1 files changed, 0 insertions, 204 deletions
diff --git a/contrib/llvm/lib/CodeGen/UnreachableBlockElim.cpp b/contrib/llvm/lib/CodeGen/UnreachableBlockElim.cpp
deleted file mode 100644
index 177bab32bccc..000000000000
--- a/contrib/llvm/lib/CodeGen/UnreachableBlockElim.cpp
+++ /dev/null
@@ -1,204 +0,0 @@
-//===-- UnreachableBlockElim.cpp - Remove unreachable blocks for codegen --===//
-//
-// 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 pass is an extremely simple version of the SimplifyCFG pass.  Its sole
-// job is to delete LLVM basic blocks that are not reachable from the entry
-// node.  To do this, it performs a simple depth first traversal of the CFG,
-// then deletes any unvisited nodes.
-//
-// Note that this pass is really a hack.  In particular, the instruction
-// selectors for various targets should just not generate code for unreachable
-// blocks.  Until LLVM has a more systematic way of defining instruction
-// selectors, however, we cannot really expect them to handle additional
-// complexity.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/CodeGen/UnreachableBlockElim.h"
-#include "llvm/ADT/DepthFirstIterator.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/CodeGen/MachineDominators.h"
-#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineInstrBuilder.h"
-#include "llvm/CodeGen/MachineLoopInfo.h"
-#include "llvm/CodeGen/MachineModuleInfo.h"
-#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/CodeGen/Passes.h"
-#include "llvm/CodeGen/TargetInstrInfo.h"
-#include "llvm/IR/CFG.h"
-#include "llvm/IR/Constant.h"
-#include "llvm/IR/Dominators.h"
-#include "llvm/IR/Function.h"
-#include "llvm/IR/Instructions.h"
-#include "llvm/IR/Type.h"
-#include "llvm/Pass.h"
-#include "llvm/Transforms/Utils/BasicBlockUtils.h"
-using namespace llvm;
-
-namespace {
-class UnreachableBlockElimLegacyPass : public FunctionPass {
-  bool runOnFunction(Function &F) override {
-    return llvm::EliminateUnreachableBlocks(F);
-  }
-
-public:
-  static char ID; // Pass identification, replacement for typeid
-  UnreachableBlockElimLegacyPass() : FunctionPass(ID) {
-    initializeUnreachableBlockElimLegacyPassPass(
-        *PassRegistry::getPassRegistry());
-  }
-
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    AU.addPreserved<DominatorTreeWrapperPass>();
-  }
-};
-}
-char UnreachableBlockElimLegacyPass::ID = 0;
-INITIALIZE_PASS(UnreachableBlockElimLegacyPass, "unreachableblockelim",
-                "Remove unreachable blocks from the CFG", false, false)
-
-FunctionPass *llvm::createUnreachableBlockEliminationPass() {
-  return new UnreachableBlockElimLegacyPass();
-}
-
-PreservedAnalyses UnreachableBlockElimPass::run(Function &F,
-                                                FunctionAnalysisManager &AM) {
-  bool Changed = llvm::EliminateUnreachableBlocks(F);
-  if (!Changed)
-    return PreservedAnalyses::all();
-  PreservedAnalyses PA;
-  PA.preserve<DominatorTreeAnalysis>();
-  return PA;
-}
-
-namespace {
-  class UnreachableMachineBlockElim : public MachineFunctionPass {
-    bool runOnMachineFunction(MachineFunction &F) override;
-    void getAnalysisUsage(AnalysisUsage &AU) const override;
-    MachineModuleInfo *MMI;
-  public:
-    static char ID; // Pass identification, replacement for typeid
-    UnreachableMachineBlockElim() : MachineFunctionPass(ID) {}
-  };
-}
-char UnreachableMachineBlockElim::ID = 0;
-
-INITIALIZE_PASS(UnreachableMachineBlockElim, "unreachable-mbb-elimination",
-  "Remove unreachable machine basic blocks", false, false)
-
-char &llvm::UnreachableMachineBlockElimID = UnreachableMachineBlockElim::ID;
-
-void UnreachableMachineBlockElim::getAnalysisUsage(AnalysisUsage &AU) const {
-  AU.addPreserved<MachineLoopInfo>();
-  AU.addPreserved<MachineDominatorTree>();
-  MachineFunctionPass::getAnalysisUsage(AU);
-}
-
-bool UnreachableMachineBlockElim::runOnMachineFunction(MachineFunction &F) {
-  df_iterator_default_set<MachineBasicBlock*> Reachable;
-  bool ModifiedPHI = false;
-
-  MMI = getAnalysisIfAvailable<MachineModuleInfo>();
-  MachineDominatorTree *MDT = getAnalysisIfAvailable<MachineDominatorTree>();
-  MachineLoopInfo *MLI = getAnalysisIfAvailable<MachineLoopInfo>();
-
-  // Mark all reachable blocks.
