[PATCH] D107370: [X86] Split Subtarget ISA / Security / Tuning Feature Flags Definitions. NFC

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


================
Comment at: llvm/lib/Target/X86/X86.td:281-295
+// Ivy Bridge and newer processors have enhanced REP MOVSB and STOSB (aka
+// "string operations"). See "REP String Enhancement" in the Intel Software
+// Development Manual. This feature essentially means that REP MOVSB will copy
+// using the largest available size instead of copying bytes one by one, making
+// it at least as fast as REPMOVS{W,D,Q}.
+def FeatureERMSB
+    : SubtargetFeature<
----------------
craig.topper wrote:
> pengfei wrote:
> > These seem tuning features?
> They have CPUID bits and they appear in HSWAdditionalFeatures rather than HSWTuning. and ICLAdditionalFeatures rather than ICLTuning.
Yes, that was my reasoning to keep them here - I agree they (annoyingly) straddle the line between arch and tuning feature :( 


================
Comment at: llvm/lib/Target/X86/X86.td:307
+// mitigate potential Spectre v2 attacks against them.
+def FeatureRetpolineIndirectCalls
+    : SubtargetFeature<
----------------
pengfei wrote:
> Is it better if we can make security features and tuning features begin with e.g., MitigationXXXX and TuningXXX respectively?
I have no objection - a naming convention like that could help. I'd like to do that as a separate patch though.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D107370/new/

https://reviews.llvm.org/D107370