[Bug c++/66584] gcc differs in static, branch-prediction cost from icc in switch.

jmcguiness at liquidcapital dot com gcc-bugzilla@gcc.gnu.org
Thu Jun 18 15:23:00 GMT 2015


https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66584

--- Comment #4 from Jason McG <jmcguiness at liquidcapital dot com> ---
(In reply to Eric Botcazou from comment #2)
> What would you like us to document exactly?  How are we supposed to track
...

Perhaps I was unclear. I am asking that you point out to me in the gcc
documentation where it comments regarding code generation for
switch-statements, and that it might make clear that the lexographic "top-down"
approach nor the default label are preferred but other, more complex heuristics
are used that defeat static branch-prediction analysis. I do not think this is
unreasonable. So I disagree entirely that this is invalid.



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