91 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			91 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C++
		
	
	
	
| //===-- ResetMachineFunctionPass.cpp - Reset Machine Function ----*- C++ -*-==//
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| //
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| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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| // See https://llvm.org/LICENSE.txt for license information.
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| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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| //
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| //===----------------------------------------------------------------------===//
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| /// \file
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| /// This file implements a pass that will conditionally reset a machine
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| /// function as if it was just created. This is used to provide a fallback
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| /// mechanism when GlobalISel fails, thus the condition for the reset to
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| /// happen is that the MachineFunction has the FailedISel property.
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| //===----------------------------------------------------------------------===//
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| 
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| #include "llvm/ADT/ScopeExit.h"
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| #include "llvm/ADT/Statistic.h"
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| #include "llvm/CodeGen/MachineFunction.h"
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| #include "llvm/CodeGen/MachineFunctionPass.h"
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| #include "llvm/CodeGen/MachineRegisterInfo.h"
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| #include "llvm/CodeGen/Passes.h"
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| #include "llvm/CodeGen/StackProtector.h"
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| #include "llvm/IR/DiagnosticInfo.h"
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| #include "llvm/InitializePasses.h"
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| #include "llvm/Support/Debug.h"
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| using namespace llvm;
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| 
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| #define DEBUG_TYPE "reset-machine-function"
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| 
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| STATISTIC(NumFunctionsReset, "Number of functions reset");
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| STATISTIC(NumFunctionsVisited, "Number of functions visited");
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| 
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| namespace {
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|   class ResetMachineFunction : public MachineFunctionPass {
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|     /// Tells whether or not this pass should emit a fallback
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|     /// diagnostic when it resets a function.
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|     bool EmitFallbackDiag;
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|     /// Whether we should abort immediately instead of resetting the function.
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|     bool AbortOnFailedISel;
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| 
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|   public:
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|     static char ID; // Pass identification, replacement for typeid
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|     ResetMachineFunction(bool EmitFallbackDiag = false,
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|                          bool AbortOnFailedISel = false)
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|         : MachineFunctionPass(ID), EmitFallbackDiag(EmitFallbackDiag),
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|           AbortOnFailedISel(AbortOnFailedISel) {}
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| 
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|     StringRef getPassName() const override { return "ResetMachineFunction"; }
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| 
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|     void getAnalysisUsage(AnalysisUsage &AU) const override {
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|       AU.addPreserved<StackProtector>();
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|       MachineFunctionPass::getAnalysisUsage(AU);
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|     }
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| 
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|     bool runOnMachineFunction(MachineFunction &MF) override {
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|       ++NumFunctionsVisited;
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|       // No matter what happened, whether we successfully selected the function
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|       // or not, nothing is going to use the vreg types after us. Make sure they
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|       // disappear.
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|       auto ClearVRegTypesOnReturn =
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|           make_scope_exit([&MF]() { MF.getRegInfo().clearVirtRegTypes(); });
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| 
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|       if (MF.getProperties().hasProperty(
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|               MachineFunctionProperties::Property::FailedISel)) {
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|         if (AbortOnFailedISel)
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|           report_fatal_error("Instruction selection failed");
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|         LLVM_DEBUG(dbgs() << "Resetting: " << MF.getName() << '\n');
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|         ++NumFunctionsReset;
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|         MF.reset();
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|         if (EmitFallbackDiag) {
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|           const Function &F = MF.getFunction();
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|           DiagnosticInfoISelFallback DiagFallback(F);
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|           F.getContext().diagnose(DiagFallback);
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|         }
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|         return true;
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|       }
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|       return false;
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|     }
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| 
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|   };
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| } // end anonymous namespace
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| 
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| char ResetMachineFunction::ID = 0;
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| INITIALIZE_PASS(ResetMachineFunction, DEBUG_TYPE,
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|                 "Reset machine function if ISel failed", false, false)
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| 
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| MachineFunctionPass *
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| llvm::createResetMachineFunctionPass(bool EmitFallbackDiag = false,
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|                                      bool AbortOnFailedISel = false) {
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|   return new ResetMachineFunction(EmitFallbackDiag, AbortOnFailedISel);
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| }
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