[Bug target/35866] Vector load/store from a packed struct does not work (without -mstrict-align)

[froydnj 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
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                 CC|                            |froydnj at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35866