#include <stdint.h>
#include <86box/86box.h>
#include "cpu.h"
#include <86box/mem.h>
#include <86box/plat_unused.h>

#include "codegen.h"
#include "codegen_allocator.h"
#include "codegen_backend.h"
#include "codegen_ir.h"
#include "codegen_reg.h"

extern int       has_ea;
static ir_data_t ir_block;

static int codegen_unroll_start;
static int codegen_unroll_count;
static int codegen_unroll_first_instruction;

ir_data_t *
codegen_ir_init(void)
{
    ir_block.wr_pos = 0;

    codegen_unroll_count = 0;

    return &ir_block;
}

void
codegen_ir_set_unroll(int count, int start, int first_instruction)
{
    codegen_unroll_count             = count;
    codegen_unroll_start             = start;
    codegen_unroll_first_instruction = first_instruction;
}

static void
duplicate_uop(ir_data_t *ir, uop_t *uop, int offset)
{
    uop_t *new_uop = uop_alloc_unroll(ir, uop->type);

    if (!ir_reg_is_invalid(uop->src_reg_a))
        new_uop->src_reg_a = codegen_reg_read(uop->src_reg_a.reg);
    if (!ir_reg_is_invalid(uop->src_reg_b))
        new_uop->src_reg_b = codegen_reg_read(uop->src_reg_b.reg);
    if (!ir_reg_is_invalid(uop->src_reg_c))
        new_uop->src_reg_c = codegen_reg_read(uop->src_reg_c.reg);
    if (!ir_reg_is_invalid(uop->dest_reg_a))
        new_uop->dest_reg_a = codegen_reg_write(uop->dest_reg_a.reg, ir->wr_pos - 1);

    new_uop->type     = uop->type;
    new_uop->imm_data = uop->imm_data;
    new_uop->p        = uop->p;
    new_uop->pc       = uop->pc;

    if (uop->jump_dest_uop != -1) {
        new_uop->jump_dest_uop = uop->jump_dest_uop + offset;
    }
}

void
codegen_ir_compile(ir_data_t *ir, codeblock_t *block)
{
    int jump_target_at_end = -1;
    int c;

    if (codegen_unroll_count) {
        int unroll_end;

        codegen_set_loop_start(ir, codegen_unroll_first_instruction);
        unroll_end = ir->wr_pos;

        for (int unroll_count = 1; unroll_count < codegen_unroll_count; unroll_count++) {
            int offset = ir->wr_pos - codegen_unroll_start;
            //                        pclog("Unroll from %i to %i, offset %i - iteration %i\n", codegen_unroll_start, ir->wr_pos, offset, unroll_count);
            for (c = codegen_unroll_start; c < unroll_end; c++) {
                //                                pclog(" Duplicate uop %i\n", c);
                duplicate_uop(ir, &ir->uops[c], offset);
            }
        }
    }

    codegen_reg_mark_as_required();
    codegen_reg_process_dead_list(ir);
    block_write_data = codeblock_allocator_get_ptr(block->head_mem_block);
    block_pos        = 0;
    codegen_backend_prologue(block);

    for (c = 0; c < ir->wr_pos; c++) {
        uop_t *uop = &ir->uops[c];

        //                pclog("uOP %i : %08x\n", c, uop->type);

        if (uop->type & UOP_TYPE_BARRIER)
            codegen_reg_flush_invalidate(ir, block);

        if (uop->type & UOP_TYPE_JUMP_DEST) {
            uop_t *uop_dest = uop;

            while (uop_dest->jump_list_next != -1) {
                uop_dest = &ir->uops[uop_dest->jump_list_next];
                codegen_set_jump_dest(block, uop_dest->p);
            }
        }

        if ((uop->type & UOP_MASK) == UOP_INVALID)
            continue;

