2022年11月11日 · 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 …

2016年5月12日 · If the ECX register is zero then the repe cmpsb is not executed at all. This means that the following setb and seta instructions would produce garbage! Thus the …

2012年9月14日 · ecx is a x86 CPU register, which can hold a value of a certain amount of bits (32 or 64 (called rcx then) on modern x86 CPU's). The call stack is divided into stack frames . …

2018年11月18日 · @Kaunda Well, when you put the length in ecx and the pointer to the message into edx, the kernel still thinks that ecx contains the pointer to the message and edx contains …

imul also has an immediate form: imul ecx, ebx, 1234 does ecx = ebx * 1234. Many assemblers will accept imul ecx, 1234 as short-hand for imul ecx, ecx, 1234 . These 32x32 => 32-bit forms …

2011年7月24日 · mov ecx, N jmp bottom top: BODY dec ecx bottom: cmp ecx, 0 jne top Now we still do N conditional jumps but we only do ONE unconditional jump. A small savings but it just …

2014年6月10日 · ecx was the count register which held a loop counter; edx was the data register which you could use for I/O port access; edi was the destination index register which pointed …

2017年10月23日 · Unlike rep movsb/stosb/etc., it doesn't check for ECX=0 before decrementing, only after 1. The address-size determines whether it uses CX, ECX, or RCX. So in 64-bit code, …

2016年11月25日 · ECX: "Extended Counter" - often used for loop and string operations, as well as for storing function arguments. EDX: "Extended Data" - often used for I/O operations and …

2016年1月16日 · IDIV ecx in assembly, then i have read that the that the value in edx:eax is divided by the operand ecx. I also know that the quotient is stored in eax and the remainder in …