An apparatus detects a load-store collision within a microprocessor between a load operation and an older store operation each of which accesses data in the same cache line. Load and store byte masks specify which bytes contain the data specified by the load and store operation within a word of the cache line in which the load and data begins, respectively. Load and store word masks specify which words contain the data specified by the load and store operations within the cache line, respectively. Combinatorial logic uses the load and store byte masks to detect the load-store collision if the data specified by the load and store operations begin in the same cache line word, and uses the load and store word masks to detect the load-store collision if the data specified by the load and store operations do not begin in the same cache line word.