Comparison of several Assembly commands

Purple endurerOriginal

2006-10-141Version

1. assign a 32-bit value to the memory variable for an immediate numerical test
1) Use the push-pop command
0040100a |. 68 31323334 push 34333231
0040100f |. 8f05 50304000 pop dword ptr ds: [403050]
00401015 |
Command length: 015h-0ah = 0bh = 11d

2) use the mov command
0040101a |. c705 50304000> mov dword ptr ds: [403050], 34333231
00401024 |
Instruction length: 024h-01ah = 0ah = 10D

2. Assign the value of 32-Bit Memory variable A to 32-Bit Memory variable B.
1) Use the push-pop command
0040102e |. ff35 50304000 push dword ptr ds: [403050]
00401034 |. 8f05 4c304000 pop dword ptr ds: [40304c]
0040103a |
Instruction length: 03ah-02eh = 0ch = 12D

2) use the mov command to pass the Register
0040103f |. A1 50304000 mov eax, dword ptr ds: [403050]
00401044 |. A3 4c304000 mov dword ptr ds: [40304c], eax
00401049 |
Command length: 049h-03fh = 0ah = 10D

3. Call a custom function with a 32-bit value of 0.
1) directly use 32-bit value 0 as the parameter
0040104e |. 6a 00 push 0
00401050 |. 6a 00 push 0
00401052 |. 6a 00 push 0
00401054 |. 6a 00 push 0
00401056 |. 6a 00 push 0
00401058 |. E8 18000000 call test.00401075
0040105d |
Command length: 05dh-04eh = 0fh = 15d

2) set the register eax to 0, and then set the five eax parameters.
00401062 |. 33c0 XOR eax, eax
00401064 |. 50 push eax
00401065 |. 50 push eax
00401066 |. 50 push eax
00401067 |. 50 push eax
00401068 |. 50 push eax
00401069 |. E8 07000000 call test.00401075
0040106e |
Instruction length: 06eh-062h = 0ch = 12D