diff --git a/param.h b/param.h
index e8cf53f0a..efe0e1096 100644
--- a/param.h
+++ b/param.h
@@ -2225,7 +2225,17 @@ USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #define GEMM_DEFAULT_OFFSET_A 0 
 #define GEMM_DEFAULT_OFFSET_B 65536
 #define GEMM_DEFAULT_ALIGN 0x0ffffUL
-
+#if defined(__32BIT__)
+#warning using BINARY32==POWER6
+#define SGEMM_DEFAULT_UNROLL_M 4
+#define SGEMM_DEFAULT_UNROLL_N 4
+#define DGEMM_DEFAULT_UNROLL_M 4
+#define DGEMM_DEFAULT_UNROLL_N 4
+#define CGEMM_DEFAULT_UNROLL_M 2
+#define CGEMM_DEFAULT_UNROLL_N 4
+#define ZGEMM_DEFAULT_UNROLL_M 2
+#define ZGEMM_DEFAULT_UNROLL_N 4
+#else
 #define SGEMM_DEFAULT_UNROLL_M 16
 #define SGEMM_DEFAULT_UNROLL_N 8
 #define DGEMM_DEFAULT_UNROLL_M 16
@@ -2234,7 +2244,7 @@ USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #define CGEMM_DEFAULT_UNROLL_N 4
 #define ZGEMM_DEFAULT_UNROLL_M 8
 #define ZGEMM_DEFAULT_UNROLL_N 2
-
+#endif
 #define SGEMM_DEFAULT_P  1280UL
 #define DGEMM_DEFAULT_P  640UL
 #define CGEMM_DEFAULT_P  640UL