7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24
25 package org.graalvm.compiler.java;
26
27 import static org.graalvm.compiler.nodes.cfg.ControlFlowGraph.multiplyProbabilities;
28
29 import java.util.List;
30
31 import jdk.internal.vm.compiler.collections.EconomicMap;
32 import org.graalvm.compiler.nodes.AbstractBeginNode;
33 import org.graalvm.compiler.nodes.AbstractMergeNode;
34 import org.graalvm.compiler.nodes.ControlSplitNode;
35 import org.graalvm.compiler.nodes.FixedNode;
36 import org.graalvm.compiler.nodes.LoopBeginNode;
37 import org.graalvm.compiler.nodes.LoopExitNode;
38 import org.graalvm.compiler.nodes.StructuredGraph;
39 import org.graalvm.compiler.nodes.cfg.ControlFlowGraph;
40 import org.graalvm.compiler.phases.Phase;
41 import org.graalvm.compiler.phases.graph.ReentrantNodeIterator;
42
43 public final class ComputeLoopFrequenciesClosure extends ReentrantNodeIterator.NodeIteratorClosure<Double> {
44
45 private static final ComputeLoopFrequenciesClosure INSTANCE = new ComputeLoopFrequenciesClosure();
46
47 private ComputeLoopFrequenciesClosure() {
58 protected Double merge(AbstractMergeNode merge, List<Double> states) {
59 // a merge has the sum of all predecessor probabilities
60 double result = 0.0;
61 for (double d : states) {
62 result += d;
63 }
64 return result;
65 }
66
67 @Override
68 protected Double afterSplit(AbstractBeginNode node, Double oldState) {
69 // a control split splits up the probability
70 ControlSplitNode split = (ControlSplitNode) node.predecessor();
71 return oldState * split.probability(node);
72 }
73
74 @Override
75 protected EconomicMap<LoopExitNode, Double> processLoop(LoopBeginNode loop, Double initialState) {
76 EconomicMap<LoopExitNode, Double> exitStates = ReentrantNodeIterator.processLoop(this, loop, 1D).exitStates;
77
78 double exitProbability = 0.0;
79 for (double d : exitStates.getValues()) {
80 exitProbability += d;
81 }
82 exitProbability = Math.min(1.0, exitProbability);
83 exitProbability = Math.max(ControlFlowGraph.MIN_PROBABILITY, exitProbability);
84 double loopFrequency = 1.0 / exitProbability;
85 loop.setLoopFrequency(loopFrequency);
86
87 double adjustmentFactor = initialState * loopFrequency;
88 exitStates.replaceAll((exitNode, probability) -> multiplyProbabilities(probability, adjustmentFactor));
89
90 return exitStates;
91 }
92
93 /**
94 * Computes the frequencies of all loops in the given graph. This is done by performing a
95 * reverse postorder iteration and computing the probability of all fixed nodes. The combined
96 * probability of all exits of a loop can be used to compute the loop's expected frequency.
97 */
98 public static void compute(StructuredGraph graph) {
99 if (graph.hasLoops()) {
100 ReentrantNodeIterator.apply(INSTANCE, graph.start(), 1D);
101 }
102 }
103
104 public static class ComputeLoopFrequencyPhase extends Phase {
105
106 @Override
107 protected void run(StructuredGraph graph) {
108 compute(graph);
|
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24
25 package org.graalvm.compiler.java;
26
27 import static org.graalvm.compiler.nodes.cfg.ControlFlowGraph.multiplyRelativeFrequencies;
28
29 import java.util.List;
30
31 import jdk.internal.vm.compiler.collections.EconomicMap;
32 import org.graalvm.compiler.nodes.AbstractBeginNode;
33 import org.graalvm.compiler.nodes.AbstractMergeNode;
34 import org.graalvm.compiler.nodes.ControlSplitNode;
35 import org.graalvm.compiler.nodes.FixedNode;
36 import org.graalvm.compiler.nodes.LoopBeginNode;
37 import org.graalvm.compiler.nodes.LoopExitNode;
38 import org.graalvm.compiler.nodes.StructuredGraph;
39 import org.graalvm.compiler.nodes.cfg.ControlFlowGraph;
40 import org.graalvm.compiler.phases.Phase;
41 import org.graalvm.compiler.phases.graph.ReentrantNodeIterator;
42
43 public final class ComputeLoopFrequenciesClosure extends ReentrantNodeIterator.NodeIteratorClosure<Double> {
44
45 private static final ComputeLoopFrequenciesClosure INSTANCE = new ComputeLoopFrequenciesClosure();
46
47 private ComputeLoopFrequenciesClosure() {
58 protected Double merge(AbstractMergeNode merge, List<Double> states) {
59 // a merge has the sum of all predecessor probabilities
60 double result = 0.0;
61 for (double d : states) {
62 result += d;
63 }
64 return result;
65 }
66
67 @Override
68 protected Double afterSplit(AbstractBeginNode node, Double oldState) {
69 // a control split splits up the probability
70 ControlSplitNode split = (ControlSplitNode) node.predecessor();
71 return oldState * split.probability(node);
72 }
73
74 @Override
75 protected EconomicMap<LoopExitNode, Double> processLoop(LoopBeginNode loop, Double initialState) {
76 EconomicMap<LoopExitNode, Double> exitStates = ReentrantNodeIterator.processLoop(this, loop, 1D).exitStates;
77
78 double exitRelativeFrequency = 0.0;
79 for (double d : exitStates.getValues()) {
80 exitRelativeFrequency += d;
81 }
82 exitRelativeFrequency = Math.min(1.0, exitRelativeFrequency);
83 exitRelativeFrequency = Math.max(ControlFlowGraph.MIN_RELATIVE_FREQUENCY, exitRelativeFrequency);
84 double loopFrequency = 1.0 / exitRelativeFrequency;
85 loop.setLoopFrequency(loopFrequency);
86
87 double adjustmentFactor = initialState * loopFrequency;
88 exitStates.replaceAll((exitNode, frequency) -> multiplyRelativeFrequencies(frequency, adjustmentFactor));
89
90 return exitStates;
91 }
92
93 /**
94 * Computes the frequencies of all loops in the given graph. This is done by performing a
95 * reverse postorder iteration and computing the probability of all fixed nodes. The combined
96 * probability of all exits of a loop can be used to compute the loop's expected frequency.
97 */
98 public static void compute(StructuredGraph graph) {
99 if (graph.hasLoops()) {
100 ReentrantNodeIterator.apply(INSTANCE, graph.start(), 1D);
101 }
102 }
103
104 public static class ComputeLoopFrequencyPhase extends Phase {
105
106 @Override
107 protected void run(StructuredGraph graph) {
108 compute(graph);
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