Displaying 3 results from an estimated 3 matches for "accesstop1".
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accesstop0
2017 Apr 11
2
[RFC] Design of a TBAA sanitizer
...gt; digress). You can also recreate the pattern with realloc.
> > >
> >
> > In both of your examples there is no place in the program where both P0
> and
> > P1 are live simultaneously,
> > i.e. no analysis path is expected to query MayAlias(AccessToP0,
> > AccessToP1). No?
>
> I may be misunderstanding what you meant, but I don't see why not.
>
> Say you had (all values are SSA values):
>
> %p0 = malloc()
> store i32 0, i32* %p0 // S0
> free(%p0)
> %p1 = malloc()
> store i32 1, i32* %p1 // S1
>
> and some pass wanted to...
2017 Apr 11
2
[RFC] Design of a TBAA sanitizer
...s issue here in LLVM's semantics, but I don't want to
> digress). You can also recreate the pattern with realloc.
>
In both of your examples there is no place in the program where both P0 and
P1 are live simultaneously,
i.e. no analysis path is expected to query MayAlias(AccessToP0,
AccessToP1). No?
>
> The same problem exists with constant addresses. LLVM states that
> constant locations are noalias with themselves, and you again have the
> "noalias does not imply pointer inequality" problem.
>
That won't even have to be special cased, because if we emit...
2017 Apr 11
2
[RFC] Design of a TBAA sanitizer
Hi Kostya,
On April 11, 2017 at 1:30:10 PM, Kostya Serebryany (kcc at google.com) wrote:
> of course, but accesses are done via pointers, and if TBAA queries
> MayAlias(AccessViaP1, AccessViaP2)
> there should (??) be a point in the IR where both P1 and P2 exist together
> and can be compared.
That may not be possible (though I'm second guessing what exactly you
have in mind so