path: root/src/fp.cpp

#include <mcl/op.hpp>
#include <mcl/util.hpp>
#include "conversion.hpp"
#ifdef MCL_USE_XBYAK
#include "fp_generator.hpp"
#endif
#include "low_func.hpp"
#ifdef MCL_USE_LLVM
#include "proto.hpp"
#include "low_func_llvm.hpp"
#endif

#ifdef _MSC_VER
    #pragma warning(disable : 4127)
#endif

namespace mcl {

namespace fp {

#ifdef MCL_USE_XBYAK
FpGenerator *Op::createFpGenerator()
{
    return new FpGenerator();
}
void Op::destroyFpGenerator(FpGenerator *fg)
{
    delete fg;
}
#else
FpGenerator *Op::createFpGenerator()
{
    return 0;
}
void Op::destroyFpGenerator(FpGenerator *)
{
}
#endif

/*
    use prefix if base conflicts with prefix
*/
inline const char *verifyStr(bool *isMinus, int *base, const std::string& str)
{
    const char *p = str.c_str();
    if (*p == '-') {
        *isMinus = true;
        p++;
    } else {
        *isMinus = false;
    }
    if (p[0] == '0') {
        if (p[1] == 'x') {
            *base = 16;
            p += 2;
        } else if (p[1] == 'b') {
            *base = 2;
            p += 2;
        }
    }
    if (*base == 0) *base = 10;
    if (*p == '\0') throw cybozu::Exception("fp:verifyStr:str is empty");
    return p;
}

bool strToMpzArray(size_t *pBitSize, Unit *y, size_t maxBitSize, mpz_class& x, const std::string& str, int base)
{
    bool isMinus;
    const char *p = verifyStr(&isMinus, &base, str);
    if (!gmp::setStr(x, p, base)) {
        throw cybozu::Exception("fp:strToMpzArray:bad format") << str;
    }
    const size_t bitSize = gmp::getBitSize(x);
    if (bitSize > maxBitSize) throw cybozu::Exception("fp:strToMpzArray:too large str") << str << bitSize << maxBitSize;
    if (pBitSize) *pBitSize = bitSize;
    gmp::getArray(y, (maxBitSize + UnitBitSize - 1) / UnitBitSize, x);
    return isMinus;
}

const char *ModeToStr(Mode mode)
{
    switch (mode) {
    case FP_AUTO: return "auto";
    case FP_GMP: return "gmp";
    case FP_GMP_MONT: return "gmp_mont";
    case FP_LLVM: return "llvm";
    case FP_LLVM_MONT: return "llvm_mont";
    case FP_XBYAK: return "xbyak";
    default:
        throw cybozu::Exception("ModeToStr") << mode;
    }
}

Mode StrToMode(const std::string& s)
{
    static const struct {
        const char *s;
        Mode mode;
    } tbl[] = {
        { "auto", FP_AUTO },
        { "gmp", FP_GMP },
        { "gmp_mont", FP_GMP_MONT },
        { "llvm", FP_LLVM },
        { "llvm_mont", FP_LLVM_MONT },
        { "xbyak", FP_XBYAK },
    };
    for (size_t i = 0; i < CYBOZU_NUM_OF_ARRAY(tbl); i++) {
        if (s == tbl[i].s) return tbl[i].mode;
    }
    throw cybozu::Exception("StrToMode") << s;
}

void dumpUnit(Unit x)
{
#if CYBOZU_OS_BIT == 32
    printf("%08x", (uint32_t)x);
#else
    printf("%016llx", (unsigned long long)x);
#endif
}
void UnitToHex(char *buf, size_t maxBufSize, Unit x)
{
#if CYBOZU_OS_BIT == 32
    CYBOZU_SNPRINTF(buf, maxBufSize, "%08x", (uint32_t)x);
#else
    CYBOZU_SNPRINTF(buf, maxBufSize, "%016llx ", (unsigned long long)x);
#endif
}

static inline void set_mpz_t(mpz_t& z, const Unit* p, int n)
{
    int s = n;
    while (s > 0) {
        if (p[s - 1]) break;
        s--;
    }
    z->_mp_alloc = n;
    z->_mp_size = s;
    z->_mp_d = (mp_limb_t*)const_cast<Unit*>(p);
}

static inline void fp_invOpC(Unit *y, const Unit *x, const Op& op)
{
    const int N = (int)op.N;
    mpz_class my;
    mpz_t mx, mp;
    set_mpz_t(mx, x, N);
    set_mpz_t(mp, op.p, N);
    mpz_invert(my.get_mpz_t(), mx, mp);
    gmp::getArray(y, N, my);
}

