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Re: rs6000: Trivial code generation stupidity
- From: David Edelsohn <dje at watson dot ibm dot com>
- To: degger at fhm dot edu
- Cc: gcc at gcc dot gnu dot org
- Date: Mon, 17 Dec 2001 16:20:57 -0500
- Subject: Re: rs6000: Trivial code generation stupidity
>>>>> degger writes:
degger> Is there anything that can be done about it? Gcc 3.1 (or what it is now)
degger> generates quite good code for me at the moment except for in some really
degger> obvious cases (like the ones mentioned) and thus it would be a shame to
degger> give away some performance by those nasties.
Also, you can look at the output from intermediate passes and see
where gcc-2.95 chose the output in the correct register while gcc-3.1
introduces the extra copies. Track down which phase in gcc-3.1 is not
collapsing the register copies or why it is introducing register copies.
David