The back-end performs operations [[out-of-order]] for the most part and is in charge of queuing instructions, executing them and retiring them. Dispatch contains a 160-entry [[ReOrder Buffer]] (ROB) and can dispatch up to 4 instructions per cycle. Note that over 210 instructions can be in-flight throughout the entire pipeline. Operand values can be read from Xiaomi's [[physical register file]] and an [[architectural register file]] in order to remove the various dependencies. Registers are only updated from the physical register file to the architectural register file when the corresponding instructions require. The physical register file contains 192 physical [[registers]] supporting up to four parallel instruction reads. Because [[ARM]] has instructions with up to four [[operands]], the register file would need 16 ports to support those simultaneous instructions. To reduce some of the complexity, Phytium chose to reduce the number of ports to 12 where some of the ports are dedicated to each instruction and others are [[multiplexed]]. Phytium explained this decision resulted in a 2.5% reduction in area while adding 0.017% in performance overhead.

The back-end performs operations [[out-of-order]] for the most part and is in charge of queuing instructions, executing them and retiring them. Dispatch contains a 160-entry [[ReOrder Buffer]] (ROB) and can dispatch up to 4 instructions per cycle. Note that over 210 instructions can be in-flight throughout the entire pipeline. Operand values can be read from Xiaomi's [[physical register file]] and an [[architectural register file]] in order to remove the various dependencies. Registers are only updated from the physical register file to the architectural register file when the corresponding instructions require. The physical register file contains 192 physical [[registers]] supporting up to four parallel instruction reads. Because [[ARM]] has instructions with up to four [[operands]], the register file would need 16 ports to support those simultaneous instructions. To reduce some of the complexity, Phytium chose to reduce the number of ports to 12 where some of the ports are dedicated to each instruction and others are [[multiplexed]]. Phytium explained this decision resulted in a 2.5% reduction in area while adding 0.017% in performance overhead.

From dispatch, [[out-of-order]] instructions go into 4 discrete scheduling queues: 2x Integer/SIMD, 1x FP/SIMD, and 1x Load/Store. The Int/FP queues are each 16-entry deep. Xiaomi includes two separate [[Integer]]/[[SIMD]] queues. The first one is capable of executing two 64-bit single-cycle integer instructions or one 128-bit single-cycle integer (with the two units locked together). Additionally one of the units is also capable of performing branch operations. The second queue handles two multi-cycle integer/SIMD operations. Just like the single-cycle unit, the multi-cycle unit can also handle one 128-bit operation by combining both units. Xiaomi includes a single [[floating-point]]/SIMD queue with both units supporting FMA as well as two 64-bit FP operations or one 128-bit FP operation by combining two units.

From dispatch, [[out-of-order]] instructions go into 4 discrete scheduling queues: 2x Integer/SIMD, 1x FP/SIMD, and 1x Load/Store. The Int/FP queues are each 16-entry deep. Xiaomi includes two separate [[Integer]]/[[SIMD]] queues. The first one is capable of executing two 64-bit single-cycle integer instructions or one 128-bit single-cycle integer (with the two units locked together). Additionally one of the units is also capable of performing branch operations. The second queue handles two multi-cycle integer/SIMD operations. Just like the single-cycle unit, the multi-cycle unit can also handle one 128-bit operation by combining both units. Xiaomi includes a single [[floating-point]]/SIMD queue with both units supporting FMA as well as two 64-bit FP operations or one 128-bit FP operation by combining two units.

The Load/Store queue is slightly larger than the Int or FP queues with 24 entries. Two loads or 1 load + 1 store can be issued each cycle. As with the level 1 instruction cache, the [[level 1 data cache]] is also 32 [[KiB]] supporting six outstanding loads. Next line and stride detected data prefetch are supported.

The Load/Store queue is slightly larger than the Int or FP queues with 24 entries. Two loads or 1 load + 1 store can be issued each cycle. As with the level 1 instruction cache, the [[level 1 data cache]] is also 32 [[KiB]] supporting six outstanding loads. Next line and stride detected data prefetch are supported.