F中的數組遍歷＃

Question

在F＃中迭代數組的最快方法是什麼？使用Array。[index]似乎創建（通過查看在釋放模式下生成的程序集）調用asm指令。 有沒有辦法避免這種情況？ 感謝

120:    me.[i] <- me.[i] ||| you.[i] 
    0000005b 8B 45 F8    mov   eax,dword ptr [ebp-8] 
    0000005e 8B 55 E0    mov   edx,dword ptr [ebp-20h] 
    00000061 3B 42 04    cmp   eax,dword ptr [edx+4] 
    00000064 72 05    jb   0000006B 
    00000066 E8 35 CD B9 65  call  65B9CDA0 
    0000006b 8B 4C C2 08   mov   ecx,dword ptr [edx+eax*8+8] 
    0000006f 8B 5C C2 0C   mov   ebx,dword ptr [edx+eax*8+0Ch] 
    00000073 8B 45 F8    mov   eax,dword ptr [ebp-8] 
    00000076 8B 55 DC    mov   edx,dword ptr [ebp-24h] 
    00000079 3B 42 04    cmp   eax,dword ptr [edx+4] 
    0000007c 72 05    jb   00000083 
    0000007e E8 1D CD B9 65  call  65B9CDA0 
    00000083 0B 4C C2 08   or   ecx,dword ptr [edx+eax*8+8] 
    00000087 0B 5C C2 0C   or   ebx,dword ptr [edx+eax*8+0Ch] 
    0000008b 89 4D EC    mov   dword ptr [ebp-14h],ecx 
    0000008e 89 5D F0    mov   dword ptr [ebp-10h],ebx 
    00000091 8B 45 F8    mov   eax,dword ptr [ebp-8] 
    00000094 8B 55 E0    mov   edx,dword ptr [ebp-20h] 
    00000097 3B 42 04    cmp   eax,dword ptr [edx+4] 
    0000009a 72 05    jb   000000A1 
    0000009c E8 FF CC B9 65  call  65B9CDA0 
    000000a1 8B 4D EC    mov   ecx,dword ptr [ebp-14h] 
    000000a4 8B 5D F0    mov   ebx,dword ptr [ebp-10h] 
    000000a7 89 4C C2 08   mov   dword ptr [edx+eax*8+8],ecx 
    000000ab 89 5C C2 0C   mov   dword ptr [edx+eax*8+0Ch],ebx 

更新：使用Array.iter給我：

122:   me |> Array.iteri (fun i elem -> me.[i] <- me.[i] ||| you.[i]) 
0000003a B9 18 26 70 00  mov   ecx,702618h 
0000003f E8 7C 53 A5 FF  call  FFA553C0 
00000044 89 45 E0    mov   dword ptr [ebp-20h],eax 
00000047 FF 75 E4    push  dword ptr [ebp-1Ch] 
0000004a 8B 55 E8    mov   edx,dword ptr [ebp-18h] 
0000004d 8B 4D E0    mov   ecx,dword ptr [ebp-20h] 
00000050 FF 15 00 26 70 00 call  dword ptr ds:[00702600h] 
00000056 8B 55 E8    mov   edx,dword ptr [ebp-18h] 
00000059 8B 4D E0    mov   ecx,dword ptr [ebp-20h] 
0000005c 8B 05 DC 27 70 00 mov   eax,dword ptr ds:[007027DCh] 
00000062 6A 00    push  0 
00000064 6A 00    push  0 
00000066 6A 01    push  1 
00000068 50     push  eax 
00000069 83 3D 88 A2 63 66 00 cmp   dword ptr ds:[6663A288h],0 
00000070 74 09    je   0000007B 
00000072 51     push  ecx 
00000073 52     push  edx 
00000074 E8 C2 DE C1 65  call  65C1DF3B 
00000079 5A     pop   edx 
0000007a 59     pop   ecx 
0000007b E8 A7 5C 96 65  call  65965D27 
00000080 CC     int   3 

Answer 1

作爲一個猜測，你已經在調試器下運行時獲得拆卸源。調試器的存在阻止了許多JIT優化。作爲示範：

let assign (a : _[]) (b : _[]) = 
    for i = 0 to a.Length do 
     a.[i] <- b.[i] 
     System.Diagnostics.Trace.Assert(false) 
     |> ignore 

assign [|1|] [|0|] 

釋放，與調試器：

 a.[i] <- b.[i] 
0000003b mov   eax,dword ptr [ebp-8] 
0000003e mov   edx,dword ptr [ebp-14h] 
00000041 cmp   eax,dword ptr [edx+4] 
00000044 jb   0000004B 
00000046 call  762798A8 
0000004b mov   eax,dword ptr [edx+eax*4+8] 
0000004f mov   dword ptr [ebp-0Ch],eax 
00000052 mov   eax,dword ptr [ebp-8] 
00000055 mov   edx,dword ptr [ebp-10h] 
00000058 cmp   eax,dword ptr [edx+4] 
0000005b jb   00000062 
0000005d call  762798A8 
00000062 mov   ecx,dword ptr [ebp-0Ch] 
00000065 mov   dword ptr [edx+eax*4+8],ecx 
.... 

發行，無需調試器（使用Ctrl + F5的運行，按重試時斷言窗口彈出，然後才連接調試處理）

 a.[i] <- b.[i] 
00000017 cmp   esi,dword ptr [ebx+4] 
0000001a jae   00000043 
0000001c mov   eax,dword ptr [ebx+esi*4+8] 
00000020 cmp   esi,dword ptr [edi+4] 
00000023 jae   00000043 
00000025 mov   dword ptr [edi+esi*4+8],eax 
.... 

Answer 2

你試過Array.iter？

http://msdn.microsoft.com/en-us/library/ee353672.aspx