On Thu, Jan 10, 2013 at 12:12:26PM -0500, John Fine wrote: > > > horseriver wrote: > > 1. why use "fc ff ff ff " in call instruction? > The call uses PC relative addressing that at execution time is > relative to the address of the instruction AFTER the call > instruction. > But the relative fixup that the compiler can request from the linker > is relative to the location being fixed, which is inside the call > instruction. > So the final value required is four less than the fixup the linker > will require, so the compiler has initialized the value to be fixed > as minus four. this means : $PC + 0xfffffffc = $pc-4 >
