/*
 * Copyright (c) 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
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
package com.oracle.graal.hotspot.target.amd64;

import static com.oracle.graal.api.code.CiCallingConvention.Type.*;
import static com.oracle.graal.api.code.CiValueUtil.*;
import static com.oracle.graal.hotspot.ri.HotSpotXirGenerator.*;
import static com.oracle.max.asm.target.amd64.AMD64.*;

import java.lang.reflect.*;

import com.oracle.graal.api.code.*;
import com.oracle.graal.api.meta.*;
import com.oracle.graal.compiler.*;
import com.oracle.graal.compiler.gen.*;
import com.oracle.graal.compiler.target.*;
import com.oracle.graal.compiler.target.amd64.*;
import com.oracle.graal.graph.*;
import com.oracle.graal.hotspot.*;
import com.oracle.graal.hotspot.counters.*;
import com.oracle.graal.hotspot.ri.*;
import com.oracle.graal.lir.*;
import com.oracle.graal.lir.amd64.*;
import com.oracle.graal.lir.asm.*;
import com.oracle.graal.nodes.*;
import com.oracle.graal.nodes.java.*;
import com.oracle.max.asm.*;
import com.oracle.max.asm.target.amd64.AMD64Assembler.ConditionFlag;
import com.oracle.max.asm.target.amd64.*;
import com.oracle.max.cri.xir.*;

public class HotSpotAMD64Backend extends Backend {

    public HotSpotAMD64Backend(CodeCacheProvider runtime, CiTarget target) {
        super(runtime, target);
    }

    @Override
    public LIRGenerator newLIRGenerator(Graph graph, FrameMap frameMap, ResolvedJavaMethod method, LIR lir, RiXirGenerator xir, CiAssumptions assumptions) {
        return new AMD64LIRGenerator(graph, runtime, target, frameMap, method, lir, xir, assumptions) {

            @Override
            public void visitSafepointNode(SafepointNode i) {
                LIRDebugInfo info = state();
                append(new AMD64SafepointOp(info, ((HotSpotRuntime) runtime).config));
            }

            @Override
            public void visitExceptionObject(ExceptionObjectNode x) {
                HotSpotVMConfig config = ((HotSpotRuntime) runtime).config;
                CiRegisterValue thread = r15.asValue();
                CiAddress exceptionAddress = new CiAddress(Kind.Object, thread, config.threadExceptionOopOffset);
                CiAddress pcAddress = new CiAddress(Kind.Long, thread, config.threadExceptionPcOffset);
                Value exception = emitLoad(exceptionAddress, false);
                emitStore(exceptionAddress, Constant.NULL_OBJECT, false);
                emitStore(pcAddress, Constant.LONG_0, false);
                setResult(x, exception);
            }

            @Override
            protected void emitPrologue() {
                super.emitPrologue();
                MethodEntryCounters.emitCounter(this, method);
            }
        };
    }

    @Override
    public AMD64XirAssembler newXirAssembler() {
        return new AMD64XirAssembler(target);
    }

    class HotSpotFrameContext implements FrameContext {

        @Override
        public void enter(TargetMethodAssembler tasm) {
            FrameMap frameMap = tasm.frameMap;
            int frameSize = frameMap.frameSize();

            AMD64MacroAssembler asm = (AMD64MacroAssembler) tasm.asm;
            emitStackOverflowCheck(tasm, false);
            asm.push(rbp);
            asm.movq(rbp, rsp);
            asm.decrementq(rsp, frameSize - 8); // account for the push of RBP above
            if (GraalOptions.ZapStackOnMethodEntry) {
                final int intSize = 4;
                for (int i = 0; i < frameSize / intSize; ++i) {
                    asm.movl(new CiAddress(Kind.Int, rsp.asValue(), i * intSize), 0xC1C1C1C1);
                }
            }
            CiCalleeSaveLayout csl = frameMap.registerConfig.getCalleeSaveLayout();
            if (csl != null && csl.size != 0) {
                int frameToCSA = frameMap.offsetToCalleeSaveArea();
                assert frameToCSA >= 0;
                asm.save(csl, frameToCSA);
            }
        }

        @Override
        public void leave(TargetMethodAssembler tasm) {
            int frameSize = tasm.frameMap.frameSize();
            AMD64MacroAssembler asm = (AMD64MacroAssembler) tasm.asm;
            CiCalleeSaveLayout csl = tasm.frameMap.registerConfig.getCalleeSaveLayout();
            CiRegisterConfig regConfig = tasm.frameMap.registerConfig;

            if (csl != null && csl.size != 0) {
                tasm.targetMethod.setRegisterRestoreEpilogueOffset(asm.codeBuffer.position());
                // saved all registers, restore all registers
                int frameToCSA = tasm.frameMap.offsetToCalleeSaveArea();
                asm.restore(csl, frameToCSA);
            }

            asm.incrementq(rsp, frameSize - 8); // account for the pop of RBP below
            asm.pop(rbp);

            if (GraalOptions.GenSafepoints) {
                HotSpotVMConfig config = ((HotSpotRuntime) runtime).config;

