[PATCH] D47474: Implement cpu_dispatch/cpu_specific Multiversioning

[Erich Keane via Phabricator via cfe-commits]

erichkeane added a comment.






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Comment at: include/clang/AST/Decl.h:2212-2213
 
+  bool isCpuDispatchMultiVersion() const;
+  bool isCpuSpecificMultiVersion() const;
+
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aaron.ballman wrote:
> aaron.ballman wrote:
> > Pedantic nit: CPU instead of Cpu?
> Thoughts on `isCPUDispatchMultiVersion()` instead of `isCpuDispatchMultiVersion()`?
Well, I can definitely switch it back if CPU is your preference.  Looking at it, we're probably about 75/25 in our codebase preferring CPU, so I prefer it as well.


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Comment at: include/clang/Basic/Attr.td:851
+  let Spellings = [Clang<"cpu_specific">];
+  let Args = [VariadicIdentifierArgument<"Cpus">];
+  let Subjects = SubjectList<[Function]>;
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aaron.ballman wrote:
> `Cpus` -> `CPUs` ?
So, I agree with you we should be consistent with spelling.  However, in this case, I'd prefer not changing this one.  This is what the generated code in Attrs.inc looks like if I change it:

    typedef IdentifierInfo ** cPUs_iterator;
    cPUs_iterator cPUs_begin() const { return cPUs_; }
    cPUs_iterator cPUs_end() const { return cPUs_ + cPUs_Size; }
    unsigned cPUs_size() const { return cPUs_Size; }
    llvm::iterator_range<cPUs_iterator> cPUs() const { return llvm::make_range(cPUs_begin(), cPUs_end()); }

I think having "Cpus" in 2 places is way better than having to spell it as cPUs_begin.  Your thoughts?


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Comment at: lib/Sema/SemaOverload.cpp:9017
+
+    return (*FirstDiff.first)->getName() < (*FirstDiff.second)->getName();
+  }
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aaron.ballman wrote:
> If there's no mismatch, doesn't this wind up dereferencing the end iterator of the range?
Yikes, you're right!  However, that would require 2 declarations to have identical cpu_specific lists, which is against the rules previously enforced.  I've put an assert in here to ensure that never happens.


https://reviews.llvm.org/D47474