X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fir%2Firgopt.h;h=e85fd4e6548c0eba606c8c8956dfad8886c87ad3;hb=e570f00fb465d212dde403160e97ab45d36d1d7e;hp=8b15048806ecaa92dea375633d4bf6e3732e2be1;hpb=f4ae1b7b653bcd43b99bc81b40425ab595a0dc7d;p=libfirm diff --git a/ir/ir/irgopt.h b/ir/ir/irgopt.h index 8b1504880..e85fd4e65 100644 --- a/ir/ir/irgopt.h +++ b/ir/ir/irgopt.h @@ -1,40 +1,60 @@ -/* Copyright (C) 1998 - 2001 by Universitaet Karlsruhe -** All rights reserved. -** -** Author: Christian Schaefer, Goetz Lindenmaier -** -** 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. + */ -/* $Id$ */ +/** + * @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.h) 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. + Further removes Bad predecesors from Blocks and the corresponding inputs to Phi nodes. Optimization 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. (@@@ Change this? -> inconsistent.) + is freed, the outs state set to no_outs. + @todo Change this? -> inconsistent. + + 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 +/** Removes Bad Bad predecesors from Blocks and the corresponding inputs to Phi nodes as in dead_node_elimination but without copying the graph. - @@@ not implemented! */ + + @todo not implemented! */ void remove_bad_predecessors(ir_graph *irg); -/* Inlines a method at the given call site. +/** 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. @@ -49,15 +69,14 @@ void remove_bad_predecessors(ir_graph *irg); if they are equal. Sets visited masterflag in current_ir_graph to the max of the flag in current and called graph. - 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 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. */ void inline_method(ir_node *call, ir_graph *called_graph); - -/* Inlines all small methods at call sites where the called address comes +/** 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: @@ -72,30 +91,67 @@ void inline_method(ir_node *call, ir_graph *called_graph); combination as control flow operation. */ void inline_small_irgs(ir_graph *irg, int size); -/* Code Placement. Pinns all floating nodes to a block where they + +/** 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. + * + * maxsize Do not inline any calls if a method has more than + * maxsize firm nodes. It may reach this limit by + * inlineing. + * leavesize Inline leave functions if they have less than leavesize + * nodes. + * 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. (@@@ This - is not tested!) - @@@ A more powerful code placement would move operations past Phi nodes - out of loops. Further the control flow should be normalized before - computing the dominator information so that there exists an optimal block - for all operations. */ + 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 simpli- */ -/* fications. 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.*/ -/********************************************************************/ +/** 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_ */