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 * Copyright (c) 2015, 2025, 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 jdk.vm.ci.aarch64;

import java.nio.ByteOrder;
import java.util.EnumSet;
import java.util.List;

import jdk.vm.ci.code.Architecture;
import jdk.vm.ci.code.CPUFeatureName;
import jdk.vm.ci.code.Register;
import jdk.vm.ci.code.Register.RegisterCategory;
import jdk.vm.ci.meta.JavaKind;
import jdk.vm.ci.meta.PlatformKind;

/**
 * Represents the AArch64 architecture.
 *
 * The value returned by {@code Architecture#getName} for an instance of this class is {@code "aarch64"}.
 */
public class AArch64 extends Architecture {

    public static final RegisterCategory CPU = new RegisterCategory("CPU");

    // General purpose CPU registers
    public static final Register r0 = new Register(0, 0, "r0", CPU);
    public static final Register r1 = new Register(1, 1, "r1", CPU);
    public static final Register r2 = new Register(2, 2, "r2", CPU);
    public static final Register r3 = new Register(3, 3, "r3", CPU);
    public static final Register r4 = new Register(4, 4, "r4", CPU);
    public static final Register r5 = new Register(5, 5, "r5", CPU);
    public static final Register r6 = new Register(6, 6, "r6", CPU);
    public static final Register r7 = new Register(7, 7, "r7", CPU);
    public static final Register r8 = new Register(8, 8, "r8", CPU);
    public static final Register r9 = new Register(9, 9, "r9", CPU);
    public static final Register r10 = new Register(10, 10, "r10", CPU);
    public static final Register r11 = new Register(11, 11, "r11", CPU);
    public static final Register r12 = new Register(12, 12, "r12", CPU);
    public static final Register r13 = new Register(13, 13, "r13", CPU);
    public static final Register r14 = new Register(14, 14, "r14", CPU);
    public static final Register r15 = new Register(15, 15, "r15", CPU);
    public static final Register r16 = new Register(16, 16, "r16", CPU);
    public static final Register r17 = new Register(17, 17, "r17", CPU);
    public static final Register r18 = new Register(18, 18, "r18", CPU);
    public static final Register r19 = new Register(19, 19, "r19", CPU);
    public static final Register r20 = new Register(20, 20, "r20", CPU);
    public static final Register r21 = new Register(21, 21, "r21", CPU);
    public static final Register r22 = new Register(22, 22, "r22", CPU);
    public static final Register r23 = new Register(23, 23, "r23", CPU);
    public static final Register r24 = new Register(24, 24, "r24", CPU);
    public static final Register r25 = new Register(25, 25, "r25", CPU);
    public static final Register r26 = new Register(26, 26, "r26", CPU);
    public static final Register r27 = new Register(27, 27, "r27", CPU);
    public static final Register r28 = new Register(28, 28, "r28", CPU);
    public static final Register r29 = new Register(29, 29, "r29", CPU);
    public static final Register r30 = new Register(30, 30, "r30", CPU);

    /*
     * r31 is not a general purpose register, but represents either the stackpointer or the
     * zero/discard register depending on the instruction. So we represent those two uses as two
     * different registers. The register numbers are kept in sync with register_aarch64.hpp and have
     * to be sequential, hence we also need a general r31 register here, which is never used.
     */
    public static final Register r31 = new Register(31, 31, "r31", CPU);
    public static final Register zr = new Register(32, 31, "zr", CPU);
    public static final Register sp = new Register(33, 31, "sp", CPU);

    public static final Register lr = r30;

    // Used by runtime code: cannot be compiler-allocated.
    public static final Register rscratch1 = r8;
    public static final Register rscratch2 = r9;

    // @formatter:off
    public static final List<Register> cpuRegisters = List.of(
        r0,  r1,  r2,  r3,  r4,  r5,  r6,  r7,
        r8,  r9,  r10, r11, r12, r13, r14, r15,
        r16, r17, r18, r19, r20, r21, r22, r23,
        r24, r25, r26, r27, r28, r29, r30, r31,
        zr,  sp
    );
    // @formatter:on

    public static final RegisterCategory SIMD = new RegisterCategory("SIMD");

