diff options
Diffstat (limited to 'gcc/tree-ssa-phiopt.cc')
| -rw-r--r-- | gcc/tree-ssa-phiopt.cc | 44 |
1 files changed, 32 insertions, 12 deletions
diff --git a/gcc/tree-ssa-phiopt.cc b/gcc/tree-ssa-phiopt.cc index e1c9e12..bdd1f73 100644 --- a/gcc/tree-ssa-phiopt.cc +++ b/gcc/tree-ssa-phiopt.cc @@ -3645,6 +3645,7 @@ cond_if_else_store_replacement_1 (basic_block then_bb, basic_block else_bb, gimple_stmt_iterator gsi; gphi *newphi; gassign *new_stmt; + bool empty_constructor = false; if (then_assign == NULL || !gimple_assign_single_p (then_assign) @@ -3659,8 +3660,7 @@ cond_if_else_store_replacement_1 (basic_block then_bb, basic_block else_bb, return false; lhs = gimple_assign_lhs (then_assign); - if (!is_gimple_reg_type (TREE_TYPE (lhs)) - || !operand_equal_p (lhs, gimple_assign_lhs (else_assign), 0)) + if (!operand_equal_p (lhs, gimple_assign_lhs (else_assign), 0)) return false; lhs_base = get_base_address (lhs); @@ -3673,6 +3673,16 @@ cond_if_else_store_replacement_1 (basic_block then_bb, basic_block else_bb, then_locus = gimple_location (then_assign); else_locus = gimple_location (else_assign); + if (!is_gimple_reg_type (TREE_TYPE (lhs))) + { + if (!operand_equal_p (then_rhs, else_rhs)) + return false; + /* Currently only handle commoning of `= {}`. */ + if (TREE_CODE (then_rhs) != CONSTRUCTOR) + return false; + empty_constructor = true; + } + if (dump_file && (dump_flags & TDF_DETAILS)) { fprintf(dump_file, "factoring out stores:\n\tthen:\n"); @@ -3699,12 +3709,17 @@ cond_if_else_store_replacement_1 (basic_block then_bb, basic_block else_bb, /* 2) Create a PHI node at the join block, with one argument holding the old RHS, and the other holding the temporary where we stored the old memory contents. */ - name = make_temp_ssa_name (TREE_TYPE (lhs), NULL, "cstore"); - newphi = create_phi_node (name, join_bb); - add_phi_arg (newphi, then_rhs, EDGE_SUCC (then_bb, 0), then_locus); - add_phi_arg (newphi, else_rhs, EDGE_SUCC (else_bb, 0), else_locus); + if (empty_constructor) + name = unshare_expr (then_rhs); + else + { + name = make_temp_ssa_name (TREE_TYPE (lhs), NULL, "cstore"); + newphi = create_phi_node (name, join_bb); + add_phi_arg (newphi, then_rhs, EDGE_SUCC (then_bb, 0), then_locus); + add_phi_arg (newphi, else_rhs, EDGE_SUCC (else_bb, 0), else_locus); + } - new_stmt = gimple_build_assign (lhs, gimple_phi_result (newphi)); + new_stmt = gimple_build_assign (lhs, name); /* Update the vdef for the new store statement. */ tree newvphilhs = make_ssa_name (gimple_vop (cfun)); tree vdef = gimple_phi_result (vphi); @@ -3715,16 +3730,21 @@ cond_if_else_store_replacement_1 (basic_block then_bb, basic_block else_bb, update_stmt (vphi); if (dump_file && (dump_flags & TDF_DETAILS)) { - fprintf(dump_file, "to use phi:\n"); - print_gimple_stmt (dump_file, newphi, 0, - TDF_VOPS|TDF_MEMSYMS); - fprintf(dump_file, "\n"); + if (!empty_constructor) + { + fprintf(dump_file, "to use phi:\n"); + print_gimple_stmt (dump_file, newphi, 0, + TDF_VOPS|TDF_MEMSYMS); + fprintf(dump_file, "\n"); + } + else + fprintf(dump_file, "to:\n"); print_gimple_stmt (dump_file, new_stmt, 0, TDF_VOPS|TDF_MEMSYMS); fprintf(dump_file, "\n\n"); } - /* 3) Insert that PHI node. */ + /* 3) Insert that new store. */ gsi = gsi_after_labels (join_bb); if (gsi_end_p (gsi)) { |