diff --git a/include_CLANG.mk b/include_CLANG.mk
index 59fa579..49b7751 100644
--- a/include_CLANG.mk
+++ b/include_CLANG.mk
@@ -1,4 +1,4 @@
-CC  = cc
+CC  = clang
 LINKER = $(CC)
 
 ANSI_CFLAGS  = -ansi
@@ -6,6 +6,8 @@ ANSI_CFLAGS += -std=c99
 ANSI_CFLAGS += -pedantic
 ANSI_CFLAGS += -Wextra
 
+#CFLAGS   = -O3 -march=native $(ANSI_CFLAGS) #-Xpreprocessor -fopenmp -g
+#CFLAGS   = -O3 -march=cascadelake $(ANSI_CFLAGS) #-Xpreprocessor -fopenmp -g
 CFLAGS   = -Ofast $(ANSI_CFLAGS) -g #-Xpreprocessor -fopenmp -g
 ASFLAGS  = -masm=intel
 LFLAGS   =
diff --git a/include_GCC.mk b/include_GCC.mk
index 954ac5d..d900a61 100644
--- a/include_GCC.mk
+++ b/include_GCC.mk
@@ -7,6 +7,8 @@ ANSI_CFLAGS += -pedantic
 ANSI_CFLAGS += -Wextra
 
 # CFLAGS   = -O0 -g  -std=c99 -fargument-noalias
+#CFLAGS   = -O3 -march=cascadelake  -ffast-math -funroll-loops # -fopenmp
+#CFLAGS   = -O3 -march=native  -ffast-math -funroll-loops # -fopenmp
 CFLAGS   = -O3 -march=znver1  -ffast-math -funroll-loops # -fopenmp
 ASFLAGS  =  -masm=intel
 LFLAGS   =
diff --git a/include_ICC.mk b/include_ICC.mk
index 37b017f..ba4b548 100644
--- a/include_ICC.mk
+++ b/include_ICC.mk
@@ -3,7 +3,7 @@ LINKER = $(CC)
 
 OPENMP  = #-qopenmp
 PROFILE  = #-profile-functions -g  -pg
- OPTS     = -Ofast -xCORE-AVX512 -qopt-zmm-usage=high $(PROFILE)
+OPTS      = -Ofast -xCORE-AVX512 -qopt-zmm-usage=high $(PROFILE)
 #OPTS     = -fast -xCORE-AVX2  $(PROFILE)
 #OPTS     = -fast -xAVX  $(PROFILE)
 #OPTS     = -fast -xSSE4.2 $(PROFILE)
diff --git a/src/util.c b/src/util.c
index 1fa01e8..0347ab6 100644
--- a/src/util.c
+++ b/src/util.c
@@ -20,6 +20,8 @@
  *   with MD-Bench.  If not, see <https://www.gnu.org/licenses/>.
  * =======================================================================================
  */
+#include <string.h>
+
 #include <util.h>
 
 /* Park/Miller RNG w/out MASKING, so as to be like f90s version */