Fold OpLoad from Private variables with constant initializers#512
Merged
LegNeato merged 1 commit intoRust-GPU:mainfrom Jan 13, 2026
Merged
Fold OpLoad from Private variables with constant initializers#512LegNeato merged 1 commit intoRust-GPU:mainfrom
LegNeato merged 1 commit intoRust-GPU:mainfrom
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Disclosure: I had AI write this and I only superficially understand the code. Replace OpLoad from Private/Function storage class variables with their constant initializers. This eliminates pointer-to-pointer patterns like `&&123` which would otherwise generate invalid SPIR-V in Logical addressing mode (pointer-to-pointer is only allowed for StorageBuffer/Workgroup, not Private). The optimization runs after inlining (which may expose such patterns) and before DCE (so the now-unused variables can be removed). Also extend DCE to treat Private storage class variables as pure, allowing them to be removed when unused. Newer versions of spirv-val catch this, acusing compiletests to fail.
Firestar99
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Jan 13, 2026
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Code looks good!
And indeed spirv-tools v2025.5 (pulled from nix unstable) introduces a new validation rule that is failing nested-ref:
error: error:0:0 - In Logical addressing, variables can only allocate a pointer to the StorageBuffer or Workgroup storage classes
%3 = OpVariable %_ptr_Private__ptr_Private_uint Private %4
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= note: spirv-val failed
= note: module `$TEST_BUILD_DIR/lang/consts/nested-ref.vulkan1.2`
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For a moment I was considering if this transformation may be unsound. There could be a situation where an |
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Disclosure: I had AI write this and I only superficially understand the code.
Replace OpLoad from Private/Function
storage class variables with their constant initializers. This eliminates pointer-to-pointer patterns like
&&123which would otherwise generate invalid SPIR-V in Logical addressing mode (pointer-to-pointer is only allowed for StorageBuffer/Workgroup, not Private).The optimization runs after inlining (which may expose such patterns) and before DCE (so the now-unused variables can be removed).
Also extend DCE to treat Private storage class variables as pure, allowing them to be removed when unused.
Newer versions of spirv-val catch this, causing our compiletests to fail.