# HG changeset patch
# User Thomas Wuerthinger <thomas.wuerthinger@oracle.com>
# Date 1347029043 -7200
# Node ID b34b2e8749482cb5539074f73883ac8dd3b2cd84
# Parent  f8ba3bb81f6f8da0d72742a1351f3b6d894dd647
Move EdgeMoveOptimizer from compiler.alloc to graal.lir

diff -r f8ba3bb81f6f -r b34b2e874948 graal/com.oracle.graal.compiler/src/com/oracle/graal/compiler/alloc/EdgeMoveOptimizer.java
--- a/graal/com.oracle.graal.compiler/src/com/oracle/graal/compiler/alloc/EdgeMoveOptimizer.java	Fri Sep 07 16:25:49 2012 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,289 +0,0 @@
-/*
- * Copyright (c) 2009, 2012, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-package com.oracle.graal.compiler.alloc;
-
-import java.util.*;
-
-import com.oracle.graal.lir.*;
-import com.oracle.graal.lir.StandardOp.*;
-import com.oracle.graal.lir.cfg.*;
-
-/**
- * This class optimizes moves, particularly those that result from eliminating SSA form.
- *
- * When a block has more than one predecessor, and all predecessors end with
- * the {@linkplain #same(LIRInstruction, LIRInstruction) same} sequence of
- * {@linkplain MoveOp move} instructions, then these sequences
- * can be replaced with a single copy of the sequence at the beginning of the block.
- *
- * Similarly, when a block has more than one successor, then same sequences of
- * moves at the beginning of the successors can be placed once at the end of
- * the block. But because the moves must be inserted before all branch
- * instructions, this works only when there is exactly one conditional branch
- * at the end of the block (because the moves must be inserted before all
- * branches, but after all compares).
- *
- * This optimization affects all kind of moves (reg->reg, reg->stack and
- * stack->reg). Because this optimization works best when a block contains only
- * a few moves, it has a huge impact on the number of blocks that are totally
- * empty.
- */
-public final class EdgeMoveOptimizer {
-
-    /**
-     * Optimizes moves on block edges.
-     *
-     * @param blockList a list of blocks whose moves should be optimized
-     */
-    public static void optimize(List<Block> blockList) {
-        EdgeMoveOptimizer optimizer = new EdgeMoveOptimizer();
-
-        // ignore the first block in the list (index 0 is not processed)
-        for (int i = blockList.size() - 1; i >= 1; i--) {
-            Block block = blockList.get(i);
-
-            if (block.numberOfPreds() > 1) {
-                optimizer.optimizeMovesAtBlockEnd(block);
-            }
-            if (block.numberOfSux() == 2) {
-                optimizer.optimizeMovesAtBlockBegin(block);
-            }
-        }
-    }
-
-    private final List<List<LIRInstruction>> edgeInstructionSeqences;
-
-    private EdgeMoveOptimizer() {
-        edgeInstructionSeqences = new ArrayList<>(4);
-    }
-
-    /**
-     * Determines if two operations are both {@linkplain MoveOp moves}
-     * that have the same {@linkplain MoveOp#getInput() source} and {@linkplain MoveOp#getResult() destination} operands.
-     *
-     * @param op1 the first instruction to compare
-     * @param op2 the second instruction to compare
-     * @return {@code true} if {@code op1} and {@code op2} are the same by the above algorithm
-     */
-    private static boolean same(LIRInstruction op1, LIRInstruction op2) {
-        assert op1 != null;
-        assert op2 != null;
-
-        if (op1 instanceof MoveOp && op2 instanceof MoveOp) {
-            MoveOp move1 = (MoveOp) op1;
-            MoveOp move2 = (MoveOp) op2;
-            if (move1.getInput() == move2.getInput() && move1.getResult() == move2.getResult()) {
-                // these moves are exactly equal and can be optimized
-                return true;
-            }
-        }
-        return false;
-    }
-
-    /**
-     * Moves the longest {@linkplain #same common} subsequence at the end all
-     * predecessors of {@code block} to the start of {@code block}.
