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List:       gcc
Subject:    Re: Performance degradation on g++ 4.6
From:       Benjamin Redelings I <benjamin.redelings () nescent ! org>
Date:       2011-07-30 13:22:36
Message-ID: 4E34059C.3060209 () nescent ! org
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Hi Oleg,

I had some performance degradation with 4.6 as well.

However, I was able to cure it by using -finline-limit=800 or 1000 I 
think.  However, this lead to a code size increase.  Were the old 
higher-performance binaries larger?

IIRC, setting finline-limit=n actually sets two params to n/2, but I 
think you may only need to change 1 to get the old performance back.  
--param max-inline-insns-single defaults to 450, but --param 
max-inline-insns-auto defaults to 90.  Perhaps you can get the old 
performance back by adjusting just one of these two parameters, or by 
setting them to different values, instead of the same value, as would be 
achieved by -finline-limit.

-BenRI
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