[llvm-dev] StringSwitch efficiency

[Chris Lattner via llvm-dev]

I agree - something that was true years ago is not necessarily still valid today.

-Chris

> On Oct 29, 2020, at 2:16 PM, Fāng-ruì Sòng <maskray at google.com> wrote:
> 
> This may still need a measurement. StringSwitch takes a StringRef
> (const char *Data + size_t Length). The compiler cannot arbitrarily
> reference Data[i] if i >= Length. It can do specialization but it
> needs to know the valid range.
> 
> On Thu, Oct 29, 2020 at 11:53 AM Paul C. Anagnostopoulos via llvm-dev
> <llvm-dev at lists.llvm.org> wrote:
>> 
>> Excellent. Then I shall not concern myself with the efficiency of StringSwitch.
>> 
>> At 10/29/2020 02:28 PM, Chris Lattner wrote:
>>> Yeah, years ago, the compiler did the right thing through a combination of jump threading and simple redundancy elimination.  StringSwitch does a first character specialization IIRC.
>>> 
>>> -Chris
>> 
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> 
> 
> -- 
> 宋方睿