static Variant HHVM_FUNCTION(bcpowmod, const String& left, const String& right,
const String& modulus, int64_t scale /* = -1 */) {
if (scale < 0) scale = BCG(bc_precision);
bc_num first, second, mod, result;
bc_init_num(&first);
bc_init_num(&second);
bc_init_num(&mod);
bc_init_num(&result);
SCOPE_EXIT {
bc_free_num(&first);
bc_free_num(&second);
bc_free_num(&mod);
bc_free_num(&result);
};
php_str2num(&first, (char*)left.data());
php_str2num(&second, (char*)right.data());
php_str2num(&mod, (char*)modulus.data());
if (bc_raisemod(first, second, mod, &result, scale) == -1) {
return false;
}
if (result->n_scale > scale) {
result->n_scale = scale;
}
String ret(bc_num2str(result), AttachString);
return ret;
}
Variant f_bcpowmod(CStrRef left, CStrRef right, CStrRef modulus,
int64 scale /* = -1 */) {
if (scale < 0) scale = BCG(bc_precision);
bc_num first, second, mod, result;
bc_init_num(&first);
bc_init_num(&second);
bc_init_num(&mod);
bc_init_num(&result);
php_str2num(&first, (char*)left.data());
php_str2num(&second, (char*)right.data());
php_str2num(&mod, (char*)modulus.data());
if (bc_raisemod(first, second, mod, &result, scale) == -1) {
return false;
}
if (result->n_scale > scale) {
result->n_scale = scale;
}
String ret(bc_num2str(result), AttachString);
bc_free_num(&first);
bc_free_num(&second);
bc_free_num(&mod);
bc_free_num(&result);
return ret;
}
// raise number by power, modulus modulus
BigNumber BigNumber::powMod (const BigNumber power, const BigNumber & modulus) const
{
BigNumber result;
bc_raisemod (num_, power.num_, modulus.num_, &result.num_, scale_);
return result;
}
