[bug #58427] Cost-base optimiser breaks short-circuit evaluation

[Bernhard Voelker]

Update of bug #58427 (project findutils):

                  Status:                    None => In Progress            
             Assigned to:                    None => berny                  

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Follow-up Comment #2:

Thanks for the report.

I see the following problems:

* Using -O0 does not turn off arm-swapping completely for those who want that.
 I suggest to change that so that -O0 skips arm-swapping.

* POSIX states for "expression [-a] expression" that "the second expression
shall not be evaluated if the first expression is false".  The optimizer
violates this rule. Still, I think that CBO makes sense where no side effects
are known.   I suggest to:
** default to level 0 when POSIXLY_CORRECT is set (overridable by the -O
option),
** fix cases like this reported one where later tests can have side effects
like EPERM.

* The documentation about the default -O level states wrongly that the default
level would be 1 while it is hard-coded to 2 in util.c:set_option_defaults().

* The packager cannot choose the default optimization level.  I suggest a new
configure option to make this possible.

Finally:
* findutils uses _"optimize"_ vs. _"optimise"_ quite inconsistently in its
code and documentation, with the latter (British English) having more hits
than the former (American English).  I suggest to harmonize in the one or the
other direction.

@James: WDYT?

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