llvm-project

686562f0 - AMDGPU: Fix tracking subreg defs when folding through reg_sequence

AMDGPU: Fix tracking subreg defs when folding through reg_sequence We weren't fully respecting the type of a def of an immediate vs. the type at the use point. Refactor the folding logic to track the value to fold, as well as a subregister to apply to the underlying value. This is similar to how PeepholeOpt tracks subregisters (though only for pure copy-like instructions, no constants). Fixes #139317