    // Simd registers
    public static final Register v0 = new Register(34, 0, "v0", SIMD);
    public static final Register v1 = new Register(35, 1, "v1", SIMD);
    public static final Register v2 = new Register(36, 2, "v2", SIMD);
    public static final Register v3 = new Register(37, 3, "v3", SIMD);
    public static final Register v4 = new Register(38, 4, "v4", SIMD);
    public static final Register v5 = new Register(39, 5, "v5", SIMD);
    public static final Register v6 = new Register(40, 6, "v6", SIMD);
    public static final Register v7 = new Register(41, 7, "v7", SIMD);
    public static final Register v8 = new Register(42, 8, "v8", SIMD);
    public static final Register v9 = new Register(43, 9, "v9", SIMD);
    public static final Register v10 = new Register(44, 10, "v10", SIMD);
    public static final Register v11 = new Register(45, 11, "v11", SIMD);
    public static final Register v12 = new Register(46, 12, "v12", SIMD);
    public static final Register v13 = new Register(47, 13, "v13", SIMD);
    public static final Register v14 = new Register(48, 14, "v14", SIMD);
    public static final Register v15 = new Register(49, 15, "v15", SIMD);
    public static final Register v16 = new Register(50, 16, "v16", SIMD);
    public static final Register v17 = new Register(51, 17, "v17", SIMD);
    public static final Register v18 = new Register(52, 18, "v18", SIMD);
    public static final Register v19 = new Register(53, 19, "v19", SIMD);
    public static final Register v20 = new Register(54, 20, "v20", SIMD);
    public static final Register v21 = new Register(55, 21, "v21", SIMD);
    public static final Register v22 = new Register(56, 22, "v22", SIMD);
    public static final Register v23 = new Register(57, 23, "v23", SIMD);
    public static final Register v24 = new Register(58, 24, "v24", SIMD);
    public static final Register v25 = new Register(59, 25, "v25", SIMD);
    public static final Register v26 = new Register(60, 26, "v26", SIMD);
    public static final Register v27 = new Register(61, 27, "v27", SIMD);
    public static final Register v28 = new Register(62, 28, "v28", SIMD);
    public static final Register v29 = new Register(63, 29, "v29", SIMD);
    public static final Register v30 = new Register(64, 30, "v30", SIMD);
    public static final Register v31 = new Register(65, 31, "v31", SIMD);

    // @formatter:off
    public static final List<Register> simdRegisters = List.of(
        v0,  v1,  v2,  v3,  v4,  v5,  v6,  v7,
        v8,  v9,  v10, v11, v12, v13, v14, v15,
        v16, v17, v18, v19, v20, v21, v22, v23,
        v24, v25, v26, v27, v28, v29, v30, v31
    );
    // @formatter:on

    // @formatter:off
    public static final List<Register> allRegisters = List.of(
        r0,  r1,  r2,  r3,  r4,  r5,  r6,  r7,
        r8,  r9,  r10, r11, r12, r13, r14, r15,
        r16, r17, r18, r19, r20, r21, r22, r23,
        r24, r25, r26, r27, r28, r29, r30, r31,
        zr,  sp,

        v0,  v1,  v2,  v3,  v4,  v5,  v6,  v7,
        v8,  v9,  v10, v11, v12, v13, v14, v15,
        v16, v17, v18, v19, v20, v21, v22, v23,
        v24, v25, v26, v27, v28, v29, v30, v31
    );
    // @formatter:on

    /**
     * Basic set of CPU features mirroring what is returned from the cpuid instruction. See:
     * {@code VM_Version::cpuFeatureFlags}.
     */
    public enum CPUFeature implements CPUFeatureName {
        FP,
        ASIMD,
        EVTSTRM,
        AES,
        PMULL,
        SHA1,
        SHA2,
        CRC32,
        LSE,
        DCPOP,
        SHA3,
        SHA512,
        SVE,
        PACA,
        SVEBITPERM,
        SVE2,
        A53MAC,
        FPHP,
        ASIMDHP,
    }

    private final EnumSet<CPUFeature> features;

    public AArch64(EnumSet<CPUFeature> features) {
        super("aarch64", AArch64Kind.QWORD, ByteOrder.LITTLE_ENDIAN, true, allRegisters, 0, 0, 0);
        this.features = features;
    }

    @Override
    public EnumSet<CPUFeature> getFeatures() {
        return features;
    }

    @Override
    public PlatformKind getPlatformKind(JavaKind javaKind) {
        switch (javaKind) {
            case Boolean:
            case Byte:
                return AArch64Kind.BYTE;
            case Short:
            case Char:
                return AArch64Kind.WORD;
            case Int:
                return AArch64Kind.DWORD;
            case Long:
            case Object:
                return AArch64Kind.QWORD;
            case Float:
                return AArch64Kind.SINGLE;
            case Double:
                return AArch64Kind.DOUBLE;
            default:
                return null;
        }
    }

    @Override
    public boolean canStoreValue(RegisterCategory category, PlatformKind platformKind) {
        AArch64Kind kind = (AArch64Kind) platformKind;
        if (kind.isInteger()) {
            return category.equals(CPU);
        } else if (kind.isSIMD()) {
            return category.equals(SIMD);
        }
        return false;
    }

    @Override
    public AArch64Kind getLargestStorableKind(RegisterCategory category) {
        if (category.equals(CPU)) {
            return AArch64Kind.QWORD;
        } else if (category.equals(SIMD)) {
            return AArch64Kind.V128_QWORD;
        } else {
            return null;
        }
    }
}
