# HG changeset patch
# User Thomas Wuerthinger <thomas@wuerthinger.net>
# Date 1305728733 -7200
# Node ID 618f545fcac56bb73dbc34b2e38cbe8958df4267
# Parent  2186ca5c2dabd5cbce6acec4545012b2704dca51
Removed control flow optimizer.

diff -r 2186ca5c2dab -r 618f545fcac5 graal/GraalCompiler/src/com/sun/c1x/C1XOptions.java
--- a/graal/GraalCompiler/src/com/sun/c1x/C1XOptions.java	Wed May 18 16:09:55 2011 +0200
+++ b/graal/GraalCompiler/src/com/sun/c1x/C1XOptions.java	Wed May 18 16:25:33 2011 +0200
@@ -91,10 +91,6 @@
     public static boolean PrintAssumptions                   = ____;
     public static boolean QuietBailout                       = ____;
 
-    // all optimization settings
-    public static boolean OptBlockSkipping;
-    public static boolean OptControlFlow;
-
     // optimistic optimization settings
     public static boolean UseAssumptions                = true;
 
@@ -156,7 +152,6 @@
 
         // Level 1 optimizations
         PhiLoopStores                   = l;
-        OptControlFlow                  = l;
 
         // Level 2 optimizations
         OptInline                       = ll;
@@ -164,6 +159,5 @@
         // Level 3 optimizations
         UseStackMapTableLiveness        = lll;
         UseAssumptions                  = lll;
-        OptBlockSkipping                = lll;
     }
 }
diff -r 2186ca5c2dab -r 618f545fcac5 graal/GraalCompiler/src/com/sun/c1x/alloc/ControlFlowOptimizer.java
--- a/graal/GraalCompiler/src/com/sun/c1x/alloc/ControlFlowOptimizer.java	Wed May 18 16:09:55 2011 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,273 +0,0 @@
-/*
- * Copyright (c) 2009, 2011, 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.sun.c1x.alloc;
-
-import java.util.*;
-
-import com.sun.c1x.*;
-import com.sun.c1x.graph.*;
-import com.sun.c1x.ir.*;
-import com.sun.c1x.lir.*;
-import com.sun.c1x.util.*;
-import com.sun.cri.ci.*;
-
-/**
- * This class performs basic optimizations on the control flow graph after LIR generation.
- *
- * @author Thomas Wuerthinger
- */
-final class ControlFlowOptimizer {
-
-    /**
-     * Performs control flow optimizations on the given IR graph.
-     * @param ir the IR graph that should be optimized
-     */
-    public static void optimize(IR ir) {
-        ControlFlowOptimizer optimizer = new ControlFlowOptimizer(ir);
-        List<BlockBegin> code = ir.linearScanOrder();
-        optimizer.reorderShortLoops(code);
-        optimizer.deleteEmptyBlocks(code);
-        optimizer.deleteUnnecessaryJumps(code);
-        optimizer.deleteJumpsToReturn(code);
-    }
-
-    private final IR ir;
-
-    private ControlFlowOptimizer(IR ir) {
-        this.ir = ir;
-    }
-
-    private void reorderShortLoop(List<BlockBegin> code, BlockBegin headerBlock, int headerIdx) {
-        int i = headerIdx + 1;
-        int maxEnd = Math.min(headerIdx + C1XOptions.MaximumShortLoopSize, code.size());
-        while (i < maxEnd && code.get(i).loopDepth() >= headerBlock.loopDepth()) {
-            i++;
-        }
-
-        if (i == code.size() || code.get(i).loopDepth() < headerBlock.loopDepth()) {
-            int endIdx = i - 1;
-            BlockBegin endBlock = code.get(endIdx);
-
-            if (endBlock.numberOfSux() == 1 && endBlock.suxAt(0) == headerBlock) {
-                // short loop from headerIdx to endIdx found . reorder blocks such that
-                // the headerBlock is the last block instead of the first block of the loop
-
-                for (int j = headerIdx; j < endIdx; j++) {
-                    code.set(j, code.get(j + 1));
-                }
-                code.set(endIdx, headerBlock);
-
-                // correct the flags so that any loop alignment occurs in the right place.
-                assert code.get(endIdx).checkBlockFlag(BlockBegin.BlockFlag.BackwardBranchTarget) : "must be backward branch target";
-                code.get(endIdx).clearBlockFlag(BlockBegin.BlockFlag.BackwardBranchTarget);
-                code.get(headerIdx).setBlockFlag(BlockBegin.BlockFlag.BackwardBranchTarget);
-            }
-        }
-    }
-
-    private void reorderShortLoops(List<BlockBegin> code) {
-        for (int i = code.size() - 1; i >= 0; i--) {
-            BlockBegin block = code.get(i);
-
-            if (block.checkBlockFlag(BlockBegin.BlockFlag.LinearScanLoopHeader)) {
-                reorderShortLoop(code, block, i);
-            }
-        }
-
-        assert verify(code);
-    }
-
-    // only blocks with exactly one successor can be deleted. Such blocks
-    // must always end with an unconditional branch to this successor
