Module Module1

Sub Main()
    Dim x = 0
    Console.WriteLine(PlusEqual1(x))
    Console.WriteLine(Add1(x))
    Console.WriteLine(PlusEqual2(x))
    Console.WriteLine(Add2(x))
    Console.ReadLine()
End Sub

Public Function PlusEqual1(ByVal x As Integer) As Integer
    x += 1
    Return x
End Function

Public Function Add1(ByVal x As Integer) As Integer
    x = x + 1
    Return x
End Function

Public Function PlusEqual2(ByVal x As Integer) As Integer
    x += 2
    Return x
End Function

Public Function Add2(ByVal x As Integer) As Integer
    x = x + 2
    Return x
End Function

End Module

.method public static int32 Add1(int32 x) cil managed
{
.maxstack 2
.locals init (
    [0] int32 Add1)
L_0000: nop
L_0001: ldarg.0
L_0002: ldc.i4.1
L_0003: add.ovf
L_0004: starg.s x
L_0006: ldarg.0
L_0007: stloc.0
L_0008: br.s L_000a
L_000a: ldloc.0
L_000b: ret
}

.method public static int32 Add2(int32 x) cil managed
{
.maxstack 2
.locals init (
    [0] int32 Add2)
L_0000: nop
L_0001: ldarg.0
L_0002: ldc.i4.2
L_0003: add.ovf
L_0004: starg.s x
L_0006: ldarg.0
L_0007: stloc.0
L_0008: br.s L_000a
L_000a: ldloc.0
L_000b: ret
}

static void Main(string[] args)
{
    int i = 0;
    i += 1;
    i = i + 1;
    Console.WriteLine(i);
}

private static void Main(string[] args)
{
    int i = 0;
    i++;
    i++;
    Console.WriteLine(i);
}

static void Main(string[] args)
{
    int x = 2;
    int y = 3;
    x += 1;
    y = y + 1;
    Console.WriteLine(x);
    Console.WriteLine(y);
}

x=x+1

x+=1

instruction type        example                      cycles

ADD reg,reg             add ax,bx                       1
ADD mem,reg             add total, cx                   3
ADD reg,mem             add cx,incr                     2
ADD reg,immed           add bx,6                        1
ADD mem,immed           add pointers[bx][si],6          3
ADD accum,immed         add ax,10                       1

INC reg                 inc bx                          1
INC mem                 inc vpage                       3

MOV reg,reg             mov bp,sp                       1
MOV mem,reg             mov array[di],bx                1
MOV reg,mem             mov bx,pointer                  1
MOV mem,immed           mov [bx],15                     1
MOV reg,immed           mov cx,256                      1
MOV mem,accum           mov total,ax                    1
MOV accum,mem           mov al,string                   1
MOV segreg,reg16        mov ds,ax                       2, 3
MOV segreg,mem16        mov es,psp                      2, 3
MOV reg16,segreg        mov ax,ds                       1
MOV mem16,segreg        mov stack_save,ss               1
MOV reg32,controlreg    mov eax,cr0                     22
                        mov eax,cr2                     12
                        mov eax,cr3                     21, 46
                        mov eax,cr4                     14
MOV controlreg,reg32    mov cr0,eax                     4
MOV reg32,debugreg      mov edx,dr0                     DR0-DR3,DR6,DR7=11;
                                                        DR4,DR5=12
MOV debugreg,reg32      mov dr0,ecx                     DR0-DR3,DR6,DR7=11;
                                                        DR4,DR5=12

;for i = i+1   ; cycles
mov  ax,   [i]  ; 1
add  ax,   1    ; 1
mov  [i],  ax   ; 1

;for i += 1
; dunno the syntax of instruction. it should be the pointers one :S

;for i++
inc  i          ; 3
;or
mov  ax,   [i]  ; 1
inc  ax         ; 1
mov  [i],  ax   ; 1

;for ++i
mov  ax,   [i]  ; 1
;do  stuff      ; matters not
inc  ax         ; 1
mov  [i],  ax   ; 1

int i = 0;
i = i + 5.5; // doesn't compile.
i += 5.5; // compiles.