diff options
Diffstat (limited to 'Include')
| -rw-r--r-- | Include/longintrepr.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/Include/longintrepr.h b/Include/longintrepr.h index 9ed1fe7..254076e 100644 --- a/Include/longintrepr.h +++ b/Include/longintrepr.h @@ -15,7 +15,8 @@ extern "C" { (at most (BASE-1)*(2*BASE+1) == MASK*(2*MASK+3)). Also, x_sub assumes that 'digit' is an unsigned type, and overflow is handled by taking the result mod 2**N for some N > SHIFT. - And, at some places it is assumed that MASK fits in an int, as well. */ + And, at some places it is assumed that MASK fits in an int, as well. + long_pow() requires that SHIFT be divisible by 5. */ typedef unsigned short digit; typedef unsigned int wdigit; /* digit widened to parameter size */ @@ -27,6 +28,10 @@ typedef BASE_TWODIGITS_TYPE stwodigits; /* signed variant of twodigits */ #define BASE ((digit)1 << SHIFT) #define MASK ((int)(BASE - 1)) +#if SHIFT % 5 != 0 +#error "longobject.c requires that SHIFT be divisible by 5" +#endif + /* Long integer representation. The absolute value of a number is equal to SUM(for i=0 through abs(ob_size)-1) ob_digit[i] * 2**(SHIFT*i) |