#ifdef CODEGEN_BACKEND_HAS_MOV_IMM
        if ((uop->type & UOP_MASK) == (UOP_MOV_IMM & UOP_MASK) && reg_is_native_size(uop->dest_reg_a) && !codegen_reg_is_loaded(uop->dest_reg_a) && reg_version[IREG_GET_REG(uop->dest_reg_a.reg)][uop->dest_reg_a.version].refcount <= 0) {
            /*Special case for UOP_MOV_IMM - if destination not already in host register
              and won't be used again then just store directly to memory*/
            codegen_reg_write_imm(block, uop->dest_reg_a, uop->imm_data);
        } else
#endif
            if ((uop->type & UOP_MASK) == (UOP_MOV & UOP_MASK) && reg_version[IREG_GET_REG(uop->src_reg_a.reg)][uop->src_reg_a.version].refcount <= 1 && reg_is_native_size(uop->src_reg_a) && reg_is_native_size(uop->dest_reg_a)) {
            /*Special case for UOP_MOV - if source register won't be used again then
              just rename it to dest register instead of moving*/
            codegen_reg_alloc_register(invalid_ir_reg, uop->src_reg_a, invalid_ir_reg, invalid_ir_reg);
            uop->src_reg_a_real = codegen_reg_alloc_read_reg(block, uop->src_reg_a, NULL);
            codegen_reg_rename(block, uop->src_reg_a, uop->dest_reg_a);
            if (uop->type & UOP_TYPE_ORDER_BARRIER)
                codegen_reg_flush(ir, block);
        } else {
            if (uop->type & UOP_TYPE_PARAMS_REGS) {
                codegen_reg_alloc_register(uop->dest_reg_a, uop->src_reg_a, uop->src_reg_b, uop->src_reg_c);
                if (uop->src_reg_a.reg != IREG_INVALID) {
                    uop->src_reg_a_real = codegen_reg_alloc_read_reg(block, uop->src_reg_a, NULL);
                }
                if (uop->src_reg_b.reg != IREG_INVALID) {
                    uop->src_reg_b_real = codegen_reg_alloc_read_reg(block, uop->src_reg_b, NULL);
                }
                if (uop->src_reg_c.reg != IREG_INVALID) {
                    uop->src_reg_c_real = codegen_reg_alloc_read_reg(block, uop->src_reg_c, NULL);
                }
            }

            if (uop->type & UOP_TYPE_ORDER_BARRIER)
                codegen_reg_flush(ir, block);

            if (uop->type & UOP_TYPE_PARAMS_REGS) {
                if (uop->dest_reg_a.reg != IREG_INVALID) {
                    uop->dest_reg_a_real = codegen_reg_alloc_write_reg(block, uop->dest_reg_a);
                }
            }
#ifndef RELEASE_BUILD
            if (!uop_handlers[uop->type & UOP_MASK])
                fatal("!uop_handlers[uop->type & UOP_MASK] %08x\n", uop->type);
#endif
            uop_handlers[uop->type & UOP_MASK](block, uop);
        }

        if (uop->type & UOP_TYPE_JUMP) {
            if (uop->jump_dest_uop == ir->wr_pos) {
                if (jump_target_at_end == -1)
                    jump_target_at_end = c;
                else {
                    uop_t *uop_dest = &ir->uops[jump_target_at_end];

                    while (uop_dest->jump_list_next != -1)
                        uop_dest = &ir->uops[uop_dest->jump_list_next];

                    uop_dest->jump_list_next = c;
                }
            } else {
                uop_t *uop_dest = &ir->uops[uop->jump_dest_uop];

                while (uop_dest->jump_list_next != -1)
                    uop_dest = &ir->uops[uop_dest->jump_list_next];

                uop_dest->jump_list_next = c;
                ir->uops[uop->jump_dest_uop].type |= UOP_TYPE_JUMP_DEST;
            }
        }
    }

    codegen_reg_flush_invalidate(ir, block);

    if (jump_target_at_end != -1) {
        uop_t *uop_dest = &ir->uops[jump_target_at_end];

        while (1) {
            codegen_set_jump_dest(block, uop_dest->p);
            if (uop_dest->jump_list_next == -1)
                break;
            uop_dest = &ir->uops[uop_dest->jump_list_next];
        }
    }

    codegen_backend_epilogue(block);
    block_write_data = NULL;
#if 0
    if (has_ea)
        fatal("IR compilation complete\n");
#endif
}
