This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug target/35866] Vector load/store from a packed struct does not work (without -mstrict-align)
- From: "froydnj at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 9 May 2008 03:14:18 -0000
- Subject: [Bug target/35866] Vector load/store from a packed struct does not work (without -mstrict-align)
- References: <bug-35866-6528@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #4 from froydnj at gcc dot gnu dot org 2008-05-09 03:14 -------
If I understand correctly, one would just need to add vector modes with
appropriate alignment restrictions to SLOW_UNALIGNED_ACCESS. If I add an extra
|| (((MODE) == V4SFmode || (MODE) == V2DFmode) && (ALIGN) < 128)
to SLOW_UNALIGNED_ACCESS, and compile without -mstrict-align, I get
semi-reasonable looking code at -O2:
f:
stwu 1,-48(1)
addi 9,1,16
stw 28,32(1)
stw 29,36(1)
stvx 2,0,9
lwz 8,12(9)
lwz 5,0(9)
lwz 6,4(9)
mr 0,8
lwz 7,8(9)
stw 8,13(3)
addi 8,1,16
stw 5,1(3)
stw 7,9(3)
stw 6,5(3)
stw 5,0(8)
stw 6,4(8)
stw 7,8(8)
stw 0,12(8)
lvx 2,0,8
lwz 28,32(1)
lwz 29,36(1)
addi 1,1,48
blr
It could be improved, but it's a lot better than -mstrict-align code.
--
froydnj at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |froydnj at gcc dot gnu dot
| |org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35866