-/* Copyright (C) 1998 - 2000 by Universitaet Karlsruhe
-** All rights reserved.
-**
-** Author: Christian Schaefer
-**
-** dead node elimination
-** walks one time through the whole graph and copies it into another graph,
-** so unreachable nodes will be lost.
-*/
+/*
+ * 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.
+
+ 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.
+ @todo Change this? -> inconsistent.
+
+ Backedge information is conserved.
+ Removes old attributes of nodes. Sets link field to NULL.
+ 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! */
+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.
+ 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. */
+void 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);
+
+/** 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_ */
projects / libfirm / blobdiff