[AMDGPU] Refine 64 bit misaligned LDS ops selection

Here is the performance data:
```
Using platform: AMD Accelerated Parallel Processing
Using device: gfx900:xnack-

ds_write_b64

[AMDGPU] Refine 64 bit misaligned LDS ops selection

Here is the performance data:
```
Using platform: AMD Accelerated Parallel Processing
Using device: gfx900:xnack-

ds_write_b64 aligned by 8: 3.2 sec
ds_write2_b32 aligned by 8: 3.2 sec
ds_write_b16 * 4 aligned by 8: 7.0 sec
ds_write_b8 * 8 aligned by 8: 13.2 sec
ds_write_b64 aligned by 1: 7.3 sec
ds_write2_b32 aligned by 1: 7.5 sec
ds_write_b16 * 4 aligned by 1: 14.0 sec
ds_write_b8 * 8 aligned by 1: 13.2 sec
ds_write_b64 aligned by 2: 7.3 sec
ds_write2_b32 aligned by 2: 7.5 sec
ds_write_b16 * 4 aligned by 2: 7.1 sec
ds_write_b8 * 8 aligned by 2: 13.3 sec
ds_write_b64 aligned by 4: 4.6 sec
ds_write2_b32 aligned by 4: 3.2 sec
ds_write_b16 * 4 aligned by 4: 7.1 sec
ds_write_b8 * 8 aligned by 4: 13.3 sec
ds_read_b64 aligned by 8: 2.3 sec
ds_read2_b32 aligned by 8: 2.2 sec
ds_read_u16 * 4 aligned by 8: 4.8 sec
ds_read_u8 * 8 aligned by 8: 8.6 sec
ds_read_b64 aligned by 1: 4.4 sec
ds_read2_b32 aligned by 1: 7.3 sec
ds_read_u16 * 4 aligned by 1: 14.0 sec
ds_read_u8 * 8 aligned by 1: 8.7 sec
ds_read_b64 aligned by 2: 4.4 sec
ds_read2_b32 aligned by 2: 7.3 sec
ds_read_u16 * 4 aligned by 2: 4.8 sec
ds_read_u8 * 8 aligned by 2: 8.7 sec
ds_read_b64 aligned by 4: 4.4 sec
ds_read2_b32 aligned by 4: 2.3 sec
ds_read_u16 * 4 aligned by 4: 4.8 sec
ds_read_u8 * 8 aligned by 4: 8.7 sec

Using platform: AMD Accelerated Parallel Processing
Using device: gfx1030

ds_write_b64 aligned by 8: 4.4 sec
ds_write2_b32 aligned by 8: 4.3 sec
ds_write_b16 * 4 aligned by 8: 7.9 sec
ds_write_b8 * 8 aligned by 8: 13.0 sec
ds_write_b64 aligned by 1: 23.2 sec
ds_write2_b32 aligned by 1: 23.1 sec
ds_write_b16 * 4 aligned by 1: 44.0 sec
ds_write_b8 * 8 aligned by 1: 13.0 sec
ds_write_b64 aligned by 2: 23.2 sec
ds_write2_b32 aligned by 2: 23.1 sec
ds_write_b16 * 4 aligned by 2: 7.9 sec
ds_write_b8 * 8 aligned by 2: 13.1 sec
ds_write_b64 aligned by 4: 13.5 sec
ds_write2_b32 aligned by 4: 4.3 sec
ds_write_b16 * 4 aligned by 4: 7.9 sec
ds_write_b8 * 8 aligned by 4: 13.1 sec
ds_read_b64 aligned by 8: 3.5 sec
ds_read2_b32 aligned by 8: 3.4 sec
ds_read_u16 * 4 aligned by 8: 5.3 sec
ds_read_u8 * 8 aligned by 8: 8.5 sec
ds_read_b64 aligned by 1: 13.1 sec
ds_read2_b32 aligned by 1: 22.7 sec
ds_read_u16 * 4 aligned by 1: 43.9 sec
ds_read_u8 * 8 aligned by 1: 7.9 sec
ds_read_b64 aligned by 2: 13.1 sec
ds_read2_b32 aligned by 2: 22.7 sec
ds_read_u16 * 4 aligned by 2: 5.6 sec
ds_read_u8 * 8 aligned by 2: 7.9 sec
ds_read_b64 aligned by 4: 13.1 sec
ds_read2_b32 aligned by 4: 3.4 sec
ds_read_u16 * 4 aligned by 4: 5.6 sec
ds_read_u8 * 8 aligned by 4: 7.9 sec
```

GFX10 exposes a different pattern for sub-DWORD load/store performance
than GFX9. On GFX9 it is faster to issue a single unaligned load or
store than a fully split b8 access, where on GFX10 even a full split
is better. However, this is a theoretical only gain because splitting
an access to a sub-dword level will require more registers and packing/
unpacking logic, so ignoring this option it is better to use a single
64 bit instruction on a misaligned data with the exception of 4 byte
aligned data where ds_read2_b32/ds_write2_b32 is better.

