Commit 6e0b6d02 authored by David Steinberg's avatar David Steinberg Committed by Damien George
Browse files

py: Fix float to int conversion for large exponents.

parent ffc96a90
......@@ -590,6 +590,14 @@ mpz_t *mpz_from_ll(long long val, bool is_signed) {
return z;
}
#if MICROPY_PY_BUILTINS_FLOAT
mpz_t *mpz_from_float(mp_float_t val) {
mpz_t *z = mpz_zero();
mpz_set_from_float(z, val);
return z;
}
#endif
mpz_t *mpz_from_str(const char *str, mp_uint_t len, bool neg, mp_uint_t base) {
mpz_t *z = mpz_zero();
mpz_set_from_str(z, str, len, neg, base);
......@@ -682,6 +690,80 @@ void mpz_set_from_ll(mpz_t *z, long long val, bool is_signed) {
}
}
#if MICROPY_PY_BUILTINS_FLOAT
void mpz_set_from_float(mpz_t *z, mp_float_t src) {
#if MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_DOUBLE
#define EXP_SZ 11
#define FRC_SZ 52
typedef uint64_t mp_float_int_t;
#else
#define EXP_SZ 8
#define FRC_SZ 23
typedef uint32_t mp_float_int_t;
#endif
union {
mp_float_t f;
struct { mp_float_int_t frc:FRC_SZ, exp:EXP_SZ, sgn:1; } p;
} u = {src};
z->neg = u.p.sgn;
if (u.p.exp == 0) {
// value == 0 || value < 1
mpz_init_zero(z);
} else if (u.p.exp == ((1 << EXP_SZ) - 1)) {
// inf or NaN
#if 0
// TODO: this probably isn't the right place to throw an exception
if(u.p.frc == 0)
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_OverflowError, "cannot convert float infinity to integer"));
else
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "cannot convert float NaN to integer"));
#else
mpz_init_zero(z);
#endif
} else {
const int adj_exp = (int)u.p.exp - ((1 << (EXP_SZ - 1)) - 1);
if (adj_exp < 0) {
// value < 1 , truncates to 0
mpz_init_zero(z);
} else if (adj_exp == 0) {
// 1 <= value < 2 , so truncates to 1
mpz_init_from_int(z, 1);
} else {
// 2 <= value
const int dig_cnt = (adj_exp + 1 + (DIG_SIZE - 1)) / DIG_SIZE;
const unsigned int rem = adj_exp % DIG_SIZE;
int dig_ind, shft;
mp_float_int_t frc = u.p.frc | ((mp_float_int_t)1 << FRC_SZ);
if (adj_exp < FRC_SZ) {
shft = 0;
dig_ind = 0;
frc >>= FRC_SZ - adj_exp;
} else {
shft = (rem - FRC_SZ) % DIG_SIZE;
dig_ind = (adj_exp - FRC_SZ) / DIG_SIZE;
}
mpz_need_dig(z, dig_cnt);
z->len = dig_cnt;
if (dig_ind != 0) {
memset(z->dig, 0, dig_ind * sizeof(mpz_dig_t));
}
if (shft != 0) {
z->dig[dig_ind++] = (frc << shft) & DIG_MASK;
frc >>= DIG_SIZE - shft;
}
while (dig_ind != dig_cnt) {
z->dig[dig_ind++] = frc & DIG_MASK;
frc >>= DIG_SIZE;
}
}
}
}
#undef EXP_SZ
#undef FRC_SZ
#endif
// returns number of bytes from str that were processed
mp_uint_t mpz_set_from_str(mpz_t *z, const char *str, mp_uint_t len, bool neg, mp_uint_t base) {
assert(base < 36);
......
......@@ -85,6 +85,9 @@ void mpz_deinit(mpz_t *z);
mpz_t *mpz_zero(void);
mpz_t *mpz_from_int(mp_int_t i);
mpz_t *mpz_from_ll(long long i, bool is_signed);
#if MICROPY_PY_BUILTINS_FLOAT
mpz_t *mpz_from_float(mp_float_t i);
#endif
mpz_t *mpz_from_str(const char *str, mp_uint_t len, bool neg, mp_uint_t base);
void mpz_free(mpz_t *z);
......@@ -93,6 +96,9 @@ mpz_t *mpz_clone(const mpz_t *src);
void mpz_set(mpz_t *dest, const mpz_t *src);
void mpz_set_from_int(mpz_t *z, mp_int_t src);
void mpz_set_from_ll(mpz_t *z, long long i, bool is_signed);
#if MICROPY_PY_BUILTINS_FLOAT
void mpz_set_from_float(mpz_t *z, mp_float_t src);
#endif
mp_uint_t mpz_set_from_str(mpz_t *z, const char *str, mp_uint_t len, bool neg, mp_uint_t base);
bool mpz_is_zero(const mpz_t *z);
......
......@@ -298,9 +298,9 @@ mp_obj_t mp_obj_new_int_from_uint(mp_uint_t value) {
#if MICROPY_PY_BUILTINS_FLOAT
mp_obj_t mp_obj_new_int_from_float(mp_float_t val) {
// TODO: This doesn't handle numbers with large exponent
long long i = MICROPY_FLOAT_C_FUN(trunc)(val);
return mp_obj_new_int_from_ll(i);
mp_obj_int_t *o = mp_obj_int_new_mpz();
mpz_set_from_float(&o->mpz, val);
return o;
}
#endif
......
# This case occurs with time.time() values
print(int(1418774543.))
# TODO: General case with large exponent
#print(int(2.**100))
print(int(2.**100))
print("%d" % 1418774543.)
# TODO: General case with large exponent
#print("%d" % 2.**100)
print("%d" % 2.**100)
testpass = True
for i in range(0,1024):
bitcnt = len(bin(int(2.**i))) - 3;
if i != bitcnt:
print('fail: 2**%u was %u bits long' % (i, bitcnt));
testpass = False
print("power of 2 test: %s" % (testpass and 'passed' or 'failed'))
testpass = True
for i in range(0,23):
digcnt = len(str(int(10.**i))) - 1;
if i != digcnt:
print('fail: 10**%u was %u digits long' % (i, digcnt));
testpass = False
print("power of 10 test: %s" % (testpass and 'passed' or 'failed'))
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