X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fir%2Firgopt.h;h=2175030f2602c01d0d77b276b696fc2f0f7e199f;hb=3c0c36c0f87487188e250318645aa50b147fc90b;hp=624e6287f7a6f8c1ea3a5dc97039b9473ba4de0f;hpb=2fa17934abe60b32409bf3b797ec3aa675a1b1a0;p=libfirm diff --git a/ir/ir/irgopt.h b/ir/ir/irgopt.h index 624e6287f..2175030f2 100644 --- a/ir/ir/irgopt.h +++ b/ir/ir/irgopt.h @@ -1,20 +1,169 @@ -/* Copyright (C) 1998 - 2000 by Universitaet Karlsruhe -** All rights reserved. -** -** Author: Christian Schaefer -** -** Optimizations for a whole ir graph, i.e., a procedure. -*/ +/* + * Project: libFIRM + * File name: ir/ir/irgopt.h + * Purpose: Optimizations for a whole ir graph, i.e., a procedure. + * Author: Christian Schaefer, Goetz Lindenmaier + * Modified by: Sebastian Felis + * Created: + * CVS-ID: $Id$ + * Copyright: (c) 1998-2003 Universität Karlsruhe + * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE. + */ + +/** + * @file irgopt.h + * + * Optimizations for a whole ir graph, i.e., a procedure. + * + * @author Christian Schaefer, Goetz Lindenmaier + */ # ifndef _IRGOPT_H_ # define _IRGOPT_H_ # include "irgraph.h" -/* Applies local optimizations (see iropt) to all nodes in the graph. */ +/** Applies local optimizations (see iropt.h) to all nodes in the graph. */ void local_optimize_graph (ir_graph *irg); -/* Performs dead node elimination by copying the ir graph to a new obstack. */ +/** Performs dead node elimination by copying the ir graph to a new obstack. + * + * The major intention of this pass is to free memory occupied by + * dead nodes and outdated analyses information. Further this + * function removes Bad predecesors from Blocks and the corresponding + * inputs to Phi nodes. This opens optmization potential for other + * optimizations. Further this phase reduces dead Block<->Jmp + * self-cycles to Bad nodes. + * + * Dead_node_elimination is only performed if options `optimize' and + * `opt_dead_node_elimination' are set. The graph may + * not be in state phase_building. The outs datasturcture is freed, + * the outs state set to no_outs. Backedge information is conserved. + * Removes old attributes of nodes. Sets link field to NULL. + * Callee information must be freed (irg_callee_info_none). + * + * Attention: the numbers assigned to nodes if the library is compiled for + * development/debugging are not conserved by copying. */ void dead_node_elimination(ir_graph *irg); +/** Removes Bad Bad predecesors from Blocks and the corresponding + inputs to Phi nodes as in dead_node_elimination but without + copying the graph. + + @todo not implemented! / buggy? */ +void remove_bad_predecessors(ir_graph *irg); + +/** Inlines a method at the given call site. + * + * Removes the call node and splits the basic block the call node + * belongs to. Inserts a copy of the called graph between these nodes. + * Assumes that call is a Call node in current_ir_graph and that + * the type in the Call nodes type attribute is the same as the + * type of the called graph. + * Further it assumes that all Phi nodes in a block of current_ir_graph + * are assembled in a "link" list in the link field of the corresponding + * block nodes. Further assumes that all Proj nodes are in a "link" list + * in the nodes producing the tuple. (This is only an optical feature + * for the graph.) Conserves this feature for the old + * nodes of the graph. This precondition can be established by a call to + * collect_phisprojs(), see irgmod.h. + * As dead_node_elimination this function reduces dead Block<->Jmp + * self-cycles to Bad nodes. + * + * Called_graph must be unequal to current_ir_graph. Will not inline + * if they are equal. + * Sets visited masterflag in current_ir_graph to the max of the flag in + * current and called graph. + * Assumes that both, the called and the calling graph are in state + * "pinned". + * It is recommended to call local_optimize_graph after inlining as this + * function leaves a set of obscure Tuple nodes, e.g. a Proj-Tuple-Jmp + * combination as control flow operation. + * + * @param call the call node that should be inlined + * @param called_graph the IR-graph that is called at call + * + * @return zero if method could not be inlined (recursion for instance), + * non-zero if all went ok +**/ +int inline_method(ir_node *call, ir_graph *called_graph); + +/** Inlines all small methods at call sites where the called address comes + * from a Const node that references the entity representing the called + * method. + * The size argument is a rough measure for the code size of the method: + * Methods where the obstack containing the firm graph is smaller than + * size are inlined. Further only a limited number of calls are inlined. + * If the method contains more than 1024 inlineable calls none will be + * inlined. + * Inlining is only performed if flags `optimize' and `inlineing' are set. + * The graph may not be in state phase_building. + * It is recommended to call local_optimize_graph after inlining as this + * function leaves a set of obscure Tuple nodes, e.g. a Proj-Tuple-Jmp + * combination as control flow operation. */ +void inline_small_irgs(ir_graph *irg, int size); + + +/** Inlineing with a different heuristic than inline_small_irgs. + * + * Inlines leave functions. If inlinening creates new leave + * function inlines these, too. (If g calls f, and f calls leave h, + * h is first inlined in f and then f in g.) + * + * Then inlines all small functions (this is not recursive). + * + * For a heuristic this inlineing uses firm node counts. It does + * not count auxiliary nodes as Proj, Tuple, End, Start, Id, Sync. + * + * @param maxsize Do not inline any calls if a method has more than + * maxsize firm nodes. It may reach this limit by + * inlineing. + * @param leavesize Inline leave functions if they have less than leavesize + * nodes. + * @param size Inline all function smaller than size. + */ +void inline_leave_functions(int maxsize, int leavesize, int size); + +/** Code Placement. Pinns all floating nodes to a block where they + will be executed only if needed. Depends on the flag opt_global_cse. + Graph may not be in phase_building. Does not schedule control dead + code. Uses dominator information which it computes if the irg is not + in state dom_consistent. Destroys the out information as it moves nodes + to other blocks. Optimizes Tuples in Control edges. + @todo This is not tested! + + Call remove_critical_cf_edges() before place_code(). This normalizes + the control flow graph so that for all operations a basic block exists + where they can be optimally placed. + + @todo A more powerful code placement would move operations past Phi nodes + out of loops. */ +void place_code(ir_graph *irg); + +/** Control flow optimization. + * Removes empty blocks doing if simplifications and loop simplifications. + * A block is empty if it contains only a Jmp node and Phi nodes. + * Merges single entry single exit blocks with their predecessor + * and propagates dead control flow by calling equivalent_node. + * Independent of compiler flag it removes Tuples from cf edges, + * Bad predecessors form blocks and unnecessary predecessors of End. + * + * @bug So far destroys backedge information. + * @bug Chokes on Id nodes if called in a certain order with other + * optimizations. Call local_optimize_graph before to remove + * Ids. + */ +void optimize_cf(ir_graph *irg); + + +/** Places an empty basic block on critical control flow edges thereby + removing them. + A critical control flow edge is an edge from a block with several + control exits to a block with several control entries (See Muchnic + p. 407). + Is only executed if flag set_opt_critical_edges() is set. + @param irg IR Graph +*/ +void remove_critical_cf_edges(ir_graph *irg); + # endif /* _IRGOPT_H_ */