Commit df0117c8 authored by Nicko van Someren's avatar Nicko van Someren Committed by Paul Sokolovsky
Browse files

py: Added optimised support for 3-argument calls to builtin.pow()

Updated modbuiltin.c to add conditional support for 3-arg calls to
pow() using MICROPY_PY_BUILTINS_POW3 config parameter. Added support in
objint_mpz.c for for optimised implementation.
parent 2486c4ff
......@@ -378,7 +378,14 @@ MP_DEFINE_CONST_FUN_OBJ_1(mp_builtin_ord_obj, mp_builtin_ord);
STATIC mp_obj_t mp_builtin_pow(size_t n_args, const mp_obj_t *args) {
switch (n_args) {
case 2: return mp_binary_op(MP_BINARY_OP_POWER, args[0], args[1]);
default: return mp_binary_op(MP_BINARY_OP_MODULO, mp_binary_op(MP_BINARY_OP_POWER, args[0], args[1]), args[2]); // TODO optimise...
default:
#if !MICROPY_PY_BUILTINS_POW3
mp_raise_msg(&mp_type_NotImplementedError, "3-arg pow() not supported");
#elif MICROPY_LONGINT_IMPL != MICROPY_LONGINT_IMPL_MPZ
return mp_binary_op(MP_BINARY_OP_MODULO, mp_binary_op(MP_BINARY_OP_POWER, args[0], args[1]), args[2]);
#else
return mp_obj_int_pow3(args[0], args[1], args[2]);
#endif
}
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_builtin_pow_obj, 2, 3, mp_builtin_pow);
......
......@@ -490,6 +490,11 @@
#define MICROPY_LONGINT_IMPL (MICROPY_LONGINT_IMPL_NONE)
#endif
// Support for calls to pow() with 3 integer arguments
#ifndef MICROPY_PY_BUILTINS_POW3
#define MICROPY_PY_BUILTINS_POW3 (0)
#endif
#if MICROPY_LONGINT_IMPL == MICROPY_LONGINT_IMPL_LONGLONG
typedef long long mp_longint_impl_t;
#endif
......
......@@ -1395,9 +1395,6 @@ void mpz_pow_inpl(mpz_t *dest, const mpz_t *lhs, const mpz_t *rhs) {
mpz_free(n);
}
#if 0
these functions are unused
/* computes dest = (lhs ** rhs) % mod
can have dest, lhs, rhs the same; mod can't be the same as dest
*/
......@@ -1436,6 +1433,9 @@ void mpz_pow3_inpl(mpz_t *dest, const mpz_t *lhs, const mpz_t *rhs, const mpz_t
mpz_free(n);
}
#if 0
these functions are unused
/* computes gcd(z1, z2)
based on Knuth's modified gcd algorithm (I think?)
gcd(z1, z2) >= 0
......
......@@ -123,6 +123,7 @@ void mpz_add_inpl(mpz_t *dest, const mpz_t *lhs, const mpz_t *rhs);
void mpz_sub_inpl(mpz_t *dest, const mpz_t *lhs, const mpz_t *rhs);
void mpz_mul_inpl(mpz_t *dest, const mpz_t *lhs, const mpz_t *rhs);
void mpz_pow_inpl(mpz_t *dest, const mpz_t *lhs, const mpz_t *rhs);
void mpz_pow3_inpl(mpz_t *dest, const mpz_t *lhs, const mpz_t *rhs, const mpz_t *mod);
void mpz_and_inpl(mpz_t *dest, const mpz_t *lhs, const mpz_t *rhs);
void mpz_or_inpl(mpz_t *dest, const mpz_t *lhs, const mpz_t *rhs);
void mpz_xor_inpl(mpz_t *dest, const mpz_t *lhs, const mpz_t *rhs);
......
