[RegressionTest] Add bitcode E2E test by SAP for cost-based function outlining with indirectbr/blockaddr (#293)

* Add regression bitcode test for SAP usecase

* Add purpose section to README of test

* Apply feedback

* Delete ll file

* Rephase purpose

* Remove llvm-as section in README

Author: marcauberer

Bitcode/Regression/CMakeLists.txt

@@ -9,4 +9,7 @@ if(ARCH STREQUAL "x86")
      NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS "5.0")
   add_subdirectory(fft)
   endif()
+
+  # E2E regression tests from SAP
+  add_subdirectory(sap_fct_splitting)
 endif()

Bitcode/Regression/sap_fct_splitting/CMakeLists.txt

@@ -0,0 +1,7 @@
+SET_SOURCE_FILES_PROPERTIES(${CMAKE_CURRENT_SOURCE_DIR}/sap_fct_splitting.bc PROPERTIES LANGUAGE C)
+SET_SOURCE_FILES_PROPERTIES(${CMAKE_CURRENT_SOURCE_DIR}/mocks.c PROPERTIES LANGUAGE C)
+
+llvm_multisource(sap_fct_splitting
+  ${CMAKE_CURRENT_SOURCE_DIR}/sap_fct_splitting.bc
+  ${CMAKE_CURRENT_SOURCE_DIR}/mocks.c
+)

Bitcode/Regression/sap_fct_splitting/README.md

@@ -0,0 +1,27 @@
+# SAP function splitting regression test
+
+## Purpose
+This tests the correct compilation of `indirectbr` and `blockaddr` in combination with custom cost-based function outlining.
+
+## Produce bitcode file
+This bitcode test was generated from this high level program:
+
+```
+Int32 main() {
+  Bool x;
+  Int32 counter = test::produce(5);
+  while (counter < 10) {
+    counter++;
+// Creation of subfunction forced here - start
+    if (counter >= 8) {
+      break; // triggers indirectbr
+    } else if (counter >= 4) {
+      continue; // triggers indirectbr
+    }
+// Creation of subfunction forced here - end
+    test::consume(counter);
+  }
+  return 1;
+}
+
+```

Bitcode/Regression/sap_fct_splitting/mocks.c

@@ -0,0 +1,20 @@
+#include <stdint.h>
+
+typedef char* opaque_ptr;
+
+// Globals
+opaque_ptr _debugInfo = 0;
+opaque_ptr _sourceCodeObj = 0;
+
+// Mock functions
+uint64_t llangStackTracePushVoid(opaque_ptr context, uint32_t lineNumber, uint64_t returnCode, opaque_ptr literal, opaque_ptr debugInfo, opaque_ptr sourceCodeObj) {
+  return 0;
+}
+
+int64_t llangTestProduce(opaque_ptr obj, int64_t input) {
+  return input;
+}
+
+int64_t llangTestConsume(opaque_ptr obj, int64_t input) {
+  return input;
+}