/*
    inv(xR) = (1/x)R^-1 -toMont-> 1/x -toMont-> (1/x)R
*/
static void fp_invMontOpC(Unit *y, const Unit *x, const Op& op)
{
    fp_invOpC(y, x, op);
    op.fp_mul(y, y, op.R3, op.p);
}

/*
    large (N * 2) specification of AddPre, SubPre
*/
template<size_t N, bool enable>
struct SetFpDbl {
    static inline void exec(Op&) {}
};

template<size_t N>
struct SetFpDbl<N, true> {
    static inline void exec(Op& op)
    {
//      if (!op.isFullBit) {
            op.fpDbl_addPre = AddPre<N * 2, Ltag>::f;
            op.fpDbl_subPre = SubPre<N * 2, Ltag>::f;
//      }
    }
};

template<size_t N, class Tag, bool enableFpDbl>
void setOp2(Op& op)
{
    op.fp_shr1 = Shr1<N, Tag>::f;
    op.fp_neg = Neg<N, Tag>::f;
    op.fp_add = Add<N, Tag>::f;
    op.fp_sub = Sub<N, Tag>::f;
    if (op.isMont) {
        op.fp_mul = Mont<N, Tag>::f;
        op.fp_sqr = SqrMont<N, Tag>::f;
        op.fpDbl_mod = MontRed<N, Tag>::f;
    } else {
        op.fp_mul = Mul<N, Tag>::f;
        op.fp_sqr = Sqr<N, Tag>::f;
        op.fpDbl_mod = Dbl_Mod<N, Tag>::f;
    }
    op.fp_mulUnit = MulUnit<N, Tag>::f;
    op.fpDbl_mulPre = MulPre<N, Tag>::f;
    op.fpDbl_sqrPre = SqrPre<N, Tag>::f;
    op.fp_mulUnitPre = MulUnitPre<N, Tag>::f;
    op.fpN1_mod = N1_Mod<N, Tag>::f;
    op.fpDbl_add = DblAdd<N, Tag>::f;
    op.fpDbl_sub = DblSub<N, Tag>::f;
    op.fp_addPre = AddPre<N, Tag>::f;
    op.fp_subPre = SubPre<N, Tag>::f;
    SetFpDbl<N, enableFpDbl>::exec(op);
}

template<size_t N>
void setOp(Op& op)
{
    // generic setup
    op.fp_isZero = isZeroC<N>;
    op.fp_clear = clearC<N>;
    op.fp_copy = copyC<N>;
    if (op.isMont) {
        op.fp_invOp = fp_invMontOpC;
    } else {
        op.fp_invOp = fp_invOpC;
    }
    setOp2<N, Gtag, true>(op);
#ifdef MCL_USE_LLVM
    setOp2<N, Ltag, (N * UnitBitSize <= 256)>(op);
#endif
}

#ifdef MCL_USE_XBYAK
inline void invOpForMontC(Unit *y, const Unit *x, const Op& op)
{
    Unit r[maxOpUnitSize];
    int k = op.fp_preInv(r, x);
    /*
        S = UnitBitSize
        xr = 2^k
        R = 2^(N * S)
        get r2^(-k)R^2 = r 2^(N * S * 2 - k)
    */
    op.fp_mul(y, r, op.invTbl.data() + k * op.N, op.p);
}

static void initInvTbl(Op& op)
{
    const size_t N = op.N;
    const Unit *p = op.p;
    const size_t invTblN = N * sizeof(Unit) * 8 * 2;
    op.invTbl.resize(invTblN * N);
    Unit *tbl = op.invTbl.data() + (invTblN - 1) * N;
    Unit t[maxOpUnitSize] = {};
    t[0] = 2;
    op.toMont(tbl, t);
    for (size_t i = 0; i < invTblN - 1; i++) {
        op.fp_add(tbl - N, tbl, tbl, p);
        tbl -= N;
    }
}
#endif

