On Sat, Jun 19, 2021 at 10:51 PM apinski--- via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> From: Andrew Pinski <apin...@marvell.com>
>
> Since match and simplify does not have all of the inverted
> comparison patterns, it make sense to just have
> phi-opt try to do the inversion and try match and simplify again.
>
> OK? Bootstrapped and tested on x86_64-linux-gnu.
OK.
Richard.
> Thanks,
> Andrew Pinski
>
> gcc/ChangeLog:
>
> * tree-ssa-phiopt.c (match_simplify_replacement):
> If "A ? B : C" fails to simplify, try "(!A) ? C : B".
> ---
> gcc/tree-ssa-phiopt.c | 21 ++++++++++++++++++++-
> 1 file changed, 20 insertions(+), 1 deletion(-)
>
> diff --git a/gcc/tree-ssa-phiopt.c b/gcc/tree-ssa-phiopt.c
> index feb8ca8d0d1..3b3762a668b 100644
> --- a/gcc/tree-ssa-phiopt.c
> +++ b/gcc/tree-ssa-phiopt.c
> @@ -879,7 +879,26 @@ match_simplify_replacement (basic_block cond_bb,
> basic_block middle_bb,
> arg0, arg1,
> &seq, NULL);
> if (!result)
> - return false;
> + {
> + /* Try !A ? arg1 : arg0 instead.
> + Not all match patterns support inverted comparisons. */
> + enum tree_code comp_code = gimple_cond_code (stmt);
> + tree cmp0 = gimple_cond_lhs (stmt);
> + tree cmp1 = gimple_cond_rhs (stmt);
> + comp_code = invert_tree_comparison (comp_code, HONOR_NANS (cmp0));
> + if (comp_code != ERROR_MARK)
> + {
> + cond = build2_loc (gimple_location (stmt),
> + comp_code, boolean_type_node,
> + cmp0, cmp1);
> + result = gimple_simplify (COND_EXPR, type,
> + cond,
> + arg1, arg0,
> + &seq, NULL);
> + }
> + if (!result)
> + return false;
> + }
>
> gsi = gsi_last_bb (cond_bb);
> if (stmt_to_move)
> --
> 2.27.0
>
