On Tue, Jul 19, 2011 at 2:15 PM, Richard Sandiford
<richard.sandif...@linaro.org> wrote:
> In 49742, we have:
>
> vect_array.21 = LOAD_LANES (MEM[(int[512] *)vect_pin.17_56]);
> vect_var_.22_58 = vect_array.21[0];
>
> predcom doesn't think that there are any dependencies between
> the two statements, so hoists the second one as an invariant.
> This in turn is because get_references_in_stmt ignores the lhs
> of calls.
>
> Tested on x86_64-linux-gnu and arm-linux-gnueabi. OK to install?
Ok.
Thanks,
Richard.
> Richard
>
>
> gcc/
> PR tree-optimization/49742
> * tree-data-ref.c (get_references_in_stmt): Treat the lhs of a call
> as a potential write.
>
> Index: gcc/tree-data-ref.c
> ===================================================================
> --- gcc/tree-data-ref.c 2011-07-19 10:53:10.000000000 +0100
> +++ gcc/tree-data-ref.c 2011-07-19 13:08:12.000000000 +0100
> @@ -4158,33 +4158,37 @@ get_references_in_stmt (gimple stmt, VEC
> ref->pos = op1;
> ref->is_read = true;
> }
> -
> - if (DECL_P (*op0)
> - || (REFERENCE_CLASS_P (*op0) && get_base_address (*op0)))
> - {
> - ref = VEC_safe_push (data_ref_loc, heap, *references, NULL);
> - ref->pos = op0;
> - ref->is_read = false;
> - }
> }
> else if (stmt_code == GIMPLE_CALL)
> {
> - unsigned i, n = gimple_call_num_args (stmt);
> + unsigned i, n;
>
> + op0 = gimple_call_lhs_ptr (stmt);
> + n = gimple_call_num_args (stmt);
> for (i = 0; i < n; i++)
> {
> - op0 = gimple_call_arg_ptr (stmt, i);
> + op1 = gimple_call_arg_ptr (stmt, i);
>
> - if (DECL_P (*op0)
> - || (REFERENCE_CLASS_P (*op0) && get_base_address (*op0)))
> + if (DECL_P (*op1)
> + || (REFERENCE_CLASS_P (*op1) && get_base_address (*op1)))
> {
> ref = VEC_safe_push (data_ref_loc, heap, *references, NULL);
> - ref->pos = op0;
> + ref->pos = op1;
> ref->is_read = true;
> }
> }
> }
> + else
> + return clobbers_memory;
>
> + if (*op0
> + && (DECL_P (*op0)
> + || (REFERENCE_CLASS_P (*op0) && get_base_address (*op0))))
> + {
> + ref = VEC_safe_push (data_ref_loc, heap, *references, NULL);
> + ref->pos = op0;
> + ref->is_read = false;
> + }
> return clobbers_memory;
> }
>
>
