davemgreen wrote: I don't believe the undef is the issue - I think the issue is that AArch64InstrInfo::isCopyInstrImpl is saying that a W-reg orr is a copy, even if it is really a zextend because the entire X output register is depended upon.
Can you try and add something to isCopyInstImpl instead, that says: If the register is virtual then it should not be a subreg, and if the register is physical then there should not be an implicit def of the X reg. Would that solve your issue, and would it cause other problems in AArch64 codegen? Thanks https://github.com/llvm/llvm-project/pull/74682 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
