diff options
Diffstat (limited to 'gcc/cp/cp-gimplify.cc')
| -rw-r--r-- | gcc/cp/cp-gimplify.cc | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/gcc/cp/cp-gimplify.cc b/gcc/cp/cp-gimplify.cc index 2111dca..1662336 100644 --- a/gcc/cp/cp-gimplify.cc +++ b/gcc/cp/cp-gimplify.cc @@ -200,6 +200,33 @@ genericize_if_stmt (tree *stmt_p) } } + if (IF_STMT_VACUOUS_INIT_P (stmt)) + { + gcc_checking_assert (integer_zerop (cond)); + gcc_checking_assert (!else_ || !TREE_SIDE_EFFECTS (else_)); + tree lab = create_artificial_label (UNKNOWN_LOCATION); + VACUOUS_INIT_LABEL_P (lab) = 1; + tree goto_expr = build_stmt (UNKNOWN_LOCATION, GOTO_EXPR, lab); + tree label_expr = build_stmt (UNKNOWN_LOCATION, LABEL_EXPR, lab); + if (TREE_CODE (then_) == STATEMENT_LIST) + { + tree_stmt_iterator i = tsi_start (then_); + tsi_link_before (&i, goto_expr, TSI_CONTINUE_LINKING); + i = tsi_last (then_); + tsi_link_after (&i, label_expr, TSI_CONTINUE_LINKING); + stmt = then_; + } + else + { + stmt = NULL_TREE; + append_to_statement_list (goto_expr, &stmt); + append_to_statement_list (then_, &stmt); + append_to_statement_list (label_expr, &stmt); + } + *stmt_p = stmt; + return; + } + if (!then_) then_ = build_empty_stmt (locus); if (!else_) @@ -603,6 +630,38 @@ cp_gimplify_arg (tree *arg_p, gimple_seq *pre_p, location_t call_location, } +/* Emit a decl = {CLOBBER(bob)}; stmt before DECL_EXPR or first + TARGET_EXPR gimplification for -flifetime-dse=2. */ + +static void +maybe_emit_clobber_object_begin (tree decl, gimple_seq *pre_p) +{ + if (VAR_P (decl) + && auto_var_p (decl) + && TREE_TYPE (decl) != error_mark_node + && DECL_NONTRIVIALLY_INITIALIZED_P (decl) + /* Don't do it if it is fully initialized. */ + && DECL_INITIAL (decl) == NULL_TREE + && !DECL_HAS_VALUE_EXPR_P (decl) + && !OPAQUE_TYPE_P (TREE_TYPE (decl)) + /* Nor going to have decl = .DEFERRED_INIT (...); added. */ + && (flag_auto_var_init == AUTO_INIT_UNINITIALIZED + || lookup_attribute ("uninitialized", DECL_ATTRIBUTES (decl)) + || lookup_attribute ("indeterminate", DECL_ATTRIBUTES (decl)))) + { + tree eltype = strip_array_types (TREE_TYPE (decl)); + if (RECORD_OR_UNION_TYPE_P (eltype) + && !is_empty_class (eltype)) + { + tree clobber + = build_clobber (TREE_TYPE (decl), CLOBBER_OBJECT_BEGIN); + gimple *g = gimple_build_assign (decl, clobber); + gimple_set_location (g, DECL_SOURCE_LOCATION (decl)); + gimple_seq_add_stmt_without_update (pre_p, g); + } + } +} + /* Do C++-specific gimplification. Args are as for gimplify_expr. */ int @@ -918,6 +977,10 @@ cp_gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p) on the rhs of an assignment, as in constexpr-aggr1.C. */ gcc_checking_assert (!TARGET_EXPR_ELIDING_P (*expr_p) || !TREE_ADDRESSABLE (TREE_TYPE (*expr_p))); + if (flag_lifetime_dse > 1 + && TARGET_EXPR_INITIAL (*expr_p) + && VOID_TYPE_P (TREE_TYPE (TARGET_EXPR_INITIAL (*expr_p)))) + maybe_emit_clobber_object_begin (TARGET_EXPR_SLOT (*expr_p), pre_p); ret = GS_UNHANDLED; break; @@ -929,6 +992,12 @@ cp_gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p) ret = GS_OK; break; + case DECL_EXPR: + if (flag_lifetime_dse > 1) + maybe_emit_clobber_object_begin (DECL_EXPR_DECL (*expr_p), pre_p); + ret = GS_UNHANDLED; + break; + case RETURN_EXPR: if (TREE_OPERAND (*expr_p, 0) && (TREE_CODE (TREE_OPERAND (*expr_p, 0)) == INIT_EXPR |