Compiler Principles Background

• The final phase in our compiler model • Requirements imposed on a code generator – Preserving the semantic meaning of the source program and being of high quality – Making effective use of the available resources of the target machine – The code generator itself must run efficiently. • A code generator has three primary tasks: – Instruction selection, register allocation, and instruction ordering Compiler Principles Input to the Code Generator • The input to the code generator is – the intermediate representation of the source program produced by the frontend – information in the symbol table • Choices for the IR – Three-address representations, such as quadruples – Virtual machine representations, such as bytecodes – Linear representations, such as postfix notation – Graphical representation, such as syntax trees and DAG’