4.1 Function units

Defoe is a 64-bit architecture with the following function units.

• Two load/store units.
• Two simple ALUs that perform add, subtract, shift and logical operations on 64-bit numbers and packed 32, 16 and 8-bit numbers. In addition, these units also support multiplication of packed 16 and 8-bit numbers.
• One complex ALU that can perform multiply and divide on 64-bit integers and packed 32, 16 and 8-bit integers.
• One branch unit that performs branch, call and comparison operations.

There is no support for floating point. Figure 1 shows a simplified diagram of the Defoe architecture.