# HG changeset patch
# User Josef Eisl <josef.eisl@jku.at>
# Date 1429538558 -7200
# Node ID a4d68add31f61334765cbcae0bb7e82efd6a37d4
# Parent  ca85b783309c915607b00d5fa0d76286a1e434a0
Add SSADestructionPhase.

diff -r ca85b783309c -r a4d68add31f6 graal/com.oracle.graal.lir/src/com/oracle/graal/lir/phases/PreAllocationOptimizationStage.java
--- a/graal/com.oracle.graal.lir/src/com/oracle/graal/lir/phases/PreAllocationOptimizationStage.java	Thu Apr 23 14:35:28 2015 +0200
+++ b/graal/com.oracle.graal.lir/src/com/oracle/graal/lir/phases/PreAllocationOptimizationStage.java	Mon Apr 20 16:02:38 2015 +0200
@@ -22,11 +22,17 @@
  */
 package com.oracle.graal.lir.phases;
 
+import static com.oracle.graal.compiler.common.GraalOptions.*;
+
 import com.oracle.graal.lir.constopt.*;
 import com.oracle.graal.lir.phases.PreAllocationOptimizationPhase.*;
+import com.oracle.graal.lir.ssa.*;
 
 public class PreAllocationOptimizationStage extends LIRPhaseSuite<PreAllocationOptimizationContext> {
     public PreAllocationOptimizationStage() {
+        if (SSA_LIR.getValue()) {
+            appendPhase(new SSADestructionPhase());
+        }
         if (ConstantLoadOptimization.Options.LIROptConstantLoadOptimization.getValue()) {
             appendPhase(new ConstantLoadOptimization());
         }
diff -r ca85b783309c -r a4d68add31f6 graal/com.oracle.graal.lir/src/com/oracle/graal/lir/ssa/SSADestructionPhase.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.graal.lir/src/com/oracle/graal/lir/ssa/SSADestructionPhase.java	Mon Apr 20 16:02:38 2015 +0200
@@ -0,0 +1,83 @@
+/*
+ * Copyright (c) 2015, 2015, 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.ssa;
+
+import java.util.*;
+
+import com.oracle.graal.api.code.*;
+import com.oracle.graal.api.meta.*;
+import com.oracle.graal.compiler.common.cfg.*;
+import com.oracle.graal.lir.*;
+import com.oracle.graal.lir.StandardOp.JumpOp;
+import com.oracle.graal.lir.StandardOp.LabelOp;
+import com.oracle.graal.lir.gen.*;
+import com.oracle.graal.lir.phases.*;
+
+public final class SSADestructionPhase extends PreAllocationOptimizationPhase {
+
+    @Override
+    protected <B extends AbstractBlockBase<B>> void run(TargetDescription target, LIRGenerationResult lirGenRes, List<B> codeEmittingOrder, List<B> linearScanOrder, LIRGeneratorTool lirGen) {
+        LIR lir = lirGenRes.getLIR();
+        AbstractControlFlowGraph<?> cfg = lir.getControlFlowGraph();
+        for (AbstractBlockBase<?> block : cfg.getBlocks()) {
+            doBlock(block, lir, lirGen);
+
+        }
+
+    }
+
+    private static void doBlock(AbstractBlockBase<?> block, LIR lir, LIRGeneratorTool lirGen) {
+        if (block.getPredecessorCount() > 1) {
+            LabelOp label = (LabelOp) lir.getLIRforBlock(block).get(0);
+            for (AbstractBlockBase<?> pred : block.getPredecessors()) {
+                assert pred.getSuccessorCount() == 1 : String.format("Merge predecessor block %s has more than one successor? %s", pred, pred.getSuccessors());
+
+                List<LIRInstruction> instructions = lir.getLIRforBlock(pred);
+                JumpOp jump = (JumpOp) instructions.get(instructions.size() - 1);
+
+                resolvePhi(label, jump, lirGen, instructions);
+                jump.clearOutgoingValues();
+            }
+            label.clearIncomingValues();
+        }
+    }
+
+    private static void resolvePhi(LabelOp label, JumpOp jump, LIRGeneratorTool gen, List<LIRInstruction> instructions) {
+        int incomingSize = label.getIncomingSize();
+        int outgoingSize = jump.getOutgoingSize();
+        assert incomingSize == outgoingSize : String.format("Phi In/Out size mismatch: in=%d vs. out=%d", incomingSize, outgoingSize);
+
+        int insertBefore = instructions.size() - 1;
+        assert instructions.get(insertBefore) == jump;
+
+        PhiResolver resolver = PhiResolver.create(gen, new LIRInsertionBuffer(), instructions, insertBefore);
+        for (int i = 0; i < incomingSize; i++) {
+            Value phiIn = label.getIncomingValue(i);
+            Value phiOut = jump.getOutgoingValue(i);
+            resolver.move(phiIn, phiOut);
+        }
+        resolver.dispose();
+
+    }
+
+}