diff options
Diffstat (limited to 'gcc/tree-ssa-phiprop.c')
| -rw-r--r-- | gcc/tree-ssa-phiprop.c | 98 |
1 files changed, 58 insertions, 40 deletions
diff --git a/gcc/tree-ssa-phiprop.c b/gcc/tree-ssa-phiprop.c index 4e6e09c477d..6ccc30ec808 100644 --- a/gcc/tree-ssa-phiprop.c +++ b/gcc/tree-ssa-phiprop.c @@ -90,12 +90,12 @@ along with GCC; see the file COPYING3. If not see /* Structure to keep track of the value of a dereferenced PHI result - and the set of virtual operands used for that dereference. */ + and the virtual operand used for that dereference. */ struct phiprop_d { tree value; - gimple vop_stmt; + tree vuse; }; /* Verify if the value recorded for NAME in PHIVN is still valid at @@ -104,34 +104,27 @@ struct phiprop_d static bool phivn_valid_p (struct phiprop_d *phivn, tree name, basic_block bb) { - gimple vop_stmt = phivn[SSA_NAME_VERSION (name)].vop_stmt; - tree vuse; + tree vuse = phivn[SSA_NAME_VERSION (name)].vuse; + gimple use_stmt; + imm_use_iterator ui2; + bool ok = true; - /* The def stmts of all virtual uses need to be post-dominated - by bb. */ - if ((vuse = gimple_vuse (vop_stmt))) - { - gimple use_stmt; - imm_use_iterator ui2; - bool ok = true; + /* The def stmts of the virtual uses need to be dominated by bb. */ + gcc_assert (vuse != NULL_TREE); - FOR_EACH_IMM_USE_STMT (use_stmt, ui2, vuse) + FOR_EACH_IMM_USE_STMT (use_stmt, ui2, vuse) + { + /* If BB does not dominate a VDEF, the value is invalid. */ + if ((gimple_vdef (use_stmt) != NULL_TREE + || gimple_code (use_stmt) == GIMPLE_PHI) + && !dominated_by_p (CDI_DOMINATORS, gimple_bb (use_stmt), bb)) { - /* If BB does not dominate a VDEF, the value is invalid. */ - if (((is_gimple_assign (use_stmt) - && gimple_vdef (use_stmt)) - || gimple_code (use_stmt) == GIMPLE_PHI) - && !dominated_by_p (CDI_DOMINATORS, gimple_bb (use_stmt), bb)) - { - ok = false; - BREAK_FROM_IMM_USE_STMT (ui2); - } + ok = false; + BREAK_FROM_IMM_USE_STMT (ui2); } - if (!ok) - return false; } - return true; + return ok; } /* Insert a new phi node for the dereference of PHI at basic_block @@ -154,6 +147,12 @@ phiprop_insert_phi (basic_block bb, gimple phi, gimple use_stmt, res = gimple_assign_lhs (use_stmt); SSA_NAME_DEF_STMT (res) = new_phi = create_phi_node (res, bb); + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "Inserting PHI for result of load "); + print_gimple_stmt (dump_file, use_stmt, 0, 0); + } + /* Add PHI arguments for each edge inserting loads of the addressable operands. */ FOR_EACH_EDGE (e, ei, bb->preds) @@ -171,8 +170,19 @@ phiprop_insert_phi (basic_block bb, gimple phi, gimple use_stmt, } if (TREE_CODE (old_arg) == SSA_NAME) - /* Reuse a formerly created dereference. */ - new_var = phivn[SSA_NAME_VERSION (old_arg)].value; + { + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, " for edge defining "); + print_generic_expr (dump_file, PHI_ARG_DEF_FROM_EDGE (phi, e), 0); + fprintf (dump_file, " reusing PHI result "); + print_generic_expr (dump_file, + phivn[SSA_NAME_VERSION (old_arg)].value, 0); + fprintf (dump_file, "\n"); + } + /* Reuse a formerly created dereference. */ + new_var = phivn[SSA_NAME_VERSION (old_arg)].value; + } else { gcc_assert (TREE_CODE (old_arg) == ADDR_EXPR); @@ -188,9 +198,15 @@ phiprop_insert_phi (basic_block bb, gimple phi, gimple use_stmt, gimple_assign_set_lhs (tmp, new_var); gsi_insert_on_edge (e, tmp); - update_stmt (tmp); - mark_symbols_for_renaming (tmp); + + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, " for edge defining "); + print_generic_expr (dump_file, PHI_ARG_DEF_FROM_EDGE (phi, e), 0); + fprintf (dump_file, " inserting load "); + print_gimple_stmt (dump_file, tmp, 0, 0); + } } add_phi_arg (new_phi, new_var, e); @@ -198,6 +214,9 @@ phiprop_insert_phi (basic_block bb, gimple phi, gimple use_stmt, update_stmt (new_phi); + if (dump_file && (dump_flags & TDF_DETAILS)) + print_gimple_stmt (dump_file, new_phi, 0, 0); + return res; } @@ -270,6 +289,7 @@ propagate_with_phi (basic_block bb, gimple phi, struct phiprop_d *phivn, phi_inserted = false; FOR_EACH_IMM_USE_STMT (use_stmt, ui, ptr) { + gimple def_stmt; tree vuse; /* Check whether this is a load of *ptr. */ @@ -281,17 +301,15 @@ propagate_with_phi (basic_block bb, gimple phi, struct phiprop_d *phivn, && !stmt_can_throw_internal (use_stmt))) continue; - /* Check if we can move the loads. The def stmts of all virtual uses - need to be post-dominated by bb. */ - if ((vuse = gimple_vuse (use_stmt)) != NULL_TREE) - { - gimple def_stmt = SSA_NAME_DEF_STMT (vuse); - if (!SSA_NAME_IS_DEFAULT_DEF (vuse) - && (gimple_bb (def_stmt) == bb - || !dominated_by_p (CDI_DOMINATORS, - bb, gimple_bb (def_stmt)))) - goto next; - } + /* Check if we can move the loads. The def stmt of the virtual use + needs to be in a different basic block dominating bb. */ + vuse = gimple_vuse (use_stmt); + def_stmt = SSA_NAME_DEF_STMT (vuse); + if (!SSA_NAME_IS_DEFAULT_DEF (vuse) + && (gimple_bb (def_stmt) == bb + || !dominated_by_p (CDI_DOMINATORS, + bb, gimple_bb (def_stmt)))) + goto next; /* Found a proper dereference. Insert a phi node if this is the first load transformation. */ @@ -301,7 +319,7 @@ propagate_with_phi (basic_block bb, gimple phi, struct phiprop_d *phivn, /* Remember the value we created for *ptr. */ phivn[SSA_NAME_VERSION (ptr)].value = res; - phivn[SSA_NAME_VERSION (ptr)].vop_stmt = use_stmt; + phivn[SSA_NAME_VERSION (ptr)].vuse = vuse; /* Remove old stmt. The phi is taken care of by DCE, if we want to delete it here we also have to delete all intermediate |