[PATCH] D157680: [X86]Support options -mno-gather -mno-scatter

[Phoebe Wang via Phabricator via cfe-commits]

pengfei added inline comments.


================
Comment at: llvm/lib/Target/X86/X86.td:437
+    : SubtargetFeature<"prefer-no-gather", "PreferGather", "false",
+                       "Indicates if gather prefer to be disabled">;
+def FeaturePreferNoScatter
----------------
XinWang10 wrote:
> skan wrote:
> > Does "Prefer no gather instructions" sound better?
> > 
> > I think these two should be put under "X86 Subtarget Tuning features"?
> I think the two options are to mitigate security issues. Could refer to link in summary.
It depends on if the micro code was applied. We should assume user care of this option should have applied the micro code. So it's more like a performance turning rather than mitigation. And you cannot disable all gather/scatter instructions with these options.


Repository:
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CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D157680/new/

https://reviews.llvm.org/D157680