src: cpu: aarch64: injectors: eltwise_injector - improve gelu performance for block size 16

[nikhilfujitsu]

Description

Improvement: gelu performance for block size 16 in jit_uni_eltwise_injector
This commit improves the performance of gelu function jit_uni_eltwise_injector for block size 16:

Major Code changes:

• Added a new function gelu_erf_minimax_approx_compute_vector_fwd(const TRegS &vmm_src) for
computing gelu_erf for block size 16.
• Added new gelu_minimax constants and polynomial constants table.

Checklist

General

[✓] Do all unit and benchdnn tests (make test and make test_benchdnn_*) pass locally for each commit? Yes
Test output is same with and without this commit.
make test summary :

95% tests passed, 11 tests failed out of 200

Total Test time (real) = 3750.50 sec

The following tests FAILED:
55 - test_convolution_backward_data_f32 (Subprocess aborted)
123 - test_graph_c_api_compile_parametrized_usm_cpu (Failed)
153 - test_graph_unit_dnnl_conv_usm_cpu (Failed)
157 - test_graph_unit_dnnl_group_norm_usm_cpu (Failed)
159 - test_graph_unit_dnnl_large_partition_usm_cpu (Failed)
160 - test_graph_unit_dnnl_layer_norm_usm_cpu (Failed)
161 - test_graph_unit_dnnl_matmul_usm_cpu (Failed)
162 - test_graph_unit_dnnl_mqa_decomp_usm_cpu (Failed)
163 - test_graph_unit_dnnl_pool_usm_cpu (Failed)
168 - test_graph_unit_dnnl_sdp_decomp_usm_cpu (Failed)
169 - test_graph_unit_dnnl_softmax_usm_cpu (Failed)
Errors while running CTest
Output from these tests are in: /home/nikhil/oneDNN/build/Testing/Temporary/LastTest.log
Use "--rerun-failed --output-on-failure" to re-run the failed cases verbosely.
[✓] Have you formatted the code using clang-format? Yes

[abhijain1204fujitsu]

@vpirogov , @jondea , Kindly support to review the PR

[jondea]

Do you have any specific benchdnn calls which will exercise this path?

[jondea]

Also, I'm not seeing the same failures on this patch (or before) as you. E.g., out of the CI failures, I can only see test_benchdnn_modeC_graph_ci_cpu. Would you be able to investigate this please?

Also, do you have any measurements of the speedup of this optimization?

[nikhilfujitsu]

Do you have any specific benchdnn calls which will exercise this path?

Hi, please checkout these log, the machine is A64FX and uses jit_sve_512.

I have used:

./benchdnn --eltwise --batch=inputs/eltwise/test_eltwise_all | grep eltwise_gelu_erf

to extract these logs.

A64_FX_benchdnn_eltwise_gelu.log

Here export ONEDNN_VERBOSE=1 is used before running the command.
A64_FX_benchdnn_VERBOSE_eltwise_gelu.log

[nikhilfujitsu]

Also, I'm not seeing the same failures on this patch (or before) as you. E.g., out of the CI failures, I can only see test_benchdnn_modeC_graph_ci_cpu. Would you be able to investigate this please?

Also, do you have any measurements of the speedup of this optimization?
Eltwise_results.xlxs.pdf

[jondea]

Thanks for the logs and numbers, they are really useful. I ran this on a Graviton 3, and there was no effect on performance. Just to check: this is what you expected? I'm guessing this because the bulk of the added code is guarded by SVE length == 512.

But, given that you got a ~5x speedup, I was curious if this optimization could be applied to the Graviton 3, so I removed the check and measured the performance. Surprisingly, I got ~1.5x slowdown on Graviton 3. I don't think this should block this PR because you have added the guard, but it is surprising. Could it be that exp_compute_vector_fwd is slower than it could be for some reason for SVE 512?

Anyways, in summary, I'm happy to approve once you've investigated the extra unit test failures.

[jondea]

Sorry, accidentally approved

[nikhilfujitsu]

Thanks for the logs and numbers, they are really useful. I ran this on a Graviton 3, and there was no effect on performance. Just to check: this is what you expected? I'm guessing this because the bulk of the added code is guarded by SVE length == 512.

