machine-code

来源： https://stackoverflow.com/questions/55674951/how-to-run-machine-code-as-a-function-in-c

来源： https://stackoverflow.com/questions/3702171/are-bytes-words-addresses-signed-or-unsigned-in-z80-assembler-machine-code

来源： https://stackoverflow.com/questions/23123106/mips-i-instruction-immediate-field

来源： https://stackoverflow.com/questions/23123106/mips-i-instruction-immediate-field

来源： https://stackoverflow.com/questions/18090317/visual-c-appends-0xcc-int3-bytes-at-the-end-of-functions

来源： https://stackoverflow.com/questions/18090317/visual-c-appends-0xcc-int3-bytes-at-the-end-of-functions

来源： https://stackoverflow.com/questions/60371470/how-is-part-of-ldm-r1-r2-instruction-in-armv6-m-architecture-encoded

问题 xor dword [0x301a80], 0x12345 How many memory access when we know the op code and addressing mode is 2 bytes? If I understand correctly, even thought it is 0x12345, this is acctually still 4 bytes and we cant attach it to 0x301a80, right? So we have here: 2 + 4 + 4 bytes (And not 2 + 3.5 + 2.5 = 8) which is 4 memory access. Am I think right? 回答1: The total instruction size is 10 bytes (in 32-bit mode). That takes probably 0 to 2 I-cache accesses on a modern x86 to fetch in aligned 16-byte

问题 The reason this gets me confused is that all addresses hold a sequence of 1's and 0's. So how does the CPU differentiate, let's say, 00000100 (integer) from 00000100 (CPU instruction)? 回答1: First of all, different commands have different values (opcodes). That's how the CPU knows what to do. Finally, the questions remains: What's a command, what's data? Modern PCs are working with the von Neumann -Architecture ( https://en.wikipedia.org/wiki/John_von_Neumann) where data and opcodes are stored

问题 So I wanted to ask a rather existential question today, and it's one that I feel as though most programmers skip over and just accept as something that works, without really asking the question of "how" it works. The question is rather simple: how is the >= operator compiled down to machine code, and what does that machine code look like? Down at the very bottom, it must be a greater than test, mixed with an "is equal" test. But how is this actually implemented? Thinking about it seems rather