Imported Upstream version 5.18.0.247

Former-commit-id: 2d6af2e4ed0eda5cbdc2946446ef7718456ad190

external/llvm/lib/Target/WebAssembly/WebAssemblyReplacePhysRegs.cpp

@@ -1,99 +0,0 @@
-//===-- WebAssemblyReplacePhysRegs.cpp - Replace phys regs with virt regs -===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-///
-/// \file
-/// \brief This file implements a pass that replaces physical registers with
-/// virtual registers.
-///
-/// LLVM expects certain physical registers, such as a stack pointer. However,
-/// WebAssembly doesn't actually have such physical registers. This pass is run
-/// once LLVM no longer needs these registers, and replaces them with virtual
-/// registers, so they can participate in register stackifying and coloring in
-/// the normal way.
-///
-//===----------------------------------------------------------------------===//
-
-#include "MCTargetDesc/WebAssemblyMCTargetDesc.h"
-#include "WebAssembly.h"
-#include "WebAssemblyMachineFunctionInfo.h"
-#include "WebAssemblySubtarget.h"
-#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/CodeGen/Passes.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/raw_ostream.h"
-using namespace llvm;
-
-#define DEBUG_TYPE "wasm-replace-phys-regs"
-
-namespace {
-class WebAssemblyReplacePhysRegs final : public MachineFunctionPass {
-public:
-  static char ID; // Pass identification, replacement for typeid
-  WebAssemblyReplacePhysRegs() : MachineFunctionPass(ID) {}
-
-private:
-  StringRef getPassName() const override {
-    return "WebAssembly Replace Physical Registers";
-  }
-
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    AU.setPreservesCFG();
-    MachineFunctionPass::getAnalysisUsage(AU);
-  }
-
-  bool runOnMachineFunction(MachineFunction &MF) override;
-};
-} // end anonymous namespace
-
-char WebAssemblyReplacePhysRegs::ID = 0;
-FunctionPass *llvm::createWebAssemblyReplacePhysRegs() {
-  return new WebAssemblyReplacePhysRegs();
-}
-
-bool WebAssemblyReplacePhysRegs::runOnMachineFunction(MachineFunction &MF) {
-  DEBUG({
-    dbgs() << "********** Replace Physical Registers **********\n"
-           << "********** Function: " << MF.getName() << '\n';
-  });
-
-  MachineRegisterInfo &MRI = MF.getRegInfo();
-  const auto &TRI = *MF.getSubtarget<WebAssemblySubtarget>().getRegisterInfo();
-  bool Changed = false;
-
-  assert(!mustPreserveAnalysisID(LiveIntervalsID) &&
-         "LiveIntervals shouldn't be active yet!");
-  // We don't preserve SSA or liveness.
-  MRI.leaveSSA();
-  MRI.invalidateLiveness();
-
-  for (unsigned PReg = WebAssembly::NoRegister + 1;
-       PReg < WebAssembly::NUM_TARGET_REGS; ++PReg) {
-    // Skip fake registers that are never used explicitly.
-    if (PReg == WebAssembly::VALUE_STACK || PReg == WebAssembly::ARGUMENTS)
-      continue;
-
-    // Replace explicit uses of the physical register with a virtual register.
-    const TargetRegisterClass *RC = TRI.getMinimalPhysRegClass(PReg);
-    unsigned VReg = WebAssembly::NoRegister;
-    for (auto I = MRI.reg_begin(PReg), E = MRI.reg_end(); I != E; ) {
-      MachineOperand &MO = *I++;
-      if (!MO.isImplicit()) {
-        if (VReg == WebAssembly::NoRegister)
-          VReg = MRI.createVirtualRegister(RC);
-        MO.setReg(VReg);
-        if (MO.getParent()->isDebugValue())
-          MO.setIsDebug();
-        Changed = true;
-      }
-    }
-  }
-
-  return Changed;
-}