#include "config.h"#include "system.h"#include "coretypes.h"#include "tm.h"#include "tree.h"#include "gimple.h"#include "rtl.h"#include "bitmap.h"#include "tree-cfg.h"#include "tree-inline.h"#include "langhooks.h"#include "pointer-set.h"#include "toplev.h"#include "flags.h"#include "ggc.h"#include "debug.h"#include "target.h"#include "diagnostic.h"#include "params.h"#include "intl.h"#include "function.h"#include "ipa-prop.h"#include "tree-iterator.h"#include "tree-dump.h"#include "gimple-pretty-print.h"#include "coverage.h"#include "ipa-inline.h"#include "ipa-utils.h"#include "lto-streamer.h"#include "except.h"#include "gt-cgraphclones.h"
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| struct cgraph_edge * | cgraph_clone_edge (struct cgraph_edge *e, struct cgraph_node *n, gimple call_stmt, unsigned stmt_uid, gcov_type count_scale, int freq_scale, bool update_original) |
| struct cgraph_node * | cgraph_clone_node (struct cgraph_node *n, tree decl, gcov_type count, int freq, bool update_original, vec< cgraph_edge_p > redirect_callers, bool call_duplication_hook, struct cgraph_node *new_inlined_to) |
| tree | clone_function_name () |
| struct cgraph_node * | cgraph_create_virtual_clone (struct cgraph_node *old_node, vec< cgraph_edge_p > redirect_callers, vec< ipa_replace_map_p, va_gc > *tree_map, bitmap args_to_skip, const char *suffix) |
| struct cgraph_node * | cgraph_find_replacement_node () |
| void | cgraph_set_call_stmt_including_clones (struct cgraph_node *orig, gimple old_stmt, gimple new_stmt, bool update_speculative) |
| void | cgraph_create_edge_including_clones (struct cgraph_node *orig, struct cgraph_node *callee, gimple old_stmt, gimple stmt, gcov_type count, int freq, cgraph_inline_failed_t reason) |
| bool | cgraph_remove_node_and_inline_clones () |
| static void | update_call_expr () |
| struct cgraph_node * | cgraph_copy_node_for_versioning (struct cgraph_node *old_version, tree new_decl, vec< cgraph_edge_p > redirect_callers, bitmap bbs_to_copy) |
| struct cgraph_node * | cgraph_function_versioning (struct cgraph_node *old_version_node, vec< cgraph_edge_p > redirect_callers, vec< ipa_replace_map_p, va_gc > *tree_map, bitmap args_to_skip, bool skip_return, bitmap bbs_to_copy, basic_block new_entry_block, const char *clone_name) |
| static void | cgraph_materialize_clone () |
| void | cgraph_materialize_all_clones () |
Variables | |
| static unsigned int | clone_fn_id_num |
Function Documentation
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Callgraph clones Copyright (C) 2003-2013 Free Software Foundation, Inc. Contributed by Jan Hubicka
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/. This module provide facilities for clonning functions. I.e. creating new functions based on existing functions with simple modifications, such as replacement of parameters.
To allow whole program optimization without actual presence of function bodies, an additional infrastructure is provided for so-called virtual clones
A virtual clone in the callgraph is a function that has no associated body, just a description of how to create its body based on a different function (which itself may be a virtual clone).
The description of function modifications includes adjustments to the function's signature (which allows, for example, removing or adding function arguments), substitutions to perform on the function body, and, for inlined functions, a pointer to the function that it will be inlined into.
It is also possible to redirect any edge of the callgraph from a function to its virtual clone. This implies updating of the call site to adjust for the new function signature.
Most of the transformations performed by inter-procedural optimizations can be represented via virtual clones. For instance, a constant propagation pass can produce a virtual clone of the function which replaces one of its arguments by a constant. The inliner can represent its decisions by producing a clone of a function whose body will be later integrated into a given function.
Using virtual clones, the program can be easily updated during the Execute stage, solving most of pass interactions problems that would otherwise occur during Transform.
