Example code showing finally cloning (asm, no cloning)

finally_net462.asm

; Assembly listing for method Test:Update(byref,byref)
; Emitting BLENDED_CODE for X64 CPU with SSE2
; optimized code
; rbp based frame
; fully interruptible
; Final local variable assignments
;
;  V00 arg0         [V00,T00] (  4,   4  )   byref  ->  rcx        
;  V01 arg1         [V01,T01] (  4,   4  )   byref  ->  [rbp+0x18]   do-not-enreg[H]
;  V02 OutArgs      [V02    ] (  1,   1  )  lclBlk (32) [rsp+0x00]  
;  V03 PSPSym       [V03    ] (  1,   1  )    long  ->  [rbp-0x10]   do-not-enreg[X] addr-exposed
;
; Lcl frame size = 48

G_M62690_IG01:
       55                   push     rbp                         ; set up call frame
       4883EC30             sub      rsp, 48
       488D6C2430           lea      rbp, [rsp+30H]
       488965F0             mov      qword ptr [rbp-10H], rsp
       48895518             mov      bword ptr [rbp+18H], rdx    ; store pointer to `right` in frame

G_M62690_IG02:
       8B01                 mov      eax, dword ptr [rcx]
       83C001               add      eax, 1                      ; compute `left + 1`
       7004                 jo       SHORT G_M62690_IG03         ; raise exception on overflow
       8901                 mov      dword ptr [rcx], eax        ; store new value to `left`
       EB06                 jmp      SHORT G_M62690_IG04

G_M62690_IG03:
       E8CEF3AB5F           call     CORINFO_HELP_OVERFLOW
       CC                   int3     

G_M62690_IG04:
       488BCC               mov      rcx, rsp
       E807000000           call     G_M62690_IG07    ; non-excpetion path: call finally handler

G_M62690_IG05:
       90                   nop      

G_M62690_IG06:
       488D6500             lea      rsp, [rbp]       ; tear down call frame
       5D                   pop      rbp
       C3                   ret                       ; return

;; Code above is all of method `Update` except for the `finally` clause

;; Code below is all the `finally` clause of method `Update`
G_M62690_IG07:
       55                   push     rbp                        ; set up a new frame for the `finally` handler
       4883EC30             sub      rsp, 48
       488B6920             mov      rbp, qword ptr [rcx+32]    ; find the original frame for the `Update` method
       48896C2420           mov      qword ptr [rsp+20H], rbp
       488D6D30             lea      rbp, [rbp+30H]

G_M62690_IG08:
       488B4518             mov      rax, bword ptr [rbp+18H]   ; load pointer to `right` from parent frame
       830001               add      dword ptr [rax], 1         ; increment `right`

G_M62690_IG09:
       4883C430             add      rsp, 48                    ; tear down handler frame
       5D                   pop      rbp
       C3                   ret                                 ; return (to either exception dispatch code or `Update`)

; Total bytes of code 81, prolog size 18 for method Test:Update(byref,byref)
; ============================================================