[NewPM] Port the MIR Printing pass to new pass manager.

[czhang]

rebase & clang-format

[probinson]

Minor stylistic things. Someone who understands passes should look at this.

llvm/include/llvm/CodeGen/MIRPrintingPass.h

2

Filename is .h not .cpp; also, needs a 'C++' tag.

llvm/lib/CodeGen/MIRPrintingPass.cpp

16

Includes aren't sorted properly.

[czhang]

Rebase

[czhang]

Alphabetize

[fedor.sergeev]

I'm not familiar with MIR printing usecases, and there are no tests for MIR printer.
Yet if MIR printing pass is to be applied to the Module only then there is no need to make it a MachineFunction pass, just do everything in a single run(Module...) method.

I would expect to see a registration of this pass in PassRegistry.def as a module pass. Perhaps named as print-mir?

Also, this patch should definitely have some dependencies on prior work introducing MachineFunction as IRUnit etc...

llvm/lib/CodeGen/MIRPrintingPass.cpp

27–31

This looks as something artificial.
If you want to iterate through machine functions and print them there is no need to use pass manager.
Just manually iterate and print.

[fedor.sergeev]

I took the liberty of setting a parent revision, hopefully thats what you did intend to do...

[czhang]

Thank you! Phabricator is still a mystery to me.

[czhang]

In D64188#1606039, @fedor.sergeev wrote:

I'm not familiar with MIR printing usecases, and there are no tests for MIR printer.
Yet if MIR printing pass is to be applied to the Module only then there is no need to make it a MachineFunction pass, just do everything in a single run(Module...) method.

I would expect to see a registration of this pass in PassRegistry.def as a module pass. Perhaps named as print-mir?

Also, this patch should definitely have some dependencies on prior work introducing MachineFunction as IRUnit etc...

I'm not so clear on the use case of the MIR printing pass either, but for sure, llc uses it. To be safe, I just followed how the legacy pass manager did things to try and keep the original intent the same. For example, I did not register the pass in the pass registry, because it is not actually part of the created pass pipeline in the legacy pass manager in llc. There is no way to specify print-mir as part of -run-pass, perhaps because it is already triggered by other command flags. So since MIR printing is done separately in llc, I have followed that convention and done the same in my llc patch.

llvm/lib/CodeGen/MIRPrintingPass.cpp

27–31

In the legacy pass manager, printing MIR functions is done exactly this way. I suspect the reason is that MIR printing for individual MachineFunctions is needed for debugging. Another reason I followed the design of the legacy pass manager is that it is quite a lot of boiler plate and analysis querying just to iterate over every function of a module, and then querying MachineModuleInfo to get the MachineFunction out of each Function. In fact, since the adaptors abstract exactly that, I followed the established precedent. Perhaps we could abstract the idea of iterating over the machine functions of a module some other way?

[thegameg]

The MIRPrinter is used to print MIR when used with -stop-before / -stop-after / -run-pass flags in llc (see https://llvm.org/docs/MIRLangRef.html#mir-testing-guide).

In the case of -stop-*, LLVMTargetMachine.cpp:addPassesToEmitFile sets it up.
In the case of -run-pass, llc.cpp:compileModule does (if (!RunPassNames->empty()) { ...).

As for tests, basically all .mir tests that use the flags above use it.

llvm/include/llvm/CodeGen/MIRPrintingPass.h

+//===- MIRPrintingPass.cpp - Pass that prints out using the MIR format ----===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file descibes the pass that prints out the LLVM module using the MIR
+// serialization format.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_MIRPRINTINGPASS_H
+#define LLVM_CODEGEN_MIRPRINTINGPASS_H
+
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/IR/PassManager.h"
+#include "llvm/CodeGen/PassManager.h"
+#include "llvm/Support/raw_ostream.h"
+
+namespace llvm {
+
+// The MIR Printing pass.
+struct MIRPrintingPass : PassInfoMixin<MIRPrintingPass> {
+  raw_ostream &OS;
+  MIRPrintingPass(raw_ostream &OS) : OS(OS){};
+  PreservedAnalyses run(MachineFunction &MF, MachineFunctionAnalysisManager &);
+  PreservedAnalyses run(Module &M, ModuleAnalysisManager &);
+};
+}
+
+#endif // LLVM_CODEGEN_MIRPRINTINGPASS_H

