diff options
| -rw-r--r-- | Objects/longobject.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/Objects/longobject.c b/Objects/longobject.c index 2e8ef19..858be50 100644 --- a/Objects/longobject.c +++ b/Objects/longobject.c @@ -1786,12 +1786,11 @@ least 2*shift+2 digits, and there's not obviously enough room for the extra two bits. We need a sharper analysis in this case. The major laziness was in the "the same is true of ah+al" clause: ah+al can't actually have shift+1 digits + 1 bit unless bsize is odd and asize == bsize. In that -case, we actually have (2*shift+1)*2 - shift = 3*shift + 2 allocated digits -remaining, and that's obviously plenty to hold 2*shift + 2 digits + 2 bits. +case, we actually have (2*shift+1)*2 - shift = 3*shift+2 allocated digits +remaining, and that's obviously plenty to hold 2*shift+2 digits + 2 bits. Else (bsize is odd and asize < bsize) ah and al each have at most shift digits, so ah+al has at most shift digits + 1 bit, and (ah+al)*(bh+bl) has at most -2*shift+1 digits + 2 bits, and again 2*shift+2 digits + 2 bits is -enough to hold it. +2*shift+1 digits + 2 bits, and again 2*shift+2 digits is enough to hold it. */ /* b has at least twice the digits of a, and a is big enough that Karatsuba |