/*******************************************************************************
 * 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/llvm/vm_base.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 llvm {
namespace fp_impl {
void add_fp_functions_2_module(::llvm::Module *, unsigned, unsigned);
}

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

template <typename ARCH> class vm_impl : public iss::llvm::vm_base<ARCH> {
public:
    using traits = arch::traits<ARCH>;
    using super = typename iss::llvm::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 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 vm_base<ARCH>::get_reg_ptr;

    inline const char *name(size_t index){return traits::reg_aliases.at(index);}

    template <typename T> inline ConstantInt *size(T type) {
        return ConstantInt::get(getContext(), APInt(32, type->getType()->getScalarSizeInBits()));
    }

    void setup_module(Module* m) override {
        super::setup_module(m);
        iss::llvm::fp_impl::add_fp_functions_2_module(m, traits::FP_REGS_SIZE, traits::XLEN);
    }

    inline Value *gen_choose(Value *cond, Value *trueVal, Value *falseVal, unsigned size) {
        return super::gen_cond_assign(cond, this->gen_ext(trueVal, size), this->gen_ext(falseVal, size));
    }

    std::tuple<continuation_e, BasicBlock *> gen_single_inst_behavior(virt_addr_t &, unsigned int &, BasicBlock *) override;

    void gen_leave_behavior(BasicBlock *leave_blk) override;
    void gen_raise_trap(uint16_t trap_id, uint16_t cause);
    void gen_leave_trap(unsigned lvl);
    void gen_wait(unsigned type);
    void set_tval(uint64_t new_tval);
    void set_tval(Value* new_tval);
    void gen_trap_behavior(BasicBlock *) override;
    void gen_instr_prologue();
    void gen_instr_epilogue(BasicBlock *bb);

    inline Value *gen_reg_load(unsigned i, unsigned level = 0) {
        return this->builder.CreateLoad(this->get_typeptr(i), get_reg_ptr(i), false);
    }

    inline void gen_set_pc(virt_addr_t pc, unsigned reg_num) {
        Value *next_pc_v = this->builder.CreateSExtOrTrunc(this->gen_const(traits::XLEN, pc.val),
                                                           this->get_type(traits::XLEN));
        this->builder.CreateStore(next_pc_v, get_reg_ptr(reg_num), true);
    }

    // some compile time constants

    using this_class = vm_impl<ARCH>;
    using compile_func = std::tuple<continuation_e, BasicBlock *> (this_class::*)(virt_addr_t &pc,
                                                                                  code_word_t instr,
                                                                                  BasicBlock *bb);
    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}: ${instr.name} */
    std::tuple<continuation_e, BasicBlock*> __${generator.functionName(instr.name)}(virt_addr_t& pc, code_word_t instr, BasicBlock* bb){
        uint64_t PC = pc.val;
        <%instr.fields.eachLine{%>${it}
        <%}%>if(this->disass_enabled){
            /* generate console output when executing the command */<%instr.disass.eachLine{%>
            ${it}<%}%>
            std::vector<Value*> args {
                this->core_ptr,
                this->gen_const(64, pc.val),
                this->builder.CreateGlobalStringPtr(mnemonic),
            };
            this->builder.CreateCall(this->mod->getFunction("print_disass"), args);
        }
        bb->setName(fmt::format("${instr.name}_0x{:X}",pc.val));
        this->gen_sync(PRE_SYNC,${idx});
        
        this->gen_set_pc(pc, traits::PC);
        this->set_tval(instr);
        pc=pc+ ${instr.length/8};
        this->gen_set_pc(pc, traits::NEXT_PC);
        
