[Bug c/85923] invalid code generation when incrementing pointer referenced by pointer

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85923

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |INVALID

--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
This is because you are violating strict-aliasing rules by accessing *Ptr
both via char * and unsigned char * which are two different pointer types.

Declaring Ptr as [const] unsigned char * or compiling with -fno-strict-aliasing
fixes your code.