search for: isphysdeftriviallydead

...has a special configuration register that many instructions read implicitly, configuring for example if an add instruction should saturate at over/underflow or not. Now, I have a problem where the MachineCSE removes a setting of this configuration register in a basic block, because MachineCSE::isPhysDefTriviallyDead can't find any uses of it in the basic block where it's defined. Similar to other special physical registers, e.g the stack pointer, this configuration register is marked as "reserved". Is there anything else I need to do for the MachineCSE to leave this register and not remo...