I use erts_debug:df/1 to have a look the .dis file
but it’s nothing out to the .dis( OTP24, on window or wls) erts_debug:disassemble/1 seems always return false
I will check how compiler optimize code by using .S file
And I want to know more about how .P, .E, .S, .core, .dis file help us
When running the JIT it is no longer possible to dump the disassembly of a module after it has been loaded. You now have to start the emulator using the +JDdump true flag and it will dump the x86/arm assembly to disk for all loaded modules.
If you want to use erts_debug:df/1 you have to compile a non-JIT emulator.