-  for (MachineBasicBlock *BB : depth_first_ext(&F, Reachable))
-    (void)BB/* Mark all reachable blocks */;
-
-  // Loop over all dead blocks, remembering them and deleting all instructions
-  // in them.
-  std::vector<MachineBasicBlock*> DeadBlocks;
-  for (MachineFunction::iterator I = F.begin(), E = F.end(); I != E; ++I) {
-    MachineBasicBlock *BB = &*I;
-
-    // Test for deadness.
-    if (!Reachable.count(BB)) {
-      DeadBlocks.push_back(BB);
-
-      // Update dominator and loop info.
-      if (MLI) MLI->removeBlock(BB);
-      if (MDT && MDT->getNode(BB)) MDT->eraseNode(BB);
-
-      while (BB->succ_begin() != BB->succ_end()) {
-        MachineBasicBlock* succ = *BB->succ_begin();
-
-        MachineBasicBlock::iterator start = succ->begin();
-        while (start != succ->end() && start->isPHI()) {
-          for (unsigned i = start->getNumOperands() - 1; i >= 2; i-=2)
-            if (start->getOperand(i).isMBB() &&
-                start->getOperand(i).getMBB() == BB) {
-              start->RemoveOperand(i);
-              start->RemoveOperand(i-1);
-            }
-
-          start++;
-        }
-
-        BB->removeSuccessor(BB->succ_begin());
-      }
-    }
-  }
-
-  // Actually remove the blocks now.
-  for (unsigned i = 0, e = DeadBlocks.size(); i != e; ++i)
-    DeadBlocks[i]->eraseFromParent();
-
-  // Cleanup PHI nodes.
-  for (MachineFunction::iterator I = F.begin(), E = F.end(); I != E; ++I) {
-    MachineBasicBlock *BB = &*I;
-    // Prune unneeded PHI entries.
-    SmallPtrSet<MachineBasicBlock*, 8> preds(BB->pred_begin(),
-                                             BB->pred_end());
-    MachineBasicBlock::iterator phi = BB->begin();
-    while (phi != BB->end() && phi->isPHI()) {
-      for (unsigned i = phi->getNumOperands() - 1; i >= 2; i-=2)
-        if (!preds.count(phi->getOperand(i).getMBB())) {
-          phi->RemoveOperand(i);
-          phi->RemoveOperand(i-1);
-          ModifiedPHI = true;
-        }
-
-      if (phi->getNumOperands() == 3) {
-        const MachineOperand &Input = phi->getOperand(1);
-        const MachineOperand &Output = phi->getOperand(0);
-        unsigned InputReg = Input.getReg();
-        unsigned OutputReg = Output.getReg();
-        assert(Output.getSubReg() == 0 && "Cannot have output subregister");
-        ModifiedPHI = true;
-
-        if (InputReg != OutputReg) {
-          MachineRegisterInfo &MRI = F.getRegInfo();
-          unsigned InputSub = Input.getSubReg();
-          if (InputSub == 0 &&
-              MRI.constrainRegClass(InputReg, MRI.getRegClass(OutputReg)) &&
-              !Input.isUndef()) {
-            MRI.replaceRegWith(OutputReg, InputReg);
-          } else {
-            // The input register to the PHI has a subregister or it can't be
-            // constrained to the proper register class or it is undef:
-            // insert a COPY instead of simply replacing the output
-            // with the input.
-            const TargetInstrInfo *TII = F.getSubtarget().getInstrInfo();
-            BuildMI(*BB, BB->getFirstNonPHI(), phi->getDebugLoc(),
-                    TII->get(TargetOpcode::COPY), OutputReg)
-                .addReg(InputReg, getRegState(Input), InputSub);
-          }
-          phi++->eraseFromParent();
-        }
-        continue;
-      }
-
-      ++phi;
-    }
-  }
-
-  F.RenumberBlocks();
-
-  return (!DeadBlocks.empty() || ModifiedPHI);
-}