assembly-x86

# x86-64 assembly GCC and Clang emit AT&T syntax by default. This skill reads that output, writes inline asm, and keeps register use inside the System V AMD64 ABI. ## Contract | Field | Bound contract | |---|---| | Trigger | The task reads compiler assembly output, writes inline asm in C or C++, decides AT&T versus Intel syntax, or explains calling conventions and stack layout in a disassembly. | | Authority | Read-only. The skill explains and drafts; edits land through the normal coding path. No remote mutation. | | Side effect | None. | | Done | The drafted assembly assembles with `gcc -c` or `clang -c`, or the compiler output under discussion is explained register by register. | ## Inputs - The C or C++ source, compiler output, or assembly fragment: required. - The compiler: required. AT&T versus Intel output and inline asm details follow it. - The ABI: required. System V for Linux and macOS; the Microsoft x64 ABI changes the register map entirely. ## Procedure 1. Generate the baseline. Read the compiler's own output before writing any. Done when: the disassembly of the function under discussion is on screen. ```bash gcc -O2 -S -fverbose-asm foo.c -o foo.s gcc -O2 -c foo.c -o foo.o && objdump -d -M intel foo.o ``` 2. Map registers by role. Done when: every register in the fragment is classified. | Register | 32-bit view | Role | |----------|-------------|------| | `rax` | `eax` | Accumulator, 1st return value, caller saved | | `rbx` | `ebx` | Base, callee saved |...