[SYCL][NewOffloadModel] Support -fno-sycl-rdc at compile step (-c) by srividya-sundaram · Pull Request #22833 · intel/llvm

srividya-sundaram · 2026-07-30T21:44:15Z

Summary

Adds -fno-sycl-rdc -c support in the new offload model, matching old model ergonomics. Previously -fno-sycl-rdc was only meaningful at link time in the new model.

Each TU's device code is finalized at compile time via a per-TU clang-linker-wrapper --sycl-device-link --no-sycl-rdc invocation, producing a self-contained device image embedded into the host object via a new -fsycl-include-target-binary CC1 option.

Depends on #22832.

Key changes

clang/include/clang/Options/Options.td: New -fsycl-include-target-binary CC1 option (analog of -fcuda-include-gpubinary)
clang/include/clang/Basic/CodeGenOptions.h: New SYCLTargetBinaryFileName field to marshal the option
clang/lib/Driver/Driver.cpp: Insert per-TU LinkerWrapperJobAction in BuildOffloadingActions when -fno-sycl-rdc -c is used
clang/lib/Driver/ToolChains/Clang.cpp: Route finalized image to -fsycl-include-target-binary instead of -fembed-offload-object; use isDeviceOffloading(OFK_SYCL) to correctly scope --sycl-device-link to per-TU invocations only
clang/lib/CodeGen/CodeGenModule.cpp: Read finalized image and call wrapSYCLBinaries to embed and register at compile time
sycl/doc/design/OffloadDesign.md: Updated to reflect compile-step support is now implemented
sycl/test-e2e/AOT/early_aot.cpp: Updated comment to reflect both compile and link steps are supported
clang/test/Driver/sycl-no-rdc-compile-step.cpp: New driver test verifying per-TU pipeline shape, RDC regression, and link-step regression
clang/test/Driver/sycl-no-rdc-new-driver.cpp: Updated pipeline shape for 2-TU case; removed stale CHK-COMPILE-STEP-ERROR test

Implements compile-step support tracked in CMPLRLLVM-51875.

Test plan

clang/test/Driver/sycl-no-rdc-compile-step.cpp — per-TU pipeline shape, RDC regression, link-step regression
clang/test/Driver/sycl-no-rdc-new-driver.cpp — updated pipeline shape for 2-TU case

🤖 Generated with Claude Code

…floadModel.

Fix --no-offload-old-driver typo to --no-offload-new-driver in the old offload model usage example. Add a note that compile-step support for -fno-sycl-rdc (matching the old model's -c usage pattern) will be implemented in a follow-up patch via clang-linker-wrapper --sycl-device-link --no-sycl-rdc per translation unit.

Adds support for specifying -fno-sycl-rdc at the compile step in the new offload model, matching the old offload model's usage pattern. Previously, -fno-sycl-rdc was only meaningful at the link step in the new model. Design (mirrors CUDA/HIP -fno-gpu-rdc per-TU finalize model): - BuildOffloadingActions: when -fno-sycl-rdc is passed at compile time, insert a per-TU LinkerWrapperJobAction (OffloadPackager + clang-linker-wrapper --sycl-device-link --no-sycl-rdc) to finalize the TU's device code immediately, producing a self-contained device image. - Clang::ConstructJob: route the finalized image to the new -fsycl-include-target-binary CC1 option instead of -fembed-offload-object, so the host CodeGen embeds and registers the image at compile time rather than deferring it to link time. - CodeGenModule::Release: when -fsycl-include-target-binary is set on the host cc1, read the device image file and call wrapSYCLBinaries to embed the binary and emit __sycl_register_lib/__sycl_unregister_lib ctors into the host module. The final clang-linker-wrapper invocation then finds no SYCL device input and performs a plain host link. - Downstream uses clang-linker-wrapper --sycl-device-link instead of the upstream's clang-sycl-linker, as all Intel SYCL pipeline logic resides in clang-linker-wrapper. New files/options: - -fsycl-include-target-binary <file>: new CC1 option (analog of -fcuda-include-gpubinary) marshalled into CodeGenOpts.SYCLTargetBinaryFileName - clang/test/Driver/sycl-no-rdc-compile-step.cpp: driver tests verifying per-TU pipeline shape, RDC default regression, and link-step regression. Implements compile-step support tracked in CMPLRLLVM-51875. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Copilot

Pull request overview

Adds compile-step (-c) support for -fno-sycl-rdc in the new SYCL offload model by finalizing each TU’s device image during compilation (via a per-TU clang-linker-wrapper --sycl-device-link --no-sycl-rdc) and embedding/registering the finalized image into the host object using a new cc1 option.

