jcai19 marked an inline comment as done. jcai19 added a comment. In D103184#2793055 <https://reviews.llvm.org/D103184#2793055>, @DavidSpickett wrote:
> $ cat /tmp/test.s > irg x0, x0 > $ aarch64-unknown-linux-gnu-as -march=armv8.5-a+memtag -march=armv8.1-a > /tmp/test.s -o /dev/null > /tmp/test.s: Assembler messages: > /tmp/test.s:1: Error: selected processor does not support `irg x0,x0' > > GAS is also taking the last value of `march`. So if we were to follow clang > Arm's behaviour, the result would be the same. > > Except we don't have to rely on the llvm backend picking the last of > "target-feature". Which probably works for architecture versions but for > individual extensions I don't think so. > > If we make it additive this could happen: > > -march=armv8.5-a+memtag -march=armv8.2-a > > Becomes: (mte is the backend name for memtag for silly reasons) > > -target-feature +v8.5-a -target-feature mte -target-feature +v8.2-a > > So now instead of getting `v8.2` only, the user now has `v8.2+memtag`. Only > if they do `armv8.2-a+nomemtag` will they get what they expect (well, what > I'd expect). Which means they'd need to know every previous march value. Thanks for double checking! I've changed my implementation since I made that comment to take the last value of -Wa,march (and only for assembly files) and added more test cases. It should now follows the Arm behavior. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D103184/new/ https://reviews.llvm.org/D103184 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
