Golang : Convert source code to assembly language

If you ever have the urge to convert your Golang source code to assembly language, check out this online tool :

http://go.godbolt.org/

One draw back about http://go.godbolt.org/ is that it cannot disassemble third-parties packges (such as those in the import block ).

To get full assembly source code from your Golang code, use this command go build -gcflags -S

For example :

 package main

 import "fmt"

 func main() {

 fmt.Println("Hello World!");

 }

go build -gcflags -S hello.go

will produce :

 # command-line-arguments
 "".main t=1 size=240 value=0 args=0x0 locals=0x78
 0x0000 00000 (/root/hello.go:5) TEXT "".main+0(SB),$120-0
 0x0000 00000 (/root/hello.go:5) MOVQ (TLS),CX
 0x0009 00009 (/root/hello.go:5) CMPQ SP,16(CX)
 0x000d 00013 (/root/hello.go:5) JHI ,22
 0x000f 00015 (/root/hello.go:5) CALL ,runtime.morestack_noctxt(SB)
 0x0014 00020 (/root/hello.go:5) JMP ,0
 0x0016 00022 (/root/hello.go:5) SUBQ $120,SP
 0x001a 00026 (/root/hello.go:5) FUNCDATA $0,gclocals·73423680ca5f2d7df4fe760a82d507fb+0(SB)
 0x001a 00026 (/root/hello.go:5) FUNCDATA $1,gclocals·1eb9d8ec9969f1d922533aa863dff6f6+0(SB)
 0x001a 00026 (/root/hello.go:7) LEAQ go.string."Hello World!"+0(SB),BX
 0x0021 00033 (/root/hello.go:7) MOVQ (BX),BP
 0x0024 00036 (/root/hello.go:7) MOVQ BP,"".autotmp_0001+64(SP)
 0x0029 00041 (/root/hello.go:7) MOVQ 8(BX),BP
 0x002d 00045 (/root/hello.go:7) MOVQ BP,"".autotmp_0001+72(SP)
 0x0032 00050 (/root/hello.go:7) LEAQ "".autotmp_0000+80(SP),BX
 0x0037 00055 (/root/hello.go:7) MOVQ $0,(BX)
 0x003e 00062 (/root/hello.go:7) MOVQ $0,8(BX)
 0x0046 00070 (/root/hello.go:7) LEAQ "".autotmp_0000+80(SP),BX
 0x004b 00075 (/root/hello.go:7) CMPQ BX,$0
 0x004f 00079 (/root/hello.go:7) JEQ $1,223
 0x0055 00085 (/root/hello.go:7) MOVQ $1,DX
 0x005c 00092 (/root/hello.go:7) MOVQ $1,CX
 ...

Good read : https://blog.cloudflare.com/go-crypto-bridging-the-performance-gap/