-    private boolean canDeleteBlock(BlockBegin block) {
-        if (block.numberOfSux() != 1 ||
-            block.numberOfExceptionHandlers() != 0 ||
-            block == ir.startBlock ||
-            block.isExceptionEntry() ||
-            block.suxAt(0) == block) {
-            return false;
-        }
-
-        List<LIRInstruction> instructions = block.lir().instructionsList();
-
-        assert instructions.size() >= 2 : "block must have label and branch";
-        assert instructions.get(0).code == LIROpcode.Label : "first instruction must always be a label";
-        assert instructions.get(instructions.size() - 1) instanceof LIRBranch : "last instruction must always be a branch";
-        assert ((LIRBranch) instructions.get(instructions.size() - 1)).cond() == Condition.TRUE : "branch must be unconditional";
-        assert ((LIRBranch) instructions.get(instructions.size() - 1)).block() == block.suxAt(0) : "branch target must be the successor";
-
-        // block must have exactly one successor
-
-        return instructions.size() == 2 && instructions.get(instructions.size() - 1).info == null;
-    }
-
-    private void deleteEmptyBlocks(List<BlockBegin> code) {
-        int oldPos = 0;
-        int newPos = 0;
-        int numBlocks = code.size();
-
-        while (oldPos < numBlocks) {
-            BlockBegin block = code.get(oldPos);
-
-            if (canDeleteBlock(block)) {
-                BlockBegin newTarget = block.suxAt(0);
-
-                // propagate backward branch target flag for correct code alignment
-                if (block.checkBlockFlag(BlockBegin.BlockFlag.BackwardBranchTarget)) {
-                    newTarget.setBlockFlag(BlockBegin.BlockFlag.BackwardBranchTarget);
-                }
-
-                // update the block references in any branching LIR instructions
-                for (BlockEnd pred : block.blockPredecessors()) {
-                    for (LIRInstruction instr : pred.begin().lir().instructionsList()) {
-                        if (instr instanceof LIRBranch) {
-                            ((LIRBranch) instr).substitute(block, newTarget);
-                        } else if (instr instanceof LIRTableSwitch) {
-                            ((LIRTableSwitch) instr).substitute(block, newTarget);
-                        }
-                    }
-                }
-
-                // adjust successor and predecessor lists
-                ir.replaceBlock(block, newTarget);
-                C1XMetrics.BlocksDeleted++;
-            } else {
-                // adjust position of this block in the block list if blocks before
-                // have been deleted
-                if (newPos != oldPos) {
-                    code.set(newPos, code.get(oldPos));
-                }
-                newPos++;
-            }
-            oldPos++;
-        }
-        Util.truncate(code, newPos);
-
-        assert verify(code);
-    }
-
-    private void deleteUnnecessaryJumps(List<BlockBegin> code) {
-        // skip the last block because there a branch is always necessary
-        for (int i = code.size() - 2; i >= 0; i--) {
-            BlockBegin block = code.get(i);
-            List<LIRInstruction> instructions = block.lir().instructionsList();
-
-            LIRInstruction lastOp = instructions.get(instructions.size() - 1);
-            if (lastOp.code == LIROpcode.Branch) {
-                assert lastOp instanceof LIRBranch : "branch must be of type LIRBranch";
-                LIRBranch lastBranch = (LIRBranch) lastOp;
-
-                assert lastBranch.block() != null : "last branch must always have a block as target";
-                assert lastBranch.label() == lastBranch.block().label() : "must be equal";
-
-                if (lastBranch.info == null) {
-                    if (lastBranch.block() == code.get(i + 1)) {
-                        // delete last branch instruction
-                        Util.truncate(instructions, instructions.size() - 1);
-
-                    } else {
-                        LIRInstruction prevOp = instructions.get(instructions.size() - 2);
-                        if (prevOp.code == LIROpcode.Branch || prevOp.code == LIROpcode.CondFloatBranch) {
-                            assert prevOp instanceof LIRBranch : "branch must be of type LIRBranch";
-                            LIRBranch prevBranch = (LIRBranch) prevOp;
-
-                            if (prevBranch.block() == code.get(i + 1) && prevBranch.info == null) {
-                                // eliminate a conditional branch to the immediate successor
