We are seeing different results from dgemm depending on which machine we run on. We see these differences when we run with an AMD 6344 processor versus any machine that does not support AVX, FMA3, and FMA4. I am running with ACML 5.3.1. I have tried gfortran64 and gfortran64_fma4 library and both libraries produced the same results on a given machine. I get consistent answer when running on a variety of Intel and AMD machines that do not support AVX, FMA3, and FMA4. It is only the AMD 6344 that produces different answers. This is the only processor I have access to that supports AVX, FMA3, and FMA4.
Is this a bug? Is there a setting we can use to get the AMD 6344 to produce the same answers as the other machines?