commit 36cafdcf218c6b3595e1371dcbff18eaaef355bd
author Joseph Huber <jhuber6@vols.utk.edu> Thu Jul 21 14:38:11 2022 -0400
committer Copybara-Service <copybara-worker@google.com> Fri Jul 22 05:25:45 2022 -0700
tree 97ec27a503d9da70b531bf1ce941832d352eafe7
parent 1bb2aff90deaa684e4aa931a0ba7f9e9a4707de2

[Libomptarget] Only export needed definitions in the BC library

This patch adds the use of the `-internalize-public-api-file` option in
the internalization pass to internalize any definition that isn't
explicitly needed for the interface. This will allow us to perform more
optimizations on the file that normally would not have been possible
with functions internal to the library not being internal.

Depends on D130293

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D130298

GitOrigin-RevId: 908054df4f15d44a5e1e72d95aa2bcf92ddb6e1a

libomptarget/DeviceRTL/CMakeLists.txt

diff --git a/libomptarget/DeviceRTL/CMakeLists.txt b/libomptarget/DeviceRTL/CMakeLists.txt
index 0c74006..04ee959 100644
--- a/libomptarget/DeviceRTL/CMakeLists.txt
+++ b/libomptarget/DeviceRTL/CMakeLists.txt
@@ -108,6 +108,7 @@
 
 set(clang_opt_flags -O3 -mllvm -openmp-opt-disable -DSHARED_SCRATCHPAD_SIZE=512)
 set(link_opt_flags  -O3        -openmp-opt-disable)
+set(link_export_flag -passes=internalize -internalize-public-api-file=${source_directory}/exports)
 
 # Prepend -I to each list element
 set (LIBOMPTARGET_LLVM_INCLUDE_DIRS_DEVICERTL "${LIBOMPTARGET_LLVM_INCLUDE_DIRS}")
@@ -173,10 +174,17 @@
       COMMENT "Linking LLVM bitcode ${bclib_name}"
   )
 
+  add_custom_command(OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/internalized_${bclib_name}
+      COMMAND ${OPT_TOOL} ${link_export_flag} ${CMAKE_CURRENT_BINARY_DIR}/linked_${bclib_name}
+                      -o ${CMAKE_CURRENT_BINARY_DIR}/internalized_${bclib_name}
+      DEPENDS ${source_directory}/exports ${CMAKE_CURRENT_BINARY_DIR}/linked_${bclib_name}
+      COMMENT "Internalizing LLVM bitcode ${bclib_name}"
+  )
+
   add_custom_command(OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${bclib_name}
-      COMMAND ${OPT_TOOL} ${link_opt_flags} ${CMAKE_CURRENT_BINARY_DIR}/linked_${bclib_name}
+      COMMAND ${OPT_TOOL} ${link_opt_flags} ${CMAKE_CURRENT_BINARY_DIR}/internalized_${bclib_name}
                       -o ${CMAKE_CURRENT_BINARY_DIR}/${bclib_name}
-      DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/linked_${bclib_name}
+      DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/internalized_${bclib_name}
       COMMENT "Optimizing LLVM bitcode ${bclib_name}"
   )
 

libomptarget/DeviceRTL/src/exports

diff --git a/libomptarget/DeviceRTL/src/exports b/libomptarget/DeviceRTL/src/exports
new file mode 100644
index 0000000..58cbeb1
--- /dev/null
+++ b/libomptarget/DeviceRTL/src/exports
@@ -0,0 +1,3 @@
+omp_*
+*llvm_*
+__kmpc_*