fix(nvvm): use PassMode::Cast for align(16) ADTs#362
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Snehal-Reddy wants to merge 1 commit intoRust-GPU:mainfrom
Open
fix(nvvm): use PassMode::Cast for align(16) ADTs#362Snehal-Reddy wants to merge 1 commit intoRust-GPU:mainfrom
Snehal-Reddy wants to merge 1 commit intoRust-GPU:mainfrom
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The NVVM backend was defaulting to
PassMode::Directfor all ADTs. On NVPTX, LLVM often aligns generic aggregate types to 8 bytes, even if the Rust type requires 16-byte alignment. This caused the kernel to read arguments from incorrect offsets, leading to crashes.The Fix:
PassMode::Castusingi128units. This compels LLVM to emit.param .align 16(or.b128) in PTX, guaranteeing the correct ABI contract.attrs.pointee_alignwhen usingPassMode::Directto ensure LLVM respects the type's alignment attribute.Fixes #361