#include "compiler/VectorArraysToRegs.h"
#include "compiler/CError.h"
#include "compiler/CFunc.h"
#include "compiler/BitVectors.h"
#include "compiler/CompilerTools.h"
#include "compiler/PCode.h"
#include "compiler/PCodeInfo.h"
#include "compiler/Registers.h"
#include "compiler/UseDefChains.h"
#include "compiler/objects.h"
#include "compiler/types.h"

typedef struct LocalVectorArray {
    struct LocalVectorArray *next;
    Object *object;
    unsigned int invalid:1;
    SInt32 arraySize;
    SInt32 elementCount;
    int totalUses;
    int elements[1];
} LocalVectorArray;

typedef struct VectorPropInfo {
    UInt32 *use;
    UInt32 *def;
    UInt32 *in;
    UInt32 *out;
} VectorPropInfo;

typedef struct ADDI {
    PCode *instr;
    RegUseOrDef *list;
} ADDI;

static int number_of_ADDIs;
static ADDI *ADDIs;
static VectorPropInfo *vectorpropinfo;
static int *naddsinblock;
static int *firstaddinblock;
static Boolean converted_arrays;

static LocalVectorArray *scanforlocalvectorarrays(void) {
    SInt32 elementCount;
    LocalVectorArray *head;
    LocalVectorArray *array;
    ObjectList *list;
    int i;
    SInt32 arraySize;

    head = NULL;

    for (list = locals; list; list = list->next) {
        if (
            list->object &&
            !(IS_TYPE_POINTER(list->object->type) ? (TPTR_QUAL(list->object->type) & Q_VOLATILE) : (list->object->qual & Q_VOLATILE)) &&
            list->object->type &&
            IS_TYPE_ARRAY(list->object->type) &&
            IS_TYPE_VECTOR(TPTR_TARGET(list->object->type))
            ) {
            arraySize = list->object->type->size;
            elementCount = arraySize / 16;
            if (elementCount > 0 && elementCount <= 8) {
                array = oalloc(sizeof(int) * (elementCount - 1) + sizeof(LocalVectorArray));
                array->next = head;
                head = array;

                array->object = list->object;
                array->arraySize = arraySize;
                array->elementCount = elementCount;
                array->totalUses = 0;
                array->invalid = 0;

                for (i = 0; i < elementCount; i++) {
                    array->elements[i] = 0;
                }
            }
        }
    }

    return head;
}

static LocalVectorArray *lookup_vector_array_object(LocalVectorArray *arrays, Object *object) {
    while (arrays) {
        if (arrays->object == object)
            return arrays;
        arrays = arrays->next;
    }
    return NULL;
}

static void scaninstructions(LocalVectorArray *arrays) {
    PCodeBlock *block;
    PCode *instr;
    int counter;
    int i;
    PCodeArg *op;
    LocalVectorArray *array;
    int element;

    naddsinblock = oalloc(sizeof(int) * pcblockcount);
    memclrw(naddsinblock, sizeof(int) * pcblockcount);

    firstaddinblock = oalloc(sizeof(int) * pcblockcount);
    memclrw(firstaddinblock, sizeof(int) * pcblockcount);

    number_of_ADDIs = 0;

    for (block = pcbasicblocks; block; block = block->nextBlock) {
        firstaddinblock[block->blockIndex] = number_of_ADDIs;
        counter = 0;
        for (instr = block->firstPCode; instr; instr = instr->nextPCode) {
            if (!(instr->flags & fIsBranch) && instr->argCount) {
                op = instr->args;
                i = instr->argCount;
                while (i--) {
                    if (
                        op->kind == PCOp_MEMORY &&
                        (PCOpMemoryArg) op->arg == PCOpMemory1 &&
                        (array = lookup_vector_array_object(arrays, op->data.mem.obj)) &&
                        !array->invalid
                        )
                    {
                        if (instr->op != PC_ADDI) {
                            array->invalid = 1;
                        } else if (instr->args[0].data.reg.reg < n_real_registers[RegClass_GPR]) {
                            array->invalid = 1;
                        } else {
                            number_of_ADDIs++;
                            counter++;
                        }

