[all-commits] [llvm/llvm-project] 4a4874: [HLSL] Update indexed vector elements individually...

[Helena Kotas via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 4a48740831d0f0779780e0bea64ec4a16d9f6d97
      https://github.com/llvm/llvm-project/commit/4a48740831d0f0779780e0bea64ec4a16d9f6d97
  Author: Helena Kotas <hekotas at microsoft.com>
  Date:   2025-12-01 (Mon, 01 Dec 2025)

  Changed paths:
    M clang/lib/CodeGen/CGExpr.cpp
    M clang/test/CodeGenHLSL/BoolVector.hlsl
    A clang/test/CodeGenHLSL/builtins/VectorElementStore.hlsl
    M clang/test/CodeGenHLSL/builtins/lit.hlsl

  Log Message:
  -----------
  [HLSL] Update indexed vector elements individually (#169144)

When an individual element of a vector is updated via indexing into the vector, it needs to be handled as a store operation on that one vector element.

Clang treats vectors as one unit, so a vector element needs to be updated, the whole vector is loaded, the element is modified, and then the whole vector is stored. In HLSL vector elements are handled individually. We need to avoid this load/modify/store sequence to prevent overwriting other vector elements that might be getting updated in parallel.

Fixes #167729

Contributes to #160208.



To unsubscribe from these emails, change your notification settings at https://github.com/llvm/llvm-project/settings/notifications