[LegacyPM] Port example pass SimplifyCFG to new PM

This is part of effort in removing -enable-new-pm flag.
As a prat of this effort one of example passes SimplifyCFG must
be ported to new PM which will allow to remove the flag
calls from the tests that are using this pass.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D137103

Author: speryt

llvm/examples/IRTransforms/CMakeLists.txt

@@ -1,15 +1,19 @@
-set(LLVM_LINK_COMPONENTS
-  Analysis
-  Core
-  Support
-  )
+if(LLVM_EXAMPLEIRTRANSFORMS_LINK_INTO_TOOLS)
+    message(WARNING "Setting LLVM_EXAMPLEIRTRANSFORMS_LINK_INTO_TOOLS=ON only makes sense for testing purpose")
+endif()
 
-add_llvm_example_library(ExampleIRTransforms
-  InitializePasses.cpp
-  SimplifyCFG.cpp
+# The plugin expects to not link against the Support and Core libraries,
+# but expects them to exist in the process loading the plugin. This doesn't
+# work with DLLs on Windows (where a shared library can't have undefined
+# references), so just skip this example on Windows.
+if (NOT WIN32)
+  add_llvm_pass_plugin(ExampleIRTransforms
+    SimplifyCFG.cpp
+    DEPENDS
+    intrinsics_gen
+    BUILDTREE_ONLY
+    )
 
-  ADDITIONAL_HEADER_DIRS
-
-  DEPENDS
-  intrinsics_gen
-  )
+  install(TARGETS ${name} RUNTIME DESTINATION "${LLVM_EXAMPLES_INSTALL_DIR}")
+  set_target_properties(${name} PROPERTIES FOLDER "Examples")
+endif()

llvm/examples/IRTransforms/InitializePasses.cpp

@@ -27,20 +27,18 @@
 //     predecessor, if that block has a single successor.
 //
 // TODOs
-//  * Hook up pass to the new pass manager.
 //  * Preserve LoopInfo.
 //  * Add fixed point iteration to delete all dead blocks
 //  * Add implementation using reachability to discover dead blocks.
 //===----------------------------------------------------------------------===//
 
-#include "SimplifyCFG.h"
-#include "InitializePasses.h"
 #include "llvm/Analysis/DomTreeUpdater.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/PassManager.h"
 #include "llvm/IR/PatternMatch.h"
-#include "llvm/InitializePasses.h"
+#include "llvm/Passes/PassBuilder.h"
+#include "llvm/Passes/PassPlugin.h"
 #include "llvm/Support/CommandLine.h"
 
 using namespace llvm;
@@ -369,46 +367,48 @@ static bool doSimplify_v3(Function &F, DominatorTree &DT) {
 }
 
 namespace {
-struct SimplifyCFGLegacyPass : public FunctionPass {
-  static char ID;
-  SimplifyCFGLegacyPass() : FunctionPass(ID) {
-    initializeSimplifyCFGLegacyPassPass(*PassRegistry::getPassRegistry());
-  }
-
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    AU.addRequired<DominatorTreeWrapperPass>();
-    // Version 1 of the implementation does not preserve the dominator tree.
-    if (Version != V1)
-      AU.addPreserved<DominatorTreeWrapperPass>();
-
-    FunctionPass::getAnalysisUsage(AU);
-  }
-
-  bool runOnFunction(Function &F) override {
-    if (skipFunction(F))
-      return false;
-
+struct SimplifyCFGPass : public PassInfoMixin<SimplifyCFGPass> {
+  PreservedAnalyses run(Function &F, FunctionAnalysisManager &FAM) {
     switch (Version) {
     case V1:
-      return doSimplify_v1(F);
+      doSimplify_v1(F);
+      break;
     case V2: {
-      auto &DT = getAnalysis<DominatorTreeWrapperPass>().getDomTree();
-      return doSimplify_v2(F, DT);
+      DominatorTree &DT = FAM.getResult<DominatorTreeAnalysis>(F);
+      doSimplify_v2(F, DT);
+      break;
     }
     case V3: {
-      auto &DT = getAnalysis<DominatorTreeWrapperPass>().getDomTree();
-      return doSimplify_v3(F, DT);
+      DominatorTree &DT = FAM.getResult<DominatorTreeAnalysis>(F);
+      doSimplify_v3(F, DT);
+      break;
     }
     }
 
-    llvm_unreachable("Unsupported version");
+    return PreservedAnalyses::none();
   }
 };
 } // namespace
 