        this->gen_instr_prologue();
        /*generate behavior*/
        <%instr.behavior.eachLine{%>${it}
        <%}%>
        this->gen_sync(POST_SYNC, ${idx});
        this->gen_instr_epilogue(bb);
        this->builder.CreateBr(bb);
    	return returnValue;        
    }
    <%}%>
    /****************************************************************************
     * end opcode definitions
     ****************************************************************************/
    std::tuple<continuation_e, BasicBlock *> illegal_instruction(virt_addr_t &pc, code_word_t instr, BasicBlock *bb) {
        if(this->disass_enabled){
            auto mnemonic = std::string("illegal_instruction");
            std::vector<Value*> args {
                this->core_ptr,
                this->gen_const(64, pc.val),
                this->builder.CreateGlobalStringPtr(mnemonic),
            };
            this->builder.CreateCall(this->mod->getFunction("print_disass"), args);
        }
		this->gen_sync(iss::PRE_SYNC, instr_descr.size());
        this->builder.CreateStore(this->builder.CreateLoad(this->get_typeptr(traits::NEXT_PC), get_reg_ptr(traits::NEXT_PC), true),
                                   get_reg_ptr(traits::PC), true);
        this->builder.CreateStore(
            this->builder.CreateAdd(this->builder.CreateLoad(this->get_typeptr(traits::ICOUNT), get_reg_ptr(traits::ICOUNT), true),
                                     this->gen_const(64U, 1)),
            get_reg_ptr(traits::ICOUNT), true);
        pc = pc + ((instr & 3) == 3 ? 4 : 2);
        this->set_tval(instr);
        this->gen_raise_trap(0, 2);     // illegal instruction trap
		this->gen_sync(iss::POST_SYNC, instr_descr.size());
        this->gen_instr_epilogue(this->leave_blk);
        return std::make_tuple(BRANCH, nullptr);
    }    
    //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 CODE_WORD> void debug_fn(CODE_WORD instr) {
    volatile CODE_WORD x = instr;
    instr = 2 * x;
}

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>
std::tuple<continuation_e, BasicBlock *>
vm_impl<ARCH>::gen_single_inst_behavior(virt_addr_t &pc, unsigned int &inst_cnt, BasicBlock *this_block) {
    // we fetch at max 4 byte, alignment is 2
    enum {TRAP_ID=1<<16};
    code_word_t instr = 0;
    // const typename traits::addr_t upper_bits = ~traits::PGMASK;
    phys_addr_t paddr(pc);
    auto *const data = (uint8_t *)&instr;
    if(this->core.has_mmu())
        paddr = this->core.virt2phys(pc);
    //TODO: re-add page handling
//    if ((pc.val & upper_bits) != ((pc.val + 2) & upper_bits)) { // we may cross a page boundary
//        auto res = this->core.read(paddr, 2, data);
//        if (res != iss::Ok) throw trap_access(TRAP_ID, pc.val);
//        if ((instr & 0x3) == 0x3) { // this is a 32bit instruction
//            res = this->core.read(this->core.v2p(pc + 2), 2, data + 2);
//        }
//    } else {
        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'
    // curr pc on stack
    ++inst_cnt;
    auto f = decode_instr(root, instr);
    if (f == nullptr) {
        f = &this_class::illegal_instruction;
    }
    return (this->*f)(pc, instr, this_block);
}

template <typename ARCH>
void vm_impl<ARCH>::gen_leave_behavior(BasicBlock *leave_blk) {
    this->builder.SetInsertPoint(leave_blk);
    this->builder.CreateRet(this->builder.CreateLoad(this->get_typeptr(traits::NEXT_PC),get_reg_ptr(traits::NEXT_PC), false));
}

template <typename ARCH>
void vm_impl<ARCH>::gen_raise_trap(uint16_t trap_id, uint16_t cause) {
    auto *TRAP_val = this->gen_const(32, 0x80 << 24 | (cause << 16) | trap_id);
    this->builder.CreateStore(TRAP_val, get_reg_ptr(traits::TRAP_STATE), true);
}

