3 ms·

Intel syntax has more intuitive memory access syntax: AT&T syntax: movl mem_location(%ebx,%ecx,4), %eax Intel syntax: mov eax, [ebx + ecx*4 + mem_lo

• lokedhs 12y ago
  I can agree with most of that, except for the fact that Intel arguments are backwards. That throws me off every time. I don't know of any other assembler syntax that uses that argument order.
  • oso2k 12y ago
    For me, I remember the notation by correlating it to its "high-level" equivalent. mov eax, [ ptr ] is like eax = *ptr; // or, eax = ptr[ 0 ]; The offset/multiplier memory addressing format for AT&T syntax was always more troubling for me. Coming from a TASM/MASM/NASM/PASCAL/x86 background first, it felt "icky" to put offsets outside of the "brackets" (or parenthesis, as it were) [0][1]. [0] https://github.com/lpsantil/rt0/blob/master/src/lib/00_start.c#L14 https://github.com/lpsantil/rt0/blob/master/src/lib/00_start... [1] https://github.com/lpsantil/rt0/blob/master/src/lib/00_start.c#L21 https://github.com/lpsantil/rt0/blob/master/src/lib/00_start...
  • userbinator 12y ago
    Standard ARM, MIPS, PowerPC, x86, and Z80 Asm syntax all have the destination on the far left. 68k, Alpha, PDP-11, SPARC, and VAX have the destination on the far right. The order is probably as contentious as the great endianness debate, but I think one of the most awkward parts of having src, dst order is that subtraction looks backwards. I prefer dst, src because it corresponds closely with the direction of assignment in higher-level languages: op a, b, c ; a = b op c op a, b ; a op= b