Inline assembly

a := 100 b := 20 mut c := 0 asm amd64 { mov eax, a add eax, b mov c, eax ; =r (c) as c // output ; r (a) as a // input r (b) as b } println('a: ${a}') // 100 println('b: ${b}') // 20 println('c: ${c}') // 120

For more examples, see Assembler Tests.