[AMDGPU] Occupancy w.r.t. workgroup size range is also a range (#123748)

Occupancy (i.e., the number of waves per EU) depends, in addition to
register usage, on per-workgroup LDS usage as well as on

[AMDGPU] Occupancy w.r.t. workgroup size range is also a range (#123748)

Occupancy (i.e., the number of waves per EU) depends, in addition to
register usage, on per-workgroup LDS usage as well as on the range of
possible workgroup sizes. Mirroring the latter, occupancy should
therefore be expressed as a range since different group sizes generally
yield different achievable occupancies.

`getOccupancyWithLocalMemSize` currently returns a scalar occupancy
based on the maximum workgroup size and LDS usage. With respect to the
workgroup size range, this scalar can be the minimum, the maximum, or
neither of the two of the range of achievable occupancies. This commit
fixes the function by making it compute and return the range of
achievable occupancies w.r.t. workgroup size and LDS usage; it also
renames it to `getOccupancyWithWorkGroupSizes` since it is the range of
workgroup sizes that produces the range of achievable occupancies.

Computing the achievable occupancy range is surprisingly involved.
Minimum/maximum workgroup sizes do not necessarily yield maximum/minimum
occupancies i.e., sometimes workgroup sizes inside the range yield the
occupancy bounds. The implementation finds these sizes in constant time;
heavy documentation explains the rationale behind the sometimes
relatively obscure calculations.

As a justifying example, consider a target with 10 waves / EU, 4 EUs/CU,
64-wide waves. Also consider a function with no LDS usage and a flat
workgroup size range of [513,1024].

- A group of 513 items requires 9 waves per group. Only 4 groups made up
of 9 waves each can fit fully on a CU at any given time, for a total of
36 waves on the CU, or 9 per EU. However, filling as much as possible
the remaining 40-36=4 wave slots without decreasing the number of groups
reveals that a larger group of 640 items yields 40 waves on the CU, or
10 per EU.
- Similarly, a group of 1024 items requires 16 waves per group. Only 2
groups made up of 16 waves each can fit fully on a CU ay any given time,
for a total of 32 waves on the CU, or 8 per EU. However, removing as
many waves as possible from the groups without being able to fit another
equal-sized group on the CU reveals that a smaller group of 896 items
yields 28 waves on the CU, or 7 per EU.

Therefore the achievable occupancy range for this function is not [8,9]
as the group size bounds directly yield, but [7,10].

Naturally this change causes a lot of test churn as instruction
scheduling is driven by achievable occupancy estimates. In most unit
tests the flat workgroup size range is the default [1,1024] which,
ignoring potential LDS limitations, would previously produce a scalar
occupancy of 8 (derived from 1024) on a lot of targets, whereas we now
consider the maximum occupancy to be 10 in such cases. Most tests are
updated automatically and checked manually for sanity. I also manually
changed some non-automatically generated assertions when necessary.

Fixes #118220.

show more ...

Reapply "[AMDGPU] Still set up the two SGPRs for queue ptr even it is COV5 (#112403)"

This reverts commit ca33649abe5fad93c57afef54e43ed9b3249cd86.

Revert "[AMDGPU] Still set up the two SGPRs for queue ptr even it is COV5 (#112403)"

This reverts commit e215a1e27d84adad2635a52393621eb4fa439dc9 as it broke both
hip and openmp buildbots.

[AMDGPU] Still set up the two SGPRs for queue ptr even it is COV5 (#112403)

[AMDGPU] Skip VGPR deallocation for waveslot limited kernels (#112765)

MSG_DEALLOC_VGPRS slows down very small waveslot limited kernels. It's
been identified this message is only really needed for

[AMDGPU] Skip VGPR deallocation for waveslot limited kernels (#112765)

MSG_DEALLOC_VGPRS slows down very small waveslot limited kernels. It's
been identified this message is only really needed for VGPR limited
kernels. A kernel becomes VGPR limited if a total number of VGPRs per
SIMD / number of used VGPRs is more than a number of wave slots.

show more ...

