[Bug middle-end/53533] [4.7 regression] loop unrolling as measured by Adobe's C++Benchmark is twice as slow versus 4.4-4.6

matt at use dot net gcc-bugzilla@gcc.gnu.org
Mon Jun 11 20:02:00 GMT 2012


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53533

--- Comment #5 from Matt Hargett <matt at use dot net> 2012-06-11 20:02:41 UTC ---
Got rid of graphite options, it made no difference. I reduced the original test
from the suite and attached it's source, preprocessor output from 4.6 and 4.7
(no major difference), and callgrind output. To keep things simple, I'm just
using -O3 and -fwhole-program.

According to callgrind, 4.7's instruction references went up by 60% and D1
misses went up by 15% at -O3 versus 4.6 at -O3.

Let me know if you need any more information to continue triaging.

Thanks!



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