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code_native

code_native(f, types)

Prints the native assembly instructions generated for running the method matching the given generic function and type signature to STDOUT.

Examples

julia> mysin(x) = ccall((:sin,"libm"), Cdouble, (Cdouble,), x)
    @vectorize_1arg Real mysin
    mysin([1,2,3,4])
    code_native(mysin, (Float64,))
.text
Filename: In[11]
Source line: 1
    push    RBP
    mov RBP, RSP
    movabs  RAX, 140193336993536
Source line: 1
    call    RAX
    pop RBP
    ret

1. Print native assembly instructions for a function with specific types:

   julia> function add_numbers(a::Int, b::Int)
             return a + b
          end
   julia> code_native(add_numbers, (Int, Int))
   
          .text
   ; ┌ @ In[1]:2 within `add_numbers`
          push    RBP
          mov     RBP, RSP
          add     RDI, RSI
          mov     RAX, RDI
          pop     RBP
          ret
          nop
          nop
   ; └

   This example shows the native assembly instructions generated for the add_numbers function when called with two Int arguments.

2. Inspect native assembly instructions for a generic function:

   julia> function multiply_numbers(a, b)
             return a * b
          end
   julia> code_native(multiply_numbers, (Any, Any))
   
          .text
   ; ┌ @ In[2]:2 within `multiply_numbers`
          push    RBP
          mov     RBP, RSP
          push    RSI
          push    RDI
          push    RAX
          mov     RAX, RSI
          mul     RDI
          pop     RDX
          pop     RDX
          pop     RDX
          mov     RDI, RAX
          pop     RBP
          ret
          nop
          nop
   ; └

   This example demonstrates the native assembly instructions generated for the multiply_numbers generic function when called with any argument types.

Common mistake example:

julia> code_native(println, (String,))
ERROR: MethodError: no method matching println(::Type{String})
Closest candidates are:
  println(::Any, ::Any, ::Any, ::Any...) at io.jl:104
  println(::Any, ::Any, ::Any...) at io.jl:105
  println(::IJulia.IJuliaStdio{Base.PipeEndpoint}, ::Any, ::Any, ::Any...) at /Users/runner/.julia/packages/IJulia/DrVMH/src/stdio.jl:273
  ...

In this example, the println function is not defined for the specific type String. Make sure to provide valid function and type arguments to code_native to avoid such errors.

See Also

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