Differential Revision: https://reviews.llvm.org/D123956

show more ...

[AMDGPU] SILoadStoreOptimizer: avoid unbounded register pressure increases

Previously when combining two loads this pass would sink the
first one down to the second one, putting the combined load
wh

[AMDGPU] SILoadStoreOptimizer: avoid unbounded register pressure increases

Previously when combining two loads this pass would sink the
first one down to the second one, putting the combined load
where the second one was. It would also sink any intervening
instructions which depended on the first load down to just
after the combined load.

For example, if we started with this sequence of
instructions (code flowing from left to right):

X A B C D E F Y

After combining loads X and Y into XY we might end up with:

A B C D E F XY

But if B D and F depended on X, we would get:

A C E XY B D F

Now if the original code had some short disjoint live ranges
from A to B, C to D and E to F, in the transformed code
these live ranges will be long and overlapping. In this way
a single merge of two loads could cause an unbounded
increase in register pressure.

To fix this, change the way the way that loads are moved in
order to merge them so that:
- The second load is moved up to the first one. (But when
merging stores, we still move the first store down to the
second one.)
- Intervening instructions are never moved.
- Instead, if we find an intervening instruction that would
need to be moved, give up on the merge. But this case
should now be pretty rare because normal stores have no
outputs, and normal loads only have address register
inputs, but these will be identical for any pair of loads
that we try to merge.

As well as fixing the unbounded register pressure increase
problem, moving loads up and stores down seems like it
should usually be a win for memory latency reasons.

Differential Revision: https://reviews.llvm.org/D119006

show more ...

AMDGPU: Stop reserving 36-bytes before kernel arguments for amdpal

This was inheriting the mesa behavior, and as far as I know nobody is
using opencl kernels with amdpal. The isMesaKernel check was

AMDGPU: Stop reserving 36-bytes before kernel arguments for amdpal

This was inheriting the mesa behavior, and as far as I know nobody is
using opencl kernels with amdpal. The isMesaKernel check was
irrelevant because this property needs to be held for all functions.

show more ...

AMDGPU: Enable fixed function ABI by default

Code using indirect calls is broken without this, and there isn't
really much value in supporting the old attempt to vary the argument
placement based on

AMDGPU: Enable fixed function ABI by default

Code using indirect calls is broken without this, and there isn't
really much value in supporting the old attempt to vary the argument
placement based on uses. This resulted in more argument shuffling code
anyway.

Also have the option stop implying all inputs need to be passed. This
will no rely on the amdgpu-no-* attributes to avoid passing
unnecessary values.

show more ...

