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Add generate_identity_sequences helper and replace lambdas with named functors#4828

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users/tenpercent/ck/reduce-template-instantiations
Feb 28, 2026
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Add generate_identity_sequences helper and replace lambdas with named functors#4828
shumway merged 2 commits intodevelopfrom
users/tenpercent/ck/reduce-template-instantiations

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@tenpercent tenpercent commented Feb 23, 2026

Summary

  • Add generate_identity_sequences<N>() helper that returns Tuple<Sequence<0>, Sequence<1>, ..., Sequence<N-1>>
  • Replace lambdas with named functors in transform_tensor_descriptor
  • Add unpack_and_merge_sequences helper functor
  • Reduces transform_tensor_descriptor instantiations from 388 to 32 (92% reduction)

Motivation

Multiple call sites use generate_tuple([](auto i) { return Sequence<i>{}; }, Number<N>{}) pattern. A named helper reduces lambda instantiations.

Additionally, each lambda in transform_tensor_descriptor creates a unique closure type, causing the function to be instantiated separately for every call site. Named functors share a single type, so the compiler reuses the same instantiation.

Changes

Part 1: generate_identity_sequences helper

  • Replaces common lambda pattern for generating identity sequences
  • Each lambda expression creates a unique closure type, causing separate template instantiations at every call site
  • Named helper shares a single type across all uses

Part 2: Named functors in transform_tensor_descriptor

  • Add unpack_and_merge_sequences helper to replace lambda in GetNumOfHiddenDimension
  • Use generate_identity_sequences in matrix_padder.hpp

Test Plan

  • Added 7 unit tests:
    • 4 tests for generate_identity_sequences
    • 3 tests for unpack_and_merge_sequences
  • Waiting for full CI

Related PRs

This PR merges the functionality from:

Part of PR stack for issue #4229 (Reduce CK/CKTile Build Times)

Note: This PR supersedes #4283, ROCm/composable_kernel#3588 and ROCm/composable_kernel#3589, which can be closed once this is merged.

🔁 Imported from ROCm/composable_kernel#3628
🧑‍💻 Originally authored by @tenpercent

@tenpercent tenpercent requested a review from a team as a code owner February 23, 2026 23:26
@tenpercent tenpercent requested review from a team as code owners February 23, 2026 23:38
@github-actions github-actions bot added External CI github actions project: none Does not target any component labels Feb 23, 2026
@tenpercent tenpercent force-pushed the users/tenpercent/ck/reduce-template-instantiations branch from a058c59 to 11d1d3b Compare February 23, 2026 23:42
@tenpercent @claude
Add generate_identity_sequences helper and replace lambdas with named…
776da28 
… functors

## Summary

- Add `generate_identity_sequences<N>()` helper that returns `Tuple<Sequence<0>, Sequence<1>, ..., Sequence<N-1>>`
- Replace lambdas with named functors in `transform_tensor_descriptor`
- Add `unpack_and_merge_sequences` helper functor
- Reduces `transform_tensor_descriptor` instantiations from 388 to 32 (92% reduction)

## Motivation

Multiple call sites use `generate_tuple([](auto i) { return Sequence<i>{}; }, Number<N>{})` pattern. A named helper reduces lambda instantiations.

Additionally, each lambda in `transform_tensor_descriptor` creates a unique closure type, causing the function to be instantiated separately for every call site. Named functors share a single type, so the compiler reuses the same instantiation.

## Changes

### Part 1: generate_identity_sequences helper
- Replaces common lambda pattern for generating identity sequences
- Each lambda expression creates a unique closure type, causing separate template instantiations at every call site
- Named helper shares a single type across all uses

### Part 2: Named functors in transform_tensor_descriptor
- Add `unpack_and_merge_sequences` helper to replace lambda in `GetNumOfHiddenDimension`
- Use `generate_identity_sequences` in `matrix_padder.hpp`

## Test Plan

- Added 7 unit tests:
  - 4 tests for `generate_identity_sequences` in unit_sequence_helper.cpp
  - 3 tests for `unpack_and_merge_sequences` in unit_tensor_descriptor_functors.cpp
- Added unit_ford test from develop to test/util/CMakeLists.txt