Virtual clones are later materialized in the LTRANS stage and turned into real functions. Passes executed after the virtual clone were introduced also perform their Transform stage on new functions, so for a pass there is no significant difference between operating on a real function or a virtual clone introduced before its Execute stage.
Optimization passes then work on virtual clones introduced before their Execute stage as if they were real functions. The only difference is that clones are not visible during the Generate Summary stage. Create clone of E in the node N represented by CALL_EXPR the callgraph.
We do not want to ignore loop nest after frequency drops to 0.
Clone flags that depend on call_stmt availability manually.
References apply_probability(), cgraph_edge::call_stmt_cannot_inline_p, cgraph_edge::callee, cgraph_edge::can_throw_external, cgraph_call_edge_duplication_hooks(), cgraph_create_edge(), cgraph_create_indirect_edge(), CGRAPH_FREQ_BASE, CGRAPH_FREQ_MAX, cgraph_get_node(), count, cgraph_edge::count, cgraph_indirect_call_info::ecf_flags, cgraph_edge::frequency, gcc_checking_assert, gimple_call_fndecl(), cgraph_edge::indirect_info, cgraph_edge::indirect_inlining_edge, cgraph_edge::indirect_unknown_callee, cgraph_edge::inline_failed, cgraph_edge::lto_stmt_uid, and cgraph_edge::speculative.
Referenced by update_call_expr().
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Create node representing clone of N executed COUNT times. Decrease the execution counts from original node too. The new clone will have decl set to DECL that may or may not be the same as decl of N.
When UPDATE_ORIGINAL is true, the counts are subtracted from the original function's profile to reflect the fact that part of execution is handled by node. When CALL_DUPLICATOIN_HOOK is true, the ipa passes are acknowledged about the new clone. Otherwise the caller is responsible for doing so later.
If the new node is being inlined into another one, NEW_INLINED_TO should be the outline function the new one is (even indirectly) inlined to. All hooks will see this in node's global.inlined_to, when invoked. Can be NULL if the node is not inlined.
Redirect calls to the old version node to point to its new version.
Referenced by clone_inlined_nodes(), and input_overwrite_node().
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Create a new cgraph node which is the new version of OLD_VERSION node. REDIRECT_CALLERS holds the callers edges which should be redirected to point to NEW_VERSION. ALL the callees edges of OLD_VERSION are cloned to the new version node. Return the new version node.
If non-NULL BLOCK_TO_COPY determine what basic blocks was copied to prevent duplications of calls that are dead in the clone.
Redirect calls to the old version node to point to its new version.
| void cgraph_create_edge_including_clones | ( | struct cgraph_node * | orig, |
| struct cgraph_node * | callee, | ||
| gimple | old_stmt, | ||
| gimple | stmt, | ||
| gcov_type | count, | ||
| int | freq, | ||
| cgraph_inline_failed_t | reason | ||
| ) |
Like cgraph_create_edge walk the clone tree and update all clones sharing same function body. If clones already have edge for OLD_STMT; only update the edge same way as cgraph_set_call_stmt_including_clones does.
TODO: COUNT and LOOP_DEPTH should be properly distributed based on relative frequencies of the clones.
It is possible that clones already contain the edge while master didn't. Either we promoted indirect call into direct call in the clone or we are processing clones of unreachable master where edges has been removed.
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Create callgraph node clone with new declaration. The actual body will be copied later at compilation stage.
TODO: after merging in ipa-sra use function call notes instead of args_to_skip bitmap interface.
Make a new FUNCTION_DECL tree node
These pointers represent function body and will be populated only when clone is materialized.
We can not do DECL_RESULT (new_decl) = NULL; here because of LTO partitioning sometimes storing only clone decl instead of original.
Generate a new name for the new version.
Update the properties. Make clone visible only within this translation unit. Make sure that is not weak also. ??? We cannot use COMDAT linkage because there is no ABI support for this.
Clones of global symbols or symbols with unique names are unique.
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NODE is being removed from symbol table; see if its entry can be replaced by other inline clone.
If there is inline clone of the node being removed, we need to put it into the position of removed node and reorganize all other clones to be based on it.
Unlink inline clone from the list of clones of removed node.
