What are some of the ways a compiler eliminates repeated subexpressions recomputations? How do you keep track of the sub-expressions? And How do you identify the repeated ones? Besides the usage o...

I was reading about various intermediate forms but I cant get information about A-normal forms besides the wiki-like entries. Does anyone here know about this or has good resources about it?

I'm creating a compiler with Lex and YACC (actually Flex and Bison). The language allows unlimited forward references to any symbol (like C#). The problem is that it's impossible to parse the langu...