control flow intrinisic patterns.
Also add option to disable exec mask opt pass. Since this pass is
unsound, it may be useful to turn it off until it is fixed.
llvm-svn: 357091
The AMDGPU implementation of getReservedRegs depends on
MachineFunctionInfo fields that are parsed from the YAML section. This
was reserving the wrong register since it was setting the reserved
regs before parsing the correct one.
Some tests were relying on the default reserved set for the assumed
default calling convention.
llvm-svn: 357083
Without a VALU instruction in the return block, these were mostly
testing the path to delete exec mask code before s_endpgm rather than
the end cf handling.
llvm-svn: 356955
I think this is correct, but may not necessarily be the correct fix
for the assertion I'm really trying to solve. If a scheduling region
was found that only has dbg_value instructions, the RegPressure
tracker would end up in an inconsistent state because it would skip
over any debug instructions and point to an instruction outside of the
scheduling region. It may still be possible for this to happen if
there are some real schedulable instructions between dbg_values, but I
haven't managed to break this.
The testcase is extremely sensitive and I'm not sure how to make it
more resistent to future scheduler changes that would avoid stressing
this situation.
llvm-svn: 356926
Some image ops return three or five dwords. Previously, we modeled that
with a 4 or 8 dword register class. The register allocator could
cleverly spot that some subregs were dead and allocate something else
there, but that caused the de-optimization that waitcnt insertion would
think that the result was used immediately.
This commit allows such an image op to have a result with a three or
five dword result, avoiding the above de-optimization.
Differential Revision: https://reviews.llvm.org/D58905
Change-Id: I3651211bbd7ed22721ee7b9fefd7bcc60a809d8b
llvm-svn: 356757
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
They are not used by anything yet, but a subsequent commit will start
using them for image ops that return 5 dwords.
Differential Revision: https://reviews.llvm.org/D58903
Change-Id: I63e1904081e39a6d66e4eb96d51df25ad399d271
llvm-svn: 356735
The AArch64 test was broken since the result register already had a
set register class, so this test was a no-op. The mapping verify call
would fail because the result size is not the same as the inputs like
in a copy or phi.
The AMDGPU testcases are half broken and introduce illegal VGPR->SGPR
copies which need much more work to handle correctly (same for phis),
but add them as a baseline.
llvm-svn: 356713
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
Machine DCE cannot remove a dead definition if there are non-dbg uses.
A use however can be in the same instruction:
dead %0 = INST %0
Such instructions sometimes created by Detect dead lanes pass.
Allow this instruction to be deleted despite the use if the only use
belongs to the same instruction.
Differential Revision: https://reviews.llvm.org/D59565
llvm-svn: 356619
The constantness shouldn't change the register bank choice. We also
don't need to restrict this to only indexing VGPRs, since it's
possible to index SGPRs (but SelectionDAG made using this
difficult). Allow directly indexing SGPRs when appropriate.
llvm-svn: 356611
Summary:
- Should use `targetconstant` instead of `constant` operand for clamp
bit, which is expected as an immediate operand. Under certain
conditions, such as a common `i1 false` constant is used in other
place and selected before the instruction with clamp bit, register
operand may be added instead of immediate one. Use `targetcosntant` to
enforce that.
Subscribers: arsenm, kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59608
llvm-svn: 356608
Summary:
PAL metadata now supports both the old linear reg=val pairs format and
the new MsgPack format.
The MsgPack format uses YAML as its textual representation. On output to
YAML, a mnemonic name is provided for some hardware registers.
Differential Revision: https://reviews.llvm.org/D57028
Change-Id: I2bbaabaaca4b3574f7e03b80fbef7c7a69d06a94
llvm-svn: 356591
Summary:
This commit introduces a new AMDGPUPALMetadata class that:
* is inside the AMDGPU target;
* keeps an in-memory representation of PAL metadata;
* provides a method to read the frontend-supplied metadata from LLVM IR;
* provides methods for the asm printer to set metadata items;
* provides methods to write the metadata as a binary blob to put in a
.note record or as an asm directive;
* provides a method to read the metadata as a binary blob from a .note
record.
