How to view the assembly behind the code using Visual C++?

Specify the /FA switch for the cl compiler. Depending on the value of the switch either only assembly code or high-level code and assembly code is integrated. The filename gets .asm file extension. Here are the supported values:


  • /FA Assembly code; .asm
  • /FAc Machine and assembly code; .cod
  • /FAs Source and assembly code; .asm
  • /FAcs Machine, source, and assembly code; .cod

Additional note: there is big difference between Debug assembler output and Release one. The first one is good to learn how compiler produces assembler code from C++. The second one is good to learn how compiler optimizes various C++ constructs. In this case some C++-to-asm transformations are not obvious.


There are several approaches:

  1. You can normally see assembly code while debugging C++ in visual studio (and eclipse too). For this in Visual Studio put a breakpoint on code in question and when debugger hits it rigth click and find "Go To Assembly" ( or press CTRL+ALT+D )

  2. Second approach is to generate assembly listings while compiling. For this go to project settings -> C/C++ -> Output Files -> ASM List Location and fill in file name. Also select "Assembly Output" to "Assembly With Source Code".

  3. Compile the program and use any third-party debugger. You can use OllyDbg or WinDbg for this. Also you can use IDA (interactive disassembler). But this is hardcore way of doing it.