/*******************************************************************************
 * Copyright (C) 2017-2024 MINRES Technologies GmbH
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 *******************************************************************************/
// clang-format off
#include <iss/arch/${coreDef.name.toLowerCase()}.h>
#include <iss/debugger/gdb_session.h>
#include <iss/debugger/server.h>
#include <iss/iss.h>
#include <iss/asmjit/vm_base.h>
#include <asmjit/asmjit.h>
#include <util/logging.h>

#ifndef FMT_HEADER_ONLY
#define FMT_HEADER_ONLY
#endif
#include <fmt/format.h>

#include <array>
#include <iss/debugger/riscv_target_adapter.h>

namespace iss {
namespace asmjit {


namespace ${coreDef.name.toLowerCase()} {
using namespace ::asmjit;
using namespace iss::arch;
using namespace iss::debugger;

template <typename ARCH> class vm_impl : public iss::asmjit::vm_base<ARCH> {
public:
    using traits = arch::traits<ARCH>;
    using super = typename iss::asmjit::vm_base<ARCH>;
    using virt_addr_t = typename super::virt_addr_t;
    using phys_addr_t = typename super::phys_addr_t;
    using code_word_t = typename super::code_word_t;
    using mem_type_e = typename super::mem_type_e;
    using addr_t = typename super::addr_t;

    vm_impl();

    vm_impl(ARCH &core, unsigned core_id = 0, unsigned cluster_id = 0);

    void enableDebug(bool enable) { super::sync_exec = super::ALL_SYNC; }

    target_adapter_if *accquire_target_adapter(server_if *srv) override {
        debugger_if::dbg_enabled = true;
        if (vm_base<ARCH>::tgt_adapter == nullptr)
            vm_base<ARCH>::tgt_adapter = new riscv_target_adapter<ARCH>(srv, this->get_arch());
        return vm_base<ARCH>::tgt_adapter;
    }

protected:
    using super::mov;
    using super::cmp;
    using super::get_ptr_for;
    using super::get_reg;
    using super::get_reg_Gp;
    using super::get_reg_for;
    using super::get_reg_for_Gp;
    using super::load_reg_from_mem;
    using super::load_reg_from_mem_Gp;
    using super::write_reg_to_mem;
    using super::gen_ext;
    using super::gen_read_mem;
    using super::gen_write_mem;
    using super::gen_wait;
    using super::gen_leave;
    using super::gen_operation;
    using super::gen_sync;
    using super::gen_set_tval;
   
    using this_class = vm_impl<ARCH>;
    using compile_func = continuation_e (this_class::*)(virt_addr_t&, code_word_t, jit_holder&);

    continuation_e gen_single_inst_behavior(virt_addr_t&, unsigned int &, jit_holder&) override;
    void gen_block_prologue(jit_holder& jh) override;
    void gen_block_epilogue(jit_holder& jh) override;
    inline const char *name(size_t index){return traits::reg_aliases.at(index);}

    void gen_instr_prologue(jit_holder& jh);
    void gen_instr_epilogue(jit_holder& jh);
    inline void gen_raise(jit_holder& jh, uint16_t trap_id, uint16_t cause);

    template<unsigned W, typename U, typename S = typename std::make_signed<U>::type>
    inline S sext(U from) {
        auto mask = (1ULL<<W) - 1;
        auto sign_mask = 1ULL<<(W-1);
        return (from & mask) | ((from & sign_mask) ? ~mask : 0);
    } 
private:
    /****************************************************************************
     * start opcode definitions
     ****************************************************************************/
    struct instruction_descriptor {
        size_t length;
        uint32_t value;
        uint32_t mask;
        compile_func op;
    };
    struct decoding_tree_node{
        std::vector<instruction_descriptor> instrs;
        std::vector<decoding_tree_node*> children;
        uint32_t submask = std::numeric_limits<uint32_t>::max();
        uint32_t value;
        decoding_tree_node(uint32_t value) : value(value){}
    };

    decoding_tree_node* root {nullptr};

    const std::array<instruction_descriptor, ${instructions.size()}> instr_descr = {{
         /* entries are: size, valid value, valid mask, function ptr */<%instructions.each{instr -> %>
        /* instruction ${instr.instruction.name}, encoding '${instr.encoding}' */
        {${instr.length}, ${instr.encoding}, ${instr.mask}, &this_class::__${generator.functionName(instr.name)}},<%}%>
    }};
 