Because llvm-readobj cannot call directly into a target, I had to remove
llvm-readobj's ability to dump PAL metadata, pending a resolution to
https://reviews.llvm.org/D52821
Differential Revision: https://reviews.llvm.org/D57027
Change-Id: I756dc830894fcb6850324cdcfa87c0120eb2cf64
llvm-svn: 356582
Summary:
If an MIMG instruction has managed to get through to adjustWritemask in isel but
has no uses (and doesn't enable TFC) then prevent an assertion by not attempting
to adjust the writemask.
The instruction will be removed anyway.
Change-Id: I9a5dba6bafe1f35ac99c1b73df390936e2ac27a7
Subscribers: arsenm, kzhuravl, jvesely, wdng, nhaehnle, yaxunl, tpr, t-tye, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58964
llvm-svn: 356540
I found this really weird WWM-related case whereby through the WWM
transformations our isel lowering was trying to promote 2 min's into a
min3 for the i8 type, which our hardware doesn't support.
The new min3_i8.ll test case would previously spew the error:
PromoteIntegerResult #0: t69: i8 = SMIN3 t70, Constant:i8<0>, t68
Before the simple fix to our isel lowering to not do it for i8 MVT's.
Differential Revision: https://reviews.llvm.org/D59543
llvm-svn: 356464
Allow the clamp modifier on vop3 int arithmetic instructions in assembly
and disassembly.
This involved adding a clamp operand to the affected instructions in MIR
and MC, and thus having to fix up several places in codegen and MIR
tests.
Differential Revision: https://reviews.llvm.org/D59267
Change-Id: Ic7775105f02a985b668fa658a0cd7837846a534e
llvm-svn: 356399
This commit allows v_cndmask_b32_e64 with abs, neg source
modifiers on src0, src1 to be assembled and disassembled.
This does appear to be allowed, even though they are floating point
modifiers and the operand type is b32.
To do this, I added src0_modifiers and src1_modifiers to the
MachineInstr, which involved fixing up several places in codegen and mir
tests.
Differential Revision: https://reviews.llvm.org/D59191
Change-Id: I69bf4a8c73ebc65744f6110bb8fc4e937d79fbea
llvm-svn: 356398
Add an experimental buffer fat pointer address space that is currently
unhandled in the backend. This commit reserves address space 7 as a
non-integral pointer repsenting the 160-bit fat pointer (128-bit buffer
descriptor + 32-bit offset) that is heavily used in graphics workloads
using the AMDGPU backend.
Differential Revision: https://reviews.llvm.org/D58957
llvm-svn: 356373
There are a few different issues, mostly stemming from using
generation based checks for anything instead of subtarget
features. Stop adding flat-address-space as a feature for HSA, as it
should only be a device property. This was incorrectly allowing flat
instructions to select for SI.
Increase the default generation for HSA to avoid the encoding error
when emitting objects. This has some other side effects from various
checks which probably should be separate subtarget features (in the
cost model and for dealing with the DS offset folding issue).
Partial fix for bug 41070. It should probably be an error to try using
amdhsa without flat support.
llvm-svn: 356347
AMDGPU would like to have MVTs for v3i32, v3f32, v5i32, v5f32. This
commit does not add them, but makes preparatory changes:
* Fixed assumptions of power-of-2 vector type in kernel arg handling,
and added v5 kernel arg tests and v3/v5 shader arg tests.
* Added v5 tests for cost analysis.
* Added vec3/vec5 arg test cases.
Some of this patch is from Matt Arsenault, also of AMD.
Differential Revision: https://reviews.llvm.org/D58928
Change-Id: I7279d6b4841464d2080eb255ef3c589e268eabcd
llvm-svn: 356342
Summary:
At the exit of the loop, the compiler uses a register to remember and accumulate
the number of threads that have already exited. When all active threads exit the
loop, this register is used to restore the exec mask, and the execution continues
for the post loop code.
When there is a "continue" in the loop, the compiler made a mistake to reset the
register to 0 when the "continue" backedge is taken. This will result in some
threads not executing the post loop code as they are supposed to.
This patch fixed the issue.
Reviewers:
nhaehnle, arsenm
Differential Revision:
https://reviews.llvm.org/D59312
llvm-svn: 356298
Summary:
- During the fixing of SGPR copying from VGPR, ensure users of SCC is
properly propagated, i.e.
