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package org.graalvm.compiler.hotspot.amd64;

import static org.graalvm.compiler.hotspot.HotSpotBackend.Options.GraalArithmeticStubs;

import org.graalvm.compiler.api.replacements.Snippet;
import org.graalvm.compiler.core.amd64.AMD64LoweringProviderMixin;
import org.graalvm.compiler.core.common.spi.ForeignCallsProvider;
import org.graalvm.compiler.debug.DebugHandlersFactory;
import org.graalvm.compiler.graph.Node;
import org.graalvm.compiler.hotspot.GraalHotSpotVMConfig;
import org.graalvm.compiler.hotspot.HotSpotGraalRuntimeProvider;
import org.graalvm.compiler.hotspot.meta.DefaultHotSpotLoweringProvider;
import org.graalvm.compiler.hotspot.meta.HotSpotProviders;
import org.graalvm.compiler.hotspot.meta.HotSpotRegistersProvider;
import org.graalvm.compiler.hotspot.nodes.profiling.ProfileNode;
import org.graalvm.compiler.hotspot.replacements.profiling.ProbabilisticProfileSnippets;
import org.graalvm.compiler.nodes.StructuredGraph;
import org.graalvm.compiler.nodes.calc.FloatConvertNode;
import org.graalvm.compiler.nodes.extended.ForeignCallNode;
import org.graalvm.compiler.nodes.spi.LoweringTool;
import org.graalvm.compiler.options.OptionValues;
import org.graalvm.compiler.replacements.amd64.AMD64ArrayIndexOfDispatchNode;
import org.graalvm.compiler.replacements.amd64.AMD64ConvertSnippets;
import org.graalvm.compiler.replacements.nodes.UnaryMathIntrinsicNode;
import org.graalvm.compiler.replacements.nodes.UnaryMathIntrinsicNode.UnaryOperation;
import org.graalvm.compiler.serviceprovider.JavaVersionUtil;

import jdk.vm.ci.code.TargetDescription;
import jdk.vm.ci.hotspot.HotSpotConstantReflectionProvider;
import jdk.vm.ci.meta.MetaAccessProvider;
import jdk.vm.ci.meta.ResolvedJavaMethod;

public class AMD64HotSpotLoweringProvider extends DefaultHotSpotLoweringProvider implements AMD64LoweringProviderMixin {

    private AMD64ConvertSnippets.Templates convertSnippets;
    private ProbabilisticProfileSnippets.Templates profileSnippets;
    private AMD64X87MathSnippets.Templates mathSnippets;

    public AMD64HotSpotLoweringProvider(HotSpotGraalRuntimeProvider runtime, MetaAccessProvider metaAccess, ForeignCallsProvider foreignCalls, HotSpotRegistersProvider registers,
                    HotSpotConstantReflectionProvider constantReflection, TargetDescription target) {
        super(runtime, metaAccess, foreignCalls, registers, constantReflection, target);
    }

    @Override
    public void initialize(OptionValues options, Iterable<DebugHandlersFactory> factories, HotSpotProviders providers, GraalHotSpotVMConfig config) {
        convertSnippets = new AMD64ConvertSnippets.Templates(options, factories, providers, providers.getSnippetReflection(), providers.getCodeCache().getTarget());
        if (JavaVersionUtil.JAVA_SPEC <= 8) {
            // AOT only introduced in JDK 9
            profileSnippets = null;
        } else {
            profileSnippets = new ProbabilisticProfileSnippets.Templates(options, factories, providers, providers.getCodeCache().getTarget());
        }
        mathSnippets = new AMD64X87MathSnippets.Templates(options, factories, providers, providers.getSnippetReflection(), providers.getCodeCache().getTarget());
        super.initialize(options, factories, providers, config);
    }

    @Override
    public void lower(Node n, LoweringTool tool) {
        if (n instanceof FloatConvertNode) {
            convertSnippets.lower((FloatConvertNode) n, tool);
        } else if (profileSnippets != null && n instanceof ProfileNode) {
            profileSnippets.lower((ProfileNode) n, tool);
        } else if (n instanceof UnaryMathIntrinsicNode) {
            lowerUnaryMath((UnaryMathIntrinsicNode) n, tool);
        } else if (n instanceof AMD64ArrayIndexOfDispatchNode) {
            lowerArrayIndexOf((AMD64ArrayIndexOfDispatchNode) n);
        } else {
            super.lower(n, tool);
        }
    }

    private void lowerUnaryMath(UnaryMathIntrinsicNode math, LoweringTool tool) {
        if (tool.getLoweringStage() == LoweringTool.StandardLoweringStage.HIGH_TIER) {
            return;
        }
        StructuredGraph graph = math.graph();
        ResolvedJavaMethod method = graph.method();
        if (method != null) {
            if (method.getAnnotation(Snippet.class) != null) {
                // In the context of SnippetStub, i.e., Graal-generated stubs, use the LIR
                // lowering to emit the stub assembly code instead of the Node lowering.
                return;
            }
        }
        if (!GraalArithmeticStubs.getValue(graph.getOptions())) {
            switch (math.getOperation()) {
                case SIN:
                case COS:
                case TAN:
                    // Math.sin(), .cos() and .tan() guarantee a value within 1 ULP of the exact
                    // result, but x87 trigonometric FPU instructions are only that accurate within
                    // [-pi/4, pi/4]. The snippets fall back to a foreign call to HotSpot stubs
                    // should the inputs outside of that interval.
                    mathSnippets.lower(math, tool);
                    return;
                case LOG:
                    math.replaceAtUsages(graph.addOrUnique(new AMD64X87MathIntrinsicNode(math.getValue(), UnaryOperation.LOG)));
                    return;
                case LOG10:
                    math.replaceAtUsages(graph.addOrUnique(new AMD64X87MathIntrinsicNode(math.getValue(), UnaryOperation.LOG10)));
                    return;
            }
        }

        ForeignCallNode call = graph.add(new ForeignCallNode(foreignCalls, math.getOperation().foreignCallDescriptor, math.getValue()));
        graph.addAfterFixed(tool.lastFixedNode(), call);
        math.replaceAtUsages(call);
    }

    private void lowerArrayIndexOf(AMD64ArrayIndexOfDispatchNode dispatchNode) {
        StructuredGraph graph = dispatchNode.graph();
        ForeignCallNode call = graph.add(new ForeignCallNode(foreignCalls, dispatchNode.getStubCallDescriptor(), dispatchNode.getStubCallArgs()));
        graph.replaceFixed(dispatchNode, call);
    }
}
