[ScottTodd]

Motivation

We were setting:

CMAKE_C_COMPILER_LAUNCHER=sccache
CMAKE_CXX_COMPILER_LAUNCHER=sccache
# Linux-only
HIP_CLANG_LAUNCHER=sccache

We can now just set these options for both platforms:

CMAKE_C_COMPILER_LAUNCHER=sccache
CMAKE_CXX_COMPILER_LAUNCHER=sccache
CMAKE_HIP_COMPILER_LAUNCHER=sccache

This will improve build performance (especially on Windows) and allows us to remove layers of indirection in build_tools/setup_sccache_rocm.py.

See also:

• Progress on [Feature/RFC]: Allow caching of HIP compilations #9091
• Follow-up to fix(hip-tests): use ccache for hip-tests #8783
• Follow-up to fix(CI): Set ccache as HIP_COMPILER_LAUNCHER #8824
• This will improve time to signal for [CI] Build and test PyTorch Python packages as part of ci.yml #3291
• Related to docs(pytorch): document the sccache compiler cache #9560
• Docs: https://github.com/ROCm/TheRock/blob/main/docs/development/hipcc_migration.md

Technical Details

The remote cache server we use is still configured directly in workflow .yml files such as

TheRock/.github/workflows/multi_arch_build_portable_linux_pytorch_wheels.yml

Lines 253 to 265 in 4662763

	# TODO: Move the sccache bucket and IAM role mapping into a shared script.
	SCCACHE_BUCKET: >-
	${{
	inputs.release_type == 'dev-bkc' && 'therock-pytorch-sccache-dev'
	|| inputs.release_type == 'nightly-bkc' && 'therock-pytorch-sccache-nightly'
	|| format('therock-pytorch-sccache-{0}', inputs.release_type)
	}}
	SCCACHE_REGION: us-east-1
	SCCACHE_S3_KEY_PREFIX: "linux/multiarch/v1/"
	SCCACHE_S3_USE_SSL: "true"
	SCCACHE_S3_SERVER_SIDE_ENCRYPTION: "true"
	SCCACHE_IDLE_TIMEOUT: "0" # never idle-out; keeps stats accurate on long builds
	SCCACHE_LOG: warn

This PR deletes build_tools/setup_sccache_rocm.py as it reduced down to 3 lines of code, but we could add it back or merge with build_tools/github_actions/compute_pytorch_cache_type.py in the style of build_tools/setup_ccache.py - having the script write the configuration (server to use, other settings).

Test Plan

Local testing on Windows

Expand for repro commands

rustup update stable
cargo install sccache --locked
sccache --version
# sccache 0.19.0

cd external-builds\pytorch\
python -m venv .venv && .venv\Scripts\activate.bat
pip install --index-url https://nightly.repo.amd.com/rocm/whl-next/ rocm[libraries,devel,device-gfx1100]
pip install -r packaging

python pytorch_torch_repo.py checkout ^
    --gitrepo-origin https://github.com/ROCm/pytorch.git ^
    --repo-hashtag release/2.14 ^
    --checkout-dir D:/b/pytorch

# three times
#    1. cold cache
#    2. cache with CMAKE_HIP_COMPILER_LAUNCHER
#    3. cache without CMAKE_HIP_COMPILER_LAUNCHER
python build_prod_wheels.py build ^
    --pytorch-dir D:/b/pytorch ^
    --no-build-pytorch-audio --no-build-pytorch-vision ^
    --pytorch-rocm-arch=gfx1100 ^
    --output-dir %HOME%/.therock/pytorch ^
    --use-sccache

Cache status	Build time	C/C++ cache hit rate	HIP cache hit rate
Cold cache	24 minutes	0.00%	0.00%
Warm cache without CMAKE_HIP_COMPILER_LAUNCHER	11 minutes	72.30%	0.00%
Warm cache with CMAKE_HIP_COMPILER_LAUNCHER	6 minutes	72.30%	100.00%

CI testing on Linux and Windows

I re-ran CI jobs to check cache behavior:

• https://github.com/ROCm/TheRock/actions/runs/41889393295/attempts/1?pr=9744 cold cache.

  Platform	Build time	C/C++ cache hit rate	HIP cache hit rate
  Linux	36m 0s	99.10%	0.00%
  Windows	1h 9m 29s	99.34 %	0.00%

• https://github.com/ROCm/TheRock/actions/runs/41889393295/attempts/2?pr=9744 warm cache

  Platform	Build time	C/C++ cache hit rate	HIP cache hit rate
  Linux	7m 1s	99.80%	100.00%
  Windows	26m 47s	99.34 %	100.00%

Submission Checklist

• Look over the contributing guidelines at https://github.com/ROCm/TheRock/blob/main/CONTRIBUTING.md.

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