On Sun, Jun 8, 2025 at 1:06 AM Andrew Pinski <quic_apin...@quicinc.com> wrote:
>
> Since r13-707-g68e0063397ba82 COND_EXPR in gimple assign does
> not have a special case for COND_EXPR and conditional as the first operand.
> This removes the code from tree-ssa-math-opts.cc which was for that special
> case.
>
> Bootstrapped and tested on x86_64-linux-gnu.
>
> PR tree-optimization/120477
> gcc/ChangeLog:
>
> * tree-ssa-math-opts.cc (maybe_optimize_guarding_check): Remove
> special case for COND_EXPR.
> (arith_overflow_check_p): Likewise.
> (match_arith_overflow): Likewise, changing into a gcc_unreachable.
>
> Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
> ---
> gcc/tree-ssa-math-opts.cc | 58 ++-------------------------------------
> 1 file changed, 3 insertions(+), 55 deletions(-)
>
> diff --git a/gcc/tree-ssa-math-opts.cc b/gcc/tree-ssa-math-opts.cc
> index 7e819f37446..d5f18540ffd 100644
> --- a/gcc/tree-ssa-math-opts.cc
> +++ b/gcc/tree-ssa-math-opts.cc
> @@ -3775,20 +3775,7 @@ maybe_optimize_guarding_check (vec<gimple *>
> &mul_stmts, gimple *cond_stmt,
> if (gimple_phi_arg_def (phi, succ_edge->dest_idx) != lhs)
> return;
> tree other_val = gimple_phi_arg_def (phi, other_edge->dest_idx);
> - if (gimple_assign_rhs_code (cond_stmt) == COND_EXPR)
> - {
> - tree cond = gimple_assign_rhs1 (cond_stmt);
> - if (TREE_CODE (cond) == NE_EXPR)
> - {
> - if (!operand_equal_p (other_val,
> - gimple_assign_rhs3 (cond_stmt), 0))
> - return;
> - }
> - else if (!operand_equal_p (other_val,
> - gimple_assign_rhs2 (cond_stmt), 0))
> - return;
So this last check would still do something - it's not clear from the
context that we can
elide this? Shouldn't we keep
if (gimple_assign_rhs_code (cond_stmt) == COND_EXPR)
return;
as you remove all COND_EXPR handling elsewhere? Jakub probably knows this code
best.
Richard.
> - }
> - else if (gimple_assign_rhs_code (cond_stmt) == NE_EXPR)
> + if (gimple_assign_rhs_code (cond_stmt) == NE_EXPR)
> {
> if (!integer_zerop (other_val))
> return;
> @@ -3903,18 +3890,6 @@ arith_overflow_check_p (gimple *stmt, gimple
> *cast_stmt, gimple *&use_stmt,
> crhs1 = gimple_assign_rhs1 (cur_use_stmt);
> crhs2 = gimple_assign_rhs2 (cur_use_stmt);
> }
> - else if (gimple_assign_rhs_code (cur_use_stmt) == COND_EXPR)
> - {
> - tree cond = gimple_assign_rhs1 (cur_use_stmt);
> - if (COMPARISON_CLASS_P (cond))
> - {
> - ccode = TREE_CODE (cond);
> - crhs1 = TREE_OPERAND (cond, 0);
> - crhs2 = TREE_OPERAND (cond, 1);
> - }
> - else
> - return 0;
> - }
> else
> return 0;
> }
> @@ -3947,18 +3922,6 @@ arith_overflow_check_p (gimple *stmt, gimple
> *cast_stmt, gimple *&use_stmt,
> crhs1 = gimple_assign_rhs1 (cur_use_stmt);
> crhs2 = gimple_assign_rhs2 (cur_use_stmt);
> }
> - else if (gimple_assign_rhs_code (cur_use_stmt) == COND_EXPR)
> - {
> - tree cond = gimple_assign_rhs1 (cur_use_stmt);
> - if (COMPARISON_CLASS_P (cond))
> - {
> - ccode = TREE_CODE (cond);
> - crhs1 = TREE_OPERAND (cond, 0);
> - crhs2 = TREE_OPERAND (cond, 1);
> - }
> - else
> - return 0;
> - }
> else
> {
> enum tree_code sc = gimple_assign_rhs_code (cur_use_stmt);
> @@ -4827,15 +4790,7 @@ match_arith_overflow (gimple_stmt_iterator *gsi,
> gimple *stmt,
> else if (gimple_assign_cast_p (use_stmt))
> gimple_assign_set_rhs1 (use_stmt, ovf);
> else
> - {
> - tree_code sc = gimple_assign_rhs_code (use_stmt);
> - gcc_checking_assert (sc == COND_EXPR);
> - tree cond = gimple_assign_rhs1 (use_stmt);
> - cond = build2 (TREE_CODE (cond),
> - boolean_type_node, ovf,
> - build_int_cst (type, 0));
> - gimple_assign_set_rhs1 (use_stmt, cond);
> - }
> + gcc_unreachable();
> }
> update_stmt (use_stmt);
> gsi_remove (&gsiu, true);
> @@ -4853,14 +4808,7 @@ match_arith_overflow (gimple_stmt_iterator *gsi,
> gimple *stmt,
> }
> }
> else
> - {
> - gcc_checking_assert (gimple_assign_rhs_code (use_stmt)
> - == COND_EXPR);
> - tree cond = build2 (ovf_use == 1 ? NE_EXPR : EQ_EXPR,
> - boolean_type_node, ovf,
> - build_int_cst (type, 0));
> - gimple_assign_set_rhs1 (use_stmt, cond);
> - }
> + gcc_unreachable ();
> }
> update_stmt (use_stmt);
> if (code == MULT_EXPR && use_stmt != orig_use_stmt)
> --
> 2.43.0
>
