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Re: [Patch,AVR]: Fix PR27663

2011/5/2 Georg-Johann Lay <>:
> This is a fix for an optimization flaw when a long value is composed
> from byte values.
> For -fsplit-wide-types (which is still default for avr) the code is
> worse than with -fno-split-wide-types. The code for the test case is
> better in either situations, i.e. compared to code without the patch,
> but it is still not optimal.
> Fixing this by some combine patterns is the only thing the BE can do.
> I did not write more complex patterns because things get too complex
> with little performance gain.
> Tested without regressions.
> Johann
> 2011-05-02 ÂGeorg-Johann Lay Â<>
> Â Â Â ÂPR target/27663
> Â Â Â Â* config/avr/ (const_8_16_24_operand): New predicate.
> Â Â Â Â* config/avr/ ("*ior<mode>qi.byte0",
> Â Â Â Â"*ior<mode>qi.byte1-3"): New define_insn_and_split patterns.

I'm sorry, but I dot'n like to have a both combiner related patches in
port because code improvement isn't much and your patterns are
difficult to understand and maintain.

May be somebody else have a different oppinion ?
I'm open to discussion.


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