Test cases for testing speculative execution of instructions are replicated into a memory with non-naturally aligned data boundaries to create a non-contiguous instruction stream to efficiently test a processor. Placing test cases with test code and test data in the non-naturally aligned data boundaries as described herein allows test code to test speculative execution of branches. The test case includes a branch with a hint bit set to cause the hardware to mispredict the path of the branch to cause speculative execution of test code, bad code or erroneously execute data. The processor can then be tested to see if it properly flushes the speculatively executed code upon taking the opposite branch of the mispredicted path.