fix : correctly compile a comple test program and issues mul/div emul…

…ation functions from compiler-rt runtime.

README.md

@@ -120,4 +120,40 @@ cmake -G "Ninja" \
   -DLLVM_ENABLE_RUNTIMES="compiler-rt" \
   -DLLVM_ENABLE_THREADS=Off \
   ../llvm/
-```
+```
+
+### Building COMPILER-RT
+```sh
+cmake ../compiler-rt/ \
+  -G Ninja \
+  -DCOMPILER_RT_BUILD_BUILTINS=ON \
+  -DCOMPILER_RT_BUILD_SANITIZERS=OFF \
+  -DCOMPILER_RT_BUILD_XRAY=OFF \
+  -DCOMPILER_RT_BUILD_LIBFUZZER=OFF \
+  -DCOMPILER_RT_BUILD_PROFILE=OFF \
+  -DCMAKE_C_COMPILER=clang-10 \
+  -DCMAKE_CXX_COMPILER=clang-10 \
+  -DCMAKE_AR=../build/bin/llvm-ar \
+  -DCMAKE_NM=../build/bin/llvm-nm \
+  -DCMAKE_RANLIB=../build/bin/llvm-ranlib \
+  -DCMAKE_EXE_LINKER_FLAGS="-fuse-ld=lld -nostdlib -Wl,-m,elf32ldlx" \
+  -DCMAKE_C_COMPILER_TARGET="dlx32-unknown-elf" \
+  -DCMAKE_ASM_COMPILER_TARGET="dlx32-unknown-elf" \
+  -DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON \
+  -DLLVM_CONFIG_PATH=../build/bin/llvm-config \
+  -DCMAKE_C_FLAGS="-integrated-as" \
+  -DCMAKE_CXX_FLAGS="-integrated-as" \
+  -DCOMPILER_RT_USE_PTHREADS=OFF \
+  -DCOMPILER_RT_BAREMETAL_BUILD=ON
+```
+
+### Compiling a simple program
+Just compile the program with the following command:
+```sh
+../build/bin/clang -target dlx32-unknown-elf -integrated-as -O2 -nostartfiles -nostdlib -c main.c -o main
+```
+
+Then link it to the library:
+```sh
+../build/bin/ld.lld main -L ../build-compiler-rt/lib/linux -lclang_rt.builtins-dlx32
+```

compiler-rt/lib/builtins/CMakeLists.txt

@@ -108,6 +108,7 @@ set(GENERIC_SOURCES
   muldc3.c
   muldf3.c
   muldi3.c
+  mulsi3.c
   mulodi4.c
   mulosi4.c
   muloti4.c

compiler-rt/lib/builtins/mulsi3.c

@@ -0,0 +1,39 @@
+/* Generic 32 bit multiply.
+   Copyright (C) 2009-2024 Free Software Foundation, Inc.
+   Contributed by Embecosm on behalf of Adapteva, Inc.
+
+This file is part of GCC.
+
+This file is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by the
+Free Software Foundation; either version 3, or (at your option) any
+later version.
+
+This file is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+unsigned int
+__mulsi3 (unsigned int a, unsigned int b)
+{
+  unsigned int r = 0;
+
+  while (a)
+    {
+      if (a & 1)
+	r += b;
+      a >>= 1;
+      b <<= 1;
+    }
+  return r;
+}

lld/ELF/InputFiles.cpp

@@ -131,6 +131,10 @@ static bool isCompatible(InputFile *file) {
   if (!file->isElf() && !isa<BitcodeFile>(file))
     return true;
 
+  outs() << "filename: " << file->getName() << "\n";
+  outs() << "config->ekind: " << config->ekind << "config->emachine: " << config->emachine << "\n";
+  outs() << "file->ekind: " << file->ekind << "file->emachine: " << file->emachine << "\n";
+
   if (file->ekind == config->ekind && file->emachine == config->emachine) {
     if (config->emachine != EM_MIPS)
       return true;

tests/main.c

@@ -11,12 +11,55 @@ int acc(int n)
 	return tmp;
 }
 
+int partition(int *arr, int low, int high)
+{
+	int pivot = arr[high];
+	int i = low - 1;
+
+	for (int j = low; j <= high - 1; j++)
+	{
+		if (arr[j] < pivot)
+		{
+			i++;
+			int tmp = arr[i];
+			arr[i] = arr[j];
+			arr[j] = tmp;
+		}
+	}
+
+	int tmp = arr[i + 1];
+	arr[i + 1] = arr[high];
+	arr[high] = tmp;
+
+	return i + 1;
+}
+
+int quick_sort(int *arr, int low, int high)
+{
+	if (low < high)
+	{
+		int pi = partition(arr, low, high);
+
+		quick_sort(arr, low, pi - 1);
+		quick_sort(arr, pi + 1, high);
+	}
+}
+
+unsigned div(unsigned a, unsigned b)
+{
+	return a / b;
+}
+
 int main(void)
 {
 	int a = 2;
 	int b = 1;
 
-	return acc(a) + acc(b);
+	int array [5] = {5, 4, 3, 2, 1};
+
+	quick_sort(array, 0, 4);
+
+	return div((unsigned) (acc(a) + acc(b)), (unsigned)array[0]);
 }