Assembler (Inline): Overview
Assembly language serves many purposes, such as improving program speed, reducing memory needs, and controlling hardware. You can use the inline assembler to embed assembly-language instructions directly in your C and C++ source programs without extra assembly and link steps. The inline assembler is built into the compiler — you don't need a separate assembler such as the Microsoft Macro Assembler (MASM).
Note Programs with inline assembler code are not fully portable to other hardware platforms. If you are designing for portability, avoid using inline assembler.