Torben Ægidius Mogensen's "Basics of Compiler Design, Chapter 9 and Chapter 10"
Read Chapters 9 and 10. Chapter 9 overlaps the above reading, and is a supplementary discussion of the problem of mapping a large number of variables used in an intermediate language translation into a smaller number of registers, plus memory locations available on the target machine. Chapter 10 covers function calls using a stack, activation records, and frame pointers. Look over these chapters and read the parts that will add to your understanding of register allocation and function calls.
Click http://web.archive.org/web/20120915222417/http://www.diku.dk/hjemmesider/ansatte/torbenm/Basics/basics_lulu2.pdf link to open resource.