                // If at the return point, then the frame has already been popped
                // so deoptimization cannot be performed here. The HotSpot runtime
                // detects this case - see the definition of frame::should_be_deoptimized()

                CiRegister scratch = regConfig.getScratchRegister();
                if (config.isPollingPageFar) {
                    asm.movq(scratch, config.safepointPollingAddress);
                    tasm.recordMark(MARK_POLL_RETURN_FAR);
                    asm.movq(scratch, new CiAddress(tasm.target.wordKind, scratch.asValue()));
                } else {
                    tasm.recordMark(MARK_POLL_RETURN_NEAR);
                    asm.movq(scratch, new CiAddress(tasm.target.wordKind, rip.asValue()));
                }
            }
        }
    }

    @Override
    public TargetMethodAssembler newAssembler(FrameMap frameMap, LIR lir) {
        // Omit the frame if the method:
        //  - has no spill slots or other slots allocated during register allocation
        //  - has no callee-saved registers
        //  - has no incoming arguments passed on the stack
        //  - has no instructions with debug info
        boolean canOmitFrame =
            frameMap.frameSize() == frameMap.initialFrameSize &&
            frameMap.registerConfig.getCalleeSaveLayout().registers.length == 0 &&
            !lir.hasArgInCallerFrame() &&
            !lir.hasDebugInfo();

        AbstractAssembler masm = new AMD64MacroAssembler(target, frameMap.registerConfig);
        HotSpotFrameContext frameContext = canOmitFrame ? null : new HotSpotFrameContext();
        TargetMethodAssembler tasm = new TargetMethodAssembler(target, runtime, frameMap, masm, frameContext, lir.stubs);
        tasm.setFrameSize(frameMap.frameSize());
        tasm.targetMethod.setCustomStackAreaOffset(frameMap.offsetToCustomArea());
        return tasm;
    }

    @Override
    public void emitCode(TargetMethodAssembler tasm, ResolvedJavaMethod method, LIR lir) {
        AMD64MacroAssembler asm = (AMD64MacroAssembler) tasm.asm;
        FrameMap frameMap = tasm.frameMap;
        CiRegisterConfig regConfig = frameMap.registerConfig;
        HotSpotVMConfig config = ((HotSpotRuntime) runtime).config;
        Label unverifiedStub = new Label();

        // Emit the prefix
        tasm.recordMark(MARK_OSR_ENTRY);

        boolean isStatic = Modifier.isStatic(method.accessFlags());
        if (!isStatic) {
            tasm.recordMark(MARK_UNVERIFIED_ENTRY);
            CiCallingConvention cc = regConfig.getCallingConvention(JavaCallee, new Kind[] {Kind.Object}, target, false);
            CiRegister inlineCacheKlass = rax; // see definition of IC_Klass in c1_LIRAssembler_x86.cpp
            CiRegister receiver = asRegister(cc.locations[0]);
            CiAddress src = new CiAddress(target.wordKind, receiver.asValue(), config.hubOffset);

            asm.cmpq(inlineCacheKlass, src);
            asm.jcc(ConditionFlag.notEqual, unverifiedStub);
        }

        asm.align(config.codeEntryAlignment);
        tasm.recordMark(MARK_VERIFIED_ENTRY);

        // Emit code for the LIR
        lir.emitCode(tasm);

        boolean frameOmitted = tasm.frameContext == null;
        if (!frameOmitted) {
            tasm.recordMark(MARK_EXCEPTION_HANDLER_ENTRY);
            AMD64Call.directCall(tasm, asm, config.handleExceptionStub, null);
            AMD64Call.shouldNotReachHere(tasm, asm);

            tasm.recordMark(MARK_DEOPT_HANDLER_ENTRY);
            AMD64Call.directCall(tasm, asm, config.handleDeoptStub, null);
            AMD64Call.shouldNotReachHere(tasm, asm);
        } else {
            // No need to emit the stubs for entries back into the method since
            // it has no calls that can cause such "return" entries
            assert !frameMap.accessesCallerFrame();
        }

        if (!isStatic) {
            asm.bind(unverifiedStub);
            AMD64Call.directJmp(tasm, asm, config.inlineCacheMissStub);
        }

        for (int i = 0; i < GraalOptions.MethodEndBreakpointGuards; ++i) {
            asm.int3();
        }
    }
}