static void initForMont(Op& op, const Unit *p, Mode mode)
{
    const size_t N = op.N;
    {
        mpz_class t = 1, R;
        gmp::getArray(op.one, N, t);
        R = (t << (N * UnitBitSize)) % op.mp;
        t = (R * R) % op.mp;
        gmp::getArray(op.R2, N, t);
        t = (R * R * R) % op.mp;
        gmp::getArray(op.R3, N, t);
    }
    op.rp = getMontgomeryCoeff(p[0]);
    if (mode != FP_XBYAK) return;
#ifdef MCL_USE_XBYAK
    FpGenerator *fg = op.fg;
    if (fg == 0) return;
    fg->init(op);

    if (op.isMont && N <= 4) {
        op.fp_invOp = &invOpForMontC;
        initInvTbl(op);
    }
#endif
}

void Op::init(const std::string& mstr, size_t maxBitSize, Mode mode)
{
    assert(sizeof(mp_limb_t) == sizeof(Unit));
    clear();
    if (maxBitSize > MCL_MAX_BIT_SIZE) {
        throw cybozu::Exception("Op:init:too large maxBitSize") << maxBitSize << MCL_MAX_BIT_SIZE;
    }
    {
        bool isMinus = fp::strToMpzArray(&bitSize, p, maxBitSize, mp, mstr, 0);
        if (isMinus) throw cybozu::Exception("Op:init:mstr is minus") << mstr;
    }
    if (mp == 0) throw cybozu::Exception("Op:init:mstr is zero") << mstr;
/*
    priority : MCL_USE_XBYAK > MCL_USE_LLVM > none
    Xbyak > llvm_mont > llvm > gmp_mont > gmp
*/
#ifdef MCL_USE_XBYAK
    if (mode == fp::FP_AUTO) mode = fp::FP_XBYAK;
    if (mode == fp::FP_XBYAK && bitSize > 521) {
        mode = fp::FP_AUTO;
    }
#else
    if (mode == fp::FP_XBYAK) mode = fp::FP_AUTO;
#endif
#ifdef MCL_USE_LLVM
    if (mode == fp::FP_AUTO) mode = fp::FP_LLVM_MONT;
#else
    if (mode == fp::FP_LLVM || mode == fp::FP_LLVM_MONT) mode = fp::FP_AUTO;
#endif
    isMont = mode == fp::FP_GMP_MONT || mode == fp::FP_LLVM_MONT || mode == fp::FP_XBYAK;
#if 0
    fprintf(stderr, "mode=%s, isMont=%d, maxBitSize=%d"
#ifdef MCL_USE_XBYAK
        " MCL_USE_XBYAK"
#endif
#ifdef MCL_USE_LLVM
        " MCL_USE_LLVM"
#endif
    "\n", ModeToStr(mode), isMont, (int)maxBitSize);
#endif
    isFullBit = (bitSize % UnitBitSize) == 0;

#if defined(MCL_USE_LLVM) || defined(MCL_USE_XBYAK)
    if ((mode == FP_AUTO || mode == FP_LLVM || mode == FP_XBYAK)
        && mp == mpz_class("0xfffffffffffffffffffffffffffffffeffffffffffffffff")) {
        primeMode = PM_NICT_P192;
        isMont = false;
        isFastMod = true;
    }
    if ((mode == FP_AUTO || mode == FP_LLVM || mode == FP_XBYAK)
        && mp == mpz_class("0x1ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff")) {
        primeMode = PM_NICT_P521;
        isMont = false;
        isFastMod = true;
    }
#endif
    N = (bitSize + UnitBitSize - 1) / UnitBitSize;
    switch (N) {
    case 1:  setOp<1>(*this); break;
    case 2:  setOp<2>(*this); break;
    case 3:  setOp<3>(*this); break;
    case 4:  setOp<4>(*this); break; // 256 if 64-bit
    case 5:  setOp<5>(*this); break;
    case 6:  setOp<6>(*this); break;
    case 7:  setOp<7>(*this); break;
    case 8:  setOp<8>(*this); break;
    case 9:  setOp<9>(*this); break; // 576 if 64-bit
#if CYBOZU_OS_BIT == 32 || MCL_MAX_BIT_SIZE == 768
    case 10:  setOp<10>(*this); break;
    case 11:  setOp<11>(*this); break;
    case 12:  setOp<12>(*this); break; // 768 if 64-bit
#endif
#if CYBOZU_OS_BIT == 32
    case 13:  setOp<13>(*this); break;
    case 14:  setOp<14>(*this); break;
    case 15:  setOp<15>(*this); break;
    case 16:  setOp<16>(*this); break;
    case 17:  setOp<17>(*this); break; // 544 if 32-bit
#endif
    default:
        throw cybozu::Exception("Op::init:not:support") << N << mstr;
    }
#ifdef MCL_USE_LLVM
    if (primeMode == PM_NICT_P192) {
        fp_mul = &mcl_fp_mulNIST_P192L;
        fp_sqr = &mcl_fp_sqr_NIST_P192L;
        fpDbl_mod = &mcl_fpDbl_mod_NIST_P192L;
    }
    if (primeMode == PM_NICT_P521) {
        fpDbl_mod = &mcl_fpDbl_mod_NIST_P521L;
    }
#endif
    fp::initForMont(*this, p, mode);
    sq.set(mp);
}

