c/10339: strncmp generates imPure code

[Andreas Schwab]

Michael Ubell <ubell@mindspring.com> writes:

|> > I suspect the extra byte read is actually not relevant for the result,
|> > and because of alignment, gcc knows the second problem cannot occur,
|> > but I have neither a SPARC nor SPARC knowledge to test that.
|> > 
|> 
|> Actually if you make the compare string longer you can get it
|> to look at an arbitrary number of bytes passed the allocated part,
|> so I think this could fault if you set it up right.  Also in
|> the original problem, the first argument was not allocated locally
|> so the compiler would have no idea how big or what its alignment
|> was.  (In fact it was in a loop comparing strings from an array.)

Could you please provide a test case that actually shows the problem?

Andreas.

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Andreas Schwab, SuSE Labs, schwab@suse.de
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