                        if (!array->invalid) {
                            element = op->data.mem.offset / 16;
                            if (element < array->elementCount)
                                array->elements[element]++;
                            else
                                array->invalid = 1;
                        }
                    }
                    op++;
                }
            }
        }
        naddsinblock[block->blockIndex] = counter;
    }
}

static void computeaddilist(LocalVectorArray *arrays) {
    PCodeBlock *block;
    PCode *instr;
    RegUseOrDef *list;
    ADDI *addi;
    UInt32 *vec;
    LocalVectorArray *array;
    UseOrDef *def;
    int defID;
    UseOrDef *use;
    int useID;

    ADDIs = oalloc(sizeof(ADDI) * number_of_ADDIs);
    memclrw(ADDIs, sizeof(ADDI) * number_of_ADDIs);

    vec = oalloc(4 * ((number_of_Uses + 31) >> 5));

    for (block = pcbasicblocks; block; block = block->nextBlock) {
        if (naddsinblock[block->blockIndex]) {
            bitvectorcopy(vec, usedefinfo[block->blockIndex].usevec1C, number_of_Uses);
            addi = &ADDIs[firstaddinblock[block->blockIndex] + naddsinblock[block->blockIndex] - 1];
            for (instr = block->lastPCode; instr; instr = instr->prevPCode) {
                if (!(instr->flags & fIsBranch) && instr->argCount) {
                    int reg; // r18
                    if (
                        instr->op == PC_ADDI &&
                        (reg = instr->args[0].data.reg.reg) >= n_real_registers[RegClass_GPR] &&
                        instr->args[2].kind == PCOp_MEMORY &&
                        (PCOpMemoryArg) instr->args[2].arg == PCOpMemory1 &&
                        (array = lookup_vector_array_object(arrays, instr->args[2].data.mem.obj)) &&
                        !array->invalid
                        )
                    {
                        addi->instr = instr;
                        addi->list = NULL;
                        for (list = reg_Uses[RegClass_GPR][reg]; list; list = list->next) {
                            if (bitvectorgetbit(list->id, vec)) {
                                RegUseOrDef *node = oalloc(sizeof(RegUseOrDef));
                                node->id = list->id;
                                node->next = addi->list;
                                addi->list = node;
                            }
                        }
                        addi--;
                    }

                    for (def = &Defs[defID = instr->defID]; defID < number_of_Defs && def->pcode == instr; def++, defID++) {
                        if (def->v.kind == PCOp_REGISTER) {
                            RegUseOrDef *l;
                            for (l = reg_Uses[def->v.arg][def->v.u.reg]; l; l = l->next)
                                bitvectorclearbit(l->id, vec);
                        }
                    }

                    for (use = &Uses[useID = instr->useID]; useID < number_of_Uses && use->pcode == instr; use++, useID++) {
                        if (use->v.kind == PCOp_REGISTER)
                            bitvectorsetbit(useID, vec);
                    }
                }
            }
        }
    }
}

static void allocatevectorpropinfo(void) {
    VectorPropInfo *info;
    int i;

    vectorpropinfo = oalloc(sizeof(VectorPropInfo) * pcblockcount);
    for (i = 0, info = vectorpropinfo; i < pcblockcount; i++, info++) {
        info->use = oalloc(4 * ((number_of_ADDIs + 31) >> 5));
        info->def = oalloc(4 * ((number_of_ADDIs + 31) >> 5));
        info->in = oalloc(4 * ((number_of_ADDIs + 31) >> 5));
        info->out = oalloc(4 * ((number_of_ADDIs + 31) >> 5));
    }
}

static void computelocalvectorpropinfo(LocalVectorArray *arrays) {
    VectorPropInfo *info;
    PCodeBlock *block;
    PCode *instr;
    UInt32 *vec0;
    UInt32 *vec4;
    int index;
    PCodeArg *op;
    int i;
    int addi_i;
    ADDI *addi;
    LocalVectorArray *array;

    for (block = pcbasicblocks; block; block = block->nextBlock) {
        info = &vectorpropinfo[block->blockIndex];
        vec0 = info->use;
        vec4 = info->def;
        bitvectorinitialize(vec0, number_of_ADDIs, 0);
        bitvectorinitialize(vec4, number_of_ADDIs, 0);
        index = firstaddinblock[block->blockIndex];

