What’s the difference between EAX, EBX, and ECX in assembly?
WEBNov 11, 2022 · eax, ebx, ecx and so on are actually registers, which can be seen as "hardware" variables, somewhat similar to higher level-language's variables. Registers can be used in your software directly with instructions such as mov, add or cmp. The leading e stands for e xtended and means that your register is 32 bits wide.
What does the bracket in `movl (%eax), %eax` mean?
WEBLaC is right. Symbol () means the address of the register. And %eax is the value of that address. so 'movl 8 (%ebp), %eax' means set %eax with the address of the %ebp. answered Nov 8, 2021 at 20:25. vikas william. 11 1. LEA sets EAX = the address. MOV sets EAX = the value from memory at that address.
assembly - How is "rax" different from "eax"? - Stack Overflow
WEBJul 7, 2017 · The registers starting with r as in rax, rbx, etc, are the 64-bit registers introduced with the AMD64 extension to the existing 32-bit x86 ISA. That ISA extension was subsequently adopted by Intel and is often known by the more neutral name x86-64. Essentially all x86 chips released in the last decade from AMD and Intel support this ISA.
What does X mean in EAX,EBX,ECX ... in assembly?
WEBMar 30, 2010 · The following is a brief explanation of what each of the x86 general-purpose registers stands for: EAX: "Extended Accumulator" - used for arithmetic and logical operations, as well as for storing return values from functions. EBX: "Extended Base" - often used as a pointer to data in the data segment of memory.
assembly - The point of test %eax %eax - Stack Overflow
WEBOct 25, 2012 · JE [Jump if Equals] tests the zero flag and jumps if the flag is set. JE is an alias of JZ [Jump if Zero] so the disassembler cannot select one based on the opcode. JE is named such because the zero flag is set if the arguments to CMP are equal. So, TEST %eax, %eax. JE 400e77 <phase_1+0x23>. jumps if the %eax is zero.
assembly - How do AX, AH, AL map onto EAX? - Stack Overflow
WEBAH is the bits 8 through 15 (zero-based), the top half of AX. So AX is composed of AH:AL halves, and is itself the low half of EAX. (The upper half of EAX isn't directly accessible as a 16-bit register; you can shift or rotate EAX if you want to get at it.) x86-64 CPUs extend the integer registers to 64-bit: RAX is the full 64-bit value, with ...
What is the purpose of XORing a register with itself?
WEBSep 9, 2009 · The XOR EAX,EAX simply 0's out the EAX register, it executes faster than a MOV EAX,$0 and doesn't need to fetch immediate data of 0 to load into eax It's very obvious this is the "return 0" that MSVC is optimizing EAX is the register used to return a value from a function in MSVC
What is the function of the push / pop instructions used on …
WEBJan 3, 2011 · Like push 1 (2 bytes) / pop eax (1 byte) for 3 bytes total, vs. mov eax, 1 (5 bytes total, with 3 zero bytes in the imm32 so it's also a problem for shellcode). See Tips for golfing in x86/x64 machine code. Also, swapping registers that way is insane vs. xchg eax, ebx (1 byte, 3 uops on modern Intel CPUs but none of them are memory access. And ...
c - Why is eax used on 64-bit? - Stack Overflow
WEBMay 11, 2021 · 2. %eax refers to the lower 32 bits of the 64-bit %rax register. So, if %rax is initially 0, and you execute the instruction movl $5, %eax, then %rax will also take on the value 5. However, they are not entirely independent, so one should be careful. For example, on my machine, if you set all bits of %rax to 1, and then perform xor %eax, %eax ...
Dashboard EAX - Forex Factory
WEBDec 2, 2015 · If you don't need any other pair in your current MT4 setup, in the market watch sub-window enable only these 28 plus the one you'll be using to attach the dashboard and hide/disable any other. This will save you bandwidth (and probably some headache). Make sure that your broker supports all these pairs.