I'm not sure about the current state of compiler optimisations, but IIRC in the olde-days, a not not in an if() statement would assemble to JZ, saving a clock

I'm not sure about the current state of compiler optimisations, but IIRC in the olde-days, a not not in an if() statement would assemble to JZ, saving a clock cycle (& an opcode?), and wouldn't need to stall to load in the full width of the register. Today's branch predicting compilers are beyond me. I still use it as a clarification that it's a deliberate boolean operation, rather than implicit.