Sure, but that requires compilation unit level analysis or inlining (when inlined you can include pointer provenance from main), otherwise you can't guarantee the relationship between x and y.
I guess what bugs me about optimizations is that it feels like something _I_ should be doing. Like if GCC told me this code optimizes down to printf 1 and why, I'd question what I was doing (and rightly so). Doing it automatically feels like too much spooky action at a distance.
In the case of the code we're talking about here, gcc/clang do rely on inlining to optimize down to the single printf. I don't think there's any actual compiler that does the dangerous and invalid optimization in the article.
OH! I've clearly misunderstood then. Rereading, it does look like this is just a hypothetical to illustrate the tension between allowing pointer-int-pointer round-trips and foiling analysis based on pointer provenance. OK I'm caught up, thank you haha.
I guess what bugs me about optimizations is that it feels like something _I_ should be doing. Like if GCC told me this code optimizes down to printf 1 and why, I'd question what I was doing (and rightly so). Doing it automatically feels like too much spooky action at a distance.