Re: Intel P6 vs P7 system call performance

billyrose@billyrose.net
Thu, 19 Dec 2002 11:10:54 -0500


Richard B. Johnson wrote:

> Because the number pushed onto the stack is a displacement, not
> an address, i.e., -4095. To have the address act as an address,
> you need to load a full-pointer, i.e. SEG:OFFSET (like the old
> 16-bit days). The offset is 32-bits and the segment is whatever
> the kernel has set up for __USER_CS (0x23). All the 'near' calls
> are calls to a signed displacement, same for jumps.

call's and jmp's use displacement, ret's are _always_ absolute.
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