This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug target/16961] Poor x86-64 performance
- From: "tomstdenis at iahu dot ca" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 10 Aug 2004 14:09:31 -0000
- Subject: [Bug target/16961] Poor x86-64 performance
- References: <20040810130811.16961.tomstdenis@iahu.ca>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From tomstdenis at iahu dot ca 2004-08-10 14:09 -------
(In reply to comment #4)
> Okay, as to the TImode problem, this is target specific. I'm not familiar
with
> i386, but I have a very hard time believing using the carry flag would lead
> to a noticeable speedup here... oh well.
Um it is. the 10 instructions GCC makes now consume decode bandwidth, require
execute time, fill the cache, etc...
Admitedly this isn't a "huge" problem because most code won't be doing 128-bit
math but if the goal is to make GCC the best it can be someone might as well
fix this up.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16961