* only propagate through live def of SCC,
* skip the SCC-def inst itself, and
* stop the propagation on the other SCC-def inst after checking its
SCC-use first.
Subscribers: arsenm, kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59362
llvm-svn: 356258
This has been a very painful missing feature that has made producing
reduced testcases difficult. In particular the various registers
determined for stack access during function lowering were necessary to
avoid undefined register errors in a large percentage of
cases. Implement a subset of the important fields that need to be
preserved for AMDGPU.
Most of the changes are to support targets parsing register fields and
properly reporting errors. The biggest sort-of bug remaining is for
fields that can be initialized from the IR section will be overwritten
by a default initialized machineFunctionInfo section. Another
remaining bug is the machineFunctionInfo section is still printed even
if empty.
llvm-svn: 356215
This is consistent with what SelectionDAG does and is much easier to
work with than the extract sequence with an artificial wide register.
For the AMDGPU control flow intrinsics, this was producing an s128 for
the i64, i1 tuple return. Any legalization that should apply to a real
s128 value would badly obscure the direct values that need to be seen.
llvm-svn: 356147
Summary:
MsgPackDocument is the lighter-weight replacement for MsgPackTypes. This
commit switches AMDGPU HSA metadata processing to use MsgPackDocument
instead of MsgPackTypes.
Differential Revision: https://reviews.llvm.org/D57024
Change-Id: I0751668013abe8c87db01db1170831a76079b3a6
llvm-svn: 356081
Summary:
A number of optimizations are inhibited by single-use TokenFactors not
being merged into the TokenFactor using it. This makes we consider if
we can do the merge immediately.
Most tests changes here are due to the change in visitation causing
minor reorderings and associated reassociation of paired memory
operations.
CodeGen tests with non-reordering changes:
X86/aligned-variadic.ll -- memory-based add folded into stored leaq
value.
X86/constant-combiners.ll -- Optimizes out overlap between stores.
X86/pr40631_deadstore_elision -- folds constant byte store into
preceding quad word constant store.
Reviewers: RKSimon, craig.topper, spatel, efriedma, courbet
Reviewed By: courbet
Subscribers: dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, javed.absar, eraman, hiraditya, kbarton, jrtc27, atanasyan, jsji, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59260
llvm-svn: 356068
This indicates an intrinsic parameter is required to be a constant,
and should not be replaced with a non-constant value.
Add the attribute to all AMDGPU and generic intrinsics that comments
indicate it should apply to. I scanned other target intrinsics, but I
don't see any obvious comments indicating which arguments are intended
to be only immediates.
This breaks one questionable testcase for the autoupgrade. I'm unclear
on whether the autoupgrade is supposed to really handle declarations
which were never valid. The verifier fails because the attributes now
refer to a parameter past the end of the argument list.
llvm-svn: 355981
Targets can potentially emit more efficient code if they know address
computations never overflow. For example ILP32 code on AArch64 (which only has
64-bit address computation) can ignore the possibility of overflow with this
extra information.
llvm-svn: 355926
Narrow Scalar G_MUL for MIPS32.
Revisit NarrowScalar implementation in LegalizerHelper.
Introduce new helper function multiplyRegisters.
It performs generic multiplication of values held in multiple registers.
Generated instructions use only types NarrowTy and i1.
Destination can be same or two times size of the source.
Differential Revision: https://reviews.llvm.org/D58824
llvm-svn: 355814
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
This avoids breaking possible value dependencies when sorting loads by
offset.
AMDGPU has some load instructions that write into the high or low bits
of the destination register, and have a tied input for the other input
bits. These can easily have the same base pointer, but be a swizzle so
the high address load needs to come first. This was inserting glue
forcing the opposite ordering, producing a cycle the InstrEmitter
would assert on. It may be potentially expensive to look for the
dependency between the other loads, so just skip any where this could
happen.
Fixes bug 40936 by reverting r351379, which added a hacky attempt to
fix this by adding chains in this case, which I think was just working
around broken glue before the InstrEmitter. The core of the patch is
re-implementing the fix for that problem.
llvm-svn: 355728
This was checking the wrong operands for the base register and the
offsets. The indexes are shifted by the number of output registers
from the machine instruction definition, and the chain is moved to the
end.
llvm-svn: 355722
- Copy kernel symbol attributes into kernel descriptor attributes
- Make sure kernel symbol's visibility is not "higher" than protected
Differential Revision: https://reviews.llvm.org/D59057
llvm-svn: 355630
A previous patch for "uniform-work-group-size" attribute was found to break
some RADV and possibly radeon SI tests and had to be retracted.