[AMDGPU] Set most sched model resource's BufferSize to one

Using a BufferSize of one for memory ProcResources will result in better
ILP since it more accurately models the dependencies between memor

[AMDGPU] Set most sched model resource's BufferSize to one

Using a BufferSize of one for memory ProcResources will result in better
ILP since it more accurately models the dependencies between memory ops
and their consumers on an in-order processor. After this change, the
scheduler will treat the data edges from loads as blocking so that
stalls are guaranteed when waiting for data to be retreaved from memory.
Since we don't actually track waitcnt here, this should do a better job
at modeling their behavior.

Practically, this means that the scheduler will trigger the 'STALL'
heuristic more often.

This type of change needs to be evaluated experimentally. Preliminary
results are positive.

Fixes: SWDEV-282962

Reviewed By: rampitec

Differential Revision: https://reviews.llvm.org/D114777

show more ...

[AMDGPU] Switch PostRA sched to MachineSched

Use GCNHazardRecognizer in postra sched.
Updated tests for the new schedules.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D1095

[AMDGPU] Switch PostRA sched to MachineSched

Use GCNHazardRecognizer in postra sched.
Updated tests for the new schedules.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D109536

Change-Id: Ia86ba2ae168f12fb34b4d8efdab491f84d936cde

show more ...

AMDGPU: Invert ABI attribute handling

Previously we assumed all callable functions did not need any
implicitly passed inputs, and added attributes to functions to
indicate when they were necessary.

AMDGPU: Invert ABI attribute handling

Previously we assumed all callable functions did not need any
implicitly passed inputs, and added attributes to functions to
indicate when they were necessary. Requiring attributes for
correctness is pretty ugly, and it makes supporting indirect and
external calls more complicated.

This inverts the direction of the attributes, so an undecorated
function is assumed to need all implicit imputs. This enables
AMDGPUAttributor by default to mark when functions are proven to not
need a given input. This strips the equivalent functionality from the
legacy AMDGPUAnnotateKernelFeatures pass.

However, AMDGPUAnnotateKernelFeatures is not fully removed at this
point although it should be in the future. It is still necessary for
the two hacky amdgpu-calls and amdgpu-stack-objects attributes, which
would be better served by a trivial analysis on the IR during
selection. Additionally, AMDGPUAnnotateKernelFeatures still
redundantly handles the uniform-work-group-size attribute to be
removed in a future commit.

At this point when not using -amdgpu-fixed-function-abi, we are still
modifying the ABI based on these newly negated attributes. In the
future, this option will be removed and the locations for implicit
inputs will always be fixed. We will then use the new attributes to
avoid passing the values when unnecessary.

show more ...

[AMDGPU] Propagate LDS align into to instructions

Differential Revision: https://reviews.llvm.org/D104316

[AMDGPU] Handle constant LDS uses from different kernels

This allows to lower an LDS variable into a kernel structure
even if there is a constant expression used from different
kernels.

Differentia

[AMDGPU] Handle constant LDS uses from different kernels

This allows to lower an LDS variable into a kernel structure
even if there is a constant expression used from different
kernels.

Differential Revision: https://reviews.llvm.org/D103655

show more ...

[AMDGPU] Increase alignment of LDS globals if necessary before LDS lowering.

Before packing LDS globals into a sorted structure, make sure that
their alignment is properly updated based on their siz

[AMDGPU] Increase alignment of LDS globals if necessary before LDS lowering.

Before packing LDS globals into a sorted structure, make sure that
their alignment is properly updated based on their size. This will make
sure that the members of sorted structure are properly aligned, and
hence it will further reduce the probability of unaligned LDS access.

Reviewed By: rampitec

Differential Revision: https://reviews.llvm.org/D103261

show more ...

Revert "[AMDGPU] Increase alignment of LDS globals if necessary before LDS lowering."

This reverts commit d71ff907ef23eaef86ad66ba2d711e4986cd6cb2.

[AMDGPU] Increase alignment of LDS globals if necessary before LDS lowering.

Before packing LDS globals into a sorted structure, make sure that
their alignment is properly updated based on their siz

[AMDGPU] Increase alignment of LDS globals if necessary before LDS lowering.