-char SimplifyCFGLegacyPass::ID = 0;
-INITIALIZE_PASS_BEGIN(SimplifyCFGLegacyPass, DEBUG_TYPE,
-                      "Tutorial CFG simplification", false, false)
-INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
-INITIALIZE_PASS_END(SimplifyCFGLegacyPass, DEBUG_TYPE,
-                    "Tutorial CFG simplifications", false, false)
+/* New PM Registration */
+llvm::PassPluginLibraryInfo getExampleIRTransformsPluginInfo() {
+  return {LLVM_PLUGIN_API_VERSION, "SimplifyCFG", LLVM_VERSION_STRING,
+          [](PassBuilder &PB) {
+            PB.registerPipelineParsingCallback(
+                [](StringRef Name, llvm::FunctionPassManager &PM,
+                   ArrayRef<llvm::PassBuilder::PipelineElement>) {
+                  if (Name == "tut-simplifycfg") {
+                    PM.addPass(SimplifyCFGPass());
+                    return true;
+                  }
+                  return false;
+                });
+          }};
+}
+
+#ifndef LLVM_SIMPLIFYCFG_LINK_INTO_TOOLS
+extern "C" LLVM_ATTRIBUTE_WEAK ::llvm::PassPluginLibraryInfo
+llvmGetPassPluginInfo() {
+  return getExampleIRTransformsPluginInfo();
+}
+#endif

llvm/examples/IRTransforms/InitializePasses.h

@@ -16,6 +16,7 @@ llvm_canonicalize_cmake_booleans(
   LLVM_BUILD_EXAMPLES
   LLVM_ENABLE_PLUGINS
   LLVM_BYE_LINK_INTO_TOOLS
+  LLVM_EXAMPLEIRTRANSFORMS_LINK_INTO_TOOLS
   LLVM_HAVE_TF_AOT
   LLVM_HAVE_TFLITE
   LLVM_INLINER_MODEL_AUTOGENERATED
@@ -190,6 +191,7 @@ if(LLVM_BUILD_EXAMPLES)
   if (NOT WIN32)
     list(APPEND LLVM_TEST_DEPENDS
       Bye
+      ExampleIRTransforms
       )
   endif()
 endif()

llvm/examples/IRTransforms/SimplifyCFG.cpp

@@ -1,7 +1,7 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -tut-simplifycfg -tut-simplifycfg-version=v1 -enable-new-pm=0 -S < %s | FileCheck %s
-; RUN: opt -tut-simplifycfg -tut-simplifycfg-version=v2 -enable-new-pm=0 -S < %s | FileCheck %s
-; RUN: opt -tut-simplifycfg -tut-simplifycfg-version=v3 -enable-new-pm=0 -S < %s | FileCheck %s
+; RUN: opt %loadexampleirtransforms -passes=tut-simplifycfg -tut-simplifycfg-version=v1 -S < %s | FileCheck %s
+; RUN: opt %loadexampleirtransforms -passes=tut-simplifycfg -tut-simplifycfg-version=v2 -S < %s | FileCheck %s
+; RUN: opt %loadexampleirtransforms -passes=tut-simplifycfg -tut-simplifycfg-version=v3 -S < %s | FileCheck %s
 
 define ptr @simp1(i32 %x) {
 ; CHECK-LABEL: @simp1(

llvm/examples/IRTransforms/SimplifyCFG.h

@@ -1,7 +1,7 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -tut-simplifycfg -tut-simplifycfg-version=v1 -enable-new-pm=0 -S < %s | FileCheck %s
-; RUN: opt -tut-simplifycfg -tut-simplifycfg-version=v2 -enable-new-pm=0 -S < %s | FileCheck %s
-; RUN: opt -tut-simplifycfg -tut-simplifycfg-version=v3 -enable-new-pm=0 -S < %s | FileCheck %s
+; RUN: opt %loadexampleirtransforms -passes=tut-simplifycfg -tut-simplifycfg-version=v1 -S < %s | FileCheck %s
+; RUN: opt %loadexampleirtransforms -passes=tut-simplifycfg -tut-simplifycfg-version=v2 -S < %s | FileCheck %s
+; RUN: opt %loadexampleirtransforms -passes=tut-simplifycfg -tut-simplifycfg-version=v3 -S < %s | FileCheck %s
 