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
@tenpercent tenpercent force-pushed the users/tenpercent/ck/reduce-template-instantiations branch from 11d1d3b to 776da28 Compare February 23, 2026 23:44
@tenpercent tenpercent removed request for a team February 23, 2026 23:47
@tenpercent tenpercent removed the request for review from a team February 23, 2026 23:47
@tenpercent tenpercent mentioned this pull request Feb 23, 2026
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cgmillette
cgmillette approved these changes Feb 26, 2026
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LGTM

@shumway shumway merged commit 7de19bb into develop Feb 28, 2026
32 checks passed
@shumway shumway deleted the users/tenpercent/ck/reduce-template-instantiations branch February 28, 2026 20:10
assistant-librarian bot pushed a commit to ROCm/composable_kernel that referenced this pull request Feb 28, 2026
@tenpercent @assistant-librarian
[rocm-libraries] ROCm/rocm-libraries#4828 (commit 7de19bb)
1dd4711 
Add generate_identity_sequences helper and replace lambdas
 with named functors (#4828)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

## Summary

- Add `generate_identity_sequences<N>()` helper that returns
`Tuple<Sequence<0>, Sequence<1>, ..., Sequence<N-1>>`
- Replace lambdas with named functors in `transform_tensor_descriptor`
- Add `unpack_and_merge_sequences` helper functor
- Reduces `transform_tensor_descriptor` instantiations from 388 to 32
(92% reduction)

## Motivation

Multiple call sites use `generate_tuple([](auto i) { return
Sequence<i>{}; }, Number<N>{})` pattern. A named helper reduces lambda
instantiations.

Additionally, each lambda in `transform_tensor_descriptor` creates a
unique closure type, causing the function to be instantiated separately
for every call site. Named functors share a single type, so the compiler
reuses the same instantiation.

## Changes

### Part 1: generate_identity_sequences helper
- Replaces common lambda pattern for generating identity sequences
- Each lambda expression creates a unique closure type, causing separate
template instantiations at every call site
- Named helper shares a single type across all uses

### Part 2: Named functors in transform_tensor_descriptor
- Add `unpack_and_merge_sequences` helper to replace lambda in
`GetNumOfHiddenDimension`
- Use `generate_identity_sequences` in `matrix_padder.hpp`

## Test Plan

- [x] Added 7 unit tests:
  - 4 tests for `generate_identity_sequences`
  - 3 tests for `unpack_and_merge_sequences`
- [ ] Waiting for full CI

## Related PRs

This PR merges the functionality from:
- #3588 (generate_identity_sequences helper)
- #3589 (Named functors in
transform_tensor_descriptor)

Part of PR stack for issue #4229 (Reduce CK/CKTile Build Times)

**Note:** This PR supersedes #4283, #3588 and
#3589, which can be closed once this is merged.
cgmillette added a commit that referenced this pull request Mar 2, 2026
@cgmillette @claude
Merge branch 'develop' into ck/cmillett/optimize_threadwise_slice_tra…
37d67b6 
…nsfer

Resolve conflicts in 7 threadwise transfer headers by keeping our
refactored versions (code was extracted into the shared util helper).
Propagate generate_identity_sequences optimization from develop (#4828)
into threadwise_tensor_slice_transfer_util.hpp.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
kokolchin pushed a commit to kokolchin/rocm-libraries that referenced this pull request Mar 4, 2026
@tenpercent @claude @kokolchin
Add generate_identity_sequences helper and replace lambdas with named…
f818d6c 
… functors (ROCm#4828)

## Summary

- Add `generate_identity_sequences<N>()` helper that returns
`Tuple<Sequence<0>, Sequence<1>, ..., Sequence<N-1>>`
- Replace lambdas with named functors in `transform_tensor_descriptor`
- Add `unpack_and_merge_sequences` helper functor
- Reduces `transform_tensor_descriptor` instantiations from 388 to 32
(92% reduction)

## Motivation

Multiple call sites use `generate_tuple([](auto i) { return
Sequence<i>{}; }, Number<N>{})` pattern. A named helper reduces lambda
instantiations.

