## ALP Programming Guide and Reference

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### Notes

Not all I/O ports can handle the rate at which the REP INS and REP OUTS instructions run.

Do not use the REP prefix with the LOOP instruction. Proper LOOP operation is not guaranteed when used with the REP prefix and the effect of this combination is unpredictable.

The behavior of the REP prefix is undefined when used with non-string instructions.

When a page fault occurs during CMPS or SCAS instructions that are prefixed with REPNE, the EFLAGS value is restored to the state prior to the processing of the instruction. Because SCAS and CMPS do not use EFLAGS as an input, the processor can resume the instruction after the page fault handler.