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 * Copyright (c) 2013, 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

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package org.graalvm.compiler.lir.aarch64;

import static org.graalvm.compiler.lir.LIRInstruction.OperandFlag.ILLEGAL;

import static org.graalvm.compiler.lir.LIRInstruction.OperandFlag.REG;

import static org.graalvm.compiler.lir.LIRInstruction.OperandFlag.STACK;

import static jdk.vm.ci.aarch64.AArch64.r8;

import static jdk.vm.ci.code.ValueUtil.asRegister;

import static jdk.vm.ci.code.ValueUtil.isRegister;

import org.graalvm.compiler.asm.Label;

import org.graalvm.compiler.asm.aarch64.AArch64Assembler;

import org.graalvm.compiler.asm.aarch64.AArch64MacroAssembler;

import org.graalvm.compiler.core.common.spi.ForeignCallLinkage;

import org.graalvm.compiler.lir.LIRFrameState;

import org.graalvm.compiler.lir.LIRInstructionClass;

import org.graalvm.compiler.lir.Opcode;

import org.graalvm.compiler.lir.asm.CompilationResultBuilder;

import jdk.vm.ci.code.Register;

import jdk.vm.ci.meta.InvokeTarget;

import jdk.vm.ci.meta.ResolvedJavaMethod;

import jdk.vm.ci.meta.Value;

public class AArch64Call {

    public abstract static class CallOp extends AArch64LIRInstruction {

        @Def({REG, ILLEGAL}) protected Value result;

        @Use({REG, STACK}) protected Value[] parameters;

        @Temp({REG, STACK}) protected Value[] temps;

        @State protected LIRFrameState state;

        protected CallOp(LIRInstructionClass<? extends CallOp> c, Value result, Value[] parameters, Value[] temps, LIRFrameState state) {

            super(c);

            this.result = result;

            this.parameters = parameters;

            this.state = state;

            this.temps = addStackSlotsToTemporaries(parameters, temps);

            assert temps != null;

        }

        @Override

        public boolean destroysCallerSavedRegisters() {

            return true;

        }

    }

    public abstract static class MethodCallOp extends CallOp {

        protected final ResolvedJavaMethod callTarget;

        protected MethodCallOp(LIRInstructionClass<? extends MethodCallOp> c, ResolvedJavaMethod callTarget, Value result, Value[] parameters, Value[] temps, LIRFrameState state) {

            super(c, result, parameters, temps, state);

            this.callTarget = callTarget;

        }

    }

    @Opcode("CALL_INDIRECT")

    public static class IndirectCallOp extends MethodCallOp {

        public static final LIRInstructionClass<IndirectCallOp> TYPE = LIRInstructionClass.create(IndirectCallOp.class);

        @Use({REG}) protected Value targetAddress;

        public IndirectCallOp(ResolvedJavaMethod callTarget, Value result, Value[] parameters, Value[] temps, Value targetAddress, LIRFrameState state) {

            this(TYPE, callTarget, result, parameters, temps, targetAddress, state);

        }

        protected IndirectCallOp(LIRInstructionClass<? extends IndirectCallOp> c, ResolvedJavaMethod callTarget, Value result, Value[] parameters, Value[] temps, Value targetAddress,

                        LIRFrameState state) {

            super(c, callTarget, result, parameters, temps, state);

            this.targetAddress = targetAddress;

        }

        @Override

        public void emitCode(CompilationResultBuilder crb, AArch64MacroAssembler masm) {

            Register target = asRegister(targetAddress);

            indirectCall(crb, masm, target, callTarget, state);

        }

        @Override

        public void verify() {

            super.verify();

            assert isRegister(targetAddress) : "The current register allocator cannot handle variables to be used at call sites, " + "it must be in a fixed register for now";

        }

    }

    @Opcode("CALL_DIRECT")

    public abstract static class DirectCallOp extends MethodCallOp {

        public static final LIRInstructionClass<DirectCallOp> TYPE = LIRInstructionClass.create(DirectCallOp.class);

        public DirectCallOp(ResolvedJavaMethod target, Value result, Value[] parameters, Value[] temps, LIRFrameState state) {

            super(TYPE, target, result, parameters, temps, state);

        }

        protected DirectCallOp(LIRInstructionClass<? extends DirectCallOp> c, ResolvedJavaMethod callTarget, Value result, Value[] parameters, Value[] temps, LIRFrameState state) {

            super(c, callTarget, result, parameters, temps, state);

        }

        @Override

        public void emitCode(CompilationResultBuilder crb, AArch64MacroAssembler masm) {

            directCall(crb, masm, callTarget, null, state);