    /* instruction definitions */<%instructions.eachWithIndex{instr, idx -> %>
    /* instruction ${idx}: ${instr.name} */
    continuation_e __${generator.functionName(instr.name)}(virt_addr_t& pc, code_word_t instr, jit_holder& jh){
        uint64_t PC = pc.val;
        <%instr.fields.eachLine{%>${it}
        <%}%>if(this->disass_enabled){
            /* generate disass */
            <%instr.disass.eachLine{%>
            ${it}<%}%>
            InvokeNode* call_print_disass;
            char* mnemonic_ptr = strdup(mnemonic.c_str());
            jh.disass_collection.push_back(mnemonic_ptr);
            jh.cc.invoke(&call_print_disass, &print_disass, FuncSignature::build<void, void *, uint64_t, char *>());
            call_print_disass->setArg(0, jh.arch_if_ptr);
            call_print_disass->setArg(1, pc.val);
            call_print_disass->setArg(2, mnemonic_ptr);

        }
        x86::Compiler& cc = jh.cc;
        cc.comment(fmt::format("${instr.name}_{:#x}:",pc.val).c_str());
        gen_sync(jh, PRE_SYNC, ${idx});
        mov(cc, jh.pc, pc.val);
        gen_set_tval(jh, instr);
        pc = pc+${instr.length/8};
        mov(cc, jh.next_pc, pc.val);

        gen_instr_prologue(jh);
        cc.comment("//behavior:");
        /*generate behavior*/
        <%instr.behavior.eachLine{%>${it}
        <%}%>
        gen_sync(jh, POST_SYNC, ${idx});
        gen_instr_epilogue(jh);
    	return returnValue;        
    }
    <%}%>
    /****************************************************************************
     * end opcode definitions
     ****************************************************************************/
    continuation_e illegal_instruction(virt_addr_t &pc, code_word_t instr, jit_holder& jh ) {
        x86::Compiler& cc = jh.cc;
        if(this->disass_enabled){          
            auto mnemonic = std::string("illegal_instruction");
            InvokeNode* call_print_disass;
            char* mnemonic_ptr = strdup(mnemonic.c_str());
            jh.disass_collection.push_back(mnemonic_ptr);
            jh.cc.invoke(&call_print_disass, &print_disass, FuncSignature::build<void, void *, uint64_t, char *>());
            call_print_disass->setArg(0, jh.arch_if_ptr);
            call_print_disass->setArg(1, pc.val);
            call_print_disass->setArg(2, mnemonic_ptr);
        }
        cc.comment(fmt::format("illegal_instruction{:#x}:",pc.val).c_str());
        gen_sync(jh, PRE_SYNC, instr_descr.size());
        mov(cc, jh.pc, pc.val);
        gen_set_tval(jh, instr);
        pc = pc + ((instr & 3) == 3 ? 4 : 2);
        mov(cc, jh.next_pc, pc.val);
        gen_instr_prologue(jh);
        cc.comment("//behavior:");
        gen_raise(jh, 0, 2);
        gen_sync(jh, POST_SYNC, instr_descr.size());
        gen_instr_epilogue(jh);
        return BRANCH;
    }
     
