Replace Magic Number with Symbolic Constant

You have a literal number with a particular meaning.
Create a constant, name it after the meaning, and replace the number with it.

        ...
        eax = 0x7fffffff;
        ...

⇓

        const int MAXINT = 0x7fffffff;
        ...
        eax = MAXINT;
        ...

Motivation

When compiling, all the semantic information concerning enumeration values, pre-processor macro definitions, and constants is lost. So all the symbolic constants must be specified during decompilation.

Mechanics

Create a new constant with the number, named after the meaning.
Replace the number with the newly created constant.