        }

    }

    public abstract static class ForeignCallOp extends CallOp {

        protected final ForeignCallLinkage callTarget;

        protected final Label label;

        protected ForeignCallOp(LIRInstructionClass<? extends ForeignCallOp> c, ForeignCallLinkage callTarget, Value result, Value[] parameters, Value[] temps, LIRFrameState state, Label label) {

            super(c, result, parameters, temps, state);

            this.callTarget = callTarget;

            this.label = label;

        }

        @Override

        public boolean destroysCallerSavedRegisters() {

            return callTarget.destroysRegisters();

        }

        @Override

        public void emitCode(CompilationResultBuilder crb, AArch64MacroAssembler masm) {

            emitCall(crb, masm);

        }

        protected abstract void emitCall(CompilationResultBuilder crb, AArch64MacroAssembler masm);

    }

    @Opcode("NEAR_FOREIGN_CALL")

    public static class DirectNearForeignCallOp extends ForeignCallOp {

        public static final LIRInstructionClass<DirectNearForeignCallOp> TYPE = LIRInstructionClass.create(DirectNearForeignCallOp.class);

        public DirectNearForeignCallOp(ForeignCallLinkage callTarget, Value result, Value[] parameters, Value[] temps, LIRFrameState state, Label label) {

            super(TYPE, callTarget, result, parameters, temps, state, label);

        }

        @Override

        protected void emitCall(CompilationResultBuilder crb, AArch64MacroAssembler masm) {

            directCall(crb, masm, callTarget, null, state, label);

        }

    }

    @Opcode("FAR_FOREIGN_CALL")

    public static class DirectFarForeignCallOp extends ForeignCallOp {

        public static final LIRInstructionClass<DirectFarForeignCallOp> TYPE = LIRInstructionClass.create(DirectFarForeignCallOp.class);

        public DirectFarForeignCallOp(ForeignCallLinkage callTarget, Value result, Value[] parameters, Value[] temps, LIRFrameState state, Label label) {

            super(TYPE, callTarget, result, parameters, temps, state, label);

        }

        @Override

        protected void emitCall(CompilationResultBuilder crb, AArch64MacroAssembler masm) {

            // We can use any scratch register we want, since we know that they have been saved

            // before calling.

            directCall(crb, masm, callTarget, r8, state, label);

        }

    }

    /**

     * Tests whether linkage can be called directly under all circumstances without the need for a

     * scratch register.

     *

     * Note this is a pessimistic assumption: This may return false despite a near call/jump being

     * adequate.

     *

     * @param linkage Foreign call description

     * @return true if foreign call can be called directly and does not need a scratch register to

     *         load the address into.

     */

    public static boolean isNearCall(ForeignCallLinkage linkage) {

        long maxOffset = linkage.getMaxCallTargetOffset();

        return maxOffset != -1 && AArch64MacroAssembler.isBranchImmediateOffset(maxOffset);

    }

    public static void directCall(CompilationResultBuilder crb, AArch64MacroAssembler masm, InvokeTarget callTarget, Register scratch, LIRFrameState info) {

        directCall(crb, masm, callTarget, scratch, info, null);

    }

    public static void directCall(CompilationResultBuilder crb, AArch64MacroAssembler masm, InvokeTarget callTarget, Register scratch, LIRFrameState info, Label label) {

        int before = masm.position();

        if (scratch != null) {

            /*

             * Offset might not fit into a 28-bit immediate, generate an indirect call with a 64-bit

             * immediate address which is fixed up by HotSpot.

             */

            masm.movNativeAddress(scratch, 0L);

            masm.blr(scratch);

        } else {

            // Address is fixed up by HotSpot.

            masm.bl(0);

        }

        if (label != null) {

            // We need this label to be the return address.

            masm.bind(label);

        }

        int after = masm.position();

        crb.recordDirectCall(before, after, callTarget, info);

        crb.recordExceptionHandlers(after, info);

        masm.ensureUniquePC();

    }

    public static void indirectCall(CompilationResultBuilder crb, AArch64MacroAssembler masm, Register dst, InvokeTarget callTarget, LIRFrameState info) {

        int before = masm.position();

        masm.blr(dst);

        int after = masm.position();

        crb.recordIndirectCall(before, after, callTarget, info);

        crb.recordExceptionHandlers(after, info);

        masm.ensureUniquePC();

    }

    }

    public static void indirectJmp(CompilationResultBuilder crb, AArch64MacroAssembler masm, Register dst, InvokeTarget target) {

        int before = masm.position();

        masm.jmp(dst);

        int after = masm.position();

        crb.recordIndirectCall(before, after, target, null);

        masm.ensureUniquePC();

    }

    public static void directConditionalJmp(CompilationResultBuilder crb, AArch64MacroAssembler masm, InvokeTarget target, AArch64Assembler.ConditionFlag cond) {

        int before = masm.position();

        masm.branchConditionally(cond);

        int after = masm.position();

        crb.recordDirectCall(before, after, target, null);

        masm.ensureUniquePC();

    }

}