OOO Specs

I4

• Everything is inorder
• Uses a fixed length pipelines scoreboard

I2O2

• Frontend and Issue are inorder
• Writeback and Commit is out-of-order
• Uses a scoreboard

I2OI

• Frontend and Issue are inorder
• Writeback is out-of-order
• Commit is inorder
• Uses a scoreboard, reorder buffer, and store buffer

IO3

• Frontend is inorder
• Issue, Writeback, and Commit are out-of-order
• Uses a scoreboard and an issue queue

IO2I

• Frontend is inorder
• Issue and Writeback are out-of-order
• Uses a scoreboard, an issue queue, a reorder buffer, and a store buffer