 define i32 @simp1() {
 ; CHECK-LABEL: @simp1(

llvm/test/CMakeLists.txt

@@ -1,7 +1,7 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -tut-simplifycfg -tut-simplifycfg-version=v1 -enable-new-pm=0 -S < %s | FileCheck %s
-; RUN: opt -tut-simplifycfg -tut-simplifycfg-version=v2 -enable-new-pm=0 -S < %s | FileCheck %s
-; RUN: opt -tut-simplifycfg -tut-simplifycfg-version=v3 -enable-new-pm=0 -S < %s | FileCheck %s
+; RUN: opt %loadexampleirtransforms -passes=tut-simplifycfg -tut-simplifycfg-version=v1 -S < %s | FileCheck %s
+; RUN: opt %loadexampleirtransforms -passes=tut-simplifycfg -tut-simplifycfg-version=v2 -S < %s | FileCheck %s
+; RUN: opt %loadexampleirtransforms -passes=tut-simplifycfg -tut-simplifycfg-version=v3 -S < %s | FileCheck %s
 
 define i32 @remove_dead_blocks() {
 ; CHECK-LABEL: @remove_dead_blocks(

llvm/test/Examples/IRTransforms/SimplifyCFG/tut-simplify-cfg-blockaddress.ll

@@ -1,7 +1,7 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -tut-simplifycfg -tut-simplifycfg-version=v1 -enable-new-pm=0 -S < %s | FileCheck %s
-; RUN: opt -tut-simplifycfg -tut-simplifycfg-version=v2 -enable-new-pm=0 -S < %s | FileCheck %s
-; RUN: opt -tut-simplifycfg -tut-simplifycfg-version=v3 -enable-new-pm=0 -S < %s | FileCheck %s
+; RUN: opt %loadexampleirtransforms -passes=tut-simplifycfg -tut-simplifycfg-version=v1 -S < %s | FileCheck %s
+; RUN: opt %loadexampleirtransforms -passes=tut-simplifycfg -tut-simplifycfg-version=v2 -S < %s | FileCheck %s
+; RUN: opt %loadexampleirtransforms -passes=tut-simplifycfg -tut-simplifycfg-version=v3 -S < %s | FileCheck %s
 
 define i32 @phi_cond_branch_eliminated() {
 ; CHECK-LABEL: @phi_cond_branch_eliminated(

llvm/test/Examples/IRTransforms/SimplifyCFG/tut-simplify-cfg1.ll

@@ -1,7 +1,7 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -tut-simplifycfg -tut-simplifycfg-version=v1 < %s -enable-new-pm=0 -S -verify-dom-info | FileCheck %s
-; RUN: opt -tut-simplifycfg -tut-simplifycfg-version=v2 < %s -enable-new-pm=0 -S -verify-dom-info | FileCheck %s
-; RUN: opt -tut-simplifycfg -tut-simplifycfg-version=v3 < %s -enable-new-pm=0 -S -verify-dom-info | FileCheck %s
+; RUN: opt %loadexampleirtransforms -passes=tut-simplifycfg -tut-simplifycfg-version=v1 < %s -S -verify-dom-info | FileCheck %s
+; RUN: opt %loadexampleirtransforms -passes=tut-simplifycfg -tut-simplifycfg-version=v2 < %s -S -verify-dom-info | FileCheck %s
+; RUN: opt %loadexampleirtransforms -passes=tut-simplifycfg -tut-simplifycfg-version=v3 < %s -S -verify-dom-info | FileCheck %s
 
 ; Check that we do not crash when we remove edges multiple times in
 ; the DomTreeUpdater.

llvm/test/Examples/IRTransforms/SimplifyCFG/tut-simplify-cfg2-dead-block-order.ll

@@ -1,7 +1,7 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -tut-simplifycfg -tut-simplifycfg-version=v1 < %s -enable-new-pm=0 -S -verify-dom-info | FileCheck %s
-; RUN: opt -tut-simplifycfg -tut-simplifycfg-version=v2 < %s -enable-new-pm=0 -S -verify-dom-info | FileCheck %s
-; RUN: opt -tut-simplifycfg -tut-simplifycfg-version=v3 < %s -enable-new-pm=0 -S -verify-dom-info | FileCheck %s
+; RUN: opt %loadexampleirtransforms -passes=tut-simplifycfg -tut-simplifycfg-version=v1 < %s -S -verify-dom-info | FileCheck %s
+; RUN: opt %loadexampleirtransforms -passes=tut-simplifycfg -tut-simplifycfg-version=v2 < %s -S -verify-dom-info | FileCheck %s
+; RUN: opt %loadexampleirtransforms -passes=tut-simplifycfg -tut-simplifycfg-version=v3 < %s -S -verify-dom-info | FileCheck %s
 
