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[Bug target/13958] Conversion from unsigned to double is painfully slow on P4
- From: "ubizjak at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 21 Mar 2008 13:45:57 -0000
- Subject: [Bug target/13958] Conversion from unsigned to double is painfully slow on P4
- References: <bug-13958-1771@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #3 from ubizjak at gmail dot com 2008-03-21 13:45 -------
This is due to partial memory access penalty. For TARGET_INTER_UNIT_MOVES, we
can create:
movd a(,%eax,4), %xmm0
movq %xmm0, (%esp)
fildll (%esp)
instead of:
movl a(,%eax,4), %eax
xorl %edx, %edx
pushl %edx
pushl %eax
fildll (%esp)
Otherwise just use -mfpmat=sse.
--
ubizjak at gmail dot com changed:
What |Removed |Added
----------------------------------------------------------------------------
AssignedTo|unassigned at gcc dot gnu |ubizjak at gmail dot com
|dot org |
Status|NEW |ASSIGNED
Last reconfirmed|2006-01-16 06:17:55 |2008-03-21 13:45:57
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13958