        for (instr = block->firstPCode; instr; instr = instr->nextPCode) {
            if (!(instr->flags & fIsBranch) && instr->argCount) {
                i = instr->argCount;
                op = instr->args;
                while (i--) {
                    if (op->kind == PCOp_REGISTER && op->arg == RegClass_GPR && (op->data.reg.effect & EffectWrite)) {
                        for (addi_i = 0, addi = ADDIs; addi_i < number_of_ADDIs; addi_i++, addi++) {
                            if (
                                addi->instr &&
                                addi->instr->args[0].arg == op->arg &&
                                addi->instr->args[0].data.reg.reg == op->data.reg.reg
                                )
                            {
                                if (addi->instr->block == block)
                                    bitvectorclearbit(addi_i, vec0);
                                else
                                    bitvectorsetbit(addi_i, vec4);
                            }
                        }
                    }
                    op++;
                }

                if (
                    instr->op == PC_ADDI &&
                    instr->args[2].kind == PCOp_MEMORY &&
                    (PCOpMemoryArg) instr->args[2].arg == PCOpMemory1 &&
                    (array = lookup_vector_array_object(arrays, instr->args[2].data.mem.obj)) &&
                    !array->invalid
                    )
                {
                    bitvectorsetbit(index, vec0);
                    index++;
                }
            }
        }
    }
}

static void computeglobalvectorpropinfo(void) {
    VectorPropInfo *info;
    PCodeBlock *block;
    UInt32 *vec0;
    UInt32 *vec4;
    UInt32 *vec8;
    UInt32 *vecC;
    int bitvecsize;
    int blockIndex;
    int i;
    int j;
    int flag;
    PCLink *preds;
    UInt32 val;

    bitvecsize = (number_of_ADDIs + 31) >> 5;
    flag = 1;
    info = &vectorpropinfo[pcbasicblocks->blockIndex];
    bitvectorinitialize(info->in, number_of_ADDIs, 0);
    bitvectorcopy(info->out, info->use, number_of_ADDIs);

    for (block = pcbasicblocks->nextBlock; block; block = block->nextBlock) {
        info = &vectorpropinfo[block->blockIndex];
        vecC = info->out;
        vec4 = info->def;
        for (i = 0; i < bitvecsize; vecC++, vec4++, i++)
            *vecC = ~*vec4;
    }

    while (flag) {
        flag = 0;
        for (blockIndex = 0; blockIndex < pcblockcount; blockIndex++) {
            if (depthfirstordering[blockIndex]) {
                info = &vectorpropinfo[depthfirstordering[blockIndex]->blockIndex];
                if ((preds = depthfirstordering[blockIndex]->predecessors)) {
                    vec8 = info->in;
                    bitvectorcopy(vec8, vectorpropinfo[preds->block->blockIndex].out, number_of_ADDIs);
                    for (preds = preds->nextLink; preds; preds = preds->nextLink)
                        bitvectorintersect(vec8, vectorpropinfo[preds->block->blockIndex].out, number_of_ADDIs);
                }

                vecC = info->out;
                vec8 = info->in;
                vec0 = info->use;
                vec4 = info->def;
                for (j = 0; j < bitvecsize; j++) {
                    val = *vec0 | (*vec8 & ~*vec4);
                    if (val != *vecC) {
                        *vecC = val;
                        flag = 1;
                    }
                    vec8++;
                    vecC++;
                    vec4++;
                    vec0++;
                }
            }
        }
    }
}

static int precedes(PCode *a, PCode *b) {
    PCode *scan;

    for (scan = a->nextPCode; scan; scan = scan->nextPCode) {
        if (scan == b)
            return 1;
    }

    return 0;
}

static int checkvectorstoreorload(int addiID, int useID) {
    PCode *addiInstr;
    UseOrDef *use;

    addiInstr = ADDIs[addiID].instr;
    use = Uses + useID;
    if (!addiInstr)
        return 0;

    if (addiInstr->args[0].data.reg.reg < n_real_registers[RegClass_GPR])
        return 0;

    if (use->pcode->op != PC_LVX && use->pcode->op != PC_STVX)
        return 0;

    if (
        use->pcode->args[1].kind != PCOp_REGISTER ||
        use->pcode->args[1].arg != RegClass_GPR ||
        use->pcode->args[1].data.reg.reg != 0
        )
        return 0;

    return use->pcode->args[2].data.reg.reg == addiInstr->args[0].data.reg.reg;
}

static int checkalluses(LocalVectorArray *arrays, int addiID) {
    RegUseOrDef *list;
    PCode *instr;
    LocalVectorArray *array;

