Merge pull request #5716 from kexinzhao/float16

Add half precision float16 data type

Author: kexinzhao

CMakeLists.txt

@@ -58,6 +58,7 @@ option(GLIDE_INSTALL    "Download and install go dependencies "         ON)
 option(USE_NNPACK       "Compile PaddlePaddle with NNPACK library"      OFF)
 option(WITH_DISTRIBUTE  "Compile with grpc distributed support"         OFF)
 option(USE_EIGEN_FOR_BLAS   "Use matrix multiplication in Eigen"        OFF)
+option(WITH_ARM_FP16    "Use half precision support on armv8.2-a cpu"   OFF)
 
 # CMAKE_BUILD_TYPE
 if(NOT CMAKE_BUILD_TYPE)

cmake/configure.cmake

@@ -24,6 +24,11 @@ if(WITH_DOUBLE)
     add_definitions(-DPADDLE_TYPE_DOUBLE)
 endif(WITH_DOUBLE)
 
+if(WITH_ARM_FP16)
+    add_definitions(-DPADDLE_ARM_FP16)
+    add_definitions("-march=armv8.2-a+fp16+simd")
+endif(WITH_ARM_FP16)
+
 if(WITH_TESTING)
     add_definitions(-DPADDLE_WITH_TESTING)
 endif(WITH_TESTING)