......@@ -66,5 +66,6 @@ mp_obj_t mp_obj_int_abs(mp_obj_t self_in);
mp_obj_t mp_obj_int_unary_op(mp_uint_t op, mp_obj_t o_in);
mp_obj_t mp_obj_int_binary_op(mp_uint_t op, mp_obj_t lhs_in, mp_obj_t rhs_in);
mp_obj_t mp_obj_int_binary_op_extra_cases(mp_uint_t op, mp_obj_t lhs_in, mp_obj_t rhs_in);
mp_obj_t mp_obj_int_pow3(mp_obj_t base, mp_obj_t exponent, mp_obj_t modulus);
#endif // __MICROPY_INCLUDED_PY_OBJINT_H__
......@@ -326,6 +326,39 @@ mp_obj_t mp_obj_int_binary_op(mp_uint_t op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
}
}
#if MICROPY_PY_BUILTINS_POW3
STATIC mpz_t *mp_mpz_for_int(mp_obj_t arg, mpz_t *temp) {
if (MP_OBJ_IS_SMALL_INT(arg)) {
mpz_init_from_int(temp, MP_OBJ_SMALL_INT_VALUE(arg));
return temp;
} else {
mp_obj_int_t *arp_p = MP_OBJ_TO_PTR(arg);
return &(arp_p->mpz);
}
}
mp_obj_t mp_obj_int_pow3(mp_obj_t base, mp_obj_t exponent, mp_obj_t modulus) {
if (!MP_OBJ_IS_INT(base) || !MP_OBJ_IS_INT(exponent) || !MP_OBJ_IS_INT(modulus)) {
mp_raise_TypeError("pow() with 3 arguments requires integers");
} else {
mp_obj_t result = mp_obj_new_int_from_ull(0); // Use the _from_ull version as this forces an mpz int
mp_obj_int_t *res_p = (mp_obj_int_t *) MP_OBJ_TO_PTR(result);
mpz_t l_temp, r_temp, m_temp;
mpz_t *lhs = mp_mpz_for_int(base, &l_temp);
mpz_t *rhs = mp_mpz_for_int(exponent, &r_temp);
mpz_t *mod = mp_mpz_for_int(modulus, &m_temp);
mpz_pow3_inpl(&(res_p->mpz), lhs, rhs, mod);
if (lhs == &l_temp) { mpz_deinit(lhs); }
if (rhs == &r_temp) { mpz_deinit(rhs); }
if (mod == &m_temp) { mpz_deinit(mod); }
return result;
}
}
#endif
mp_obj_t mp_obj_new_int(mp_int_t value) {
if (MP_SMALL_INT_FITS(value)) {
return MP_OBJ_NEW_SMALL_INT(value);
......
......@@ -8,4 +8,32 @@ print(pow(3, 8))
# 3 arg version
print(pow(3, 4, 7))
print(pow(555557, 1000002, 1000003))
# 3 arg pow is defined to only work on integers
try:
print(pow("x", 5, 6))
except TypeError:
print("TypeError expected")
try:
print(pow(4, "y", 6))
except TypeError:
print("TypeError expected")
try:
print(pow(4, 5, "z"))
except TypeError:
print("TypeError expected")
# Tests for 3 arg pow with large values
# This value happens to be prime
x = 0xd48a1e2a099b1395895527112937a391d02d4a208bce5d74b281cf35a57362502726f79a632f063a83c0eba66196712d963aa7279ab8a504110a668c0fc38a7983c51e6ee7a85cae87097686ccdc359ee4bbf2c583bce524e3f7836bded1c771a4efcb25c09460a862fc98e18f7303df46aaeb34da46b0c4d61d5cd78350f3edb60e6bc4befa712a849
y = 0x3accf60bb1a5365e4250d1588eb0fe6cd81ad495e9063f90880229f2a625e98c59387238670936afb2cafc5b79448e4414d6cd5e9901aa845aa122db58ddd7b9f2b17414600a18c47494ed1f3d49d005a5
print(hex(pow(2, 200, x))) # Should not overflow, just 1 << 200
print(hex(pow(2, x-1, x))) # Should be 1, since x is prime
print(hex(pow(y, x-1, x))) # Should be 1, since x is prime
print(hex(pow(y, y-1, x))) # Should be a 'big value'
print(hex(pow(y, y-1, y))) # Should be a 'big value'
......@@ -80,6 +80,7 @@
#define MICROPY_PY_BUILTINS_FROZENSET (1)
#define MICROPY_PY_BUILTINS_COMPILE (1)
#define MICROPY_PY_BUILTINS_NOTIMPLEMENTED (1)
#define MICROPY_PY_BUILTINS_POW3 (1)
#define MICROPY_PY_MICROPYTHON_MEM_INFO (1)
#define MICROPY_PY_ALL_SPECIAL_METHODS (1)
#define MICROPY_PY_ARRAY_SLICE_ASSIGN (1)
......
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