This patch fixes that.
Differential Revision: http://reviews.llvm.org/D58993
llvm-svn: 355574
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
Summary:
In some cases the KILL was causing a hazard to be introduced as these were
scheduled into hazard slots, but don't result in an instruction.
KILL shouldn't be considered for hazard recognition.
Change-Id: Ib6d2a2160f8c94cd0ce611ab198c7e4f46aeffcf
Subscribers: arsenm, kzhuravl, jvesely, wdng, nhaehnle, yaxunl, tpr, t-tye, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58898
llvm-svn: 355384
These were not recognized as potential atomics by memory legalizer.
The test was working not because legalizer did a right thing, but
because it has skipped all these instructions. When I have fixed
DS desciption test started to fail because region address has
changed from 4 to 2 a while ago.
Differential Revision: https://reviews.llvm.org/D58802
llvm-svn: 355179
At the moment, we mark every atomic memory access as being also volatile. This is unnecessarily conservative and prohibits many legal transforms (DCE, folding, etc..).
This patch removes MOVolatile from the MachineMemOperands of atomic, but not volatile, instructions. This should be strictly NFC after a series of previous patches which have gone in to ensure backend code is conservative about handling of isAtomic MMOs. Once it's in and baked for a bit, we'll start working through removing unnecessary bailouts one by one. We applied this same strategy to the middle end a few years ago, with good success.
To make sure this patch itself is NFC, it is build on top of a series of other patches which adjust code to (for the moment) be as conservative for an atomic access as for a volatile access and build up a test corpus (mostly in test/CodeGen/X86/atomics-unordered.ll)..
Previously landed
D57593 Fix a bug in the definition of isUnordered on MachineMemOperand
D57596 [CodeGen] Be conservative about atomic accesses as for volatile
D57802 Be conservative about unordered accesses for the moment
rL353959: [Tests] First batch of cornercase tests for unordered atomics.
rL353966: [Tests] RMW folding tests w/unordered atomic operations.
rL353972: [Tests] More unordered atomic lowering tests.
rL353989: [SelectionDAG] Inline a single use helper function, and remove last non-MMO interface
rL354740: [Hexagon, SystemZ] Be super conservative about atomics
rL354800: [Lanai] Be super conservative about atomics
rL354845: [ARM] Be super conservative about atomics
Attention Out of Tree Backend Owners: This patch may break you. If it does, you can use the TLI getMMOFlags hook to restore the MOVolatile to any instruction you need to. (See llvm-dev thread titled "PSA: Changes to how atomics are handled in backends" started Feb 27, 2019.)
Differential Revision: https://reviews.llvm.org/D57601
llvm-svn: 355025
SITargetLowering::reassociateScalarOps() does not touch constants
so that DAGCombiner::ReassociateOps() does not revert the combine.
However a global address is not a ConstantSDNode.
Switched to the method used by DAGCombiner::ReassociateOps() itself
to detect constants.
Differential Revision: https://reviews.llvm.org/D58695
llvm-svn: 354926
Try to use concat_vectors. Also remove unnecessary assert on
pointers. Fixes asserting for <4 x s16> operations and 64-bit pointers
for AMDGPU.
llvm-svn: 354828
This patch adds LazyValueInfo to LowerSwitch to compute the range of the
value being switched over and reduce the size of the tree LowerSwitch
builds to lower a switch.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D58096
llvm-svn: 354670
Summary:
This is to fix a memory dependence bug in LoadStoreOptimizer.
Reviewers:
arsenm, rampitec
Differential Revision:
https://reviews.llvm.org/D58295
llvm-svn: 354295
The Verifier is separate from the MachineVerifier, so move it to a
different directory. Some other verifier tests were scattered in
target codegen tests as well (although I'm sure I missed some). Work
towards using a more consistent naming scheme to make it clearer where
the gaps still are for generic instructions.
llvm-svn: 354138
Matt Arsenault