In an instruction execution pipeline, the misalignment of memory access
instructions is predicted. Based on the prediction, an additional
micro-operation is generated in the pipeline prior to the effective
address generation of the memory access instruction. The additional
micro-operation accesses the memory falling across a predetermined
address boundary. Predicting the misalignment and generating a
micro-operation early in the pipeline ensures that sufficient pipeline
control resources are available to generate and track the additional
micro-operation, avoiding a pipeline flush if the resources are not
available at the time of effective address generation. The misalignment
prediction may employ known conditional branch prediction techniques,
such as a flag, a bimodal counter, a local predictor, a global predictor,
and combined predictors. A misalignment predictor may be enabled or
biased by a memory access instruction flag or misaligned instruction
type.