template <typename ARCH>
void vm_impl<ARCH>::gen_leave_trap(unsigned lvl) {
    std::vector<Value *> args{ this->core_ptr, ConstantInt::get(getContext(), APInt(64, lvl)) };
    this->builder.CreateCall(this->mod->getFunction("leave_trap"), args);
    this->builder.CreateStore(this->gen_const(32U, std::numeric_limits<uint32_t>::max()), get_reg_ptr(traits::LAST_BRANCH), false);
}

template <typename ARCH>
void vm_impl<ARCH>::gen_wait(unsigned type) {
    std::vector<Value *> args{ this->core_ptr, ConstantInt::get(getContext(), APInt(64, type)) };
    this->builder.CreateCall(this->mod->getFunction("wait"), args);
}

template <typename ARCH>
inline void vm_impl<ARCH>::set_tval(uint64_t tval) {
    auto tmp_tval = this->gen_const(64, tval);
    this->set_tval(tmp_tval);
}
template <typename ARCH>
inline void vm_impl<ARCH>::set_tval(Value* new_tval) {
    this->builder.CreateStore(this->gen_ext(new_tval, 64, false), this->tval);
}
template <typename ARCH> 
void vm_impl<ARCH>::gen_trap_behavior(BasicBlock *trap_blk) {
    this->builder.SetInsertPoint(trap_blk);
    auto *trap_state_val = this->builder.CreateLoad(this->get_typeptr(traits::TRAP_STATE), get_reg_ptr(traits::TRAP_STATE), true);
    auto *cur_pc_val = this->builder.CreateLoad(this->get_typeptr(traits::PC), get_reg_ptr(traits::PC), true);
    std::vector<Value *> args{this->core_ptr,
                                this->adj_to64(trap_state_val),
                                this->adj_to64(cur_pc_val),
                              this->adj_to64(this->builder.CreateLoad(this->get_type(64),this->tval))};
    this->builder.CreateCall(this->mod->getFunction("enter_trap"), args);
    this->builder.CreateStore(this->gen_const(32U, std::numeric_limits<uint32_t>::max()), get_reg_ptr(traits::LAST_BRANCH), false);

    auto *trap_addr_val = this->builder.CreateLoad(this->get_typeptr(traits::NEXT_PC), get_reg_ptr(traits::NEXT_PC), false);
    this->builder.CreateRet(trap_addr_val);
}
template <typename ARCH>
void vm_impl<ARCH>::gen_instr_prologue() {
    auto* trap_val =
        this->builder.CreateLoad(this->get_typeptr(arch::traits<ARCH>::PENDING_TRAP), get_reg_ptr(arch::traits<ARCH>::PENDING_TRAP));
    this->builder.CreateStore(trap_val, get_reg_ptr(arch::traits<ARCH>::TRAP_STATE), false);
}
            

template <typename ARCH>
void vm_impl<ARCH>::gen_instr_epilogue(BasicBlock *bb) {
    auto* target_bb = BasicBlock::Create(this->mod->getContext(), "", this->func, bb);
    auto *v = this->builder.CreateLoad(this->get_typeptr(traits::TRAP_STATE), get_reg_ptr(traits::TRAP_STATE), true);
    this->gen_cond_branch(this->builder.CreateICmp(
                              ICmpInst::ICMP_EQ, v,
                              ConstantInt::get(getContext(), APInt(v->getType()->getIntegerBitWidth(), 0))),
                          target_bb, this->trap_blk, 1);
    this->builder.SetInsertPoint(target_bb);
    // update icount
    auto* icount_val = this->builder.CreateAdd(
        this->builder.CreateLoad(this->get_typeptr(arch::traits<ARCH>::ICOUNT), get_reg_ptr(arch::traits<ARCH>::ICOUNT)), this->gen_const(64U, 1));
    this->builder.CreateStore(icount_val, get_reg_ptr(arch::traits<ARCH>::ICOUNT), false);
}

} // namespace ${coreDef.name.toLowerCase()}

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