I had a question a while back about potential spill strategies that may be appropriate to ask here, given that a bunch of compiler people are probably crawling

I had a question a while back about potential spill strategies that may be appropriate to ask here, given that a bunch of compiler people are probably crawling this thread. Do compilers ever do "computed spilling" (for lack of a better phrase)? For example, if you have code such as: int x = f(); int y = x & MASK; use(y); // ... bunch of code that uses x, but causes y to spill ... use(y); If we're spilling 'x' and 'y', the compiler could theoretically notice that 'y' is purely derived from 'x', and turn the "spill" of 'y' into a no-op (assuming 'x' is kept live), and the "load" of 'y' into re-computing y from x (in this case using a BITAND). Mostly academic curiosity, but is this technique used by any major compiler?