-                                prevBranch.changeBlock(lastBranch.block());
-                                prevBranch.negateCondition();
-                                Util.truncate(instructions, instructions.size() - 1);
-                            }
-                        }
-                    }
-                }
-            }
-        }
-
-        assert verify(code);
-    }
-
-    private void deleteJumpsToReturn(List<BlockBegin> code) {
-        for (int i = code.size() - 1; i >= 0; i--) {
-            BlockBegin block = code.get(i);
-            List<LIRInstruction> curInstructions = block.lir().instructionsList();
-            LIRInstruction curLastOp = curInstructions.get(curInstructions.size() - 1);
-
-            assert curInstructions.get(0).code == LIROpcode.Label : "first instruction must always be a label";
-            if (curInstructions.size() == 2 && curLastOp.code == LIROpcode.Return) {
-                // the block contains only a label and a return
-                // if a predecessor ends with an unconditional jump to this block, then the jump
-                // can be replaced with a return instruction
-                //
-                // Note: the original block with only a return statement cannot be deleted completely
-                // because the predecessors might have other (conditional) jumps to this block.
-                // this may lead to unnecesary return instructions in the final code
-
-                assert curLastOp.info == null : "return instructions do not have debug information";
-
-                assert curLastOp instanceof LIROp1 : "return must be LIROp1";
-                CiValue returnOpr = ((LIROp1) curLastOp).operand();
-
-                for (int j = block.numberOfPreds() - 1; j >= 0; j--) {
-                    BlockBegin pred = block.predAt(j).begin();
-                    List<LIRInstruction> predInstructions = pred.lir().instructionsList();
-                    LIRInstruction predLastOp = predInstructions.get(predInstructions.size() - 1);
-
-                    if (predLastOp.code == LIROpcode.Branch) {
-                        assert predLastOp instanceof LIRBranch : "branch must be LIRBranch";
-                        LIRBranch predLastBranch = (LIRBranch) predLastOp;
-
-                        if (predLastBranch.block() == block && predLastBranch.cond() == Condition.TRUE && predLastBranch.info == null) {
-                            // replace the jump to a return with a direct return
-                            // Note: currently the edge between the blocks is not deleted
-                            predInstructions.set(predInstructions.size() - 1, new LIROp1(LIROpcode.Return, returnOpr));
-                        }
-                    }
-                }
-            }
-        }
-    }
-
-    private boolean verify(List<BlockBegin> code) {
-        for (BlockBegin block : code) {
-            List<LIRInstruction> instructions = block.lir().instructionsList();
-
-            for (LIRInstruction instr : instructions) {
-                if (instr instanceof LIRBranch) {
-                    LIRBranch opBranch = (LIRBranch) instr;
-                    assert opBranch.block() == null || code.contains(opBranch.block()) : "missing successor branch from: " + block + " to: " + opBranch.block();
-                    assert opBranch.unorderedBlock() == null || code.contains(opBranch.unorderedBlock()) : "missing successor branch from: " + block + " to: " + opBranch.unorderedBlock();
-                }
-            }
-
-            for (BlockBegin sux : block.end().blockSuccessors()) {
-                assert code.contains(sux) : "missing successor from: " + block + "to: " + sux;
-            }
-
-            for (BlockEnd pred : block.blockPredecessors()) {
-                assert code.contains(pred.begin()) : "missing predecessor from: " + block + "to: " + pred.begin();
-            }
-        }
-
-        return true;
-    }
-}
diff -r 2186ca5c2dab -r 618f545fcac5 graal/GraalCompiler/src/com/sun/c1x/alloc/LinearScan.java
--- a/graal/GraalCompiler/src/com/sun/c1x/alloc/LinearScan.java	Wed May 18 16:09:55 2011 +0200
+++ b/graal/GraalCompiler/src/com/sun/c1x/alloc/LinearScan.java	Wed May 18 16:25:33 2011 +0200
@@ -2288,12 +2288,7 @@
         }
 
         printLir("After register number assignment", true);
-
         EdgeMoveOptimizer.optimize(ir.linearScanOrder());
-        if (C1XOptions.OptControlFlow) {
-            ControlFlowOptimizer.optimize(ir);
-        }
-
         printLir("After control flow optimization", false);
     }