llvm/include/llvm/InitializePasses.h

 void initializeLowerExpectIntrinsicPass(PassRegistry&);
 void initializeLowerGuardIntrinsicLegacyPassPass(PassRegistry&);
 void initializeLowerWidenableConditionLegacyPassPass(PassRegistry&);
 void initializeLowerIntrinsicsPass(PassRegistry&);
 void initializeLowerInvokeLegacyPassPass(PassRegistry&);
 void initializeLowerSwitchPass(PassRegistry&);
 void initializeLowerTypeTestsPass(PassRegistry&);
 void initializeMIRCanonicalizerPass(PassRegistry &);
-void initializeMIRPrintingPassPass(PassRegistry&);
+void initializeMIRPrintingLegacyPassPass(PassRegistry &);
 void initializeMachineBlockFrequencyInfoPass(PassRegistry&);
 void initializeMachineBlockPlacementPass(PassRegistry&);
 void initializeMachineBlockPlacementStatsPass(PassRegistry&);
 void initializeMachineBranchProbabilityInfoPass(PassRegistry&);
 void initializeMachineCSELegacyPassPass(PassRegistry&);
 void initializeMachineCombinerPass(PassRegistry&);
 void initializeMachineCopyPropagationLegacyPassPass(PassRegistry&);
 void initializeMachineDominanceFrontierPass(PassRegistry&);

llvm/lib/CodeGen/MIRPrintingPass.cpp

 //===- MIRPrintingPass.cpp - Pass that prints out using the MIR format ----===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements a pass that prints out the LLVM module using the MIR
 // serialization format.
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/CodeGen/MIRPrintingPass.h"
 #include "llvm/CodeGen/MIRPrinter.h"
+#include "llvm/CodeGen/PassManager.h"
 
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/Passes.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 
 using namespace llvm;
 
+PreservedAnalyses MIRPrintingPass::run(Module &M, ModuleAnalysisManager &MAM) {
+  printMIR(OS, M);
+  // FIXME: Inefficient. Should only make this adaptor once. Put it in
+  // the class and construct it the first time.
+  return createModuleToFunctionPassAdaptor(
+             createFunctionToMachineFunctionPassAdaptor(*this))
+      .run(M, MAM);
+}
+
+PreservedAnalyses MIRPrintingPass::run(MachineFunction &MF,
+                                       MachineFunctionAnalysisManager &) {
+  printMIR(OS, MF);
+  return PreservedAnalyses::all();
+}
+
 namespace {
 
 /// This pass prints out the LLVM IR to an output stream using the MIR
 /// serialization format.
-struct MIRPrintingPass : public MachineFunctionPass {
+struct MIRPrintingLegacyPass : public MachineFunctionPass {
   static char ID;
   raw_ostream &OS;
   std::string MachineFunctions;
 
-  MIRPrintingPass() : MachineFunctionPass(ID), OS(dbgs()) {}
-  MIRPrintingPass(raw_ostream &OS) : MachineFunctionPass(ID), OS(OS) {}
+  MIRPrintingLegacyPass() : MachineFunctionPass(ID), OS(dbgs()) {}
+  MIRPrintingLegacyPass(raw_ostream &OS) : MachineFunctionPass(ID), OS(OS) {}
 
   StringRef getPassName() const override { return "MIR Printing Pass"; }
 
   void getAnalysisUsage(AnalysisUsage &AU) const override {
     AU.setPreservesAll();
     MachineFunctionPass::getAnalysisUsage(AU);
   }
 
   bool runOnMachineFunction(MachineFunction &MF) override {
     std::string Str;
     raw_string_ostream StrOS(Str);
     printMIR(StrOS, MF);
     MachineFunctions.append(StrOS.str());
     return false;
   }
 
   bool doFinalization(Module &M) override {
     printMIR(OS, M);
     OS << MachineFunctions;
     return false;
   }
 };
 
-char MIRPrintingPass::ID = 0;
+char MIRPrintingLegacyPass::ID = 0;
 
 } // end anonymous namespace
 
-char &llvm::MIRPrintingPassID = MIRPrintingPass::ID;
-INITIALIZE_PASS(MIRPrintingPass, "mir-printer", "MIR Printer", false, false)
+char &llvm::MIRPrintingPassID = MIRPrintingLegacyPass::ID;
+INITIALIZE_PASS(MIRPrintingLegacyPass, "mir-printer", "MIR Printer", false,
+                false)
 
 namespace llvm {
 
 MachineFunctionPass *createPrintMIRPass(raw_ostream &OS) {
-  return new MIRPrintingPass(OS);
+  return new MIRPrintingLegacyPass(OS);
 }
 
 } // end namespace llvm