llvm/tools/llvm-reduce/deltas/ReduceIRReferences.cpp

   1 //===- ReduceIRReferences.cpp - Specialized Delta Pass --------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file implements a function which calls the Generic Delta pass in order
  10 // to remove backreferences to the IR from MIR. In particular, this will remove
  11 // the Value references in MachineMemOperands.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "ReduceIRReferences.h"
  16 #include "Delta.h"
  17 #include "llvm/CodeGen/MachineFrameInfo.h"
  18 #include "llvm/CodeGen/MachineFunction.h"
  19 #include "llvm/CodeGen/MachineModuleInfo.h"
  20
  21 using namespace llvm;
  22
  23 static void dropIRReferencesFromInstructions(Oracle &O, MachineFunction &MF) {
  24   for (MachineBasicBlock &MBB : MF) {
  25     for (MachineInstr &MI : MBB) {
  26       if (!O.shouldKeep()) {
  27         for (MachineMemOperand *MMO : MI.memoperands()) {
  28           // Leave behind pseudo source values.
  29           // TODO: Removing all MemOperand values is a further reduction step.
  30           if (isa<const Value *>(MMO->getPointerInfo().V))
  31             MMO->setValue(static_cast<const Value *>(nullptr));
  32         }
  33
  34         // TODO: Try to remove GlobalValue references and metadata
  35       }
  36     }
  37   }
  38 }
  39
  40 static void stripIRFromInstructions(Oracle &O, ReducerWorkItem &WorkItem) {
  41   for (const Function &F : WorkItem.getModule()) {
  42     if (auto *MF = WorkItem.MMI->getMachineFunction(F))
  43       dropIRReferencesFromInstructions(O, *MF);
  44   }
  45 }
  46
  47 static void stripIRFromBlocks(Oracle &O, ReducerWorkItem &WorkItem) {
  48   for (const Function &F : WorkItem.getModule()) {
  49     if (auto *MF = WorkItem.MMI->getMachineFunction(F)) {
  50       for (MachineBasicBlock &MBB : *MF) {
  51         if (!O.shouldKeep())
  52           MBB.clearBasicBlock();
  53       }
  54     }
  55   }
  56 }
  57
  58 static void stripIRFromFunctions(Oracle &O, ReducerWorkItem &WorkItem) {
  59   for (const Function &F : WorkItem.getModule()) {
  60     if (!O.shouldKeep()) {
  61       if (auto *MF = WorkItem.MMI->getMachineFunction(F)) {
  62         MachineFrameInfo &MFI = MF->getFrameInfo();
  63         for (int I = MFI.getObjectIndexBegin(), E = MFI.getObjectIndexEnd();
  64              I != E; ++I)
  65           MFI.clearObjectAllocation(I);
  66       }
  67     }
  68   }
  69 }
  70
  71 void llvm::reduceIRInstructionReferencesDeltaPass(TestRunner &Test) {
  72   runDeltaPass(Test, stripIRFromInstructions,
  73                "Reducing IR references from instructions");
  74 }
  75
  76 void llvm::reduceIRBlockReferencesDeltaPass(TestRunner &Test) {
  77   runDeltaPass(Test, stripIRFromBlocks, "Reducing IR references from blocks");
  78 }
  79
  80 void llvm::reduceIRFunctionReferencesDeltaPass(TestRunner &Test) {
  81   runDeltaPass(Test, stripIRFromFunctions,
  82                "Reducing IR references from functions");
  83 }