On Thu, Mar 12, 2015 at 02:02:37PM -0700, David Wohlferd wrote: > To wrap this up: > > Like Ian said, the order of registers here apparently never changes. I read > more into that comment than I should have. For good luck, I experimented > with -fomit-frame-pointer, -ffixed-, etc, and nothing has any impact here. > The list is the list. > > In fact, it turns out you can use this same format with register variables: > > register int x asm("3"); // i386: ebx
On some architectures, like e.g. powerpc, people often just use numbers instead of say r<number> at least for the general purpose registers and usually the internal register numbering matches it. So, while using asm ("3") on x86 is something very unusual, on other targets it can be quite common. Jakub