Data dependence: When an instruction needs data from another instruction that is called a data dependence.

Type of data dependencies:

RAW read after write. Also called Flow, True Dependence.

The following dependencies are False or Name dependencies.

WAW write after write. Also called Output Dependence.

WAR write after read. Also called Anti-Dependence

Calculate the data dependencies (RAW, WAR, WAW) of the following three instructions:

I1) OR R1, R2, R3

I2) OR R2, R1, R4

I3) OR R1, R1, R2

For example, if you find a RAW dependency between I1 and I2, say:

RAW on R4 from I1 to I2