> Ian Lance Taylor writes: > > Andrew Haley <[EMAIL PROTECTED]> writes: > > > > > In practice, %ebp either points to a call frame -- not necessarily > the > > > most recent one -- or is null. I don't think that having an optional > > > frame pointer mees you can use %ebp for anything random at all, but > we > > > need to make a clarification request of the ABI. > > > > I don't see that as feasible. If %ebp/%rbp may be used as a general > > callee-saved register, then it can hold any value. > > Sure, we already know that, as has been clear. The question is *if* > %rbp may be used as a general callee-saved register that can hold any > value.
The amd64 ABI is specifically *designed* to allow this. Mark
