asm4:
	<+0>:	push   ebp
	<+1>:	mov    ebp,esp
	<+3>:	push   ebx
	<+4>:	sub    esp,0x10
	<+7>:	mov    DWORD PTR [ebp-0x10],0x260
	<+14>:	mov    DWORD PTR [ebp-0xc],0x0
	<+21>:	jmp    0x518 <asm4+27>|		------------->|
	<+23>:	add    DWORD PTR [ebp-0xc],0x1		      |
	<+27>:	mov    edx,DWORD PTR [ebp-0xc]  <-------------|  edx = a;
	<+30>:	mov    eax,DWORD PTR [ebp+0x8]  ; eax = a1
	<+33>:	add    eax,edx; 		; 
	<+35>:	movzx  eax,BYTE PTR [eax]
	<+38>:	test   al,al
	<+40>:	jne    0x514 <asm4+23>		                           len = strlen(a1)  
	<+42>:	mov    DWORD PTR [ebp-0x8],0x1                             c = 1;
	<+49>:	jmp    0x587 <asm4+138>
	<+51>:	mov    edx,DWORD PTR [ebp-0x8]				   
	<+54>:	mov    eax,DWORD PTR [ebp+0x8]				
	<+57>:	add    eax,edx						   
	<+59>:	movzx  eax,BYTE PTR [eax]                                  
	<+62>:	movsx  edx,al                                              edx = (unsigned int)arg1[c];
	<+65>:	mov    eax,DWORD PTR [ebp-0x8]				   
	<+68>:	lea    ecx,[eax-0x1]					   
	<+71>:	mov    eax,DWORD PTR [ebp+0x8]				   
	<+74>:	add    eax,ecx						   
	<+76>:	movzx  eax,BYTE PTR [eax]				   eax = (unsigned int)arg1[c - 1]
	<+79>:	movsx  eax,al						   ?????????
	<+82>:	sub    edx,eax						   
	<+84>:	mov    eax,edx						   
	<+86>:	mov    edx,eax 						   edx = edx - eax  = arg1[c] - arg1[c - 1]
	<+88>:	mov    eax,DWORD PTR [ebp-0x10] 			   
	<+91>:	lea    ebx,[edx+eax*1] 					   ebx = edx + a = (arg1[c] - arg1[c - 1] + a)
	<+94>:	mov    eax,DWORD PTR [ebp-0x8]				   
	<+97>:	lea    edx,[eax+0x1] 					   edx = c + 1  
	<+100>:	mov    eax,DWORD PTR [ebp+0x8] 				     
	<+103>:	add    eax,edx						   
	<+105>:	movzx  eax,BYTE PTR [eax] 				   
	<+108>:	movsx  edx,al 						   edx = (unsigned int)arg1[c + 1]
	<+111>:	mov    ecx,DWORD PTR [ebp-0x8]				   
	<+114>:	mov    eax,DWORD PTR [ebp+0x8]				   
	<+117>:	add    eax,ecx 						   
	<+119>:	movzx  eax,BYTE PTR [eax] 				   eax = (unsigned int)arg1[c]  
	<+122>:	movsx  eax,al
	<+125>:	sub    edx,eax                                             edx = arg1[c + 1] - arg1[c]
	<+127>:	mov    eax,edx						   eax = edx   
	<+129>:	add    eax,ebx						   eax = eax + ebx ( = arg1[c + 1] - arg1[c] + arg1[c] - arg1[c - 1] + a)
	<+131>:	mov    DWORD PTR [ebp-0x10],eax 			   a = eax  
	<+134>:	add    DWORD PTR [ebp-0x8],0x1  			   ++c;  
	<+138>:	mov    eax,DWORD PTR [ebp-0xc]				        eax = len
	<+141>:	sub    eax,0x1							eax -= 1
	<+144>:	cmp    DWORD PTR [ebp-0x8],eax					if (c < eax)
	<+147>:	jl     0x530 <asm4+51>						jump to  51
	<+149>:	mov    eax,DWORD PTR [ebp-0x10]
	<+152>:	add    esp,0x10
	<+155>:	pop    ebx
	<+156>:	pop    ebp
	<+157>:	ret    

ebp
-0x10 0x00000260 (a)
-0x0C 0x00000000 (len)
-0x08 0x00000001 (c)
-0x04
=0x00
+0x04
+0x08
+0x0C
+0x10