-     */
-    private void optimizeMovesAtBlockEnd(Block block) {
-        for (Block pred : block.getPredecessors()) {
-            if (pred == block) {
-                // currently we can't handle this correctly.
-                return;
-            }
-        }
-
-        // clear all internal data structures
-        edgeInstructionSeqences.clear();
-
-        int numPreds = block.numberOfPreds();
-        assert numPreds > 1 : "do not call otherwise";
-
-        // setup a list with the LIR instructions of all predecessors
-        for (Block pred : block.getPredecessors()) {
-            assert pred != null;
-            assert pred.lir != null;
-            List<LIRInstruction> predInstructions = pred.lir;
-
-            if (pred.numberOfSux() != 1) {
-                // this can happen with switch-statements where multiple edges are between
-                // the same blocks.
-                return;
-            }
-
-            if (predInstructions.get(predInstructions.size() - 1) instanceof LIRXirInstruction) {
-                return;
-            }
-
-            assert pred.suxAt(0) == block : "invalid control flow";
-            assert predInstructions.get(predInstructions.size() - 1) instanceof StandardOp.JumpOp : "block must end with unconditional jump";
-
-            if (predInstructions.get(predInstructions.size() - 1).hasState()) {
-                // can not optimize instructions that have debug info
-                return;
-            }
-
-            // ignore the unconditional branch at the end of the block
-            List<LIRInstruction> seq = predInstructions.subList(0, predInstructions.size() - 1);
-            edgeInstructionSeqences.add(seq);
-        }
-
-        // process lir-instructions while all predecessors end with the same instruction
-        while (true) {
-            List<LIRInstruction> seq = edgeInstructionSeqences.get(0);
-            if (seq.isEmpty()) {
-                return;
-            }
-
-            LIRInstruction op = last(seq);
-            for (int i = 1; i < numPreds; ++i) {
-                List<LIRInstruction> otherSeq = edgeInstructionSeqences.get(i);
-                if (otherSeq.isEmpty() || !same(op, last(otherSeq))) {
-                    return;
-                }
-            }
-
-            // insert the instruction at the beginning of the current block
-            block.lir.add(1, op);
-
-            // delete the instruction at the end of all predecessors
-            for (int i = 0; i < numPreds; i++) {
-                seq = edgeInstructionSeqences.get(i);
-                removeLast(seq);
-            }
-        }
-    }
-
-    /**
-     * Moves the longest {@linkplain #same common} subsequence at the start of all
-     * successors of {@code block} to the end of {@code block} just prior to the
-     * branch instruction ending {@code block}.
-     */
-    private void optimizeMovesAtBlockBegin(Block block) {
-
-        edgeInstructionSeqences.clear();
-        int numSux = block.numberOfSux();
-
-        List<LIRInstruction> instructions = block.lir;
-
-        assert numSux == 2 : "method should not be called otherwise";
-
-        if (instructions.get(instructions.size() - 1) instanceof LIRXirInstruction) {
-            // cannot optimize when last instruction is Xir.
-            return;
-        }
-
-        assert instructions.get(instructions.size() - 1) instanceof StandardOp.JumpOp : "block must end with unconditional jump";
-
-        if (instructions.get(instructions.size() - 1).hasState()) {
-            // cannot optimize instructions when debug info is needed
-            return;
-        }
-
-        LIRInstruction branch = instructions.get(instructions.size() - 2);
-        if (!(branch instanceof StandardOp.BranchOp) || branch.hasState()) {
-            // not a valid case for optimization
-            // currently, only blocks that end with two branches (conditional branch followed
-            // by unconditional branch) are optimized
-            return;
-        }
-
-        // now it is guaranteed that the block ends with two branch instructions.
-        // the instructions are inserted at the end of the block before these two branches
-        int insertIdx = instructions.size() - 2;
-
-        // setup a list with the lir-instructions of all successors
-        for (int i = 0; i < numSux; i++) {
-            Block sux = block.suxAt(i);
-            List<LIRInstruction> suxInstructions = sux.lir;
-
-            assert suxInstructions.get(0) instanceof StandardOp.LabelOp : "block must start with label";
-
-            if (sux.numberOfPreds() != 1) {
-                // this can happen with switch-statements where multiple edges are between
-                // the same blocks.
