Is it OK if I will answer?
There is only one loop, and there is no unrolling.
32-bit
Code:
	bool b = IsPrime(49999991);
00911047  mov         ecx,2  
0091104C  lea         esp,[esp]  
00911050  xor         edx,edx  
00911052  mov         eax,2FAF077h  
00911057  div         eax,ecx  
00911059  test        edx,edx  
0091105B  je          main+3Ah (091106Ah)  
0091105D  inc         ecx  
0091105E  cmp         ecx,2FAF077h  
00911064  jb          main+20h (0911050h)  
00911066  mov         bl,1  
00911068  jmp         main+3Ch (091106Ch)  
0091106A  xor         bl,bl
64-bit
Code:
	bool b = IsPrime(49999991);
000000013FAF1050  xor         edx,edx  
000000013FAF1052  mov         eax,2FAF077h  
000000013FAF1057  div         rax,rcx  
000000013FAF105A  test        rdx,rdx  
000000013FAF105D  je          main+40h (013FAF1070h)  
000000013FAF105F  inc         rcx  
000000013FAF1062  cmp         rcx,2FAF077h  
000000013FAF1069  jb          main+20h (013FAF1050h)  
000000013FAF106B  mov         dil,1  
000000013FAF106E  jmp         main+43h (013FAF1073h)  
000000013FAF1070  xor         dil,dil