[webkit-changes] [WebKit/WebKit] 3bbb2b: [WGSL] shader, execution, expression, call, builtin, at...

[Tadeu Zagallo]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 3bbb2b0bb5c6fdd080d522db1805c5d8d6f015af
      https://github.com/WebKit/WebKit/commit/3bbb2b0bb5c6fdd080d522db1805c5d8d6f015af
  Author: Tadeu Zagallo <tzagallo at apple.com>
  Date:   2024-01-16 (Tue, 16 Jan 2024)

  Changed paths:
    M Source/WebGPU/WGSL/Metal/MetalFunctionWriter.cpp
    M Source/WebGPU/WGSL/TypeStore.cpp
    M Source/WebGPU/WGSL/TypeStore.h

  Log Message:
  -----------
  [WGSL] shader,execution,expression,call,builtin,atomics,atomicCompareExchangeWeak:* is failing
https://bugs.webkit.org/show_bug.cgi?id=267551
rdar://121011135

Reviewed by Mike Wyrzykowski.

Fix a few problems in the atomicCompareExchange implementation to pass the CTS tests:
- The generated metal struct needs to take 2 template arguments. The second type is always
  bool, but that is necessary due to the codegen of PrimitiveStructs.
- The __wgslAtomicCompareExchange macro was copying the original value before executing
  the underlying atomic_compare_exchange metal function, which meant the wrong old_value
  was returned when the comparison failed.
- There was a typo in TypeStore::atomicCompareExchangeResultType that set the kind of
  the primitive struct to ModfResult, causing type errors.
- The TypeStore members used for caching the result structs (m_atomicCompareExchangeResultI32
  and m_atomicCompareExchangeResultU32) were not initialized to nullptr, so the lazy
  initialization could return the uninitialized value instead.

* Source/WebGPU/WGSL/Metal/MetalFunctionWriter.cpp:
(WGSL::Metal::FunctionDefinitionWriter::emitNecessaryHelpers):
* Source/WebGPU/WGSL/TypeStore.cpp:
(WGSL::TypeStore::atomicCompareExchangeResultType):
* Source/WebGPU/WGSL/TypeStore.h:

Canonical link: https://commits.webkit.org/273066@main