[VENTUS][RISCV][feat] Building libclc library into object file other than archive file

In our previous design, the libclc library is built into static library which make the generated
ELF file having a large size, now we change compiler and linker option to make generated ELF file size much smaller, detail information can be seen in this pull request https://github.com/THU-DSP-LAB/pocl/pull/11

build-ventus.sh

@@ -176,10 +176,10 @@ build_libclc() {
     -DCMAKE_LLAsm_COMPILER_WORKS=ON \
     -DCMAKE_CLC_COMPILER_WORKS=ON \
     -DCMAKE_CLC_COMPILER_FORCED=ON \
-    -DCMAKE_LLAsm_FLAGS="-target riscv32 -mcpu=ventus-gpgpu -cl-std=CL2.0 -Dcl_khr_fp64" \
-    -DCMAKE_CLC_FLAGS="-target riscv32 -mcpu=ventus-gpgpu -cl-std=CL2.0 -I${DIR}/libclc/generic/include -Dcl_khr_fp64" \
+    -DCMAKE_LLAsm_FLAGS="-target riscv32 -mcpu=ventus-gpgpu -cl-std=CL2.0 -Dcl_khr_fp64 -ffunction-sections -fdata-sections" \
+    -DCMAKE_CLC_FLAGS="-target riscv32 -mcpu=ventus-gpgpu -cl-std=CL2.0 -I${DIR}/libclc/generic/include -Dcl_khr_fp64  -ffunction-sections -fdata-sections"\
     -DLIBCLC_TARGETS_TO_BUILD="riscv32--" \
-    -DCMAKE_CXX_FLAGS="-I ${DIR}/llvm/include/ -std=c++17 -Dcl_khr_fp64" \
+    -DCMAKE_CXX_FLAGS="-I ${DIR}/llvm/include/ -std=c++17 -Dcl_khr_fp64 -ffunction-sections -fdata-sections" \
     -DCMAKE_C_COMPILER=clang \
     -DCMAKE_CXX_COMPILER=clang++ \
     -DCMAKE_INSTALL_PREFIX=${VENTUS_INSTALL_PREFIX} \
@@ -187,8 +187,8 @@ build_libclc() {
   ninja
   ninja install
   # TODO: There are bugs in linking all libclc object files now
-  echo "************* Building riscv32 libclc library archive file ************"
-  bash ${DIR}/libclc/build_riscv32_archive.sh ${VENTUS_INSTALL_PREFIX}/bin ${LIBCLC_BUILD_DIR}/riscv32--.bc ${LIBCLC_BUILD_DIR} || true
+  echo "************* Building riscv32 libclc object file ************"
+  bash ${DIR}/libclc/build_riscv32clc.sh ${DIR}/libclc ${LIBCLC_BUILD_DIR} ${VENTUS_INSTALL_PREFIX} || true
 
   DstDir=${VENTUS_INSTALL_PREFIX}/share/pocl
   if [ ! -d "${DstDir}" ]; then

clang/lib/Basic/Targets/RISCV.cpp

@@ -49,7 +49,8 @@ void RISCVTargetInfo::adjust(DiagnosticsEngine &Diags, LangOptions &Opts) {
   llvm::Triple Triple = getTriple();
   bool isRV32 = Triple.isRISCV32();
   // Only OpenCL language needs special address mapping
-  if(Opts.OpenCL) {
+  // FIXME: when meeting C code here is not valid !!
+  if(Opts.OpenCL || Opts.getOpenCLVersionString().size()) {
     UseAddrSpaceMapMangling = true;
     AddrSpaceMap = &VentusAddrSpaceMap;
     if(isRV32)