-                return;
-            }
-            assert sux.predAt(0) == block : "invalid control flow";
-
-            // ignore the label at the beginning of the block
-            List<LIRInstruction> seq = suxInstructions.subList(1, suxInstructions.size());
-            edgeInstructionSeqences.add(seq);
-        }
-
-        // process LIR instructions while all successors begin with the same instruction
-        while (true) {
-            List<LIRInstruction> seq = edgeInstructionSeqences.get(0);
-            if (seq.isEmpty()) {
-                return;
-            }
-
-            LIRInstruction op = first(seq);
-            for (int i = 1; i < numSux; i++) {
-                List<LIRInstruction> otherSeq = edgeInstructionSeqences.get(i);
-                if (otherSeq.isEmpty() || !same(op, first(otherSeq))) {
-                    // these instructions are different and cannot be optimized .
-                    // no further optimization possible
-                    return;
-                }
-            }
-
-            // insert instruction at end of current block
-            block.lir.add(insertIdx, op);
-            insertIdx++;
-
-            // delete the instructions at the beginning of all successors
-            for (int i = 0; i < numSux; i++) {
-                seq = edgeInstructionSeqences.get(i);
-                removeFirst(seq);
-            }
-        }
-    }
-
-    /**
-     * Gets the first element from a LIR instruction sequence.
-     */
-    private static LIRInstruction first(List<LIRInstruction> seq) {
-        return seq.get(0);
-    }
-
-    /**
-     * Gets the last element from a LIR instruction sequence.
-     */
-    private static LIRInstruction last(List<LIRInstruction> seq) {
-        return seq.get(seq.size() - 1);
-    }
-
-    /**
-     * Removes the first element from a LIR instruction sequence.
-     */
-    private static void removeFirst(List<LIRInstruction> seq) {
-        seq.remove(0);
-    }
-
-    /**
-     * Removes the last element from a LIR instruction sequence.
-     */
-    private static void removeLast(List<LIRInstruction> seq) {
-        seq.remove(seq.size() - 1);
-    }
-}
diff -r f8ba3bb81f6f -r b34b2e874948 graal/com.oracle.graal.lir/src/com/oracle/graal/lir/EdgeMoveOptimizer.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.graal.lir/src/com/oracle/graal/lir/EdgeMoveOptimizer.java	Fri Sep 07 16:44:03 2012 +0200
@@ -0,0 +1,288 @@
+/*
+ * Copyright (c) 2009, 2012, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.graal.lir;
+
+import java.util.*;
+
+import com.oracle.graal.lir.StandardOp.*;
+import com.oracle.graal.lir.cfg.*;
+
+/**
+ * This class optimizes moves, particularly those that result from eliminating SSA form.
+ *
+ * When a block has more than one predecessor, and all predecessors end with
+ * the {@linkplain #same(LIRInstruction, LIRInstruction) same} sequence of
+ * {@linkplain MoveOp move} instructions, then these sequences
+ * can be replaced with a single copy of the sequence at the beginning of the block.
+ *
+ * Similarly, when a block has more than one successor, then same sequences of
+ * moves at the beginning of the successors can be placed once at the end of
+ * the block. But because the moves must be inserted before all branch
+ * instructions, this works only when there is exactly one conditional branch
+ * at the end of the block (because the moves must be inserted before all
+ * branches, but after all compares).
+ *
+ * This optimization affects all kind of moves (reg->reg, reg->stack and
+ * stack->reg). Because this optimization works best when a block contains only
+ * a few moves, it has a huge impact on the number of blocks that are totally
+ * empty.
+ */
+public final class EdgeMoveOptimizer {
+
+    /**
+     * Optimizes moves on block edges.
