[all-commits] [llvm/llvm-project] 790938: [HLSL] Set visibility of cbuffer global variables ...

[Helena Kotas via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 790938d0204af8307d7d37b3e10caef27b3d527f
      https://github.com/llvm/llvm-project/commit/790938d0204af8307d7d37b3e10caef27b3d527f
  Author: Helena Kotas <hekotas at microsoft.com>
  Date:   2026-06-11 (Thu, 11 Jun 2026)

  Changed paths:
    M clang/lib/CodeGen/CGHLSLRuntime.cpp
    M clang/test/CodeGenHLSL/ArrayAssignable.hlsl
    M clang/test/CodeGenHLSL/ArrayAssignable.logicalptr.hlsl
    M clang/test/CodeGenHLSL/cbuffer-matrix-layout-keyword.hlsl
    M clang/test/CodeGenHLSL/resources/cbuffer-empty-struct-array.hlsl
    M clang/test/CodeGenHLSL/resources/cbuffer.hlsl
    M clang/test/CodeGenHLSL/resources/cbuffer_and_namespaces.hlsl
    M clang/test/CodeGenHLSL/resources/cbuffer_with_packoffset.hlsl
    M clang/test/CodeGenHLSL/resources/cbuffer_with_static_global_and_function.hlsl
    M clang/test/CodeGenHLSL/resources/default_cbuffer.hlsl
    M clang/test/CodeGenHLSL/resources/default_cbuffer_with_layout.hlsl
    M llvm/include/llvm/Frontend/HLSL/CBuffer.h
    M llvm/lib/Frontend/HLSL/CBuffer.cpp
    M llvm/lib/Target/DirectX/DXILCBufferAccess.cpp
    M llvm/lib/Target/SPIRV/SPIRVCBufferAccess.cpp
    A llvm/test/CodeGen/DirectX/cbuffer_global_elim.ll
    A llvm/test/CodeGen/SPIRV/cbuffer_global_elim.ll

  Log Message:
  -----------
  [HLSL] Set visibility of cbuffer global variables to internal (2nd attempt) (#202745)

Global variables for all resources except `cbuffer` are already emitted
with internal linkage (since #166844).
This change adds internal linkage to the `cbuffer` handle globals as
well.

One problem is that the `cbuffer` handle globals appears unused between
Clang CodeGen and `{DXIL|SPIRV}CBufferAccess` pass, which replaces
individual `cbuffer` constant globals with accesses through the
`cbuffer` handle globals. Before this pass runs, the unused globals
could get optimized away in `GlobalOptPass` with `-O3`.

To solve this, the `cbuffer` handle globals are added to the
`@llvm.compiler.used` list to make sure they stay in the module until
the `{DXIL|SPRIV}CBufferAccess` pass, which then removes them from the
list.

This is a second attempt to land this change. The [first
one](https://github.com/llvm/llvm-project/pull/200312) had to be
reverted because the use of `llvm::removeFromUsedList` introduced a
cyclic dependency between `LLVMTransformUtils` and `LLVMFrontendHLSL`.
This change fixes this by calling `llvm::removeFromUsedList` directly
from the passes.



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