In MMIX there are 256 general purpose registers
$255, the function call instruction
PUSHJ $X,callee, in a simplified situation, will push the first
X general purpose registers to stack, and let registers
$X+2… be the new
$1… It brings difficulties to implement the
CallLowering interface, because the value of
X cannot be determined in this stage until register allocation. So, is it possible in LLVM to model this unusual calling convention?
Thanks in advance!