void arrayToStr(std::string& str, const Unit *x, size_t n, int base, bool withPrefix)
{
    switch (base) {
    case 0:
    case 10:
        {
            mpz_class t;
            gmp::setArray(t, x, n);
            gmp::getStr(str, t, 10);
        }
        return;
    case 16:
        mcl::fp::toStr16(str, x, n, withPrefix);
        return;
    case 2:
        mcl::fp::toStr2(str, x, n, withPrefix);
        return;
    default:
        throw cybozu::Exception("fp:arrayToStr:bad base") << base;
    }
}

void copyAndMask(Unit *y, const void *x, size_t xByteSize, const Op& op, bool doMask)
{
    const size_t fpByteSize = sizeof(Unit) * op.N;
    if (xByteSize > fpByteSize) {
        if (!doMask) throw cybozu::Exception("fp:copyAndMask:bad size") << xByteSize << fpByteSize;
        xByteSize = fpByteSize;
    }
    memcpy(y, x, xByteSize);
    memset((char *)y + xByteSize, 0, fpByteSize - xByteSize);
    if (!doMask) {
        if (isGreaterOrEqualArray(y, op.p, op.N)) throw cybozu::Exception("fp:copyAndMask:large x");
        return;
    }
    maskArray(y, op.N, op.bitSize - 1);
    assert(isLessArray(y, op.p, op.N));
}

static bool isInUint64(uint64_t *pv, const fp::Block& b)
{
    assert(fp::UnitBitSize == 32 || fp::UnitBitSize == 64);
    const size_t start = 64 / fp::UnitBitSize;
    for (size_t i = start; i < b.n; i++) {
        if (b.p[i]) return false;
    }
#if CYBOZU_OS_BIT == 32
    *pv = b.p[0] | (uint64_t(b.p[1]) << 32);
#else
    *pv = b.p[0];
#endif
    return true;
}

uint64_t getUint64(bool *pb, const fp::Block& b)
{
    uint64_t v;
    if (isInUint64(&v, b)) {
        if (pb) *pb = true;
        return v;
    }
    if (!pb) {
        std::string str;
        arrayToStr(str, b.p, b.n, 10, false);
        throw cybozu::Exception("fp::getUint64:large value") << str;
    }
    *pb = false;
    return 0;
}

#ifdef _MSC_VER
    #pragma warning(push)
    #pragma warning(disable : 4146)
#endif

int64_t getInt64(bool *pb, fp::Block& b, const fp::Op& op)
{
    bool isNegative = false;
    if (fp::isGreaterOrEqualArray(b.p, op.half, op.N)) {
        op.fp_neg(b.v_, b.p, op.p);
        b.p = b.v_;
        isNegative = true;
    }
    uint64_t v;
    if (fp::isInUint64(&v, b)) {
        const uint64_t c = uint64_t(1) << 63;
        if (isNegative) {
            if (v <= c) { // include c
                if (pb) *pb = true;
                // -1 << 63
                if (v == c) return int64_t(-9223372036854775807ll - 1);
                return int64_t(-v);
            }
        } else {
            if (v < c) { // not include c
                if (pb) *pb = true;
                return int64_t(v);
            }
        }
    }
    if (!pb) {
        std::string str;
        arrayToStr(str, b.p, b.n, 10, false);
        throw cybozu::Exception("fp::getInt64:large value") << str << isNegative;
    }
    *pb = false;
    return 0;
}

#ifdef _WIN32
    #pragma warning(pop)
#endif

void Op::initFp2(int _xi_a)
{
    this->xi_a = _xi_a;
//  if (N * UnitBitSize != 256) throw cybozu::Exception("Op2:init:not support size") << N;
}

} } // mcl::fp