Microsoft Specific

The presence of an __asm block in a function affects optimization in several ways. First, the compiler doesn't try to optimize the __asm block itself. What you write in assembly language is exactly what you get. Second, the presence of an __asm block affects register variable storage. The compiler avoids enregistering variables across an __asm block if the register's contents would be changed by the __asm block. Finally, some other function-wide optimizations will be affected by the inclusion of assembly language in a function.

END Microsoft Specific

Inline Assembler