WAW

• EXAMPLE

  With out-of-order completion, instructions can write their results in a different order, eg.

    DIVF  R1, R2, R3
    STORE R1, A
    SUBF  R1, R4, R5
  

  The divide finishes after the subtract, leaving the wrong result in R1.

• This is called a WAW (Write-after-Write) hazard.

• WAW hazards occur because instructions no longer reach WB in order