16 Commits

Author SHA1 Message Date
Matt Arsenault
a2ba13d731 AMDGPU: Add pass to lower kernel arguments to loads
This replaces most argument uses with loads, but for
now not all.

The code in SelectionDAG for calling convention lowering
is actively harmful for amdgpu_kernel. It attempts to
split the argument types into register legal types, which
results in low quality code for arbitary types. Since
all kernel arguments are passed in memory, we just want the
raw types.

I've tried a couple of methods of mitigating this in SelectionDAG,
but it's easier to just bypass this problem alltogether. It's
possible to hack around the problem in the initial lowering,
but the real problem is the DAG then expects to be able to use
CopyToReg/CopyFromReg for uses of the arguments outside the block.

Exposing the argument loads in the IR also has the advantage
that the LoadStoreVectorizer can merge them.

I'm not sure the best approach to dealing with the IR
argument list is. The patch as-is just leaves the IR arguments
in place, so all the existing code will still compute the same
kernarg size and pointlessly lowers the arguments.

Arguably the frontend should emit kernels with an empty argument
list in the first place. Alternatively a dummy array could be
inserted as a single argument just to reserve space.

This does have some disadvantages. Local pointer kernel arguments can
no longer have AssertZext placed  on them as the equivalent !range
metadata is not valid on pointer  typed loads. This is mostly bad
for SI which needs to know about the known bits in order to use the
DS instruction offset, so in this case this is not done.

More importantly, this skips noalias arguments since this pass
does not yet convert this to the equivalent !alias.scope and !noalias
metadata. Producing this metadata correctly seems to be tricky,
although this logically is the same as inlining into a function which
doesn't exist. Additionally, exposing these loads to the vectorizer
may result in degraded aliasing information if a pointer load is
merged with another argument load.

I'm also not entirely sure this is preserving the current clover
ABI, although I would greatly prefer if it would stop widening
arguments and match the HSA ABI. As-is I think it is extending
< 4-byte arguments to 4-bytes but doesn't align them to 4-bytes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335650 91177308-0d34-0410-b5e6-96231b3b80d8
2018-06-26 19:10:00 +00:00
Matt Arsenault
a038a8340c AMDGPU: Allow SIShrinkInstructions to work in non-SSA
Immediates can be folded as long as the immediate is a vreg.

Also undo commuting instructions if it didn't fold an immediate.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@307575 91177308-0d34-0410-b5e6-96231b3b80d8
2017-07-10 19:53:57 +00:00
Alexander Timofeev
f9e9586c80 [AMDGPU] Switch scalarize global loads ON by default
Differential revision: https://reviews.llvm.org/D34407

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@307097 91177308-0d34-0410-b5e6-96231b3b80d8
2017-07-04 17:32:00 +00:00
NAKAMURA Takumi
0a256123a4 Revert r307026, "[AMDGPU] Switch scalarize global loads ON by default"
It broke a testcase.

  Failing Tests (1):
      LLVM :: CodeGen/AMDGPU/alignbit-pat.ll

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@307054 91177308-0d34-0410-b5e6-96231b3b80d8
2017-07-04 02:14:18 +00:00
Alexander Timofeev
0f9ec97238 [AMDGPU] Switch scalarize global loads ON by default
Differential revision: https://reviews.llvm.org/D34407

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@307026 91177308-0d34-0410-b5e6-96231b3b80d8
2017-07-03 14:54:11 +00:00
Matt Arsenault
d706d030af AMDGPU: Mark all unspecified CC functions in tests as amdgpu_kernel
Currently the default C calling convention functions are treated
the same as compute kernels. Make this explicit so the default
calling convention can be changed to a non-kernel.

Converted with perl -pi -e 's/define void/define amdgpu_kernel void/'
on the relevant test directories (and undoing in one place that actually
wanted a non-kernel).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298444 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-21 21:39:51 +00:00
Matt Arsenault
d019e8638a Enable FeatureFlatForGlobal on Volcanic Islands
This switches to the workaround that HSA defaults to
for the mesa path.

This should be applied to the 4.0 branch.

Patch by Vedran Miletić <vedran@miletic.net>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292982 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-24 22:02:15 +00:00
Konstantin Zhuravlyov
1d609512ed Revert "AMDGPU: Enable ConstrainCopy DAG mutation"
This reverts commit r287146.

This breaks few conformance tests.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@287233 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-17 16:41:49 +00:00
Matt Arsenault
4fbd908949 AMDGPU: Enable ConstrainCopy DAG mutation
This fixes a probably unintended divergence from the default
scheduler behavior.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@287146 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-16 20:35:23 +00:00
Matt Arsenault
8bc95d0a47 AMDGPU: Improve splitting 64-bit bit ops by constants
This addresses a TODO to handle operations besides and. This
also starts eliminating no-op operations with a constant that
can emerge later.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281488 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-14 15:19:03 +00:00
Changpeng Fang
faf7289db3 AMDGPU/SI: Enable load-store-opt by default.
Summary: Enable load-store-opt by default, and update LIT tests.

Reviewers: arsenm

Differential Revision: http://reviews.llvm.org/D20694

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@270894 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-26 19:35:29 +00:00
Matthias Braun
7adbf112c7 ScheduleDAGInstrs: Rework schedule graph builder.
Re-comitting with a change that avoids undefined uses getting put into
the VRegUses list.

The new algorithm remembers the uses encountered while walking backwards
until a matching def is found. Contrary to the previous version this:
- Works without LiveIntervals being available
- Allows to increase the precision to subregisters/lanemasks
  (not used for now)

The changes in the AMDGPU tests are necessary because the R600 scheduler
is not stable with respect to the order of nodes in the ready queues.

Differential Revision: http://reviews.llvm.org/D9068

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254683 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-04 01:51:19 +00:00
Matthias Braun
033f871101 Revert "ScheduleDAGInstrs: Rework schedule graph builder."
This works mostly fine but breaks some stage 1 builders when compiling
compiler-rt on i386. Revert for further investigation as I can't see an
obvious cause/fix.

This reverts commit r254577.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254586 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-03 03:01:10 +00:00
Matthias Braun
c0a189c379 ScheduleDAGInstrs: Rework schedule graph builder.
The new algorithm remembers the uses encountered while walking backwards
until a matching def is found. Contrary to the previous version this:
- Works without LiveIntervals being available
- Allows to increase the precision to subregisters/lanemasks
  (not used for now)

The changes in the AMDGPU tests are necessary because the R600 scheduler
is not stable with respect to the order of nodes in the ready queues.

Differential Revision: http://reviews.llvm.org/D9068

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254577 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-03 02:05:27 +00:00
Tom Stellard
adb194b458 AMDGPU/SI: Add support for shrinking v_cndmask_b32_e32 instructions
Reviewers: arsenm

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D11061

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242146 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-14 14:15:03 +00:00
Tom Stellard
953c681473 R600 -> AMDGPU rename
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239657 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-13 03:28:10 +00:00