Re: Re: When will gcc assign local variables to registers?

[visitor x <visitor20212@outlook.com>]

Thank you for the pointer.

I learned SSA and realized that the problem is more challenging than I thought. As far, my understanding of SSA is that compilers restrict the definition site of each variable to only one by introducing phi-function and other tools. In this way it facilitates data flow analysis and further optimization such as dead code elimination.

My idea before is to list all possible manners that compilers assign variables to registers, then it may be easier to recover variables from binary. Now it seems to be an impossible mission. So I rethink my ultimate goal, essentially a track to variable access sequence, which doesn’t require full decompilation (maybe).

All we need to know is whether two instructions access the same variable (or say object if compilers care about only values). It sounds like an alias analysis in binary. Is it a specialized subfield in program/binary analysis?