[AMDGPU] Codegen support for constrained multi-dword sloads (#96163)

For targets that support xnack replay feature (gfx8+), the
multi-dword scalar loads shouldn't clobber any register that
holds the

[AMDGPU] Codegen support for constrained multi-dword sloads (#96163)

For targets that support xnack replay feature (gfx8+), the
multi-dword scalar loads shouldn't clobber any register that
holds the src address. The constrained version of the scalar
loads have the early clobber flag attached to the dst operand
to restrict RA from re-allocating any of the src regs for its
dst operand.

show more ...

Reapply "AMDGPU: Move attributor into optimization pipeline (#83131)" and follow up commit "clang/AMDGPU: Defeat attribute optimization in attribute test" (#98851)

This reverts commit adaff46d087799

Reapply "AMDGPU: Move attributor into optimization pipeline (#83131)" and follow up commit "clang/AMDGPU: Defeat attribute optimization in attribute test" (#98851)

This reverts commit adaff46d087799072438dd744b038e6fd50a2d78.

Drop the -O3 checks from default-attributes.hip. I don't know why they
are different on some bots but reverting this is far too disruptive.

show more ...

Revert "AMDGPU: Move attributor into optimization pipeline (#83131)" and follow up commit "clang/AMDGPU: Defeat attribute optimization in attribute test" (#98851)

This reverts commits 677cc15e0ff2e0

Revert "AMDGPU: Move attributor into optimization pipeline (#83131)" and follow up commit "clang/AMDGPU: Defeat attribute optimization in attribute test" (#98851)

This reverts commits 677cc15e0ff2e0e6aa30538eb187990a6a8f53c0 and
78bc1b64a6dc3fb6191355a5e1b502be8b3668e7.

The test CodeGenHIP/default-attributes.hip is failing on multiple bots
even after the attempted fix including the following:
- https://lab.llvm.org/buildbot/#/builders/3/builds/1473
- https://lab.llvm.org/buildbot/#/builders/65/builds/1380
- https://lab.llvm.org/buildbot/#/builders/161/builds/595
- https://lab.llvm.org/buildbot/#/builders/154/builds/1372
- https://lab.llvm.org/buildbot/#/builders/133/builds/1547
- https://lab.llvm.org/buildbot/#/builders/81/builds/755
- https://lab.llvm.org/buildbot/#/builders/40/builds/570
- https://lab.llvm.org/buildbot/#/builders/13/builds/748
- https://lab.llvm.org/buildbot/#/builders/12/builds/1845
- https://lab.llvm.org/buildbot/#/builders/11/builds/1695
- https://lab.llvm.org/buildbot/#/builders/190/builds/1829
- https://lab.llvm.org/buildbot/#/builders/193/builds/962
- https://lab.llvm.org/buildbot/#/builders/23/builds/991
- https://lab.llvm.org/buildbot/#/builders/144/builds/2256
- https://lab.llvm.org/buildbot/#/builders/46/builds/1614

These bots have been broken for a day, so reverting to get everything
back to green.

show more ...

AMDGPU: Move attributor into optimization pipeline (#83131)

Removing it from the codegen pipeline induces a lot of test churn
because llc is no longer optimizing out implicit arguments to kernels.

AMDGPU: Move attributor into optimization pipeline (#83131)

Removing it from the codegen pipeline induces a lot of test churn
because llc is no longer optimizing out implicit arguments to kernels.

Mostly mechanical, but there are some creative test updates. I preferred
to take the changes as-is in tests where the ABI isn't relevant. In
cases where it's more relevant, or the optimize out logic was too
ingrained in the test, I pre-run the optimization. Some cases manually
add attributes to disable inputs.

show more ...

[SelectionDAG] Switch to LiveRegUnits (#84197)

[AMDGPU] CodeGen for GFX12 S_WAIT_* instructions (#77438)

Update SIMemoryLegalizer and SIInsertWaitcnts to use separate wait
instructions per counter (e.g. S_WAIT_LOADCNT) and split VMCNT into
sep

[AMDGPU] CodeGen for GFX12 S_WAIT_* instructions (#77438)

Update SIMemoryLegalizer and SIInsertWaitcnts to use separate wait
instructions per counter (e.g. S_WAIT_LOADCNT) and split VMCNT into
separate LOADCNT, SAMPLECNT and BVHCNT counters.

show more ...