Copy clone info.
Now place it into clone tree at same level at NODE.
Merge the clone list.
Update clone_of pointers.
References cgraph_node::clones, gcc_assert, cgraph_node::next_sibling_clone, and cgraph_node::prev_sibling_clone.
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Perform function versioning. Function versioning includes copying of the tree and a callgraph update (creating a new cgraph node and updating its callees and callers).
REDIRECT_CALLERS varray includes the edges to be redirected to the new version.
TREE_MAP is a mapping of tree nodes we want to replace with new ones (according to results of prior analysis). OLD_VERSION_NODE is the node that is versioned.
If non-NULL ARGS_TO_SKIP determine function parameters to remove from new version. If SKIP_RETURN is true, the new version will return void. If non-NULL BLOCK_TO_COPY determine what basic blocks to copy. If non_NULL NEW_ENTRY determine new entry BB of the clone.
Return the new version's cgraph node.
Make a new FUNCTION_DECL tree node for the new version.
Generate a new name for the new version.
When the old decl was a con-/destructor make sure the clone isn't.
Create the new version's call-graph node. and update the edges of the new node.
Copy the OLD_VERSION_NODE function tree to the new version.
Update the new version's properties. Make The new version visible only within this translation unit. Make sure that is not weak also. ??? We cannot use COMDAT linkage because there is no ABI support for this.
Clones of global symbols or symbols with unique names are unique.
Update the call_expr on the edges to call the new version node.
| void cgraph_materialize_all_clones | ( | void | ) |
Once all functions from compilation unit are in memory, produce all clones and update all calls. We might also do this on demand if we don't want to bring all functions to memory prior compilation, but current WHOPR implementation does that and it is is bit easier to keep everything right in this order.
We can also do topological order, but number of iterations should be bounded by number of IPA passes since single IPA pass is probably not going to create clones of clones it created itself.
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Given virtual clone, turn it into actual clone.
Copy the OLD_VERSION_NODE function tree to the new version.
Function is no longer clone.
References cgraph_dump_file, cgraph_get_body(), cgraph_node_name(), cgraph_node::clone, cgraph_node::clone_of, symtab_node_base::decl, FOR_EACH_FUNCTION, gimple_has_body_p(), ipa_replace_map::old_tree, print_generic_expr(), cgraph_clone_info::tree_map, vec_safe_length(), and verify_cgraph().
| bool cgraph_remove_node_and_inline_clones | ( | ) |
Remove the node from cgraph and all inline clones inlined into it. Skip however removal of FORBIDDEN_NODE and return true if it needs to be removed. This allows to call the function from outer loop walking clone tree.
| void cgraph_set_call_stmt_including_clones | ( | struct cgraph_node * | orig, |
| gimple | old_stmt, | ||
| gimple | new_stmt, | ||
| bool | update_speculative | ||
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Like cgraph_set_call_stmt but walk the clone tree and update all clones sharing the same function body. When WHOLE_SPECULATIVE_EDGES is true, all three components of speculative edge gets updated. Otherwise we update only direct call.
If UPDATE_SPECULATIVE is false, it means that we are turning speculative call into a real code sequence. Update the callgraph edges.
| tree clone_function_name | ( | ) |
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The edges representing the callers of the NEW_VERSION node were fixed by cgraph_function_versioning (), now the call_expr in their respective tree code should be updated to call the NEW_VERSION.
Update the call expr on the edges to call the new version.
References symtab_node_base::analyzed, bitmap_bit_p, cgraph_edge::call_stmt, cgraph_node::callees, cgraph_clone_edge(), cgraph_create_node(), CGRAPH_FREQ_BASE, cgraph_node::count, symtab_node_base::definition, symtab_node_base::externally_visible, gcc_assert, cgraph_node::global, cgraph_node::indirect_calls, cgraph_local_info::local, cgraph_node::local, cgraph_edge::lto_stmt_uid, cgraph_edge::next_callee, REG_BR_PROB_BASE, and cgraph_node::rtl.
Variable Documentation
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Return a new assembler name for a clone of DECL with SUFFIX.