Additionally, each lambda in `transform_tensor_descriptor` creates a
unique closure type, causing the function to be instantiated separately
for every call site. Named functors share a single type, so the compiler
reuses the same instantiation.

## Changes

### Part 1: generate_identity_sequences helper
- Replaces common lambda pattern for generating identity sequences
- Each lambda expression creates a unique closure type, causing separate
template instantiations at every call site
- Named helper shares a single type across all uses

### Part 2: Named functors in transform_tensor_descriptor
- Add `unpack_and_merge_sequences` helper to replace lambda in
`GetNumOfHiddenDimension`
- Use `generate_identity_sequences` in `matrix_padder.hpp`

## Test Plan

- [x] Added 7 unit tests:
  - 4 tests for `generate_identity_sequences`
  - 3 tests for `unpack_and_merge_sequences`
- [ ] Waiting for full CI

## Related PRs

This PR merges the functionality from:
- ROCm/composable_kernel#3588 (generate_identity_sequences helper)
- ROCm/composable_kernel#3589 (Named functors in
transform_tensor_descriptor)

Part of PR stack for issue ROCm#4229 (Reduce CK/CKTile Build Times)

**Note:** This PR supersedes ROCm#4283, ROCm/composable_kernel#3588 and
ROCm/composable_kernel#3589, which can be closed once this is merged.

---
🔁 Imported from
[ROCm/composable_kernel#3628](ROCm/composable_kernel#3628)
🧑‍💻 Originally authored by @tenpercent

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
NaveenElumalaiAMD pushed a commit that referenced this pull request Mar 6, 2026
@tenpercent @claude
Add generate_identity_sequences helper and replace lambdas with named…
183cbd5 
… functors (#4828)

## Summary

- Add `generate_identity_sequences<N>()` helper that returns
`Tuple<Sequence<0>, Sequence<1>, ..., Sequence<N-1>>`
- Replace lambdas with named functors in `transform_tensor_descriptor`
- Add `unpack_and_merge_sequences` helper functor
- Reduces `transform_tensor_descriptor` instantiations from 388 to 32
(92% reduction)

## Motivation

Multiple call sites use `generate_tuple([](auto i) { return
Sequence<i>{}; }, Number<N>{})` pattern. A named helper reduces lambda
instantiations.

Additionally, each lambda in `transform_tensor_descriptor` creates a
unique closure type, causing the function to be instantiated separately
for every call site. Named functors share a single type, so the compiler
reuses the same instantiation.

## Changes

### Part 1: generate_identity_sequences helper
- Replaces common lambda pattern for generating identity sequences
- Each lambda expression creates a unique closure type, causing separate
template instantiations at every call site
- Named helper shares a single type across all uses

### Part 2: Named functors in transform_tensor_descriptor
- Add `unpack_and_merge_sequences` helper to replace lambda in
`GetNumOfHiddenDimension`
- Use `generate_identity_sequences` in `matrix_padder.hpp`

## Test Plan

- [x] Added 7 unit tests:
  - 4 tests for `generate_identity_sequences`
  - 3 tests for `unpack_and_merge_sequences`
- [ ] Waiting for full CI

## Related PRs

This PR merges the functionality from:
- ROCm/composable_kernel#3588 (generate_identity_sequences helper)
- ROCm/composable_kernel#3589 (Named functors in
transform_tensor_descriptor)

Part of PR stack for issue #4229 (Reduce CK/CKTile Build Times)

**Note:** This PR supersedes #4283, ROCm/composable_kernel#3588 and
ROCm/composable_kernel#3589, which can be closed once this is merged.

---
🔁 Imported from
[ROCm/composable_kernel#3628](ROCm/composable_kernel#3628)
🧑‍💻 Originally authored by @tenpercent

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
jovanau pushed a commit to jovanau/rocm-libraries that referenced this pull request Mar 19, 2026
@tenpercent @claude @jovanau
Add generate_identity_sequences helper and replace lambdas with named…
e183717 
… functors (ROCm#4828)

## Summary

- Add `generate_identity_sequences<N>()` helper that returns
`Tuple<Sequence<0>, Sequence<1>, ..., Sequence<N-1>>`
- Replace lambdas with named functors in `transform_tensor_descriptor`
- Add `unpack_and_merge_sequences` helper functor
- Reduces `transform_tensor_descriptor` instantiations from 388 to 32
(92% reduction)

## Motivation

Multiple call sites use `generate_tuple([](auto i) { return
Sequence<i>{}; }, Number<N>{})` pattern. A named helper reduces lambda
instantiations.

