During analyzing PR111950 I found the loop live operation code-gen
odd, in particular only replacing a single PHI but then adjusting
possibly remaining PHIs afterwards where there shouldn't really
be any out-of-loop uses of the scalar in-loop def left.
Bootstrapped and tested together with another patch, quickly
re-testing after splitting out now.
Richard.
* tree-vect-loop.cc (vectorizable_live_operation): Simplify
LC PHI replacement.
---
gcc/tree-vect-loop.cc | 53 ++++++++++++++-----------------------------
1 file changed, 17 insertions(+), 36 deletions(-)
diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
index 2a43176bcfd..362856a6507 100644
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -10698,49 +10698,30 @@ vectorizable_live_operation (vec_info *vinfo,
stmt_vec_info stmt_info,
&stmts, true, NULL_TREE);
}
+ gimple_stmt_iterator exit_gsi = gsi_after_labels (exit_bb);
if (stmts)
- {
- gimple_stmt_iterator exit_gsi = gsi_after_labels (exit_bb);
- gsi_insert_seq_before (&exit_gsi, stmts, GSI_SAME_STMT);
+ gsi_insert_seq_before (&exit_gsi, stmts, GSI_SAME_STMT);
- /* Remove existing phi from lhs and create one copy from new_tree. */
- tree lhs_phi = NULL_TREE;
- gimple_stmt_iterator gsi;
- for (gsi = gsi_start_phis (exit_bb);
- !gsi_end_p (gsi); gsi_next (&gsi))
+ /* Remove existing phis that copy from lhs and create copies
+ from new_tree. */
+ gimple_stmt_iterator gsi;
+ for (gsi = gsi_start_phis (exit_bb); !gsi_end_p (gsi);)
+ {
+ gimple *phi = gsi_stmt (gsi);
+ if ((gimple_phi_arg_def (phi, 0) == lhs))
{
- gimple *phi = gsi_stmt (gsi);
- if ((gimple_phi_arg_def (phi, 0) == lhs))
- {
- remove_phi_node (&gsi, false);
- lhs_phi = gimple_phi_result (phi);
- gimple *copy = gimple_build_assign (lhs_phi, new_tree);
- gsi_insert_before (&exit_gsi, copy, GSI_SAME_STMT);
- break;
- }
+ remove_phi_node (&gsi, false);
+ tree lhs_phi = gimple_phi_result (phi);
+ gimple *copy = gimple_build_assign (lhs_phi, new_tree);
+ gsi_insert_before (&exit_gsi, copy, GSI_SAME_STMT);
}
+ else
+ gsi_next (&gsi);
}
- /* Replace use of lhs with newly computed result. If the use stmt is a
- single arg PHI, just replace all uses of PHI result. It's necessary
- because lcssa PHI defining lhs may be before newly inserted stmt. */
- use_operand_p use_p;
+ /* There a no further out-of-loop uses of lhs by LC-SSA construction. */
FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, lhs)
- if (!flow_bb_inside_loop_p (loop, gimple_bb (use_stmt))
- && !is_gimple_debug (use_stmt))
- {
- if (gimple_code (use_stmt) == GIMPLE_PHI
- && gimple_phi_num_args (use_stmt) == 1)
- {
- replace_uses_by (gimple_phi_result (use_stmt), new_tree);
- }
- else
- {
- FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter)
- SET_USE (use_p, new_tree);
- }
- update_stmt (use_stmt);
- }
+ gcc_assert (flow_bb_inside_loop_p (loop, gimple_bb (use_stmt)));
}
else
{
--
2.35.3