[AMDGPU,test] Change llc -march= to -mtriple= (#75982)

Similar to 806761a7629df268c8aed49657aeccffa6bca449.

For IR files without a target triple, -mtriple= specifies the full
target triple while

[AMDGPU,test] Change llc -march= to -mtriple= (#75982)

Similar to 806761a7629df268c8aed49657aeccffa6bca449.

For IR files without a target triple, -mtriple= specifies the full
target triple while -march= merely sets the architecture part of the
default target triple, leaving a target triple which may not make sense,
e.g. amdgpu-apple-darwin.

Therefore, -march= is error-prone and not recommended for tests without
a target triple. The issue has been benign as we recognize
$unknown-apple-darwin as ELF instead of rejecting it outrightly.

This patch changes AMDGPU tests to not rely on the default
OS/environment components. Tests that need fixes are not changed:

```
LLVM :: CodeGen/AMDGPU/fabs.f64.ll
LLVM :: CodeGen/AMDGPU/fabs.ll
LLVM :: CodeGen/AMDGPU/floor.ll
LLVM :: CodeGen/AMDGPU/fneg-fabs.f64.ll
LLVM :: CodeGen/AMDGPU/fneg-fabs.ll
LLVM :: CodeGen/AMDGPU/r600-infinite-loop-bug-while-reorganizing-vector.ll
LLVM :: CodeGen/AMDGPU/schedule-if-2.ll
```

show more ...

[AMDGPU] CodeGen for GFX12 64-bit scalar add/sub (#75070)

[AMDGPU] Convert some tests to opaque pointers (NFC)

[AMDGPU] Add GFX11 test coverage sharing checks with GFX10

[AMDGPU] Add some more GFX10 test coverage

AMDGPU: Select VOP3 form of add

The VOP3 form should always be the preferred selection, to be shrunk
later. This should only be an optimization issue, but this partially
works around a problem from

AMDGPU: Select VOP3 form of add

The VOP3 form should always be the preferred selection, to be shrunk
later. This should only be an optimization issue, but this partially
works around a problem from clobbering VCC when SIFixSGPRCopies
rewrites an SCC defining operation directly to VCC.

3 of the testcases are regressions from failing to fold the immediate
in cases it should. These can be avoided by improving the VCC liveness
handling in SIFoldOperands. Simply increasing the threshold to
computeRegisterLiveness works, although this is common enough that VCC
liveness should probably be tracked throughout the pass. The hack of
leaving behind an implicit_def instruction to avoid breaking iterator
wastes instruction count, which inhibits finding the VCC def in long
chains of adds. Doing this however exposes different, worse looking
regressions from poor scheduling behavior. This could probably be
avoided around by forcing the shrink of the addc here, but the
scheduler should probably be fixed.

The r600 add test needs to be split out because it asserts on the
arguments in the new test during the calling convention lowering.

llvm-svn: 360293

show more ...

[AMDGPU] Divergence driven instruction selection. Part 1.

Summary: This change is the first part of the AMDGPU target description
change. The aim of it is the effective splitting the vector

[AMDGPU] Divergence driven instruction selection. Part 1.

Summary: This change is the first part of the AMDGPU target description
change. The aim of it is the effective splitting the vector and scalar
flows at the selection stage. Selection uses predicate functions based
on the framework implemented earlier - https://reviews.llvm.org/D35267

Differential revision: https://reviews.llvm.org/D52019

Reviewers: rampitec

llvm-svn: 342719

show more ...

AMDGPU: Fix broken check lines

llvm-svn: 333458

AMDGPU: Use gfx9 carry-less add/sub instructions

llvm-svn: 319491

[AMDGPU] Switch scalarize global loads ON by default
Differential revision: https://reviews.llvm.org/D34407

llvm-svn: 307097

Revert r307026, "[AMDGPU] Switch scalarize global loads ON by default"

It broke a testcase.

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

llvm-svn: 307054

[AMDGPU] Switch scalarize global loads ON by default

Differential revision: https://reviews.llvm.org/D34407

llvm-svn: 307026

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
ca

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).

llvm-svn: 298444

show more ...

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@mi

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>

llvm-svn: 292982

show more ...