How can I see the assembly code that is generated by a gcc (any flavor) compiler for a C/C++ program?

Question

I am trying to optimize a lot of multiplications and pointer arithmetics and would like to see what the compiler does underneath when I put in optimization flags.

--Edit--

How to restrict it to a specific function or a code block?

--Edit_2--

How to let gcc generate a less verbose assembly-code?

Answer 1

Add -S switch to your command line.

Edit: Do not forget that it will place the assembly to the files you specified under -o switch.

Answer 2

How to restrict it to a specific function or a code block?

Put that function in a separate source file (and use a different command-line parameter for that one source file).

Answer 3

You could also run that program in a debugger like gdb and use a disassembly view. In gdb you could use the command disass/m to view the assembly mixed with the C code on the current location.

Answer 4

您可以停止在Visual Studio调试器中的断点处编程并执行“显示汇编”，甚至一次一步地执行它。