Abstract: In addition to speculatively executing normal (non-speculative) load instructions in advance of their program order, an out-of-order processor executes the speculative (advanced) load instructions originally compiled for in-order processors. Both the speculative-load instructions and the corresponding check instructions can be executed out-of-order. The speculative-load instructions are treated like normal-load instructions while in the instruction queue. When a speculative-load instruction is retired from the instruction queue, it is transferred to a speculative load instruction manager. Execution of the corresponding check instruction can then check the validity of the speculative-load instruction.

Abstract: An apparatus and method a method for performing two-pass real time video compression is provided. Tactical decisions such as encoding and quantization values are determined in software, whereas functional execution steps are performed in hardware. By appropriately apportioning the tasks between software and hardware, the benefits of each type of processing are exploited, while minimizing both hardware complexity and data transfer requirements. One key concept that allows the compression unit to operate in real time is that the architecture and pipelining both allow for B frames to be executed out of order. By buffering B frames, two-pass motion estimation techniques can be performed to tailor bit usage to the requirements of the frame, and thereby provide a more appealing output image.