On Fri, Aug 30, 2024 at 1:02 AM Andrew Pinski <[email protected]> wrote:
>
> This is a small speed up of the expansion of __builtin_prefetch.
> Basically for the optional arguments, no reason to call expand_normal
> on a constant integer that we know the value, just replace it with
> GEN_INT/const0_rtx instead.
>
> Bootstrapped and tested on x86_64-linux.
OK
> gcc/ChangeLog:
>
> * builtins.cc (expand_builtin_prefetch): Rewrite expansion of the
> optional
> arguments to not expand known constants.
> ---
> gcc/builtins.cc | 28 ++++++++++++++--------------
> 1 file changed, 14 insertions(+), 14 deletions(-)
>
> diff --git a/gcc/builtins.cc b/gcc/builtins.cc
> index b4d51eaeba5..37c7c98e5c7 100644
> --- a/gcc/builtins.cc
> +++ b/gcc/builtins.cc
> @@ -1280,25 +1280,22 @@ expand_builtin_prefetch (tree exp)
> zero (read) and argument 2 (locality) defaults to 3 (high degree of
> locality). */
> nargs = call_expr_nargs (exp);
> - if (nargs > 1)
> - arg1 = CALL_EXPR_ARG (exp, 1);
> - else
> - arg1 = integer_zero_node;
> - if (nargs > 2)
> - arg2 = CALL_EXPR_ARG (exp, 2);
> - else
> - arg2 = integer_three_node;
> + arg1 = nargs > 1 ? CALL_EXPR_ARG (exp, 1) : NULL_TREE;
> + arg2 = nargs > 2 ? CALL_EXPR_ARG (exp, 2) : NULL_TREE;
>
> /* Argument 0 is an address. */
> op0 = expand_expr (arg0, NULL_RTX, Pmode, EXPAND_NORMAL);
>
> /* Argument 1 (read/write flag) must be a compile-time constant int. */
> - if (TREE_CODE (arg1) != INTEGER_CST)
> + if (arg1 == NULL_TREE)
> + op1 = const0_rtx;
> + else if (TREE_CODE (arg1) != INTEGER_CST)
> {
> error ("second argument to %<__builtin_prefetch%> must be a constant");
> - arg1 = integer_zero_node;
> + op1 = const0_rtx;
> }
> - op1 = expand_normal (arg1);
> + else
> + op1 = expand_normal (arg1);
> /* Argument 1 must be either zero or one. */
> if (INTVAL (op1) != 0 && INTVAL (op1) != 1)
> {
> @@ -1308,12 +1305,15 @@ expand_builtin_prefetch (tree exp)
> }
>
> /* Argument 2 (locality) must be a compile-time constant int. */
> - if (TREE_CODE (arg2) != INTEGER_CST)
> + if (arg2 == NULL_TREE)
> + op2 = GEN_INT (3);
> + else if (TREE_CODE (arg2) != INTEGER_CST)
> {
> error ("third argument to %<__builtin_prefetch%> must be a constant");
> - arg2 = integer_zero_node;
> + op2 = const0_rtx;
> }
> - op2 = expand_normal (arg2);
> + else
> + op2 = expand_normal (arg2);
> /* Argument 2 must be 0, 1, 2, or 3. */
> if (INTVAL (op2) < 0 || INTVAL (op2) > 3)
> {
> --
> 2.43.0
>
