make building the bfloat16 functions conditional on BUILD_HALF

CMakeLists.txt

@@ -86,10 +86,13 @@ if (NOT NO_LAPACK)
   list(APPEND SUBDIRS lapack)
 endif ()
 
+if (NOT DEFINED BUILD_HALF)
+ set (BUILD_HALF false)
+endif ()
 # set which float types we want to build for
 if (NOT DEFINED BUILD_SINGLE AND NOT DEFINED BUILD_DOUBLE AND NOT DEFINED BUILD_COMPLEX AND NOT DEFINED BUILD_COMPLEX16)
   # if none are defined, build for all
-  set(BUILD_HALF true)
+#  set(BUILD_HALF true)
   set(BUILD_SINGLE true)
   set(BUILD_DOUBLE true)
   set(BUILD_COMPLEX true)
@@ -121,7 +124,7 @@ if (BUILD_COMPLEX16)
   list(APPEND FLOAT_TYPES "ZCOMPLEX") # defines COMPLEX and DOUBLE
 endif ()
 
-if (BUILD_SINGLE OR BUILD_HALF)
+if (BUILD_HALF)
   message(STATUS "Building Half Precision")
   list(APPEND FLOAT_TYPES "HALF") # defines nothing
 endif ()

Makefile.rule

@@ -273,6 +273,9 @@ COMMON_PROF = -pg
 #
 # CPP_THREAD_SAFETY_TEST = 1
 
+
+# If you want to enable the experimental BFLOAT16 support
+# BUILD_HALF = 1
 #
 #  End of user configuration
 #

Makefile.system

@@ -1395,6 +1395,7 @@ export KERNELDIR
 export FUNCTION_PROFILE
 export TARGET_CORE
 export NO_AVX512
+export BUILD_HALF
 
 export SHGEMM_UNROLL_M
 export SHGEMM_UNROLL_N