+     *
+     * @param blockList a list of blocks whose moves should be optimized
+     */
+    public static void optimize(List<Block> blockList) {
+        EdgeMoveOptimizer optimizer = new EdgeMoveOptimizer();
+
+        // ignore the first block in the list (index 0 is not processed)
+        for (int i = blockList.size() - 1; i >= 1; i--) {
+            Block block = blockList.get(i);
+
+            if (block.numberOfPreds() > 1) {
+                optimizer.optimizeMovesAtBlockEnd(block);
+            }
+            if (block.numberOfSux() == 2) {
+                optimizer.optimizeMovesAtBlockBegin(block);
+            }
+        }
+    }
+
+    private final List<List<LIRInstruction>> edgeInstructionSeqences;
+
+    private EdgeMoveOptimizer() {
+        edgeInstructionSeqences = new ArrayList<>(4);
+    }
+
+    /**
+     * Determines if two operations are both {@linkplain MoveOp moves}
+     * that have the same {@linkplain MoveOp#getInput() source} and {@linkplain MoveOp#getResult() destination} operands.
+     *
+     * @param op1 the first instruction to compare
+     * @param op2 the second instruction to compare
+     * @return {@code true} if {@code op1} and {@code op2} are the same by the above algorithm
+     */
+    private static boolean same(LIRInstruction op1, LIRInstruction op2) {
+        assert op1 != null;
+        assert op2 != null;
+
+        if (op1 instanceof MoveOp && op2 instanceof MoveOp) {
+            MoveOp move1 = (MoveOp) op1;
+            MoveOp move2 = (MoveOp) op2;
+            if (move1.getInput() == move2.getInput() && move1.getResult() == move2.getResult()) {
+                // these moves are exactly equal and can be optimized
+                return true;
+            }
+        }
+        return false;
+    }
+
+    /**
+     * Moves the longest {@linkplain #same common} subsequence at the end all
+     * predecessors of {@code block} to the start of {@code block}.
+     */
+    private void optimizeMovesAtBlockEnd(Block block) {
+        for (Block pred : block.getPredecessors()) {
+            if (pred == block) {
+                // currently we can't handle this correctly.
+                return;
+            }
+        }
+
+        // clear all internal data structures
+        edgeInstructionSeqences.clear();
+
+        int numPreds = block.numberOfPreds();
+        assert numPreds > 1 : "do not call otherwise";
+
+        // setup a list with the LIR instructions of all predecessors
+        for (Block pred : block.getPredecessors()) {
+            assert pred != null;
+            assert pred.lir != null;
+            List<LIRInstruction> predInstructions = pred.lir;
+
+            if (pred.numberOfSux() != 1) {
+                // this can happen with switch-statements where multiple edges are between
+                // the same blocks.
+                return;
+            }
+
+            if (predInstructions.get(predInstructions.size() - 1) instanceof LIRXirInstruction) {
+                return;
+            }
+
+            assert pred.suxAt(0) == block : "invalid control flow";
+            assert predInstructions.get(predInstructions.size() - 1) instanceof StandardOp.JumpOp : "block must end with unconditional jump";
+
+            if (predInstructions.get(predInstructions.size() - 1).hasState()) {
+                // can not optimize instructions that have debug info
+                return;
+            }
+
+            // ignore the unconditional branch at the end of the block
+            List<LIRInstruction> seq = predInstructions.subList(0, predInstructions.size() - 1);
+            edgeInstructionSeqences.add(seq);
+        }
+
+        // process lir-instructions while all predecessors end with the same instruction
+        while (true) {
+            List<LIRInstruction> seq = edgeInstructionSeqences.get(0);
+            if (seq.isEmpty()) {
+                return;
+            }
+
+            LIRInstruction op = last(seq);
+            for (int i = 1; i < numPreds; ++i) {
+                List<LIRInstruction> otherSeq = edgeInstructionSeqences.get(i);
+                if (otherSeq.isEmpty() || !same(op, last(otherSeq))) {
+                    return;
+                }
+            }
+
+            // insert the instruction at the beginning of the current block
+            block.lir.add(1, op);
+
+            // delete the instruction at the end of all predecessors
+            for (int i = 0; i < numPreds; i++) {
+                seq = edgeInstructionSeqences.get(i);
+                removeLast(seq);
+            }
+        }
+    }
+
+    /**
+     * Moves the longest {@linkplain #same common} subsequence at the start of all
+     * successors of {@code block} to the end of {@code block} just prior to the
+     * branch instruction ending {@code block}.
