Imported Upstream version 5.18.0.207

Former-commit-id: 3b152f462918d427ce18620a2cbe4f8b79650449

external/llvm/lib/Target/SystemZ/SystemZLDCleanup.cpp

@@ -1,146 +0,0 @@
-//===-- SystemZLDCleanup.cpp - Clean up local-dynamic TLS accesses --------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This pass combines multiple accesses to local-dynamic TLS variables so that
-// the TLS base address for the module is only fetched once per execution path
-// through the function.
-//
-//===----------------------------------------------------------------------===//
-
-#include "SystemZMachineFunctionInfo.h"
-#include "SystemZTargetMachine.h"
-#include "llvm/CodeGen/MachineDominators.h"
-#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineInstrBuilder.h"
-#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/CodeGen/TargetInstrInfo.h"
-#include "llvm/CodeGen/TargetRegisterInfo.h"
-#include "llvm/Target/TargetMachine.h"
-
-using namespace llvm;
-
-namespace {
-
-class SystemZLDCleanup : public MachineFunctionPass {
-public:
-  static char ID;
-  SystemZLDCleanup(const SystemZTargetMachine &tm)
-    : MachineFunctionPass(ID), TII(nullptr), MF(nullptr) {}
-
-  StringRef getPassName() const override {
-    return "SystemZ Local Dynamic TLS Access Clean-up";
-  }
-
-  bool runOnMachineFunction(MachineFunction &MF) override;
-  void getAnalysisUsage(AnalysisUsage &AU) const override;
-
-private:
-  bool VisitNode(MachineDomTreeNode *Node, unsigned TLSBaseAddrReg);
-  MachineInstr *ReplaceTLSCall(MachineInstr *I, unsigned TLSBaseAddrReg);
-  MachineInstr *SetRegister(MachineInstr *I, unsigned *TLSBaseAddrReg);
-
-  const SystemZInstrInfo *TII;
-  MachineFunction *MF;
-};
-
-char SystemZLDCleanup::ID = 0;
-
-} // end anonymous namespace
-
-FunctionPass *llvm::createSystemZLDCleanupPass(SystemZTargetMachine &TM) {
-  return new SystemZLDCleanup(TM);
-}
-
-void SystemZLDCleanup::getAnalysisUsage(AnalysisUsage &AU) const {
-  AU.setPreservesCFG();
-  AU.addRequired<MachineDominatorTree>();
-  MachineFunctionPass::getAnalysisUsage(AU);
-}
-
-bool SystemZLDCleanup::runOnMachineFunction(MachineFunction &F) {
-  if (skipFunction(F.getFunction()))
-    return false;
-
-  TII = static_cast<const SystemZInstrInfo *>(F.getSubtarget().getInstrInfo());
-  MF = &F;
-
-  SystemZMachineFunctionInfo* MFI = F.getInfo<SystemZMachineFunctionInfo>();
-  if (MFI->getNumLocalDynamicTLSAccesses() < 2) {
-    // No point folding accesses if there isn't at least two.
-    return false;
-  }
-
-  MachineDominatorTree *DT = &getAnalysis<MachineDominatorTree>();
-  return VisitNode(DT->getRootNode(), 0);
-}
-
-// Visit the dominator subtree rooted at Node in pre-order.
-// If TLSBaseAddrReg is non-null, then use that to replace any
-// TLS_LDCALL instructions. Otherwise, create the register
-// when the first such instruction is seen, and then use it
-// as we encounter more instructions.
-bool SystemZLDCleanup::VisitNode(MachineDomTreeNode *Node,
-                                 unsigned TLSBaseAddrReg) {
-  MachineBasicBlock *BB = Node->getBlock();
-  bool Changed = false;
-
-  // Traverse the current block.
-  for (auto I = BB->begin(), E = BB->end(); I != E; ++I) {
-    switch (I->getOpcode()) {
-      case SystemZ::TLS_LDCALL:
-        if (TLSBaseAddrReg)
-          I = ReplaceTLSCall(&*I, TLSBaseAddrReg);
-        else
-          I = SetRegister(&*I, &TLSBaseAddrReg);
-        Changed = true;
-        break;
-      default:
-        break;
-    }
-  }
-
-  // Visit the children of this block in the dominator tree.
-  for (auto I = Node->begin(), E = Node->end(); I != E; ++I)
-    Changed |= VisitNode(*I, TLSBaseAddrReg);
-
-  return Changed;
-}
-
-// Replace the TLS_LDCALL instruction I with a copy from TLSBaseAddrReg,
-// returning the new instruction.
-MachineInstr *SystemZLDCleanup::ReplaceTLSCall(MachineInstr *I,
-                                               unsigned TLSBaseAddrReg) {
-  // Insert a Copy from TLSBaseAddrReg to R2.
-  MachineInstr *Copy = BuildMI(*I->getParent(), I, I->getDebugLoc(),
-                               TII->get(TargetOpcode::COPY), SystemZ::R2D)
-                               .addReg(TLSBaseAddrReg);
-
-  // Erase the TLS_LDCALL instruction.
-  I->eraseFromParent();
-
-  return Copy;
-}
-
-// Create a virtual register in *TLSBaseAddrReg, and populate it by
-// inserting a copy instruction after I. Returns the new instruction.
-MachineInstr *SystemZLDCleanup::SetRegister(MachineInstr *I,
-                                            unsigned *TLSBaseAddrReg) {
-  // Create a virtual register for the TLS base address.
-  MachineRegisterInfo &RegInfo = MF->getRegInfo();
-  *TLSBaseAddrReg = RegInfo.createVirtualRegister(&SystemZ::GR64BitRegClass);
-
-  // Insert a copy from R2 to TLSBaseAddrReg.
-  MachineInstr *Next = I->getNextNode();
-  MachineInstr *Copy = BuildMI(*I->getParent(), Next, I->getDebugLoc(),
-                               TII->get(TargetOpcode::COPY), *TLSBaseAddrReg)
-                               .addReg(SystemZ::R2D);
-
-  return Copy;
-}
-