On Mon, 8 Feb 2016, Eric Botcazou wrote: > > This makes it less likely (for example through the PRE path) to trigger > > target bugs like PR68273 where targets use type alignment of call > > arguments to decide on the ABI. > > > > Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk. > > Thanks. I think that we can also avoid this issue by teaching SRA not to > over-align scalar types, I don't see any point in doing that. It's done in: > > misalign = (misalign + offset) & (align - 1); > if (misalign != 0) > align = (misalign & -misalign); > if (align != TYPE_ALIGN (exp_type)) > exp_type = build_aligned_type (exp_type, align); > > mem_ref = fold_build2_loc (loc, MEM_REF, exp_type, base, off);
No, that's not over-aliging a salar type, that's preserving alignment information on the memory reference. What would need to be fixed here is to see where that 'mem_ref' is assigned to a SSA name and avoid making that SSA name have an over-aligned type. Richard.
