Messages in this thread | | | Date | Tue, 17 Dec 2002 10:49:31 -0800 (PST) | From | Linus Torvalds <> | Subject | Re: Intel P6 vs P7 system call performance |
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On 17 Dec 2002, Alan Cox wrote: > > Is there any reason you can't just keep the linker out of the entire > mess by generating > > .byte whatever > .dword 0xFFFF0000 > > instead of call ?
Alan, the problem is that there _is_ no such instruction as a "call absolute".
There is only a "call relative" or "call indirect-absolute". So you either have to indirect through memory or a register, or you have to fix up the call at link-time.
Yeah, I know it sounds strange, but it makes sense. Absolute calls are actually very unusual, and using relative calls is _usually_ the right thing to do. It's only in cases like this that we really want to call a specific address.
Linus
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