Are there functions and variables in ASM.JS that must be present in any ASM.JS code?

Question

JavaScript

The situation is this. There is someone else's ASM.JS code. There is a lot of code, but more than half is not used anywhere. Those. a lot of variables and functions are declared that are never called anywhere, neither in ASM.JS itself, nor in the higher script that launches this ASM.JS. It seems to me that this ASM.JS is compiled from C / C ++ and all the extra stuff is added by the compiler. Or does the specificity of ASM.JS require you to declare some standard functions and variables, despite the fact that they are not used? Maybe someone knows? I want to remove all unnecessary, there are really a lot of them. Reduce the file size, it will load faster, compile, and maybe work faster. I understand that you just need to remove it and see if it starts or not. But there is a lot of code, it will take at least a week to qualitatively select and remove unused code. I wouldn't want to waste my time.