Re: [PATCH] configure: Disable -Wtautological-type-limit-compare

[Eric Blake]

On 6/3/20 10:45 PM, Richard Henderson wrote:
> Clang 10 enables this by default with -Wtype-limit.
>
> All of the instances flagged by this Werror so far have been
> cases in which we really do want the compiler to optimize away
> the test completely.  Disabling the warning will avoid having
> to add ifdefs to work around this.

While I proposed an alternative fix that was able to silence the most 
recent error without #if, I do like this approach better - the warning 
causes far more false positives than flagging actual bugs, especially 
when we write code to allow 32->32, 64->32, and 64->64 host->emulation 
paths, where one or more of those need the check but the others really 
do a tautological compare, by the nature of the types involved.

Reviewed-by: Eric Blake <eblake@redhat.com>

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Eric Blake, Principal Software Engineer
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