    //decoding functionality

    void populate_decoding_tree(decoding_tree_node* root){
        //create submask
        for(auto instr: root->instrs){
            root->submask &= instr.mask;
        }
        //put each instr according to submask&encoding into children
        for(auto instr: root->instrs){
            bool foundMatch = false;
            for(auto child: root->children){
                //use value as identifying trait
                if(child->value == (instr.value&root->submask)){
                    child->instrs.push_back(instr);
                    foundMatch = true;
                }
            }
            if(!foundMatch){
                decoding_tree_node* child = new decoding_tree_node(instr.value&root->submask);
                child->instrs.push_back(instr);
                root->children.push_back(child);
            }
        }
        root->instrs.clear();
        //call populate_decoding_tree for all children
        if(root->children.size() >1)
            for(auto child: root->children){
                populate_decoding_tree(child);      
            }
        else{
            //sort instrs by value of the mask, this works bc we want to have the least restrictive one last
            std::sort(root->children[0]->instrs.begin(), root->children[0]->instrs.end(), [](const instruction_descriptor& instr1, const instruction_descriptor& instr2) {
            return instr1.mask > instr2.mask;
            }); 
        }
    }
    compile_func decode_instr(decoding_tree_node* node, code_word_t word){
        if(!node->children.size()){
            if(node->instrs.size() == 1) return node->instrs[0].op;
            for(auto instr : node->instrs){
                if((instr.mask&word) == instr.value) return instr.op;
            }
        }
        else{
            for(auto child : node->children){
                if (child->value == (node->submask&word)){
                    return decode_instr(child, word);
                }  
            }  
        }
        return nullptr;
    }
};

template <typename ARCH> vm_impl<ARCH>::vm_impl() { this(new ARCH()); }

template <typename ARCH>
vm_impl<ARCH>::vm_impl(ARCH &core, unsigned core_id, unsigned cluster_id)
: vm_base<ARCH>(core, core_id, cluster_id) {
    root = new decoding_tree_node(std::numeric_limits<uint32_t>::max());
    for(auto instr: instr_descr){
        root->instrs.push_back(instr);
    }
    populate_decoding_tree(root);
}

template <typename ARCH>
continuation_e vm_impl<ARCH>::gen_single_inst_behavior(virt_addr_t &pc, unsigned int &inst_cnt, jit_holder& jh) {
    enum {TRAP_ID=1<<16};
    code_word_t instr = 0;
    phys_addr_t paddr(pc);
    auto *const data = (uint8_t *)&instr;
    if(this->core.has_mmu())
        paddr = this->core.virt2phys(pc);
    auto res = this->core.read(paddr, 4, data);
    if (res != iss::Ok)
        throw trap_access(TRAP_ID, pc.val);
    if (instr == 0x0000006f || (instr&0xffff)==0xa001)
        throw simulation_stopped(0); // 'J 0' or 'C.J 0'
    ++inst_cnt;
    auto f = decode_instr(root, instr);
    if (f == nullptr) 
        f = &this_class::illegal_instruction;
    return (this->*f)(pc, instr, jh);
}
template <typename ARCH>
void vm_impl<ARCH>::gen_instr_prologue(jit_holder& jh) {
    auto& cc = jh.cc;

    cc.comment("//gen_instr_prologue");

    x86_reg_t current_trap_state = get_reg_for(cc, traits::TRAP_STATE);
    mov(cc, current_trap_state, get_ptr_for(jh, traits::TRAP_STATE));
    mov(cc, get_ptr_for(jh, traits::PENDING_TRAP), current_trap_state);

}
template <typename ARCH>
void vm_impl<ARCH>::gen_instr_epilogue(jit_holder& jh) {
    auto& cc = jh.cc;

    cc.comment("//gen_instr_epilogue");
    x86_reg_t current_trap_state = get_reg_for(cc, traits::TRAP_STATE);
    mov(cc, current_trap_state, get_ptr_for(jh, traits::TRAP_STATE));
    cmp(cc, current_trap_state, 0);
    cc.jne(jh.trap_entry);
    cc.inc(get_ptr_for(jh, traits::ICOUNT));
}
template <typename ARCH>
void vm_impl<ARCH>::gen_block_prologue(jit_holder& jh){
    jh.pc = load_reg_from_mem_Gp(jh, traits::PC);
    jh.next_pc = load_reg_from_mem_Gp(jh, traits::NEXT_PC);
    jh.tval = get_reg_Gp(jh.cc, 64, false);
}
template <typename ARCH>
void vm_impl<ARCH>::gen_block_epilogue(jit_holder& jh){
    x86::Compiler& cc = jh.cc;
    cc.comment("//gen_block_epilogue");
    cc.ret(jh.next_pc);

    cc.bind(jh.trap_entry);
    this->write_back(jh);

    x86::Gp current_trap_state = get_reg_for_Gp(cc, traits::TRAP_STATE);
    mov(cc, current_trap_state, get_ptr_for(jh, traits::TRAP_STATE));