Before packing LDS globals into a sorted structure, make sure that
their alignment is properly updated based on their size. This will make
sure that the members of sorted structure are properly aligned, and
hence it will further reduce the probability of unaligned LDS access.

Reviewed By: rampitec

Differential Revision: https://reviews.llvm.org/D103261

show more ...

[AMDGPU] Fix kernel LDS lowering for constants

There is a trivial but severe bug in the recent code collecting
LDS globals used by kernel. It aborts scan on the first constant
without scanning furth

[AMDGPU] Fix kernel LDS lowering for constants

There is a trivial but severe bug in the recent code collecting
LDS globals used by kernel. It aborts scan on the first constant
without scanning further uses. That leads to LDS overallocation
with multiple kernels in certain cases.

Differential Revision: https://reviews.llvm.org/D103190

show more ...

[AMDGPU] Lower kernel LDS into a sorted structure

Differential Revision: https://reviews.llvm.org/D102954

[AMDGPU] Only use ds_read/write_b128 for alignment >= 16

PS: Submitting on behalf of Jay.

Reviewed By: rampitec

Differential Revision: https://reviews.llvm.org/D100008

[AMDGPU] Update subtarget features for new target ID support

Support for XNACK and SRAMECC is not static on some GPUs. We must be able
to differentiate between different scenarios for these dynamic

[AMDGPU] Update subtarget features for new target ID support

Support for XNACK and SRAMECC is not static on some GPUs. We must be able
to differentiate between different scenarios for these dynamic subtarget
features.

The possible settings are:

- Unsupported: The GPU has no support for XNACK/SRAMECC.
- Any: Preference is unspecified. Use conservative settings that can run anywhere.
- Off: Request support for XNACK/SRAMECC Off
- On: Request support for XNACK/SRAMECC On

GCNSubtarget will track the four options based on the following criteria. If
the subtarget does not support XNACK/SRAMECC we say the setting is
"Unsupported". If no subtarget features for XNACK/SRAMECC are requested we
must support "Any" mode. If the subtarget features XNACK/SRAMECC exist in the
feature string when initializing the subtarget, the settings are "On/Off".

The defaults are updated to be conservatively correct, meaning if no setting
for XNACK or SRAMECC is explicitly requested, defaults will be used which
generate code that can be run anywhere. This corresponds to the "Any" setting.

Differential Revision: https://reviews.llvm.org/D85882

show more ...

[NFC] Removed unused prefixes in test/CodeGen/AMDGPU

More patches to follow.

Differential Revision: https://reviews.llvm.org/D94121

AMDGPU: Select global saddr mode from SGPR pointer

Use the 64-bit SGPR base with a 0 offset, since it's 1 fewer
instruction to materialize the 0 vs. the 64-bit copy.

[AMDGPU] Fix ds_read2/write2 with unaligned offsets

These instructions use a scaled offset. We were wrongly selecting them
even when the required offset was not a multiple of the scale factor.

Diff

[AMDGPU] Fix ds_read2/write2 with unaligned offsets

These instructions use a scaled offset. We were wrongly selecting them
even when the required offset was not a multiple of the scale factor.

Differential Revision: https://reviews.llvm.org/D90607

show more ...

[AMDGPU] Specify a triple to avoid codegen changes depending on host OS

Revert "Fix ds_read2/write2 unaligned offsets"

This reverts commit 2e7e898c8f0b38dc11fbce2553fc715067aaf42f.

It was committed by mistake.

Fix ds_read2/write2 unaligned offsets

[AMDGPU] Precommit ds_read2/write2 with unaligned offset tests. NFC.

[AMDGPU] Generate test checks. NFC.

[AMDGPU] Remove a comment. NFC.

This was obsoleted by f78687df9b7 which added gfx9 aligned/unaligned
tests.