/*
 * Copyright (c) 2012, 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
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 * questions.
 */
package com.oracle.graal.loop;

import com.oracle.graal.api.meta.*;
import com.oracle.graal.graph.*;
import com.oracle.graal.nodes.*;
import com.oracle.graal.nodes.calc.*;
import com.oracle.graal.nodes.type.*;

public class BasicInductionVariable extends InductionVariable {

    private PhiNode phi;
    private ValueNode init;
    private ValueNode rawStride;
    private IntegerArithmeticNode op;

    public BasicInductionVariable(LoopEx loop, PhiNode phi, ValueNode init, ValueNode rawStride, IntegerArithmeticNode op) {
        super(loop);
        this.phi = phi;
        this.init = init;
        this.rawStride = rawStride;
        this.op = op;
    }

    @Override
    public StructuredGraph graph() {
        return phi.graph();
    }

    @Override
    public Direction direction() {
        Stamp stamp = rawStride.stamp();
        if (stamp instanceof IntegerStamp) {
            IntegerStamp integerStamp = (IntegerStamp) stamp;
            Direction dir = null;
            if (integerStamp.isStrictlyPositive()) {
                dir = Direction.Up;
            } else if (integerStamp.isStrictlyNegative()) {
                dir = Direction.Down;
            }
            if (dir != null) {
                if (op instanceof IntegerAddNode) {
                    return dir;
                } else {
                    assert op instanceof IntegerSubNode;
                    return dir.opposite();
                }
            }
        }
        return null;
    }

    @Override
    public PhiNode valueNode() {
        return phi;
    }

    @Override
    public ValueNode initNode() {
        return init;
    }

    @Override
    public ValueNode strideNode() {
        if (op instanceof IntegerAddNode) {
            return rawStride;
        }
        if (op instanceof IntegerSubNode) {
            return graph().unique(new NegateNode(rawStride));
        }
        throw GraalInternalError.shouldNotReachHere();
    }

    @Override
    public boolean isConstantInit() {
        return init.isConstant();
    }

    @Override
    public boolean isConstantStride() {
        return rawStride.isConstant();
    }

    @Override
    public long constantInit() {
        return init.asConstant().asLong();
    }

    @Override
    public long constantStride() {
        if (op instanceof IntegerAddNode) {
            return rawStride.asConstant().asLong();
        }
        if (op instanceof IntegerSubNode) {
            return -rawStride.asConstant().asLong();
        }
        throw GraalInternalError.shouldNotReachHere();
    }

    @Override
    public ValueNode extremumNode(boolean assumePositiveTripCount, Kind kind) {
        Kind fromKind = phi.kind();
        StructuredGraph graph = graph();
        ValueNode stride = strideNode();
        ValueNode maxTripCount = loop.counted().maxTripCountNode(assumePositiveTripCount);
        ValueNode initNode = this.initNode();
        if (fromKind != kind) {
            stride = graph.unique(new ConvertNode(fromKind, kind, stride));
            maxTripCount = graph.unique(new ConvertNode(fromKind, kind, maxTripCount));
            initNode = graph.unique(new ConvertNode(fromKind, kind, initNode));
        }
        return IntegerArithmeticNode.add(graph, IntegerArithmeticNode.mul(graph, stride, IntegerArithmeticNode.sub(graph, maxTripCount, ConstantNode.forIntegerKind(kind, 1, graph))), initNode);
    }

    @Override
    public ValueNode exitValueNode() {
        ValueNode maxTripCount = loop.counted().maxTripCountNode(false);
        return IntegerArithmeticNode.add(graph(), IntegerArithmeticNode.mul(graph(), strideNode(), maxTripCount), initNode());
    }

    @Override
    public boolean isConstantExtremum() {
        return isConstantInit() && isConstantStride() && loop.counted().isConstantMaxTripCount();
    }

    @Override
    public long constantExtremum() {
        return constantStride() * (loop.counted().constantMaxTripCount() - 1) + constantInit();
    }
}

@@ -3832,99 +3832,8 @@
 ();%0A
-        ValueNode maxTripCount = loop.counted().maxTripCountNode(assumePositiveTripCount);%0A
     
@@ -3866,32 +3866,32 @@
 his.initNode();%0A
+
         if (from
@@ -3986,96 +3986,8 @@
 ));%0A
-            maxTripCount = graph.unique(new ConvertNode(fromKind, kind, maxTripCount));%0A
     
@@ -4064,32 +4064,275 @@
 de));%0A        %7D%0A
+        ValueNode maxTripCount = loop.counted().maxTripCountNode(assumePositiveTripCount);%0A        if (maxTripCount.kind() != kind) %7B%0A            maxTripCount = graph.unique(new ConvertNode(maxTripCount.kind(), kind, maxTripCount));%0A        %7D%0A
         return I
@@ -4561,32 +4561,64 @@
 itValueNode() %7B%0A
+        Kind kind = phi.kind();%0A
         ValueNod
@@ -4670,24 +4670,178 @@
 ode(false);%0A
+        if (maxTripCount.kind() != kind) %7B%0A            maxTripCount = graph().unique(new ConvertNode(maxTripCount.kind(), kind, maxTripCount));%0A        %7D%0A
         retu

Fix wrong conversion in extremum and exit values of induction variables.