On Mon, Apr 24, 2023 at 11:33 PM Andrew Pinski via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> In the early PHIOPT mode, the original minmax_replacement, would
> replace a PHI node with up to 2 min/max expressions in some cases,
> this allows for that too.
>
> OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
OK.
> gcc/ChangeLog:
>
> * tree-ssa-phiopt.cc (phiopt_early_allow): Allow for
> up to 2 min/max expressions in the sequence/match code.
> ---
> gcc/tree-ssa-phiopt.cc | 16 +++++++++++++++-
> 1 file changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/gcc/tree-ssa-phiopt.cc b/gcc/tree-ssa-phiopt.cc
> index fb2d2c9fc1a..de1896aa91a 100644
> --- a/gcc/tree-ssa-phiopt.cc
> +++ b/gcc/tree-ssa-phiopt.cc
> @@ -542,9 +542,23 @@ phiopt_early_allow (gimple_seq &seq, gimple_match_op &op)
> return false;
> tree_code code = (tree_code)op.code;
>
> - /* For non-empty sequence, only allow one statement. */
> + /* For non-empty sequence, only allow one statement
> + except for MIN/MAX, allow max 2 statements,
> + each with MIN/MAX. */
> if (!gimple_seq_empty_p (seq))
> {
> + if (code == MIN_EXPR || code == MAX_EXPR)
> + {
> + if (!gimple_seq_singleton_p (seq))
> + return false;
> +
> + gimple *stmt = gimple_seq_first_stmt (seq);
> + /* Only allow assignments. */
> + if (!is_gimple_assign (stmt))
> + return false;
> + code = gimple_assign_rhs_code (stmt);
> + return code == MIN_EXPR || code == MAX_EXPR;
> + }
> /* Check to make sure op was already a SSA_NAME. */
> if (code != SSA_NAME)
> return false;
> --
> 2.39.1
>
