/*

 * 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 org.graalvm.compiler.replacements.amd64;

import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_8;

import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_1;

import org.graalvm.compiler.core.common.calc.FloatConvert;

import org.graalvm.compiler.core.common.type.ArithmeticOpTable.FloatConvertOp;

import org.graalvm.compiler.core.common.type.IntegerStamp;

import org.graalvm.compiler.core.common.type.Stamp;

import org.graalvm.compiler.core.common.type.StampFactory;

import org.graalvm.compiler.graph.NodeClass;

import org.graalvm.compiler.graph.spi.CanonicalizerTool;

import org.graalvm.compiler.lir.gen.ArithmeticLIRGeneratorTool;

import org.graalvm.compiler.nodeinfo.NodeInfo;

import org.graalvm.compiler.nodes.ValueNode;

import org.graalvm.compiler.nodes.calc.FloatConvertNode;

import org.graalvm.compiler.nodes.calc.UnaryArithmeticNode;

import org.graalvm.compiler.nodes.spi.ArithmeticLIRLowerable;

import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;

/**

 * This node has the semantics of the AMD64 floating point conversions. It is used in the lowering

 * of the {@link FloatConvertNode} which, on AMD64 needs a {@link AMD64FloatConvertNode} plus some

 * fixup code that handles the corner cases that differ between AMD64 and Java.

 *

 * Since this node evaluates to a special value if the conversion is inexact, its stamp must be

 * modified to avoid optimizing away {@link AMD64ConvertSnippets}.

 */

@NodeInfo(cycles = CYCLES_8, size = SIZE_1)

public final class AMD64FloatConvertNode extends UnaryArithmeticNode<FloatConvertOp> implements ArithmeticLIRLowerable {

    public static final NodeClass<AMD64FloatConvertNode> TYPE = NodeClass.create(AMD64FloatConvertNode.class);

    protected final FloatConvert op;

    public AMD64FloatConvertNode(FloatConvert op, ValueNode value) {

        this.op = op;

        this.stamp = this.stamp.meet(createInexactCaseStamp());

    }

    @Override

    public ValueNode canonical(CanonicalizerTool tool, ValueNode forValue) {

        // nothing to do

        return this;

    }

    @Override

    public Stamp foldStamp(Stamp newStamp) {

        // The semantics of the x64 CVTTSS2SI instruction allow returning 0x8000000 in the special

        // cases.

        Stamp foldedStamp = super.foldStamp(newStamp);

        return foldedStamp.meet(createInexactCaseStamp());

    }

    private Stamp createInexactCaseStamp() {

        IntegerStamp intStamp = (IntegerStamp) this.stamp;

        long inexactValue = intStamp.getBits() <= 32 ? 0x8000_0000L : 0x8000_0000_0000_0000L;

        return StampFactory.forConstant(JavaConstant.forPrimitiveInt(intStamp.getBits(), inexactValue));

    }

    @Override

    public void generate(NodeLIRBuilderTool nodeValueMap, ArithmeticLIRGeneratorTool gen) {

        nodeValueMap.setResult(this, gen.emitFloatConvert(op, nodeValueMap.operand(getValue())));

    }

}