Boost C++ Libraries: Ticket #8126: multiprecision, incorrect sign

component changed; owner set

Wed, 20 Feb 2013 21:44:29 GMT

owner set to John Maddock
component None → multiprecision

status changed; resolution set

John Maddock — Thu, 21 Feb 2013 13:05:45 GMT

status new → closed
resolution → fixed

(In [83060]) Fix sign of division in cpp_int when the values are small enough to fit in a double_limb_type. Add test cases for above. Fixes #8126.

Thu, 21 Feb 2013 14:03:59 GMT

You fixed that case but here is another one that stil doesn't work.

    cpp_int a("-26607734784073568386365259775");
    cpp_int b("8589934592");
    a = a/b;
    std::cout << a; // outputs 3097548007973652377

status changed; resolution deleted

John Maddock — Thu, 21 Feb 2013 18:34:06 GMT

status closed → reopened
resolution fixed

Not only that one actually, there's a whole bunch of divide and and modulus operators that don't behave correctly when source and destination are the same.

Testing some new fixes now...

status changed; resolution set

John Maddock — Fri, 22 Feb 2013 10:37:38 GMT

status reopened → closed
resolution → fixed

(In [83080]) Fix bug in subtraction of a limb_type. Fix bug in division/modulus algorithms that results in incorrect sign when source and destination overlap. Tweak performance of GCD algorithms. Add test cases for bug reports. Fixes #8133. Fixes #8126.