Certain optimisations from ConstantHoisting and CGP rely on Selection DAG not
seeing through to the constant in other blocks. Revert this patch while we come
up with a better way to handle that.
I will try to follow this up with some better tests.
llvm-svn: 358113
One of out of tree targets has regressed with this patch. Reverting
it for now and let liveness to be fully reconstructed in case pass
was used after the LIS is created to resolve the regression.
Differential Revision: https://reviews.llvm.org/D60466
llvm-svn: 358015
Add support for min/max flavor selects in computeConstantRange(),
which allows us to fold comparisons of a min/max against a constant
in InstSimplify. This fixes an infinite InstCombine loop, with the
test case taken from D59378.
Relative to the previous iteration, this contains some adjustments for
AMDGPU med3 tests: The AMDGPU target runs InstSimplify prior to codegen,
which ends up constant folding some existing med3 tests after this
change. To preserve these tests a hidden -amdgpu-scalar-ir-passes option
is added, which allows disabling scalar IR passes (that use InstSimplify)
for testing purposes.
Differential Revision: https://reviews.llvm.org/D59506
llvm-svn: 357870
Detect dead lanes can create some dead defs. Then RenameIndependentSubregs
will break a REG_SEQUENCE which may use these dead defs. At this point
a dead instruction can be removed but we do not run a DCE anymore.
MachineDCE was only running before live variable analysis. The patch
adds a mean to preserve LiveIntervals and SlotIndexes in case it works
past this.
Differential Revision: https://reviews.llvm.org/D59626
llvm-svn: 357805
Summary:
Teach SelectionDAG how to compute known bits of ISD::CopyFromReg if
the virtual reg used has one def only.
This can be particularly useful when calling isBaseWithConstantOffset()
with the ISD::CopyFromReg argument, as more optimizations may get enabled
in the result.
Also add a missing truncation on X86, found by testing of this patch.
Change-Id: Id1c9fceec862d118c54a5b53adf72ada5d6daefa
Reviewers: bogner, craig.topper, RKSimon
Reviewed By: RKSimon
Subscribers: lebedev.ri, nemanjai, jvesely, nhaehnle, javed.absar, jsji, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59535
llvm-svn: 357745
Relying on no spill or other code being inserted before this was
precarious. It relied on code diligently checking isBasicBlockPrologue
which is likely to be forgotten.
Ideally this could be done earlier, but this doesn't work because of
phis. Any other instruction can't be placed before them, so we have to
accept the position being incorrect during SSA.
This avoids regressions in the fast register allocator rewrite from
inverting the direction.
llvm-svn: 357634
The test should really be checking for the property directly in the
code object headers, but there are problems with this. I don't see
this directly represented in the text form, and for the binary
emission this is depending on a function level subtarget feature to
emit a global flag.
llvm-svn: 357558
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