    instr = ADDIs[addiID].instr;
    for (list = ADDIs[addiID].list; list; list = list->next) {
        if (list && !checkvectorstoreorload(addiID, list->id)) {
            array = lookup_vector_array_object(arrays, instr->args[2].data.mem.obj);
            array->invalid = 1;
            return 0;
        }
    }

    return 1;
}

static void convert_array_to_register(LocalVectorArray *arrays, int addiID) {
    ADDI *addi;
    int newReg;
    RegUseOrDef *list;
    PCode *instr;
    PCode *useInstr;
    LocalVectorArray *array;
    int element;

    addi = ADDIs + addiID;

    if (!(instr = addi->instr))
        return;

    if (
        !(array = lookup_vector_array_object(arrays, instr->args[2].data.mem.obj)) ||
        array->invalid
        )
        return;

    element = instr->args[2].data.mem.offset / 16;
    if (element > array->elementCount)
        return;

    newReg = array->elements[element];
    for (list = addi->list; list; list = list->next) {
        useInstr = Uses[list->id].pcode;
        if (useInstr->op == PC_LVX) {
            converted_arrays = 1;
            change_opcode(useInstr, PC_VMR);
            change_num_operands(useInstr, 2);
            useInstr->args[1].kind = PCOp_REGISTER;
            useInstr->args[1].arg = RegClass_VR;
            useInstr->args[1].data.reg.reg = newReg;
            useInstr->args[1].data.reg.effect = EffectRead;
        } else if (useInstr->op == PC_STVX) {
            converted_arrays = 1;
            change_opcode(useInstr, PC_VMR);
            change_num_operands(useInstr, 2);
            useInstr->args[1] = useInstr->args[0];
            useInstr->args[0].kind = PCOp_REGISTER;
            useInstr->args[0].arg = RegClass_VR;
            useInstr->args[0].data.reg.reg = newReg;
            useInstr->args[0].data.reg.effect = EffectWrite;
        } else {
            CError_FATAL(661);
        }
    }
    deletepcode(addi->instr);
}

static void convert_arrays_to_registers(LocalVectorArray *arrays) {
    int i;
    int counter;
    LocalVectorArray **ptr;
    LocalVectorArray *array;

    for (i = 0; i < number_of_ADDIs; i++)
        checkalluses(arrays, i);

    counter = 0;
    ptr = &arrays;
    array = *ptr;
    while (array) {
        if (array->invalid) {
            *ptr = array->next;
            array = *ptr;
            continue;
        }

        counter += array->elementCount;

        for (i = 0; i < array->elementCount; i++)
            array->totalUses += array->elements[i];

        array = array->next;
    }

    if (arrays) {
        while (counter > 32) {
            LocalVectorArray *best;
            int score;
            score = 0;
            best = NULL;
            for (array = arrays; array; array = array->next) {
                if (best) {
                    if (array->totalUses < score) {
                        score = array->totalUses;
                        best = array;
                    }
                } else {
                    best = array;
                    score = array->totalUses;
                }
            }

            if (!best)
                break;

            if (best == arrays) {
                arrays = best->next;
            } else {
                for (array = arrays; array; array = array->next) {
                    if (array->next == best) {
                        array->next = best->next;
                        break;
                    }
                }
            }

            counter -= best->elementCount;
        }

        if (!(array = arrays))
            return;

        while (array) {
            for (i = 0; i < array->elementCount; i++)
                array->elements[i] = used_virtual_registers[RegClass_VR]++;
            array = array->next;
        }

        if (arrays) {
            for (i = 0; i < number_of_ADDIs; i++)
                convert_array_to_register(arrays, i);
        }
    }
}

int vectorarraystoregs(void) {
    LocalVectorArray *arrays;

    converted_arrays = 0;
    if ((arrays = scanforlocalvectorarrays())) {
        scaninstructions(arrays);
        if (number_of_ADDIs > 0) {
            computeusedefchains(0);
            computeaddilist(arrays);
            allocatevectorpropinfo();
            computelocalvectorpropinfo(arrays);
            computedepthfirstordering();
            computeglobalvectorpropinfo();
            convert_arrays_to_registers(arrays);
        }
    }

    freeoheap();
    return converted_arrays;
}