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Re: does the instruction combiner regards (foo & 0xff) as a special case?


ibanez@sunplus.com wrote:
I guess the combiner generates something like
a trucation pattern when special constant are detected.
The combiner also takse a similiar action in pattern

See the section of the documentation that talks about instruction canonicalization.
http://gcc.gnu.org/onlinedocs/gccint/Insn-Canonicalizations.html
See in particular the last bullet.


Also, as Joern mentioned, you should try stepping through try_combine to see what is really happening.
--
Jim Wilson, GNU Tools Support, http://www.specifix.com



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