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Implementation of SDIV & SMOD with gmp

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This commit is contained in:
Paweł Bylica 2015-01-19 18:09:55 +01:00
parent a2822a37bf
commit b3bad23757
1 changed files with 49 additions and 6 deletions
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55
libevmjit/Arith256.cpp
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@ -180,6 +180,14 @@ namespace
const auto nLimbs = sizeof(i256) / sizeof(mp_limb_t); const auto nLimbs = sizeof(i256) / sizeof(mp_limb_t);
// FIXME: Not thread-safe
static mp_limb_t mod_limbs[] = {0, 0, 0, 0, 1};
static_assert(sizeof(mod_limbs) / sizeof(mod_limbs[0]) == nLimbs + 1, "mp_limb_t size mismatch");
static const mpz_t mod{nLimbs + 1, nLimbs + 1, &mod_limbs[0]};
static mp_limb_t tmp_limbs[nLimbs + 2];
static mpz_t tmp{nLimbs + 2, 0, &tmp_limbs[0]};
int countLimbs(i256 const* _n) int countLimbs(i256 const* _n)
{ {
static const auto limbsInWord = sizeof(_n->a) / sizeof(mp_limb_t); static const auto limbsInWord = sizeof(_n->a) / sizeof(mp_limb_t);
@ -195,6 +203,25 @@ namespace
if (_n->a != 0) return l; if (_n->a != 0) return l;
return 0; return 0;
} }
void u2s(mpz_t _u)
{
if (static_cast<std::make_signed<mp_limb_t>::type>(_u->_mp_d[nLimbs - 1]) < 0)
{
mpz_sub(tmp, mod, _u);
mpz_set(_u, tmp);
_u->_mp_size = -_u->_mp_size;
}
}
void s2u(mpz_t _s)
{
if (_s->_mp_size < 0)
{
mpz_add(tmp, mod, _s);
mpz_set(_s, tmp);
}
}
} }
} }
@ -246,16 +273,32 @@ extern "C"
EXPORT void arith_sdiv(i256* _arg1, i256* _arg2, i256* o_result) EXPORT void arith_sdiv(i256* _arg1, i256* _arg2, i256* o_result)
{ {
auto arg1 = llvm2eth(*_arg1); *o_result = {};
auto arg2 = llvm2eth(*_arg2); if (isZero(_arg2))
*o_result = eth2llvm(arg2 == 0 ? arg2 : s2u(u2s(arg1) / u2s(arg2))); return;
mpz_t x{nLimbs, countLimbs(_arg1), reinterpret_cast<mp_limb_t*>(_arg1)};
mpz_t y{nLimbs, countLimbs(_arg2), reinterpret_cast<mp_limb_t*>(_arg2)};
mpz_t z{nLimbs, 0, reinterpret_cast<mp_limb_t*>(o_result)};
u2s(x);
u2s(y);
mpz_tdiv_q(z, x, y);
s2u(z);
} }
EXPORT void arith_smod(i256* _arg1, i256* _arg2, i256* o_result) EXPORT void arith_smod(i256* _arg1, i256* _arg2, i256* o_result)
{ {
auto arg1 = llvm2eth(*_arg1); *o_result = {};
auto arg2 = llvm2eth(*_arg2); if (isZero(_arg2))
*o_result = eth2llvm(arg2 == 0 ? arg2 : s2u(u2s(arg1) % u2s(arg2))); return;
mpz_t x{nLimbs, countLimbs(_arg1), reinterpret_cast<mp_limb_t*>(_arg1)};
mpz_t y{nLimbs, countLimbs(_arg2), reinterpret_cast<mp_limb_t*>(_arg2)};
mpz_t z{nLimbs, 0, reinterpret_cast<mp_limb_t*>(o_result)};
u2s(x);
u2s(y);
mpz_tdiv_r(z, x, y);
s2u(z);
} }
EXPORT void arith_exp(i256* _arg1, i256* _arg2, i256* o_result) EXPORT void arith_exp(i256* _arg1, i256* _arg2, i256* o_result)