$ mkdir bin $ cd bin $ go tool compile -help -L show full file names in error messages -N disable optimizations -l disable inlining -m print optimization decisions $ go build -gcflags '-N -L -l -m' -o m.exe mycompany.com/course/typedebug $ ls m.exe $ go tool compile -N -L -l -m ../typedebug/typedebug.go $ ls m.exe typedebug3.o $ go tool objdump typedebug3.o TEXT %22%22.SliceIsItNil(SB) gofile../<...>/typedebug.go typedebug3.go:8 0x7fb c644242000 MOVB $0x0, 0x20(SP) typedebug3.go:9 0x800 48837c240800 CMPQ $0x0, 0x8(SP) typedebug3.go:9 0x806 0f94442420 SETE 0x20(SP) typedebug3.go:9 0x80b c3 RET

... $ go tool objdump m.exe | less

Let's look at the results together