[PATCH] D137431: [AArch64] RME MEC instructions and system registers

[Keith Walker via Phabricator via llvm-commits]

keith.walker.arm added inline comments.


================
Comment at: llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp:3490
     {"mops", {AArch64::FeatureMOPS}},
+    {"mec", {AArch64::FeatureMEC}},
     // FIXME: Unsupported extensions
----------------
lenary wrote:
> keith.walker.arm wrote:
> > lenary wrote:
> > > This should not be included. These names are supposed to be the same as command-line extension options, which MEC doesn't have.
> > > 
> > > At the very least, it's also untested, but I think it should be removed, not tested.
> > So I assume we want uses of MEC to be gated on the use of AArch64::FeatureRME instead.
> Not quite. This array is only for allowing `.arch_extension <string>` to enable specific features, which is part of the public interface, and we don't want if there's not a corresponding extension for `-march=<version>+<string>`
> 
> FeatureMEC in AArch64.td should remain.
The reason I asked is because removing just this line causes the tests to fail with an errors like:

    error: DC CIGDPAE requires: (unknown)

and 

   error: expected writable system register or pstate

So it looks to me like this line is required.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D137431/new/

https://reviews.llvm.org/D137431