steakhal added a comment.
In D113753#3156270 <https://reviews.llvm.org/D113753#3156270>, @bjope wrote:
> This seem to cause some weird results.
>
> Given this input:
>
> bar(short k) {
> k++;
> for (short f = 0; f < k; f++)
> ;
> (long)k << 16;
> }
>
> we get
>
> > clang --analyze --target=x86_64 'bbi-63538.c'
> bbi-63538.c:5:11: warning: The result of the left shift is undefined due to
> shifting '1' by '16', which is unrepresentable in the unsigned version of the
> return type 'long' [core.UndefinedBinaryOperatorResult]
> (long)k << 16;
> ~~~~~~~ ^
> bbi-63538.c:5:11: warning: The result of the left shift is undefined due to
> shifting '2' by '16', which is unrepresentable in the unsigned version of the
> return type 'long' [core.UndefinedBinaryOperatorResult]
> (long)k << 16;
> ~~~~~~~ ^
> bbi-63538.c:5:11: warning: The result of the left shift is undefined due to
> shifting '3' by '16', which is unrepresentable in the unsigned version of the
> return type 'long' [core.UndefinedBinaryOperatorResult]
> (long)k << 16;
> ~~~~~~~ ^
> 3 warnings generated.
Good catch @bjope !
Here is an example without the loop: https://godbolt.org/z/z3rqMz4bs
We'll have a closer look.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D113753/new/
https://reviews.llvm.org/D113753
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