+     */
+    private void optimizeMovesAtBlockBegin(Block block) {
+
+        edgeInstructionSeqences.clear();
+        int numSux = block.numberOfSux();
+
+        List<LIRInstruction> instructions = block.lir;
+
+        assert numSux == 2 : "method should not be called otherwise";
+
+        if (instructions.get(instructions.size() - 1) instanceof LIRXirInstruction) {
+            // cannot optimize when last instruction is Xir.
+            return;
+        }
+
+        assert instructions.get(instructions.size() - 1) instanceof StandardOp.JumpOp : "block must end with unconditional jump";
+
+        if (instructions.get(instructions.size() - 1).hasState()) {
+            // cannot optimize instructions when debug info is needed
+            return;
+        }
+
+        LIRInstruction branch = instructions.get(instructions.size() - 2);
+        if (!(branch instanceof StandardOp.BranchOp) || branch.hasState()) {
+            // not a valid case for optimization
+            // currently, only blocks that end with two branches (conditional branch followed
+            // by unconditional branch) are optimized
+            return;
+        }
+
+        // now it is guaranteed that the block ends with two branch instructions.
+        // the instructions are inserted at the end of the block before these two branches
+        int insertIdx = instructions.size() - 2;
+
+        // setup a list with the lir-instructions of all successors
+        for (int i = 0; i < numSux; i++) {
+            Block sux = block.suxAt(i);
+            List<LIRInstruction> suxInstructions = sux.lir;
+
+            assert suxInstructions.get(0) instanceof StandardOp.LabelOp : "block must start with label";
+
+            if (sux.numberOfPreds() != 1) {
+                // this can happen with switch-statements where multiple edges are between
+                // the same blocks.
+                return;
+            }
+            assert sux.predAt(0) == block : "invalid control flow";
+
+            // ignore the label at the beginning of the block
+            List<LIRInstruction> seq = suxInstructions.subList(1, suxInstructions.size());
+            edgeInstructionSeqences.add(seq);
+        }
+
+        // process LIR instructions while all successors begin with the same instruction
+        while (true) {
+            List<LIRInstruction> seq = edgeInstructionSeqences.get(0);
+            if (seq.isEmpty()) {
+                return;
+            }
+
+            LIRInstruction op = first(seq);
+            for (int i = 1; i < numSux; i++) {
+                List<LIRInstruction> otherSeq = edgeInstructionSeqences.get(i);
+                if (otherSeq.isEmpty() || !same(op, first(otherSeq))) {
+                    // these instructions are different and cannot be optimized .
+                    // no further optimization possible
+                    return;
+                }
+            }
+
+            // insert instruction at end of current block
+            block.lir.add(insertIdx, op);
+            insertIdx++;
+
+            // delete the instructions at the beginning of all successors
+            for (int i = 0; i < numSux; i++) {
+                seq = edgeInstructionSeqences.get(i);
+                removeFirst(seq);
+            }
+        }
+    }
+
+    /**
+     * Gets the first element from a LIR instruction sequence.
+     */
+    private static LIRInstruction first(List<LIRInstruction> seq) {
+        return seq.get(0);
+    }
+
+    /**
+     * Gets the last element from a LIR instruction sequence.
+     */
+    private static LIRInstruction last(List<LIRInstruction> seq) {
+        return seq.get(seq.size() - 1);
+    }
+
+    /**
+     * Removes the first element from a LIR instruction sequence.
+     */
+    private static void removeFirst(List<LIRInstruction> seq) {
+        seq.remove(0);
+    }
+
+    /**
+     * Removes the last element from a LIR instruction sequence.
+     */
+    private static void removeLast(List<LIRInstruction> seq) {
+        seq.remove(seq.size() - 1);
+    }
+}