/*

 * Copyright (c) 2015, 2016, 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 compiler.jvmci.code.amd64;

import jdk.vm.ci.amd64.AMD64;

import jdk.vm.ci.amd64.AMD64Kind;

import jdk.vm.ci.code.CodeCacheProvider;

import jdk.vm.ci.code.DebugInfo;

import jdk.vm.ci.code.Register;

import jdk.vm.ci.code.StackSlot;

import jdk.vm.ci.code.site.ConstantReference;

import jdk.vm.ci.code.site.DataSectionReference;

import jdk.vm.ci.hotspot.HotSpotCallingConventionType;

import jdk.vm.ci.hotspot.HotSpotConstant;

import jdk.vm.ci.meta.JavaKind;

import jdk.vm.ci.meta.LIRKind;

import jdk.vm.ci.meta.VMConstant;

import compiler.jvmci.code.TestAssembler;

public class AMD64TestAssembler extends TestAssembler {

    public AMD64TestAssembler(CodeCacheProvider codeCache) {

        super(codeCache, 16, 16, AMD64Kind.DWORD, AMD64.rax, AMD64.rcx, AMD64.rdi, AMD64.r8, AMD64.r9, AMD64.r10);

    }

    private void emitFatNop() {

        // 5 byte NOP:

        // NOP DWORD ptr [EAX + EAX*1 + 00H]

        code.emitByte(0x0F);

        code.emitByte(0x1F);

        code.emitByte(0x44);

        code.emitByte(0x00);

        code.emitByte(0x00);

    }

    @Override

    public void emitPrologue() {

        // WARNING: Initial instruction MUST be 5 bytes or longer so that

        // NativeJump::patch_verified_entry will be able to patch out the entry

        // code safely.

        emitFatNop();

        code.emitByte(0x50 | AMD64.rbp.encoding);  // PUSH rbp

        emitMove(true, AMD64.rbp, AMD64.rsp);      // MOV rbp, rsp

    }

    @Override

    public void emitGrowStack(int size) {

        // SUB rsp, size

        code.emitByte(0x48);

        code.emitByte(0x81);

        code.emitByte(0xEC);

        code.emitInt(size);

    }

    @Override

    public Register emitIntArg0() {

        return codeCache.getRegisterConfig().getCallingConventionRegisters(HotSpotCallingConventionType.JavaCall, JavaKind.Int)[0];

    }

    @Override

    public Register emitIntArg1() {

        return codeCache.getRegisterConfig().getCallingConventionRegisters(HotSpotCallingConventionType.JavaCall, JavaKind.Int)[1];

    }

    private void emitREX(boolean w, int r, int x, int b) {

        int wrxb = (w ? 0x08 : 0) | ((r >> 3) << 2) | ((x >> 3) << 1) | (b >> 3);

        if (wrxb != 0) {

            code.emitByte(0x40 | wrxb);

        }

    }

    private void emitModRMReg(boolean w, int opcode, int r, int m) {

        emitREX(w, r, 0, m);

        code.emitByte((byte) opcode);

        code.emitByte((byte) 0xC0 | ((r & 0x7) << 3) | (m & 0x7));

    }

    private void emitModRMMemory(boolean w, int opcode, int r, int b, int offset) {

        emitREX(w, r, 0, b);

        code.emitByte((byte) opcode);

        code.emitByte((byte) 0x80 | ((r & 0x7) << 3) | (b & 0x7));

        code.emitInt(offset);

    }

    @Override

    public Register emitLoadInt(int c) {

        Register ret = newRegister();

        emitREX(false, 0, 0, ret.encoding);

        code.emitByte(0xB8 | (ret.encoding & 0x7)); // MOV r32, imm32

        code.emitInt(c);

        return ret;

    }

    @Override

    public Register emitLoadLong(long c) {

        Register ret = newRegister();

        emitREX(true, 0, 0, ret.encoding);

        code.emitByte(0xB8 | (ret.encoding & 0x7)); // MOV r64, imm64

        code.emitLong(c);

        return ret;

    }

    @Override

    public Register emitLoadFloat(float c) {

        DataSectionReference ref = new DataSectionReference();

        ref.setOffset(data.position());

        data.emitFloat(c);

        recordDataPatchInCode(ref);

        Register ret = AMD64.xmm0;

        emitREX(false, ret.encoding, 0, 0);

        code.emitByte(0xF3);

        code.emitByte(0x0F);

        code.emitByte(0x10);                               // MOVSS xmm1, xmm2/m32

        code.emitByte(0x05 | ((ret.encoding & 0x7) << 3)); // xmm, [rip+offset]

        code.emitInt(0xDEADDEAD);

        return ret;

    }

    @Override

    public Register emitLoadPointer(HotSpotConstant c) {

        recordDataPatchInCode(new ConstantReference((VMConstant) c));

        if (c.isCompressed()) {

            Register ret = newRegister();

            emitREX(false, 0, 0, ret.encoding);

            code.emitByte(0xB8 | (ret.encoding & 0x7)); // MOV r32, imm32

            code.emitInt(0xDEADDEAD);

            return ret;