libclc/build_riscv32_archive.sh

@@ -1,26 +0,0 @@
-#!/usr/bin/bash
-
-BIN_DIR=$1
-BITCODE_FILE=$2
-BUILD_DIR=$3
-ARCHIVE_FILE_PREFIX=${BUILD_DIR}/riscv32--
-COMPILER_FLAGS="-target riscv32  -mcpu=ventus-gpgpu"
-
-if [ ! -d "${BIN_DIR}" ]; then
-	echo "ERROR: LLVM binary directory does not exist!"
-	exit 1
-fi
-
-if [ ! -f "${BITCODE_FILE}" ]; then
-	echo "ERROR: Not a file: ${BITCODE_FILE}"
-	exit 1
-fi
-
-LLVM_DIS=${BIN_DIR}/llvm-dis
-LLVM_LLC=${BIN_DIR}/llc
-LLVM_CLANG=${BIN_DIR}/clang
-LLVM_AR=${BIN_DIR}/llvm-ar
-
-${LLVM_DIS} ${BITCODE_FILE} -o ${ARCHIVE_FILE_PREFIX}.ll
-${LLVM_LLC} --filetype=obj ${ARCHIVE_FILE_PREFIX}.ll  -o ${ARCHIVE_FILE_PREFIX}.o
-${LLVM_AR} rcs ${ARCHIVE_FILE_PREFIX}.a ${ARCHIVE_FILE_PREFIX}.o

libclc/build_riscv32clc.sh

@@ -0,0 +1,28 @@
+#!/usr/bin/bash
+
+LIBCLC_DIR=$1
+LIBCLC_BUILD_DIR=$2
+BINARY_DIR=$3
+
+# Collect all the object files in build directory
+OBJECT_FILE_LIST=""
+for item in $(find ${LIBCLC_BUILD_DIR} -name "*.bc.o")
+do
+    OBJECT_FILE_LIST="${OBJECT_FILE_LIST} ${item}"
+done
+
+# Compile other left IR files
+for item in $(ls ${LIBCLC_DIR}/generic/lib | grep  ll)
+do
+    ${BINARY_DIR}/bin/clang -target riscv32 -mcpu=ventus-gpgpu \
+        -cl-std=CL2.0 \
+        -ffunction-sections -fdata-sections \
+        -c ${LIBCLC_DIR}/generic/lib/${item} \
+        -o ${LIBCLC_BUILD_DIR}/${item}.o
+    OBJECT_FILE_LIST="${OBJECT_FILE_LIST} ${LIBCLC_BUILD_DIR}/${item}.o"
+done
+
+${BINARY_DIR}/bin/ld.lld --relocatable ${OBJECT_FILE_LIST} \
+            --allow-multiple-definition \
+             -o ${LIBCLC_BUILD_DIR}/riscv32clc.o
+cp ${LIBCLC_BUILD_DIR}/riscv32clc.o	${BINARY_DIR}/lib

libclc/cmake/CMakeCLCInformation.cmake

@@ -1,7 +1,8 @@
 if(NOT CMAKE_CLC_COMPILE_OBJECT)
 
 	set(CMAKE_CLC_COMPILE_OBJECT
-	"<CMAKE_CLC_COMPILER> <DEFINES> <INCLUDES> <FLAGS> -o <OBJECT> -c <SOURCE> -emit-llvm")
+	"<CMAKE_CLC_COMPILER> <DEFINES> <INCLUDES> <FLAGS> -o <OBJECT> -c <SOURCE> -emit-llvm"
+	"<CMAKE_CLC_COMPILER> <DEFINES> <INCLUDES> <FLAGS> -o <OBJECT>.o -c <SOURCE>")
 	if( CMAKE_BUILD_TYPE STREQUAL "Debug" )
 		# This is only for depveloper's option to build debug
 		list(APPEND CMAKE_CLC_COMPILE_OBJECT
@@ -14,7 +15,7 @@ endif()
 
 if(NOT CMAKE_CLC_CREATE_STATIC_LIBRARY)
   set(CMAKE_CLC_CREATE_STATIC_LIBRARY
-    "<CMAKE_CLC_ARCHIVE> -o <TARGET> <OBJECTS>")
+  "<CMAKE_CLC_ARCHIVE> -o <TARGET> <OBJECTS>")
 endif()
 
 set(CMAKE_INCLUDE_FLAG_CLC "-I")