diff options
Diffstat (limited to 'gcc-4.4.0/gcc/tree-ssa-pre.c')
| -rw-r--r-- | gcc-4.4.0/gcc/tree-ssa-pre.c | 89 |
1 files changed, 78 insertions, 11 deletions
diff --git a/gcc-4.4.0/gcc/tree-ssa-pre.c b/gcc-4.4.0/gcc/tree-ssa-pre.c index 9d931c496..d667e5c09 100644 --- a/gcc-4.4.0/gcc/tree-ssa-pre.c +++ b/gcc-4.4.0/gcc/tree-ssa-pre.c @@ -1459,10 +1459,16 @@ phi_translate_1 (pre_expr expr, bitmap_set_t set1, bitmap_set_t set2, continue; else { + pre_expr leader, result; + bitmap temp = BITMAP_ALLOC (&grand_bitmap_obstack); unsigned int op_val_id = VN_INFO (newnary.op[i])->value_id; - pre_expr leader = find_leader_in_sets (op_val_id, set1, set2); - pre_expr result = phi_translate_1 (leader, set1, set2, - pred, phiblock, seen); + + bitmap_copy (temp, seen); + leader = find_leader_in_sets (op_val_id, set1, set2); + result = phi_translate_1 (leader, set1, set2, + pred, phiblock, seen); + bitmap_copy (seen, temp); + BITMAP_FREE (temp); if (result && result != leader) { tree name = get_representative_for (result); @@ -3153,9 +3159,10 @@ insert_into_preds_of_block (basic_block block, unsigned int exprnum, gcc_assert (get_expr_type (ae) == type || useless_type_conversion_p (type, get_expr_type (ae))); if (ae->kind == CONSTANT) - add_phi_arg (phi, PRE_EXPR_CONSTANT (ae), pred); + add_phi_arg (phi, PRE_EXPR_CONSTANT (ae), pred, UNKNOWN_LOCATION); else - add_phi_arg (phi, PRE_EXPR_NAME (avail[pred->src->index]), pred); + add_phi_arg (phi, PRE_EXPR_NAME (avail[pred->src->index]), pred, + UNKNOWN_LOCATION); } newphi = get_or_alloc_expr_for_name (gimple_phi_result (phi)); @@ -3234,6 +3241,7 @@ do_regular_insertion (basic_block block, basic_block dom) pre_expr eprime = NULL; edge_iterator ei; pre_expr edoubleprime = NULL; + bool do_insertion = false; val = get_expr_value_id (expr); if (bitmap_set_contains_value (PHI_GEN (block), val)) @@ -3285,6 +3293,10 @@ do_regular_insertion (basic_block block, basic_block dom) { avail[bprime->index] = edoubleprime; by_some = true; + /* We want to perform insertions to remove a redundancy on + a path in the CFG we want to optimize for speed. */ + if (optimize_edge_for_speed_p (pred)) + do_insertion = true; if (first_s == NULL) first_s = edoubleprime; else if (!pre_expr_eq (first_s, edoubleprime)) @@ -3295,7 +3307,8 @@ do_regular_insertion (basic_block block, basic_block dom) already existing along every predecessor, and it's defined by some predecessor, it is partially redundant. */ - if (!cant_insert && !all_same && by_some && dbg_cnt (treepre_insert)) + if (!cant_insert && !all_same && by_some && do_insertion + && dbg_cnt (treepre_insert)) { if (insert_into_preds_of_block (block, get_expression_id (expr), avail)) @@ -3857,7 +3870,7 @@ eliminate (void) { gimple_stmt_iterator i; - for (i = gsi_start_bb (b); !gsi_end_p (i); gsi_next (&i)) + for (i = gsi_start_bb (b); !gsi_end_p (i);) { gimple stmt = gsi_stmt (i); @@ -3915,6 +3928,7 @@ eliminate (void) propagate_tree_value_into_stmt (&i, sprime); stmt = gsi_stmt (i); update_stmt (stmt); + gsi_next (&i); continue; } @@ -3975,6 +3989,58 @@ eliminate (void) } } } + /* If the statement is a scalar store, see if the expression + has the same value number as its rhs. If so, the store is + dead. */ + else if (gimple_assign_single_p (stmt) + && !is_gimple_reg (gimple_assign_lhs (stmt)) + && (TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME + || is_gimple_min_invariant (gimple_assign_rhs1 (stmt)))) + { + tree rhs = gimple_assign_rhs1 (stmt); + tree val; + val = vn_reference_lookup (gimple_assign_lhs (stmt), + shared_vuses_from_stmt (stmt), + true, NULL); + if (TREE_CODE (rhs) == SSA_NAME) + rhs = VN_INFO (rhs)->valnum; + if (val + && operand_equal_p (val, rhs, 0)) + { + def_operand_p def; + use_operand_p use; + vuse_vec_p usevec; + ssa_op_iter oi; + imm_use_iterator ui; + gimple use_stmt; + + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "Deleted dead store "); + print_gimple_stmt (dump_file, stmt, 0, 0); + } + + /* Propagate all may-uses to the uses of their defs. */ + FOR_EACH_SSA_VDEF_OPERAND (def, usevec, stmt, oi) + { + tree vuse = VUSE_ELEMENT_VAR (*usevec, 0); + tree vdef = DEF_FROM_PTR (def); + + /* If the vdef is used in an abnormal PHI node we + have to propagate that flag to the vuse as well. */ + if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (vdef)) + SSA_NAME_OCCURS_IN_ABNORMAL_PHI (vuse) = 1; + + FOR_EACH_IMM_USE_STMT (use_stmt, ui, vdef) + FOR_EACH_IMM_USE_ON_STMT (use, ui) + SET_USE (use, vuse); + } + + gsi_remove (&i, true); + release_defs (stmt); + continue; + } + } /* Visit COND_EXPRs and fold the comparison with the available value-numbers. */ else if (gimple_code (stmt) == GIMPLE_COND) @@ -3999,6 +4065,8 @@ eliminate (void) todo = TODO_cleanup_cfg; } } + + gsi_next (&i); } } @@ -4220,11 +4288,11 @@ fini_pre (bool do_fre) only wants to do full redundancy elimination. */ static unsigned int -execute_pre (bool do_fre ATTRIBUTE_UNUSED) +execute_pre (bool do_fre) { unsigned int todo = 0; - do_partial_partial = optimize > 2; + do_partial_partial = optimize > 2 && optimize_function_for_speed_p (cfun); /* This has to happen before SCCVN runs because loop_optimizer_init may create new phis, etc. */ @@ -4308,8 +4376,7 @@ do_pre (void) static bool gate_pre (void) { - /* PRE tends to generate bigger code. */ - return flag_tree_pre != 0 && optimize_function_for_speed_p (cfun); + return flag_tree_pre != 0; } struct gimple_opt_pass pass_pre = |