------- Comment #12 from rguenth at gcc dot gnu dot org 2010-07-11 22:37
-------
(In reply to comment #11)
> Subject: Re: [4.6 Regression] FAIL: gcc.dg/pr35258.c execution test
>
> > > The above testcase doesn't work with 4.5 and I doubt it ever worked on
> > > PA. The pointer passed to foo is used as is. It's only the memcpy
> > > special
> > > case that is handled by 4.5 and earlier.
> >
> > On i?86 we get correct 1-byte alignment for the pointer access while on
> > my ia64-cross the MEM has 4-byte alignment which is wrong. t is properly
> > 1-byte aligned (and pointer-to packed structs for example will work only
> > because there's a handled_component_ref around the pointer dereference).
>
> On hppa64, I see
>
> (insn 7 6 8 3 xxx.c:3 (set (reg:SI 71)
> (mem:SI (reg/v/f:DI 69 [ p ]) [0 *p_1(D)+0 S4 A32])) -1 (nil))
>
> in expand. The alignment is passed into the move expander.
For reference, on i?86 I see (on the 4.5 branch):
(insn 6 5 7 3 t.c:3 (set (reg:SI 62)
(mem:SI (reg/v/f:DI 60 [ p ]) [0 S4 A8])) -1 (nil))
and on trunk:
(insn 6 5 7 3 t.c:3 (set (reg:SI 62)
(mem:SI (reg/v/f:DI 60 [ p ]) [0 *p_1(D)+0 S4 A8])) -1 (nil))
Richard.
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44903
