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comparison graal/GraalCompiler/src/com/sun/c1x/graph/CriticalEdgeFinder.java @ 2779:93ec3f067420

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Changed CriticalEdgeFinder to use LIRBlock.
author Thomas Wuerthinger <thomas@wuerthinger.net>
date Wed, 25 May 2011 11:04:59 +0200
parents 27512ea6bbcb
children 79dda81dd337
comparison
equal deleted inserted replaced
2778:2ac7b30b7290 2779:93ec3f067420
22 */ 22 */
23 package com.sun.c1x.graph; 23 package com.sun.c1x.graph;
24 24
25 import java.util.*; 25 import java.util.*;
26 26
27 import com.oracle.graal.graph.*;
27 import com.sun.c1x.*; 28 import com.sun.c1x.*;
28 import com.sun.c1x.debug.*; 29 import com.sun.c1x.debug.*;
29 import com.sun.c1x.ir.*; 30 import com.sun.c1x.ir.*;
31 import com.sun.c1x.lir.*;
30 32
31 /** 33 /**
32 * This class finds and splits "critical" edges in the control flow graph. 34 * This class finds and splits "critical" edges in the control flow graph.
33 * An edge between two blocks {@code A} and {@code B} is "critical" if {@code A} 35 * An edge between two blocks {@code A} and {@code B} is "critical" if {@code A}
34 * has more than one successor and {@code B} has more than one predecessor. Such 36 * has more than one successor and {@code B} has more than one predecessor. Such
35 * edges are split by adding a block between the two blocks. 37 * edges are split by adding a block between the two blocks.
36 */ 38 */
37 public class CriticalEdgeFinder implements BlockClosure { 39 public class CriticalEdgeFinder {
38 40
39 private final IR ir; 41 private final List<LIRBlock> lirBlocks;
42 private final Graph graph;
40 43
41 /** 44 /**
42 * The graph edges represented as a map from source to target nodes. 45 * The graph edges represented as a map from source to target nodes.
43 * Using a linked hash map makes compilation tracing more deterministic and thus eases debugging. 46 * Using a linked hash map makes compilation tracing more deterministic and thus eases debugging.
44 */ 47 */
45 private Map<BlockBegin, Set<BlockBegin>> edges = C1XOptions.DetailedAsserts ? 48 private Map<LIRBlock, Set<LIRBlock>> edges = C1XOptions.DetailedAsserts ?
46 new LinkedHashMap<BlockBegin, Set<BlockBegin>>() : 49 new LinkedHashMap<LIRBlock, Set<LIRBlock>>() :
47 new HashMap<BlockBegin, Set<BlockBegin>>(); 50 new HashMap<LIRBlock, Set<LIRBlock>>();
48 51
49 public CriticalEdgeFinder(IR ir) { 52 public CriticalEdgeFinder(List<LIRBlock> lirBlocks, Graph graph) {
50 this.ir = ir; 53 this.lirBlocks = lirBlocks;
54 this.graph = graph;
55 for (LIRBlock block : lirBlocks) {
56 apply(block);
57 }
58
51 } 59 }
52 60
53 public void apply(BlockBegin block) { 61 private void apply(LIRBlock block) {
54 BlockEnd end = block.end(); 62 if (block.numberOfSux() >= 2) {
55 if (end.blockSuccessorCount() >= 2) { 63 for (LIRBlock succ : block.blockSuccessors()) {
56 for (BlockBegin succ : end.blockSuccessors()) {
57 if (succ.numberOfPreds() >= 2) { 64 if (succ.numberOfPreds() >= 2) {
58 // TODO: (tw) probably we don't have to make it a critical edge if succ only contains the _same_ predecessor multiple times. 65 // TODO: (tw) probably we don't have to make it a critical edge if succ only contains the _same_ predecessor multiple times.
59 recordCriticalEdge(block, succ); 66 recordCriticalEdge(block, succ);
60 } 67 }
61 } 68 }
62 } 69 }
63 } 70 }
64 71
65 private void recordCriticalEdge(BlockBegin block, BlockBegin succ) { 72 private void recordCriticalEdge(LIRBlock block, LIRBlock succ) {
66 if (!edges.containsKey(block)) { 73 if (!edges.containsKey(block)) {
67 edges.put(block, new HashSet<BlockBegin>()); 74 edges.put(block, new HashSet<LIRBlock>());
68 } 75 }
69 76
70 edges.get(block).add(succ); 77 edges.get(block).add(succ);
71 } 78 }
72 79
73 public void splitCriticalEdges() { 80 public void splitCriticalEdges() {
74 for (Map.Entry<BlockBegin, Set<BlockBegin>> entry : edges.entrySet()) { 81 for (Map.Entry<LIRBlock, Set<LIRBlock>> entry : edges.entrySet()) {
75 BlockBegin from = entry.getKey(); 82 LIRBlock from = entry.getKey();
76 for (BlockBegin to : entry.getValue()) { 83 for (LIRBlock to : entry.getValue()) {
77 BlockBegin split = ir.splitEdge(from, to); 84 LIRBlock split = splitEdge(from, to);
78 if (C1XOptions.PrintHIR) { 85 if (C1XOptions.PrintHIR) {
79 TTY.println("Split edge between block %d and block %d, creating new block %d", from.blockID, to.blockID, split.blockID); 86 TTY.println("Split edge between block %d and block %d, creating new block %d", from.blockID(), to.blockID(), split.blockID());
80 } 87 }
81 } 88 }
82 } 89 }
83 } 90 }
91
92
93 /**
94 * Creates and inserts a new block between this block and the specified successor,
95 * altering the successor and predecessor lists of involved blocks appropriately.
96 * @param source the source of the edge
97 * @param target the successor before which to insert a block
98 * @return the new block inserted
99 */
100 public LIRBlock splitEdge(LIRBlock source, LIRBlock target) {
101
102 int backEdgeIndex = target.blockPredecessors().indexOf(source);
103
104 // create new successor and mark it for special block order treatment
105 LIRBlock newSucc = new LIRBlock(lirBlocks.size());
106 lirBlocks.add(newSucc);
107
108 List<Integer> removePhiInputs = null;
109 for (int i = backEdgeIndex + 1; i < target.blockPredecessors().size(); ++i) {
110 if (target.blockPredecessors().get(i) == source) {
111 if (removePhiInputs == null) {
112 removePhiInputs = new ArrayList<Integer>(4);
113 }
114 removePhiInputs.add(i);
115 }
116 }
117
118 // This goto is not a safepoint.
119 Goto e = new Goto(target.getInstructions().get(0), graph);
120 newSucc.getInstructions().add(e);
121 //e.reorderSuccessor(0, backEdgeIndex);
122
123 // link predecessor to new block
124 ((BlockEnd) source.getInstructions().get(source.getInstructions().size() - 1)).successors().replace(target.getInstructions().get(0), newSucc.getInstructions().get(0));
125 /* if (removePhiInputs != null && removePhiInputs.size() > 0) {
126
127 for (Node n : target.getInstructions().get(0).usages()) {
128 if (n instanceof Phi) {
129 Phi phi = (Phi) n;
130 int correction = 0;
131 for (int index : removePhiInputs) {
132 phi.removeInput(index - correction);
133 correction++;
134 }
135 }
136 }
137 }*/
138
139 source.substituteSuccessor(target, newSucc);
140 target.substitutePredecessor(source, newSucc);
141 newSucc.blockPredecessors().add(source);
142 newSucc.blockSuccessors().add(target);
143
144 return newSucc;
145 }
84 } 146 }