But, given that you got a ~5x speedup, I was curious if this optimization could be applied to the Graviton 3, so I removed the check and measured the performance. Surprisingly, I got ~1.5x slowdown on Graviton 3. I don't think this should block this PR because you have added the guard, but it is surprising. Could it be that exp_compute_vector_fwd is slower than it could be for some reason for SVE 512?

Anyways, in summary, I'm happy to approve once you've investigated the extra unit test failures.

It is true that we get 1.5x slowdown on G3 machines( SVE_256). That's why it is limited to SVE_512.

Extra unit cases are failing on SVE_512 machines already in the main branch.
By adding my changes no effect is there on failed test cases. The failed test cases are for SVE_512 machine not for Graviton or SVE_256 machine. If this helps.

[nikhilfujitsu]

Thanks for the logs and numbers, they are really useful. I ran this on a Graviton 3, and there was no effect on performance. Just to check: this is what you expected? I'm guessing this because the bulk of the added code is guarded by SVE length == 512.
But, given that you got a ~5x speedup, I was curious if this optimization could be applied to the Graviton 3, so I removed the check and measured the performance. Surprisingly, I got ~1.5x slowdown on Graviton 3. I don't think this should block this PR because you have added the guard, but it is surprising. Could it be that exp_compute_vector_fwd is slower than it could be for some reason for SVE 512?
Anyways, in summary, I'm happy to approve once you've investigated the extra unit test failures.

It is true that we get 1.5x slowdown on G3 machines( SVE_256). That's why it is limited to SVE_512.

Extra unit cases are failing on SVE_512 machines already in the main branch. By adding my changes no effect is there on failed test cases. The failed test cases are for SVE_512 machine not for Graviton or SVE_256 machine. If this helps.

I am also checking with latest changes in main. Will update you soon.

[nikhilfujitsu]

Thanks for the logs and numbers, they are really useful. I ran this on a Graviton 3, and there was no effect on performance. Just to check: this is what you expected? I'm guessing this because the bulk of the added code is guarded by SVE length == 512.
But, given that you got a ~5x speedup, I was curious if this optimization could be applied to the Graviton 3, so I removed the check and measured the performance. Surprisingly, I got ~1.5x slowdown on Graviton 3. I don't think this should block this PR because you have added the guard, but it is surprising. Could it be that exp_compute_vector_fwd is slower than it could be for some reason for SVE 512?
Anyways, in summary, I'm happy to approve once you've investigated the extra unit test failures.

It is true that we get 1.5x slowdown on G3 machines( SVE_256). That's why it is limited to SVE_512.
Extra unit cases are failing on SVE_512 machines already in the main branch. By adding my changes no effect is there on failed test cases. The failed test cases are for SVE_512 machine not for Graviton or SVE_256 machine. If this helps.

I am also checking with latest changes in main. Will update you soon.

@jondea After merging latest changes from main, errors are resolved. So I have updated the description also. Please consider approval. Thanks.

[vpirogov]

@nikhilfujitsu, merge commits are not allowed in production branches. Please rebase your changes.

[nikhilfujitsu]

@nikhilfujitsu, merge commits are not allowed in production branches. Please rebase your changes.

Hi I am struggling to get this rebased again could you please help me here.
What I did is.
I pressed the sync fork button which merged the main branch changes with my branch.
Now how can I rebase it and push it back here.
Should I revert my merge first then rebase it?

[vpirogov]

Hi I am struggling to get this rebased again could you please help me here.

This operation can be done from console:

git checkout gelu_erf
git rebase main
git push --force

[nikhilfujitsu]

Hi I am struggling to get this rebased again could you please help me here.

This operation can be done from console:

git checkout gelu_erf
git rebase main
git push --force

Thank you. Means a lot to me.

[nikhilfujitsu]

Hi I am struggling to get this rebased again could you please help me here.

This operation can be done from console:

git checkout gelu_erf
git rebase main
git push --force

Thank you. Means a lot to me.

@jondea @vpirogov Please approve the changes. ThankYou.

[nikhilfujitsu]

Changes Reviewed. And description changed accordingly.

[abhijain1204fujitsu]

@jondea @vpirogov could you please support to check the changes as per feedback received.

[abhijain1204fujitsu]

@vpirogov Kindly let us know if any other change is required
Kindly support for merger.