        } else {

            return emitLoadLong(0xDEADDEADDEADDEADl);

        }

    }

    private Register emitLoadPointer(DataSectionReference ref, boolean narrow) {

        recordDataPatchInCode(ref);

        Register ret = newRegister();

        emitREX(!narrow, ret.encoding, 0, 0);

        code.emitByte(0x8B);                               // MOV r64,r/m64

        code.emitByte(0x05 | ((ret.encoding & 0x7) << 3)); // r64, [rip+offset]

        code.emitInt(0xDEADDEAD);

        return ret;

    }

    @Override

    public Register emitLoadPointer(DataSectionReference ref) {

        return emitLoadPointer(ref, false);

    }

    @Override

    public Register emitLoadNarrowPointer(DataSectionReference ref) {

        return emitLoadPointer(ref, true);

    }

    @Override

    public Register emitLoadPointer(Register b, int offset) {

        Register ret = newRegister();

        emitModRMMemory(true, 0x8B, ret.encoding, b.encoding, offset); // MOV r64,r/m64

        return ret;

    }

    @Override

    public StackSlot emitIntToStack(Register a) {

        StackSlot ret = newStackSlot(LIRKind.value(AMD64Kind.DWORD));

        emitModRMMemory(false, 0x89, a.encoding, AMD64.rbp.encoding, ret.getRawOffset() + 16); // MOV r/m32,r32

        return ret;

    }

    @Override

    public StackSlot emitLongToStack(Register a) {

        StackSlot ret = newStackSlot(LIRKind.value(AMD64Kind.QWORD));

        emitModRMMemory(true, 0x89, a.encoding, AMD64.rbp.encoding, ret.getRawOffset() + 16); // MOV r/m64,r64

        return ret;

    }

    @Override

    public StackSlot emitFloatToStack(Register a) {

        StackSlot ret = newStackSlot(LIRKind.value(AMD64Kind.SINGLE));

        emitREX(false, a.encoding, 0, 0);

        code.emitByte(0xF3);

        code.emitByte(0x0F);

        code.emitByte(0x11);                               // MOVSS xmm2/m32, xmm1

        code.emitByte(0x85 | ((a.encoding & 0x7) << 3));   // [rbp+offset]

        code.emitInt(ret.getRawOffset() + 16);

        return ret;

    }

    @Override

    public StackSlot emitPointerToStack(Register a) {

        StackSlot ret = newStackSlot(LIRKind.reference(AMD64Kind.QWORD));

        emitModRMMemory(true, 0x89, a.encoding, AMD64.rbp.encoding, ret.getRawOffset() + 16); // MOV r/m64,r64

        return ret;

    }

    @Override

    public StackSlot emitNarrowPointerToStack(Register a) {

        StackSlot ret = newStackSlot(LIRKind.reference(AMD64Kind.DWORD));

        emitModRMMemory(false, 0x89, a.encoding, AMD64.rbp.encoding, ret.getRawOffset() + 16); // MOV r/m32,r32

        return ret;

    }

    @Override

    public Register emitUncompressPointer(Register compressed, long base, int shift) {

        if (shift > 0) {

            emitModRMReg(true, 0xC1, 4, compressed.encoding);

            code.emitByte(shift);

        }

        if (base == 0) {

            return compressed;

        } else {

            Register tmp = emitLoadLong(base);

            emitModRMReg(true, 0x03, tmp.encoding, compressed.encoding);

            return tmp;

        }

    }

    @Override

    public Register emitIntAdd(Register a, Register b) {

        emitModRMReg(false, 0x03, a.encoding, b.encoding);

        return a;

    }

    private void emitMove(boolean w, Register to, Register from) {

        if (to != from) {

            emitModRMReg(w, 0x8B, to.encoding, from.encoding);

        }

    }

    @Override

    public void emitIntRet(Register a) {

        emitMove(false, AMD64.rax, a);             // MOV eax, ...

        emitMove(true, AMD64.rsp, AMD64.rbp);      // MOV rsp, rbp

        code.emitByte(0x58 | AMD64.rbp.encoding);  // POP rbp

        code.emitByte(0xC3);                       // RET

    }

    @Override

    public void emitPointerRet(Register a) {

        emitMove(true, AMD64.rax, a);              // MOV rax, ...

        emitMove(true, AMD64.rsp, AMD64.rbp);      // MOV rsp, rbp

        code.emitByte(0x58 | AMD64.rbp.encoding);  // POP rbp

        code.emitByte(0xC3);                       // RET

    }

    @Override

    public void emitTrap(DebugInfo info) {

        recordImplicitException(info);

        // MOV rax, [0]

        code.emitByte(0x8B);

        code.emitByte(0x04);

        code.emitByte(0x25);

        code.emitInt(0);

    }

}