The compiler, in some limited circumstances when using Matrix Multiply Accelerator (MMA) intrinsics, may illegally place an HWAOPEN instruction in parallel with an HWALDAB instruction. If these two instructions occur in the same execute packet, an exception will be generated on the C7000 CPU. This defect does not occur in any version of the published MMALIB source code/library. The user must be coding the MMA with MMA intrinsics and in a very particular way for this defect to occur.