|
From: Tom H. <to...@co...> - 2005-10-18 09:25:12
|
In message <200...@gm...>
Dirk Mueller <dm...@gm...> wrote:
> On Tuesday 18 October 2005 00:48, Julian Seward wrote:
>
>> That said .. if the cases you show are real problems in real code,
>> and not just example test cases, then I am interested in investigating
>> further.
>
> well, the xor testcase failure is interesting, because that is indeed a real
> bug (we used to do defined-ness tracking at bitlevel for xor, while we never
> did that for multiplies so far).
There is (or was) a special case for xor of a register with itself
which caused memcheck to consider the whole thing as defined because
compilers use that trick to generate zero.
Other than that I think xor just marks an output bit as defined if
both input bits are defined as the result of xor always depends on
both inputs.
Tom
--
Tom Hughes (to...@co...)
http://www.compton.nu/
|