[clang] [llvm] [Driver][AMDGPU][HIP][SPIRV] Disable optimizations for AMDGCN SPIR-V (PR #154765)

[Sameer Sahasrabuddhe via cfe-commits]

ssahasra wrote:

> SPIRV is a storage format and flavoring it as AMDGPU shouldn't introduce unique optimization issues. If SPIRV is adding custom optimizations that is harmful to the ultimate finalization, that's an issue to directly address in the SPIRV optimizations.

This seems to me as the core issue. SPIRV being a target-neutral representation, how is it that target-neutral optimizations in LLVM are harmful to any one target? If hypothetically a HIP program were parsed into an identical LLVM IR, wouldn't the same optimizations make the same decisions for the AMDGCN target?

https://github.com/llvm/llvm-project/pull/154765