factor asm op chaining out from stmt.c:expand_asm_stmt

There are several cut-and-pasted loops in expand_asm_stmt that could be
parameterized by the functions used to access the particular operands.
The patch below does that.

Tested on x86_64-unknown-linux-gnu.  OK to commit?

-Nathan

	 * stmt.c (chain_asm_ops): New function.
	(expand_asm_stmt): Call it.

On Fri, Apr 15, 2011 at 3:19 PM, Nathan Froyd <froydnj@codesourcery.com> wrote:
> There are several cut-and-pasted loops in expand_asm_stmt that could be
> parameterized by the functions used to access the particular operands.
> The patch below does that.
>
> Tested on x86_64-unknown-linux-gnu.  OK to commit?

Hmm, it doesn't make it easier to follow though.

Just my 2cents,

Richard.

> -Nathan
>
>         * stmt.c (chain_asm_ops): New function.
>        (expand_asm_stmt): Call it.
>
> diff --git a/gcc/stmt.c b/gcc/stmt.c
> index 1a9f9e5..1fc09e9 100644
> --- a/gcc/stmt.c
> +++ b/gcc/stmt.c
> @@ -1114,13 +1114,34 @@ expand_asm_operands (tree string, tree outputs, tree inputs,
>   free_temp_slots ();
>  }
>
> +/* Return the operands of STMT, a GIMPLE_ASM, as described by OP_FN and
> +   N_OPS connected via TREE_CHAIN.  */
> +
> +static tree
> +chain_asm_ops (const_gimple stmt, unsigned (*n_ops) (const_gimple),
> +              tree (*op_fn) (const_gimple, unsigned))
> +{
> +  unsigned i, n;
> +  tree ret = NULL_TREE, t;
> +
> +  n = (*n_ops) (stmt);
> +  if (n > 0)
> +    {
> +      t = ret = (*op_fn) (stmt, 0);
> +      for (i = 1; i < n; i++)
> +       t = TREE_CHAIN (t) = (*op_fn) (stmt, i);
> +    }
> +
> +  return ret;
> +}
> +
>  void
>  expand_asm_stmt (gimple stmt)
>  {
>   int noutputs;
> -  tree outputs, tail, t;
> +  tree outputs, tail;
>   tree *o;
> -  size_t i, n;
> +  size_t i;
>   const char *s;
>   tree str, out, in, cl, labels;
>   location_t locus = gimple_location (stmt);
> @@ -1128,41 +1149,10 @@ expand_asm_stmt (gimple stmt)
>   /* Meh... convert the gimple asm operands into real tree lists.
>      Eventually we should make all routines work on the vectors instead
>      of relying on TREE_CHAIN.  */
> -  out = NULL_TREE;
> -  n = gimple_asm_noutputs (stmt);
> -  if (n > 0)
> -    {
> -      t = out = gimple_asm_output_op (stmt, 0);
> -      for (i = 1; i < n; i++)
> -       t = TREE_CHAIN (t) = gimple_asm_output_op (stmt, i);
> -    }
> -
> -  in = NULL_TREE;
> -  n = gimple_asm_ninputs (stmt);
> -  if (n > 0)
> -    {
> -      t = in = gimple_asm_input_op (stmt, 0);
> -      for (i = 1; i < n; i++)
> -       t = TREE_CHAIN (t) = gimple_asm_input_op (stmt, i);
> -    }
> -
> -  cl = NULL_TREE;
> -  n = gimple_asm_nclobbers (stmt);
> -  if (n > 0)
> -    {
> -      t = cl = gimple_asm_clobber_op (stmt, 0);
> -      for (i = 1; i < n; i++)
> -       t = TREE_CHAIN (t) = gimple_asm_clobber_op (stmt, i);
> -    }
> -
> -  labels = NULL_TREE;
> -  n = gimple_asm_nlabels (stmt);
> -  if (n > 0)
> -    {
> -      t = labels = gimple_asm_label_op (stmt, 0);
> -      for (i = 1; i < n; i++)
> -       t = TREE_CHAIN (t) = gimple_asm_label_op (stmt, i);
> -    }
> +  out = chain_asm_ops (stmt, gimple_asm_noutputs, gimple_asm_output_op);
> +  in = chain_asm_ops (stmt, gimple_asm_ninputs, gimple_asm_input_op);
> +  cl = chain_asm_ops (stmt, gimple_asm_nclobbers, gimple_asm_clobber_op);
> +  labels = chain_asm_ops (stmt, gimple_asm_nlabels, gimple_asm_label_op);
>
>   s = gimple_asm_string (stmt);
>   str = build_string (strlen (s), s);
>