    x86::Gp current_pc = get_reg_for_Gp(cc, traits::PC);
    mov(cc, current_pc, get_ptr_for(jh, traits::PC));

    cc.comment("//enter trap call;");
    InvokeNode* call_enter_trap;
    cc.invoke(&call_enter_trap, &enter_trap, FuncSignature::build<uint64_t, void*, uint64_t, uint64_t, uint64_t>());
    call_enter_trap->setArg(0, jh.arch_if_ptr);
    call_enter_trap->setArg(1, current_trap_state);
    call_enter_trap->setArg(2, current_pc);
    call_enter_trap->setArg(3, jh.tval);

    x86_reg_t current_next_pc = get_reg_for(cc, traits::NEXT_PC);
    mov(cc, current_next_pc, get_ptr_for(jh, traits::NEXT_PC));
    mov(cc, jh.next_pc, current_next_pc);

    mov(cc, get_ptr_for(jh, traits::LAST_BRANCH), std::numeric_limits<uint32_t>::max());
    cc.ret(jh.next_pc);
}
template <typename ARCH>
inline void vm_impl<ARCH>::gen_raise(jit_holder& jh, uint16_t trap_id, uint16_t cause) {
    auto& cc = jh.cc;
    cc.comment("//gen_raise");
    auto tmp1 = get_reg_for(cc, traits::TRAP_STATE);
    mov(cc, tmp1, 0x80ULL << 24 | (cause << 16) | trap_id);
    mov(cc, get_ptr_for(jh, traits::TRAP_STATE), tmp1);
}

} // namespace tgc5c

template <>
std::unique_ptr<vm_if> create<arch::${coreDef.name.toLowerCase()}>(arch::${coreDef.name.toLowerCase()} *core, unsigned short port, bool dump) {
    auto ret = new ${coreDef.name.toLowerCase()}::vm_impl<arch::${coreDef.name.toLowerCase()}>(*core, dump);
    if (port != 0) debugger::server<debugger::gdb_session>::run_server(ret, port);
    return std::unique_ptr<vm_if>(ret);
}
} // namespace asmjit
} // namespace iss

#include <iss/arch/riscv_hart_m_p.h>
#include <iss/arch/riscv_hart_mu_p.h>
#include <iss/factory.h>
namespace iss {
namespace {
volatile std::array<bool, 2> dummy = {
        core_factory::instance().register_creator("${coreDef.name.toLowerCase()}|m_p|asmjit", [](unsigned port, void* init_data) -> std::tuple<cpu_ptr, vm_ptr>{
            auto* cpu = new iss::arch::riscv_hart_m_p<iss::arch::${coreDef.name.toLowerCase()}>();
		    auto vm = new asmjit::${coreDef.name.toLowerCase()}::vm_impl<arch::${coreDef.name.toLowerCase()}>(*cpu, false);
		    if (port != 0) debugger::server<debugger::gdb_session>::run_server(vm, port);
            if(init_data){
                auto* cb = reinterpret_cast<semihosting_cb_t<arch::traits<arch::${coreDef.name.toLowerCase()}>::reg_t>*>(init_data);
                cpu->set_semihosting_callback(*cb);
            }
            return {cpu_ptr{cpu}, vm_ptr{vm}};
        }),
        core_factory::instance().register_creator("${coreDef.name.toLowerCase()}|mu_p|asmjit", [](unsigned port, void* init_data) -> std::tuple<cpu_ptr, vm_ptr>{
            auto* cpu = new iss::arch::riscv_hart_mu_p<iss::arch::${coreDef.name.toLowerCase()}>();
		    auto vm = new asmjit::${coreDef.name.toLowerCase()}::vm_impl<arch::${coreDef.name.toLowerCase()}>(*cpu, false);
		    if (port != 0) debugger::server<debugger::gdb_session>::run_server(vm, port);
            if(init_data){
                auto* cb = reinterpret_cast<semihosting_cb_t<arch::traits<arch::${coreDef.name.toLowerCase()}>::reg_t>*>(init_data);
                cpu->set_semihosting_callback(*cb);
            }
            return {cpu_ptr{cpu}, vm_ptr{vm}};
        })
};
}
}
// clang-format on