------- Comment #54 from potswa at mac dot com 2009-11-03 20:43 -------
Created an attachment (id=18959)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=18959&action=view)
A couple benchmarks for 32-bit mode and updated fwd+copy
Yikes. Just a second: yesterday I played around with the forward iterator
algorithm a little more, and discovered that the reason it benchmarked slower
in rotate_speed.txt was that I had changed it to use std::iter_swap instead of
std::swap. I don't know if 4.5.0 has whatever compilation issue caused the
difference (I'm still testing in 4.2.1), but the new benchmarks show it as
being the same speed as my rewrite in -m64 mode.
Previous data showing my algo being faster resulted from testing in -m32 mode.
Attached are updated benchmarks showing that the only significant advantage to
my rewrite is a 12% speedup in -m32 mode for the general case.
The advantage to an improved forward/bidirectional iterator version is that it
should also help sequences in containers besides std::vector. Also it would be
lower impact as the only code added would be the special cases calling
std::copy, and the separate bidirectional and RAI algos would go away
completely.
--
potswa at mac dot com changed:
What |Removed |Added
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Attachment #18934|0 |1
is obsolete| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41351