 define void @test() {
 ; CHECK-LABEL: @test(

llvm/test/Examples/IRTransforms/SimplifyCFG/tut-simplify-cfg3-phis.ll

@@ -1,7 +1,7 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -tut-simplifycfg -tut-simplifycfg-version=v1 -enable-new-pm=0 -S < %s | FileCheck %s
-; RUN: opt -tut-simplifycfg -tut-simplifycfg-version=v2 -enable-new-pm=0 -S < %s | FileCheck %s
-; RUN: opt -tut-simplifycfg -tut-simplifycfg-version=v3 -enable-new-pm=0 -S < %s | FileCheck %s
+; RUN: opt %loadexampleirtransforms -passes=tut-simplifycfg -tut-simplifycfg-version=v1 -S < %s | FileCheck %s
+; RUN: opt %loadexampleirtransforms -passes=tut-simplifycfg -tut-simplifycfg-version=v2 -S < %s | FileCheck %s
+; RUN: opt %loadexampleirtransforms -passes=tut-simplifycfg -tut-simplifycfg-version=v3 -S < %s | FileCheck %s
 
 define i32 @simp1() {
 ; CHECK-LABEL: @simp1(

llvm/test/Examples/IRTransforms/SimplifyCFG/tut-simplify-cfg4-multiple-duplicate-cfg-updates.ll

@@ -288,6 +288,13 @@ def version_int(ver):
                                  .format(config.llvm_shlib_dir,
                                          config.llvm_shlib_ext)))
 
+if config.linked_exampleirtransforms_extension:
+    config.substitutions.append(('%loadexampleirtransforms',''))
+else:
+    config.substitutions.append(('%loadexampleirtransforms',
+                                 '-load-pass-plugin={}/ExampleIRTransforms{}'
+                                 .format(config.llvm_shlib_dir,
+                                 config.llvm_shlib_ext)))
 
 # Static libraries are not built if BUILD_SHARED_LIBS is ON.
 if not config.build_shared_libs and not config.link_llvm_dylib:

llvm/test/Examples/IRTransforms/SimplifyCFG/tut-simplify-cfg5-del-phis-for-dead-block.ll

@@ -52,6 +52,7 @@ config.have_opt_viewer_modules = @LLVM_HAVE_OPT_VIEWER_MODULES@
 config.libcxx_used = @LLVM_LIBCXX_USED@
 config.has_plugins = @LLVM_ENABLE_PLUGINS@
 config.linked_bye_extension = @LLVM_BYE_LINK_INTO_TOOLS@
+config.linked_exampleirtransforms_extension = @LLVM_EXAMPLEIRTRANSFORMS_LINK_INTO_TOOLS@
 config.have_tf_aot = @LLVM_HAVE_TF_AOT@
 config.have_tflite = @LLVM_HAVE_TFLITE@
 config.llvm_inliner_model_autogenerated = @LLVM_INLINER_MODEL_AUTOGENERATED@

llvm/test/Examples/IRTransforms/SimplifyCFG/tut-simplify-cfg6-dead-self-loop.ll

@@ -40,7 +40,3 @@ add_llvm_tool(opt
   SUPPORT_PLUGINS
   )
 export_executable_symbols_for_plugins(opt)
-
-if(LLVM_BUILD_EXAMPLES)
-    target_link_libraries(opt PRIVATE ExampleIRTransforms)
-endif(LLVM_BUILD_EXAMPLES)

llvm/test/lit.cfg.py

@@ -314,10 +314,6 @@ static TargetMachine* GetTargetMachine(Triple TheTriple, StringRef CPUStr,
       codegen::getExplicitCodeModel(), GetCodeGenOptLevel());
 }
 
-#ifdef BUILD_EXAMPLES
-void initializeExampleIRTransforms(llvm::PassRegistry &Registry);
-#endif
-
 struct TimeTracerRAII {
   TimeTracerRAII(StringRef ProgramName) {
     if (TimeTrace)
@@ -470,10 +466,6 @@ int main(int argc, char **argv) {
   initializeReplaceWithVeclibLegacyPass(Registry);
   initializeJMCInstrumenterPass(Registry);
 
-#ifdef BUILD_EXAMPLES
-  initializeExampleIRTransforms(Registry);
-#endif
-
   SmallVector<PassPlugin, 1> PluginList;
   PassPlugins.setCallback([&](const std::string &PluginPath) {
     auto Plugin = PassPlugin::Load(PluginPath);

llvm/test/lit.site.cfg.py.in

@@ -82,6 +82,7 @@ write_lit_config("lit_site_cfg") {
     # No bindings are implemented in the GN build.
     "LLVM_BINDINGS=",
     "LLVM_BYE_LINK_INTO_TOOLS=0",
+    "LLVM_EXAMPLEIRTRANSFORMS_LINK_INTO_TOOLS=0",
 
     "HAVE_OCAMLOPT=0",
     "OCAMLFIND=OCAMLFIND-NOTFOUND",