Changes:

Teach the driver to insert a per-TU LinkerWrapperJobAction for SYCL NoRDC compilation and route its output to the host compile.
Introduce -fsycl-include-target-binary and plumb it through driver → CodeGen to embed/register the finalized SYCL image at compile time.
Add/update driver + e2e tests and update design documentation around NoRDC usage patterns.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
sycl/test-e2e/AOT/early_aot.cpp	Adjust RUN lines for old/new model flag placement; adds explanatory note.
sycl/doc/design/OffloadDesign.md	Document NoRDC behavior and usage scenarios for old/new offload models.
sycl/doc/design/NonRelocatableDeviceCode.md	Clarify document scope (old offload model NoRDC design).
clang/test/Driver/sycl-no-rdc-new-driver.cpp	New driver test for `-fno-sycl-rdc` propagation and pipeline shape.
clang/test/Driver/sycl-no-rdc-compile-step.cpp	New driver test covering compile-step NoRDC finalization + cc1 plumbing.
clang/lib/Driver/ToolChains/Clang.cpp	Pass finalized SYCL image to host cc1; propagate NoRDC to linker wrapper and add per-TU device-link mode logic.
clang/lib/Driver/Driver.cpp	Insert per-TU linker-wrapper finalizer action for SYCL NoRDC during compilation.
clang/lib/CodeGen/CodeGenModule.cpp	Read finalized SYCL image and call `wrapSYCLBinaries` to embed/register at compile time.
clang/include/clang/Options/Options.td	Add new `-fsycl-include-target-binary` option (marshalled to CodeGenOpts).
clang/include/clang/Basic/CodeGenOptions.h	Add `SYCLTargetBinaryFileName` storage for the new cc1 option.

Copilot

Pull request overview

Copilot reviewed 10 out of 10 changed files in this pull request and generated no new comments.

srividya-sundaram · 2026-07-31T17:54:54Z

SYCL Pre commit failure is unrelated to the changes in this PR.

srividya-sundaram · 2026-07-31T18:59:01Z

Please note that this PR is a follow-up to #22832 and currently includes its changes as a base. Once #22832 lands, this branch will be rebased on top of it so the diff only shows the compile-step additions.

sarnex · 2026-07-31T18:12:40Z

  HelpText<"Incorporate CUDA device-side binary into host object file.">,
  MarshallingInfoString<CodeGenOpts<"CudaGpuBinaryFileName">>;
+def fsycl_include_target_binary : Separate<["-"], "fsycl-include-target-binary">,
+  HelpText<"Incorporate SYCL device-side binary into host object file.">,


kind of a nit but i since the device binary will contain information on the offloading model and triple used (as it should be inside the OffloadBinary wrapper), i don't see any need for per-offload-model options, but since CUDA already did it, i guess we only can address this feedback when we implement an equivalent version of this change upstream, where we can unify them

i guess we only can address this feedback when we implement an equivalent version of this change upstream, where we can unify them

Agree.

This option was introduced based on the SYCL no-RDC design doc from @YuriPlyakhin : https://github.com/YuriPlyakhin/llvm-project/blob/6553d362c5e84114a30eff3a79cad70432fff3ef/sycl-no-rdc-plan.md#3-per-tu-device-finalize--host-compile-inclusion-cudahip-mirror

We can unify with the CUDA/HIP option when implementing the equivalent upstream change.

Would it perhaps make sense to name the new option -foffload-include-binary or similar in anticipation of future unification?

sarnex · 2026-07-31T18:24:10Z

    CmdArgs.push_back(CudaDeviceInput->getFilename());
  } else if (!HostOffloadingInputs.empty()) {
    if ((IsCuda || IsHIP) && !IsRDCMode) {
+      // CUDA/HIP no-RDC: device image finalized per-TU, embed at compile time.


since HIP already goes through this path, can we reuse the same -fcuda-include-gpubinary option so instead we could just change the if to if((IsCuda || isHIP || isSYCL) && !IsRDCMode)? this is kind of related to my comment before about the option

