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author | upstream source tree <ports@midipix.org> | 2015-03-15 20:14:05 -0400 |
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committer | upstream source tree <ports@midipix.org> | 2015-03-15 20:14:05 -0400 |
commit | 554fd8c5195424bdbcabf5de30fdc183aba391bd (patch) | |
tree | 976dc5ab7fddf506dadce60ae936f43f58787092 /gcc/cp/optimize.c | |
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Diffstat (limited to 'gcc/cp/optimize.c')
-rw-r--r-- | gcc/cp/optimize.c | 437 |
1 files changed, 437 insertions, 0 deletions
diff --git a/gcc/cp/optimize.c b/gcc/cp/optimize.c new file mode 100644 index 000000000..2ce9838a7 --- /dev/null +++ b/gcc/cp/optimize.c @@ -0,0 +1,437 @@ +/* Perform optimizations on tree structure. + Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004, 2005, 2007, 2008, 2009, + 2010 Free Software Foundation, Inc. + Written by Mark Michell (mark@codesourcery.com). + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it +under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 3, or (at your option) +any later version. + +GCC is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING3. If not see +<http://www.gnu.org/licenses/>. */ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tm.h" +#include "tree.h" +#include "cp-tree.h" +#include "input.h" +#include "params.h" +#include "hashtab.h" +#include "target.h" +#include "debug.h" +#include "tree-inline.h" +#include "flags.h" +#include "langhooks.h" +#include "diagnostic-core.h" +#include "tree-dump.h" +#include "gimple.h" +#include "tree-iterator.h" +#include "cgraph.h" + +/* Prototypes. */ + +static void update_cloned_parm (tree, tree, bool); + +/* CLONED_PARM is a copy of CLONE, generated for a cloned constructor + or destructor. Update it to ensure that the source-position for + the cloned parameter matches that for the original, and that the + debugging generation code will be able to find the original PARM. */ + +static void +update_cloned_parm (tree parm, tree cloned_parm, bool first) +{ + DECL_ABSTRACT_ORIGIN (cloned_parm) = parm; + + /* We may have taken its address. */ + TREE_ADDRESSABLE (cloned_parm) = TREE_ADDRESSABLE (parm); + + /* The definition might have different constness. */ + TREE_READONLY (cloned_parm) = TREE_READONLY (parm); + + TREE_USED (cloned_parm) = !first || TREE_USED (parm); + + /* The name may have changed from the declaration. */ + DECL_NAME (cloned_parm) = DECL_NAME (parm); + DECL_SOURCE_LOCATION (cloned_parm) = DECL_SOURCE_LOCATION (parm); + TREE_TYPE (cloned_parm) = TREE_TYPE (parm); + + DECL_GIMPLE_REG_P (cloned_parm) = DECL_GIMPLE_REG_P (parm); +} + + +/* FN is a function in High GIMPLE form that has a complete body and no + CFG. CLONE is a function whose body is to be set to a copy of FN, + mapping argument declarations according to the ARG_MAP splay_tree. */ + +static void +clone_body (tree clone, tree fn, void *arg_map) +{ + copy_body_data id; + tree stmts; + + /* Clone the body, as if we were making an inline call. But, remap + the parameters in the callee to the parameters of caller. */ + memset (&id, 0, sizeof (id)); + id.src_fn = fn; + id.dst_fn = clone; + id.src_cfun = DECL_STRUCT_FUNCTION (fn); + id.decl_map = (struct pointer_map_t *) arg_map; + + id.copy_decl = copy_decl_no_change; + id.transform_call_graph_edges = CB_CGE_DUPLICATE; + id.transform_new_cfg = true; + id.transform_return_to_modify = false; + id.transform_lang_insert_block = NULL; + + /* We're not inside any EH region. */ + id.eh_lp_nr = 0; + + stmts = DECL_SAVED_TREE (fn); + walk_tree (&stmts, copy_tree_body_r, &id, NULL); + + /* Also remap the initializer of any static variables so that they (in + particular, any label addresses) correspond to the base variant rather + than the abstract one. */ + if (DECL_NAME (clone) == base_dtor_identifier + || DECL_NAME (clone) == base_ctor_identifier) + { + unsigned ix; + tree decl; + + FOR_EACH_LOCAL_DECL (DECL_STRUCT_FUNCTION (fn), ix, decl) + walk_tree (&DECL_INITIAL (decl), copy_tree_body_r, &id, NULL); + } + + append_to_statement_list_force (stmts, &DECL_SAVED_TREE (clone)); +} + +/* DELETE_DTOR is a delete destructor whose body will be built. + COMPLETE_DTOR is the corresponding complete destructor. */ + +static void +build_delete_destructor_body (tree delete_dtor, tree complete_dtor) +{ + tree call_dtor, call_delete; + tree parm = DECL_ARGUMENTS (delete_dtor); + tree virtual_size = cxx_sizeof (current_class_type); + + /* Call the corresponding complete destructor. */ + gcc_assert (complete_dtor); + call_dtor = build_cxx_call (complete_dtor, 1, &parm); + add_stmt (call_dtor); + + add_stmt (build_stmt (0, LABEL_EXPR, cdtor_label)); + + /* Call the delete function. */ + call_delete = build_op_delete_call (DELETE_EXPR, current_class_ptr, + virtual_size, + /*global_p=*/false, + /*placement=*/NULL_TREE, + /*alloc_fn=*/NULL_TREE); + add_stmt (call_delete); + + /* Return the address of the object. */ + if (targetm.cxx.cdtor_returns_this ()) + { + tree val = DECL_ARGUMENTS (delete_dtor); + val = build2 (MODIFY_EXPR, TREE_TYPE (val), + DECL_RESULT (delete_dtor), val); + add_stmt (build_stmt (0, RETURN_EXPR, val)); + } +} + +/* Return name of comdat group for complete and base ctor (or dtor) + that have the same body. If dtor is virtual, deleting dtor goes + into this comdat group as well. */ + +static tree +cdtor_comdat_group (tree complete, tree base) +{ + tree complete_name = DECL_COMDAT_GROUP (complete); + tree base_name = DECL_COMDAT_GROUP (base); + char *grp_name; + const char *p, *q; + bool diff_seen = false; + size_t idx; + if (complete_name == NULL) + complete_name = cxx_comdat_group (complete); + if (base_name == NULL) + base_name = cxx_comdat_group (base); + gcc_assert (IDENTIFIER_LENGTH (complete_name) + == IDENTIFIER_LENGTH (base_name)); + grp_name = XALLOCAVEC (char, IDENTIFIER_LENGTH (complete_name) + 1); + p = IDENTIFIER_POINTER (complete_name); + q = IDENTIFIER_POINTER (base_name); + for (idx = 0; idx < IDENTIFIER_LENGTH (complete_name); idx++) + if (p[idx] == q[idx]) + grp_name[idx] = p[idx]; + else + { + gcc_assert (!diff_seen + && idx > 0 + && (p[idx - 1] == 'C' || p[idx - 1] == 'D') + && p[idx] == '1' + && q[idx] == '2'); + grp_name[idx] = '5'; + diff_seen = true; + } + grp_name[idx] = '\0'; + gcc_assert (diff_seen); + return get_identifier (grp_name); +} + +/* FN is a function that has a complete body. Clone the body as + necessary. Returns nonzero if there's no longer any need to + process the main body. */ + +bool +maybe_clone_body (tree fn) +{ + tree comdat_group = NULL_TREE; + tree clone; + tree fns[3]; + bool first = true; + bool in_charge_parm_used; + int idx; + bool need_alias = false; + + /* We only clone constructors and destructors. */ + if (!DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn) + && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn)) + return 0; + + /* Emit the DWARF1 abstract instance. */ + (*debug_hooks->deferred_inline_function) (fn); + + in_charge_parm_used = CLASSTYPE_VBASECLASSES (DECL_CONTEXT (fn)) != NULL; + fns[0] = NULL_TREE; + fns[1] = NULL_TREE; + fns[2] = NULL_TREE; + + /* Look for the complete destructor which may be used to build the + delete destructor. */ + FOR_EACH_CLONE (clone, fn) + if (DECL_NAME (clone) == complete_dtor_identifier + || DECL_NAME (clone) == complete_ctor_identifier) + fns[1] = clone; + else if (DECL_NAME (clone) == base_dtor_identifier + || DECL_NAME (clone) == base_ctor_identifier) + fns[0] = clone; + else if (DECL_NAME (clone) == deleting_dtor_identifier) + fns[2] = clone; + else + gcc_unreachable (); + + /* Remember if we can't have multiple clones for some reason. We need to + check this before we remap local static initializers in clone_body. */ + if (!tree_versionable_function_p (fn)) + need_alias = true; + + /* We know that any clones immediately follow FN in the TYPE_METHODS + list. */ + push_to_top_level (); + for (idx = 0; idx < 3; idx++) + { + tree parm; + tree clone_parm; + int parmno; + bool alias = false; + struct pointer_map_t *decl_map; + + clone = fns[idx]; + if (!clone) + continue; + + /* Update CLONE's source position information to match FN's. */ + DECL_SOURCE_LOCATION (clone) = DECL_SOURCE_LOCATION (fn); + DECL_DECLARED_INLINE_P (clone) = DECL_DECLARED_INLINE_P (fn); + DECL_DECLARED_CONSTEXPR_P (clone) = DECL_DECLARED_CONSTEXPR_P (fn); + DECL_COMDAT (clone) = DECL_COMDAT (fn); + DECL_WEAK (clone) = DECL_WEAK (fn); + + /* We don't copy the comdat group from fn to clone because the assembler + name of fn was corrupted by write_mangled_name by adding *INTERNAL* + to it. By doing so, it also corrupted the comdat group. */ + if (DECL_ONE_ONLY (fn)) + DECL_COMDAT_GROUP (clone) = cxx_comdat_group (clone); + DECL_SECTION_NAME (clone) = DECL_SECTION_NAME (fn); + DECL_USE_TEMPLATE (clone) = DECL_USE_TEMPLATE (fn); + DECL_EXTERNAL (clone) = DECL_EXTERNAL (fn); + DECL_INTERFACE_KNOWN (clone) = DECL_INTERFACE_KNOWN (fn); + DECL_NOT_REALLY_EXTERN (clone) = DECL_NOT_REALLY_EXTERN (fn); + TREE_PUBLIC (clone) = TREE_PUBLIC (fn); + DECL_VISIBILITY (clone) = DECL_VISIBILITY (fn); + DECL_VISIBILITY_SPECIFIED (clone) = DECL_VISIBILITY_SPECIFIED (fn); + DECL_DLLIMPORT_P (clone) = DECL_DLLIMPORT_P (fn); + DECL_ATTRIBUTES (clone) = copy_list (DECL_ATTRIBUTES (fn)); + DECL_DISREGARD_INLINE_LIMITS (clone) = DECL_DISREGARD_INLINE_LIMITS (fn); + + /* Adjust the parameter names and locations. */ + parm = DECL_ARGUMENTS (fn); + clone_parm = DECL_ARGUMENTS (clone); + /* Update the `this' parameter, which is always first. */ + update_cloned_parm (parm, clone_parm, first); + parm = DECL_CHAIN (parm); + clone_parm = DECL_CHAIN (clone_parm); + if (DECL_HAS_IN_CHARGE_PARM_P (fn)) + parm = DECL_CHAIN (parm); + if (DECL_HAS_VTT_PARM_P (fn)) + parm = DECL_CHAIN (parm); + if (DECL_HAS_VTT_PARM_P (clone)) + clone_parm = DECL_CHAIN (clone_parm); + for (; parm; + parm = DECL_CHAIN (parm), clone_parm = DECL_CHAIN (clone_parm)) + /* Update this parameter. */ + update_cloned_parm (parm, clone_parm, first); + + /* Start processing the function. */ + start_preparsed_function (clone, NULL_TREE, SF_PRE_PARSED); + + /* Tell cgraph if both ctors or both dtors are known to have + the same body. */ + if (!in_charge_parm_used + && fns[0] + && idx == 1 + && !flag_use_repository + && DECL_INTERFACE_KNOWN (fns[0]) + && (SUPPORTS_ONE_ONLY || !DECL_WEAK (fns[0])) + && (!DECL_ONE_ONLY (fns[0]) + || (HAVE_COMDAT_GROUP + && DECL_WEAK (fns[0]))) + && cgraph_same_body_alias (cgraph_node (fns[0]), clone, fns[0])) + { + alias = true; + if (DECL_ONE_ONLY (fns[0])) + { + /* For