Three address code

• Three-address code is an intermediate code. It is used by the optimizing compilers.
• In three-address code, the given expression is broken down into several separate instructions. These instructions can easily translate into assembly language.
• Each Three address code instruction has at most three operands. It is a combination of assignment and a binary operator.

Example

GivenExpression:

1. a := (-c * b) + (-c * d)  

Three-address code is as follows:

         t1 := -c
         t2 := b*t1
         t3 := -c
         t4 := d * t3
         t5 := t2 + t4
         a := t5

t is used as registers in the target program.

The three address code can be represented in two forms: quadruples and triples.