On Thu, 2 Aug 2012 09:57:40 +0100 Julian Brown <jul...@codesourcery.com> wrote:
> On Wed, 1 Aug 2012 14:43:33 -0700 > Roland McGrath <mcgra...@google.com> wrote: > > > Using e.g. -falign-labels=16 on ARM can confuse the constant-pool > > layout code such that it places pool entries too far away from their > > referring instructions. This change seems to fix it. > > > > I don't have a small test case, only a large one, which I haven't > > actually tried to get to reproduce on any vanilla ARM target. But > > the logic of the change seems straightforward and sound. > > FWIW, I've hit this issue in the past, and used a patch as follows to > fix it: > > @@ -12015,7 +12025,10 @@ create_fix_barrier (Mfix *fix, HOST_WIDE > gcc_assert (GET_CODE (from) != BARRIER); > > /* Count the length of this insn. */ > - count += get_attr_length (from); > + if (LABEL_P (from) && (align_jumps > 0 || align_loops > 0)) > + count += MAX (align_jumps, align_loops); > + else > + count += get_attr_length (from); > > /* If there is a jump table, add its length. */ > tmp = is_jump_table (from); > @@ -12435,6 +12448,8 @@ arm_reorg (void) > insn = table; > } > } > + else if (LABEL_P (insn) && (align_jumps > 0 || align_loops > > 0)) > + address += MAX (align_jumps, align_loops); > } > > fix = minipool_fix_head; > > Not sure if that's equivalent, but you might want to check > -falign-jumps too while you're at it. (...and -falign-loops. Whoops, misread :-)).