diff options
Diffstat (limited to 'src/stdlib/integers.c')
| -rw-r--r-- | src/stdlib/integers.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/src/stdlib/integers.c b/src/stdlib/integers.c index 7c623663..018798ec 100644 --- a/src/stdlib/integers.c +++ b/src/stdlib/integers.c @@ -359,6 +359,19 @@ public OptionalInt_t Int$sqrt(Int_t i) return Int$from_mpz(result); } +public bool Int$get_bit(Int_t x, Int_t bit_index) +{ + mpz_t i; + mpz_init_set_int(i, x); + if (Int$compare_value(bit_index, I(1)) < 0) + fail("Invalid bit index (expected 1 or higher): ", bit_index); + if (Int$compare_value(bit_index, Int$from_int64(INT64_MAX)) > 0) + fail("Bit index is too large! ", bit_index); + + int is_bit_set = mpz_tstbit(i, (mp_bitcnt_t)(Int64$from_int(bit_index, true)-1)); + return (bool)is_bit_set; +} + typedef struct { OptionalInt_t current, last; Int_t step; @@ -620,6 +633,13 @@ public void Int32$deserialize(FILE *in, void *outval, List_t *pointers, const Ty } \ return bit_list; \ } \ + public bool KindOfInt ## $get_bit(c_type x, Int_t bit_index) { \ + if (Int$compare_value(bit_index, I(1)) < 0) \ + fail("Invalid bit index (expected 1 or higher): ", bit_index); \ + if (Int$compare_value(bit_index, Int$from_int64(sizeof(c_type)*8)) > 0) \ + fail("Bit index is too large! There are only ", sizeof(c_type)*8, " bits, but index is: ", bit_index); \ + return ((x & (c_type)(1L << (Int64$from_int(bit_index, true)-1L))) != 0); \ + } \ typedef struct { \ Optional##KindOfInt##_t current, last; \ KindOfInt##_t step; \ |