comdat base and complete cdtors put them + into the same, *[CD]5* comdat group instead of + *[CD][12]*. */ + comdat_group = cdtor_comdat_group (fns[1], fns[0]); + DECL_COMDAT_GROUP (fns[0]) = comdat_group; + } + } + + /* Build the delete destructor by calling complete destructor + and delete function. */ + if (idx == 2) + build_delete_destructor_body (clone, fns[1]); + else if (alias) + /* No need to populate body. */ ; + else + { + /* If we can't have multiple copies of FN (say, because there's a + static local initialized with the address of a label), we need + to use an alias for the complete variant. */ + if (idx == 1 && need_alias) + { + if (DECL_STRUCT_FUNCTION (fn)->cannot_be_copied_set) + sorry (DECL_STRUCT_FUNCTION (fn)->cannot_be_copied_reason, fn); + else + sorry ("making multiple clones of %qD", fn); + } + + /* Remap the parameters. */ + decl_map = pointer_map_create (); + for (parmno = 0, + parm = DECL_ARGUMENTS (fn), + clone_parm = DECL_ARGUMENTS (clone); + parm; + ++parmno, + parm = DECL_CHAIN (parm)) + { + /* Map the in-charge parameter to an appropriate constant. */ + if (DECL_HAS_IN_CHARGE_PARM_P (fn) && parmno == 1) + { + tree in_charge; + in_charge = in_charge_arg_for_name (DECL_NAME (clone)); + *pointer_map_insert (decl_map, parm) = in_charge; + } + else if (DECL_ARTIFICIAL (parm) + && DECL_NAME (parm) == vtt_parm_identifier) + { + /* For a subobject constructor or destructor, the next + argument is the VTT parameter. Remap the VTT_PARM + from the CLONE to this parameter. */ + if (DECL_HAS_VTT_PARM_P (clone)) + { + DECL_ABSTRACT_ORIGIN (clone_parm) = parm; + *pointer_map_insert (decl_map, parm) = clone_parm; + clone_parm = DECL_CHAIN (clone_parm); + } + /* Otherwise, map the VTT parameter to `NULL'. */ + else + *pointer_map_insert (decl_map, parm) + = fold_convert (TREE_TYPE (parm), null_pointer_node); + } + /* Map other parameters to their equivalents in the cloned + function. */ + else + { + *pointer_map_insert (decl_map, parm) = clone_parm; + clone_parm = DECL_CHAIN (clone_parm); + } + } + + if (targetm.cxx.cdtor_returns_this ()) + { + parm = DECL_RESULT (fn); + clone_parm = DECL_RESULT (clone); + *pointer_map_insert (decl_map, parm) = clone_parm; + } + + /* Clone the body. */ + clone_body (clone, fn, decl_map); + + /* Clean up. */ + pointer_map_destroy (decl_map); + } + + /* The clone can throw iff the original function can throw. */ + cp_function_chain->can_throw = !TREE_NOTHROW (fn); + + /* Now, expand this function into RTL, if appropriate. */ + finish_function (0); + BLOCK_ABSTRACT_ORIGIN (DECL_INITIAL (clone)) = DECL_INITIAL (fn); + if (alias) + { + if (expand_or_defer_fn_1 (clone)) + emit_associated_thunks (clone); + } + else + expand_or_defer_fn (clone); + first = false; + } + pop_from_top_level (); + + if (comdat_group) + { + DECL_COMDAT_GROUP (fns[1]) = comdat_group; + if (fns[2]) + { + struct cgraph_node *base_dtor_node, *deleting_dtor_node; + /* If *[CD][12]* dtors go into the *[CD]5* comdat group and dtor is + virtual, it goes into the same comdat group as well. */ + DECL_COMDAT_GROUP (fns[2]) = comdat_group; + base_dtor_node = cgraph_node (fns[0]); + deleting_dtor_node = cgraph_node (fns[2]); + gcc_assert (base_dtor_node->same_comdat_group == NULL); + gcc_assert (deleting_dtor_node->same_comdat_group == NULL); + base_dtor_node->same_comdat_group = deleting_dtor_node; + deleting_dtor_node->same_comdat_group = base_dtor_node; + } + } + + /* We don't need to process the original function any further. */ + return 1; +} |