Issue in Visual Studio 2012 release build

Question

I have a program which runs fine in debug build , but when I run the same with release build my program crashes at below lines

char* iter=ptr; //ptr is already initialized

char* iter = (char*) ALIGN (iter); // crashes here

I have a preprocessor definition like below for ALIGN

Type-casting of pointers to long.

#define SIZE       8L
#define ALIGN(ptr)  \
    (((__int64)ptr & (~(SIZE - 1L))) + SIZE) \

       : (__int64)ptr)

It only gives problem when I run this program in Visual Studio 2012 in windows 8 but works fine with Visual studio 2012 in windows 7 . I dont know what flags(may be optimization flags) we have to set or unset for my program to work in release mode.
Please suggest me a solution

Answer 1

What you're doing is, basically

char* iter = iter;

If the variable iter is declared as a local variable, its contents will be indeterminate, and using that value will lead to undefined behavior. That includes using that value to initialize itself.