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py: Fix some bugs in mpz; add mpz_from_ll and mpz_set_from_ll.

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A couple of bugs in mpn_shl, and overflow bug in mpz_set_from_int.
This commit is contained in:
Damien George 2014-03-12 15:36:06 +00:00
parent 8bfec2b538
commit bb4a43f35c
2 changed files with 38 additions and 5 deletions
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40
py/mpz.c
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@ -51,6 +51,9 @@ STATIC int mpn_cmp(const mpz_dig_t *idig, uint ilen, const mpz_dig_t *jdig, uint
STATIC uint mpn_shl(mpz_dig_t *idig, mpz_dig_t *jdig, uint jlen, uint n) {
uint n_whole = (n + DIG_SIZE - 1) / DIG_SIZE;
uint n_part = n % DIG_SIZE;
if (n_part == 0) {
n_part = DIG_SIZE;
}
// start from the high end of the digit arrays
idig += jlen + n_whole - 1;
@ -67,7 +70,7 @@ STATIC uint mpn_shl(mpz_dig_t *idig, mpz_dig_t *jdig, uint jlen, uint n) {
// store remaining bits
*idig = d >> (DIG_SIZE - n_part);
idig -= n_whole - 1;
memset(idig, 0, n_whole - 1);
memset(idig, 0, (n_whole - 1) * sizeof(mpz_dig_t));
// work out length of result
jlen += n_whole;
@ -412,6 +415,12 @@ mpz_t *mpz_from_int(machine_int_t val) {
return z;
}
mpz_t *mpz_from_ll(long long val) {
mpz_t *z = mpz_zero();
mpz_set_from_ll(z, val);
return z;
}
mpz_t *mpz_from_str(const char *str, uint len, bool neg, uint base) {
mpz_t *z = mpz_zero();
mpz_set_from_str(z, str, len, neg, base);
@ -469,17 +478,38 @@ void mpz_set(mpz_t *dest, const mpz_t *src) {
void mpz_set_from_int(mpz_t *z, machine_int_t val) {
mpz_need_dig(z, MPZ_NUM_DIG_FOR_INT);
machine_uint_t uval;
if (val < 0) {
z->neg = 1;
val = -val;
uval = -val;
} else {
z->neg = 0;
uval = val;
}
z->len = 0;
while (val > 0) {
z->dig[z->len++] = val & DIG_MASK;
val >>= DIG_SIZE;
while (uval > 0) {
z->dig[z->len++] = uval & DIG_MASK;
uval >>= DIG_SIZE;
}
}
void mpz_set_from_ll(mpz_t *z, long long val) {
mpz_need_dig(z, MPZ_NUM_DIG_FOR_LL);
unsigned long long uval;
if (val < 0) {
z->neg = 1;
uval = -val;
} else {
z->neg = 0;
uval = val;
}
z->len = 0;
while (uval > 0) {
z->dig[z->len++] = uval & DIG_MASK;
uval >>= DIG_SIZE;
}
}

3
py/mpz.h
View File

@ -12,6 +12,7 @@ typedef struct _mpz_t {
#define MPZ_DIG_SIZE (15) // see mpn_div for why this needs to be at most 15
#define MPZ_NUM_DIG_FOR_INT (sizeof(machine_int_t) * 8 / MPZ_DIG_SIZE + 1)
#define MPZ_NUM_DIG_FOR_LL (sizeof(long long) * 8 / MPZ_DIG_SIZE + 1)
// convenience macro to declare an mpz with a digit array from the stack, initialised by an integer
#define MPZ_CONST_INT(z, val) mpz_t z; mpz_dig_t z ## _digits[MPZ_NUM_DIG_FOR_INT]; mpz_init_fixed_from_int(&z, z_digits, MPZ_NUM_DIG_FOR_INT, val);
@ -23,6 +24,7 @@ void mpz_deinit(mpz_t *z);
mpz_t *mpz_zero();
mpz_t *mpz_from_int(machine_int_t i);
mpz_t *mpz_from_ll(long long i);
mpz_t *mpz_from_str(const char *str, uint len, bool neg, uint base);
void mpz_free(mpz_t *z);
@ -30,6 +32,7 @@ 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, machine_int_t src);
void mpz_set_from_ll(mpz_t *z, long long i);
uint mpz_set_from_str(mpz_t *z, const char *str, uint len, bool neg, uint base);
bool mpz_is_zero(const mpz_t *z);