[DeviceMSAN] Fix false negative report due to __spirv_GroupAsyncCopy

[AllanZyne]

"__spirv_GroupAsyncCopy" is used to copy data between local and global buffer, we need to sync the shadow value of them.
I add a new function "__msan_unpoison_strided_copy" for this sync.

[yingcong-wu]

Please update the PR's description when creating one. Like giving the context of this change and some high level summary.

[Copilot]

Pull Request Overview

This PR extends DeviceMSAN to correctly handle the SPIR-V __spirv_GroupAsyncCopy intrinsic by adding a strided copy callback, demangling helper, and RTL implementation for unpoisoning shadows.

• Registers a new __msan_unpoison_strided_copy callback in the SPIR pass
• Skips sanitization for __spirv_GroupAsyncCopy calls and emits a call to the new unpoison function
• Implements the strided-copy logic and debug messaging in the msan_rtl.cpp

Reviewed Changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 3 comments.

File	Description
llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp	Added callback registration, demangling helper, and visitor hook
libdevice/sanitizer/msan_rtl.cpp	Introduced __msan_unpoison_strided_copy RTL with template copy

Files not reviewed (1)

• llvm/test/Instrumentation/MemorySanitizer/SPIRV/spirv_groupasynccopy.ll: Language not supported

Comments suppressed due to low confidence (1)

libdevice/sanitizer/msan_rtl.cpp:604

• Add unit or integration tests to verify __msan_unpoison_strided_copy correctly handles various element sizes and stride values to prevent regressions.

void __msan_unpoison_strided_copy(uptr dest, uint32_t dest_as, uptr src,

[Copilot]

Pull Request Overview

This pull request fixes a false negative report caused by misidentifying __spirv_GroupAsyncCopy. Key changes include adding a new callback function (__msan_unpoison_strided_copy) with its registration in the sanitizer, introducing helper logic to demangle __spirv_GroupAsyncCopy names, and extending RTL support via a templated GroupAsyncCopy.

Reviewed Changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 2 comments.

File	Description
llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp	Added friend declaration, new FunctionCallee for MsanUnpoisonStridedCopy, helper function for mangling demangle, and adjusted metadata exclusion for __spirv_GroupAsyncCopy calls
libdevice/sanitizer/msan_rtl.cpp	Introduced a templated GroupAsyncCopy helper and implemented __msan_unpoison_strided_copy to support strided copy unpoisoning

Files not reviewed (1)

• llvm/test/Instrumentation/MemorySanitizer/SPIRV/spirv_groupasynccopy.ll: Language not supported

[Copilot]

Pull Request Overview

Fix false negative MSan reports for __spirv_GroupAsyncCopy by adding a custom strided-copy unpoison callback and associated runtime support.

• Register and call a new __msan_unpoison_strided_copy in the SPIR-V instrumenter
• Exclude __spirv_GroupAsyncCopy from the no-sanitize filter and demangle its element type
• Implement device-side shadow propagation for strided copies in the MSan RTL

Reviewed Changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 2 comments.

File	Description
llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp	Added MsanUnpoisonStridedCopyFunc, excluded GroupAsyncCopy from no-sanitize, demangled vector types, and emitted the strided-copy call
libdevice/sanitizer/msan_rtl.cpp	Defined __msan_unpoison_strided_copy, shadow-copy loop template, and error message for unsupported types

Files not reviewed (1)

• llvm/test/Instrumentation/MemorySanitizer/SPIRV/spirv_groupasynccopy.ll: Language not supported

Comments suppressed due to low confidence (1)

libdevice/sanitizer/msan_rtl.cpp:602

• The identifier __msan_print_strided_copy_unsupport_type has a typo; rename to __msan_print_strided_copy_unsupported_type for consistency.

static __SYCL_CONSTANT__ const char __msan_print_strided_copy_unsupport_type[] = "[kernel] __msan_unpoison_strided_copy: unsupported type(%d)\n";

[yingcong-wu]

Please update the PR's description when creating one. Like giving the context of this change and some high level summary.

Hi @AllanZyne , please update the description, thanks.

[AllanZyne]

Hi @intel/llvm-gatekeepers, the failed tests are infrastructure issues, this PR is ready to merge, thanks!