gcc generates suboptimal i386 block copy code, like this:
movl $9, %ecx
rep
movsb
or this:
movl $2, %ecx
rep
movsl
movsw
Such short copies can be done with few movsl's instead.
Patch is attached. Note that I am not familiar with gcc
internals at all, so take it with reasonable suspicion.
--
Summary: optimize i386 block copy
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: rtl-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: vda at port dot imtp dot ilyichevsk dot odessa dot ua
CC: gcc-bugs at gcc dot gnu dot org
GCC build triplet: i386-pc-linux-gnu
GCC host triplet: i386-pc-linux-gnu
GCC target triplet: i386-pc-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21329
