u64 ARMv7Thread::GetFreeStackSize() const { return SP - GetStackAddr(); }
u64 PPUThread::GetFreeStackSize() const { return (GetStackAddr() + GetStackSize()) - GPR[1]; }
u64 SPUThread::GetFreeStackSize() const { return (GetStackAddr() + GetStackSize()) - GPR[1]._u32[3]; }