[Bug target/44903] [4.6 Regression] FAIL: gcc.dg/pr35258.c execution test

[dave at hiauly1 dot hia dot nrc dot ca]

------- Comment #3 from dave at hiauly1 dot hia dot nrc dot ca  2010-07-10 23:34 -------
Subject: Re:  [4.6 Regression] FAIL: gcc.dg/pr35258.c
        execution test

On Sat, 10 Jul 2010, rguenth at gcc dot gnu dot org wrote:

> I get for all memory accesses an alignment of 8 at expansion time which looks
> correct (on i?86).  Please debug this a bit, set_mem_attributes_minus_bitpos
> looks conservative enough.

The rtl in question is the following:

(insn 8 6 11 /test/gnu/gcc/gcc/gcc/testsuite/gcc.dg/pr35258.c:16 (set (reg:SI
28 %r28 [orig:94 D.1980 ] [94])
         (mem/c:SI (plus:SI (reg/f:SI 1 %r1 [95])
                         (const_int 1 [0x1])) [0 MEM[(char * {ref-all})&str +
1B]+0 S4 A8])) 37 {*pa.md:2102} (nil))

An alignment of 8 is not sufficient for a 4 byte (SImode) load on targets
that define STRICT_ALIGNMENT.  We need an alignment of 32.

I believe the i?86 hardware allows unaligned addresses, so you wouldn't
see the problem.

Dave


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44903