Additionally, each lambda in `transform_tensor_descriptor` creates a
unique closure type, causing the function to be instantiated separately
for every call site. Named functors share a single type, so the compiler
reuses the same instantiation.

## Changes

### Part 1: generate_identity_sequences helper
- Replaces common lambda pattern for generating identity sequences
- Each lambda expression creates a unique closure type, causing separate
template instantiations at every call site
- Named helper shares a single type across all uses

### Part 2: Named functors in transform_tensor_descriptor
- Add `unpack_and_merge_sequences` helper to replace lambda in
`GetNumOfHiddenDimension`
- Use `generate_identity_sequences` in `matrix_padder.hpp`

## Test Plan

- [x] Added 7 unit tests:
  - 4 tests for `generate_identity_sequences`
  - 3 tests for `unpack_and_merge_sequences`
- [ ] Waiting for full CI

## Related PRs

This PR merges the functionality from:
- ROCm/composable_kernel#3588 (generate_identity_sequences helper)
- ROCm/composable_kernel#3589 (Named functors in
transform_tensor_descriptor)

Part of PR stack for issue ROCm#4229 (Reduce CK/CKTile Build Times)

**Note:** This PR supersedes ROCm#4283, ROCm/composable_kernel#3588 and
ROCm/composable_kernel#3589, which can be closed once this is merged.

---
🔁 Imported from
[ROCm/composable_kernel#3628](ROCm/composable_kernel#3628)
🧑‍💻 Originally authored by @tenpercent

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
johannes-graner pushed a commit that referenced this pull request Mar 20, 2026
@tenpercent @claude @johannes-graner
Add generate_identity_sequences helper and replace lambdas with named…
cbf6d95 
… functors (#4828)

## Summary

- Add `generate_identity_sequences<N>()` helper that returns
`Tuple<Sequence<0>, Sequence<1>, ..., Sequence<N-1>>`
- Replace lambdas with named functors in `transform_tensor_descriptor`
- Add `unpack_and_merge_sequences` helper functor
- Reduces `transform_tensor_descriptor` instantiations from 388 to 32
(92% reduction)

## Motivation

Multiple call sites use `generate_tuple([](auto i) { return
Sequence<i>{}; }, Number<N>{})` pattern. A named helper reduces lambda
instantiations.

Additionally, each lambda in `transform_tensor_descriptor` creates a
unique closure type, causing the function to be instantiated separately
for every call site. Named functors share a single type, so the compiler
reuses the same instantiation.

## Changes

### Part 1: generate_identity_sequences helper
- Replaces common lambda pattern for generating identity sequences
- Each lambda expression creates a unique closure type, causing separate
template instantiations at every call site
- Named helper shares a single type across all uses

### Part 2: Named functors in transform_tensor_descriptor
- Add `unpack_and_merge_sequences` helper to replace lambda in
`GetNumOfHiddenDimension`
- Use `generate_identity_sequences` in `matrix_padder.hpp`

## Test Plan

- [x] Added 7 unit tests:
  - 4 tests for `generate_identity_sequences`
  - 3 tests for `unpack_and_merge_sequences`
- [ ] Waiting for full CI

## Related PRs

This PR merges the functionality from:
- ROCm/composable_kernel#3588 (generate_identity_sequences helper)
- ROCm/composable_kernel#3589 (Named functors in
transform_tensor_descriptor)

Part of PR stack for issue #4229 (Reduce CK/CKTile Build Times)

**Note:** This PR supersedes #4283, ROCm/composable_kernel#3588 and
ROCm/composable_kernel#3589, which can be closed once this is merged.

---
🔁 Imported from
[ROCm/composable_kernel#3628](ROCm/composable_kernel#3628)
🧑‍💻 Originally authored by @tenpercent

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
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