Displaying 3 results from an estimated 3 matches for "objsizemax".
2017 Jan 02
2
RFC: Allowing @llvm.objectsize to be more conservative with null.
...unknown> bit needs to be set) or in the middle end. What
is your plan here?
I also found gcc's choice of folding builtin_object_size(0, 2) to 0 and
builtin_object_size(0, 0) to -1 somewhat odd; I'd have expected the
inverse. This follows from the following "intuitive" rules
ObjSizeMax(X) = UMAX(ObjSizeMax(A), ObjSizeMax(B))
ObjSizeMin(X) = UMIN(ObjSizeMin(A), ObjSizeMin(B))
(where X is a value that can either be A or B at runtime)
and that we want to fold
ObjSizeMax(Malloc(N)) = ObjSizeMin(Malloc(N)) = N
However, since Malloc can return null:
ObjSizeMax(Malloc(N)) = UMAX(N,...
2017 Jan 02
2
RFC: Allowing @llvm.objectsize to be more conservative with null.
...>> is your plan here?
>>
>> I also found gcc's choice of folding builtin_object_size(0, 2) to 0 and
>> builtin_object_size(0, 0) to -1 somewhat odd; I'd have expected the
>> inverse. This follows from the following "intuitive" rules
>>
>> ObjSizeMax(X) = UMAX(ObjSizeMax(A), ObjSizeMax(B))
>> ObjSizeMin(X) = UMIN(ObjSizeMin(A), ObjSizeMin(B))
>>
>> (where X is a value that can either be A or B at runtime)
>>
>> and that we want to fold
>>
>> ObjSizeMax(Malloc(N)) = ObjSizeMin(Malloc(N)) = N
>>
>...
2016 Dec 21
2
RFC: Allowing @llvm.objectsize to be more conservative with null.
tl;dr: We'd like to add a bit to @llvm.objectsize to make it optionally be
conservative when it's handed a null pointer.
Happy Wednesday!
We're trying to fix PR23277, which is a bug about how clang+LLVM treat
__builtin_object_size when it's given a null pointer. For compatibility
with GCC, clang would like to be able to hand back a conservative result
(e.g. (size_t)-1), but the