@maksimsab

…Offload Model (#22832) ## Summary This patch adds `-fno-sycl-rdc` support to the new SYCL offload model in the Clang driver. It is based on the work by @maksimsab in #21973, with review fixes applied. ### What this patch does By default (`-fsycl-rdc`), all device code across translation units is linked together into one module at link time before post-link processing. With `-fno-sycl-rdc`, each object file's device code is processed independently — skipping the `llvm-link` step — which can significantly reduce peak memory and compile time. **Changes:** - `clang/lib/Driver/ToolChains/Clang.cpp`: In `LinkerWrapper::ConstructJob`, propagate `--no-sycl-rdc` to `clang-linker-wrapper` when `-fno-sycl-rdc` is passed at link time. - `sycl/doc/design/OffloadDesign.md`: Document NoRDC mode for the new offload model. - `sycl/doc/design/NonRelocatableDeviceCode.md`: Add a note clarifying that document covers the old offload model only. - `sycl/test-e2e/AOT/early_aot.cpp`: Un-XFAIL the test for the new offload model; adjust RUN lines to pass `-fno-sycl-rdc` at the correct step per model. - `clang/test/Driver/sycl-no-rdc-new-driver.cpp`: New driver test verifying `--no-sycl-rdc` is propagated to `clang-linker-wrapper` correctly. ### Key behavioral difference from the old offload model | Model | Where to pass `-fno-sycl-rdc` | |---|---| | Old (`--no-offload-new-driver`) | At each **compile** step (`-c`) | | New (`--offload-new-driver`) | At the **link** step | This inversion exists because in the new model all SYCL offload processing (post-link, AOT, wrapping) lives in `clang-linker-wrapper` at link time. ### Follow-up work Supporting `-fno-sycl-rdc -c` in the new model (matching the old model's compile-step ergonomics) will be addressed in a follow-up patch. The plan is to invoke `clang-linker-wrapper --sycl-device-link --no-sycl-rdc` per translation unit at compile time, embedding the finalized device image directly into the host object. Supporting -fno-sycl-rdc -c in the new model (matching old model compile-step ergonomics) is addressed in #22833. Fixes: CMPLRLLVM-51875 🤖 Generated with [Claude Code](https://claude.com/claude-code) --------- Co-authored-by: Sabianin, Maksim <maksim.sabianin@intel.com> Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

mdtoguchi · 2026-07-31T23:29:27Z

+/// action and routes the result to -fsycl-include-target-binary on the host
+/// cc1, instead of deferring device processing to link time.
+
+// RUN: touch %t.cpp


I didn't catch this in the first RDC PR, but why do we need to do this? We should be able just to use %s in the tests.

Move embedSYCLNoRDCBinary out of CodeGenModule::Release() into a free function in CGSYCLRuntime.cpp to keep SYCL-specific logic out of common code. CodeGenModule::Release() retains a single call site. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

…r wrapper

…p test

…ompile-step test

…line

maksimsab and others added 6 commits July 30, 2026 13:44

[SYCL][NewOffloadModel] Enable -no-sycl-rdc in Clang Driver for NewOf…

90fe7b6

…floadModel.

fix test for cross-platform execution

998d20f

[SYCL][Driver] Fix tests for -fno-sycl-rdc compile-step support

07a16e7

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

[SYCL] Fix clang-format issues

2a41c6f

srividya-sundaram requested a review from Copilot July 30, 2026 22:34

Copilot started reviewing on behalf of srividya-sundaram July 30, 2026 22:35 View session

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Comment thread clang/lib/CodeGen/CodeGenModule.cpp Outdated

Comment thread clang/lib/Driver/ToolChains/Clang.cpp Outdated

Comment thread clang/lib/CodeGen/CodeGenModule.cpp Outdated

Comment thread sycl/doc/design/OffloadDesign.md Outdated

Comment thread sycl/test-e2e/AOT/early_aot.cpp Outdated

[SYCL] Address Copilot review comments on PR intel#22833

d8ece47

srividya-sundaram requested a review from Copilot July 31, 2026 01:46

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srividya-sundaram mentioned this pull request Jul 31, 2026

[SYCL][NewOffloadModel] Enable -fno-sycl-rdc in Clang Driver for New Offload Model #22832

Merged

srividya-sundaram marked this pull request as ready for review July 31, 2026 18:59

srividya-sundaram requested review from a team as code owners July 31, 2026 18:59

srividya-sundaram requested a review from KseniyaTikhomirova July 31, 2026 18:59

sarnex reviewed Jul 31, 2026

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mdtoguchi reviewed Jul 31, 2026

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srividya-sundaram and others added 5 commits July 31, 2026 16:36

[SYCL][Driver] Use getFinalPhase to guard --sycl-device-link in linke…

7a9c782

…r wrapper

[SYCL][Driver] Trim verbose comment in SYCL no-RDC host offload block

a45367c

[SYCL][Driver] Add -fno-sycl-rdc -flto tests to sycl-no-rdc-new-driver

a2bc665

[SYCL][Driver] Trim verbose comment blocks in sycl-no-rdc-compile-ste…

0e6ce2e

…p test

srividya-sundaram added 4 commits July 31, 2026 17:11

[SYCL][Driver] Use implicit-check-not for -fembed-offload-object in c…

187c79c

…ompile-step test

[SYCL][Driver] Anchor -fsycl-include-target-binary check to host cc1 …

fede3c5

…line

[SYCL][Doc] Rework NoRDC section to describe new offload model usage

7746b37

[SYCL][Test] Pass -fno-sycl-rdc unconditionally in early_aot e2e test

2be9203

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srividya-sundaram commented Jul 30, 2026 •

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