Restoring authorship annotation for <orivej@yandex-team.ru>. Commit 2 of 2.

1 files changed, 302 insertions, 302 deletions

diff --git a/contrib/libs/llvm12/lib/Target/X86/X86WinAllocaExpander.cpp b/contrib/libs/llvm12/lib/Target/X86/X86WinAllocaExpander.cpp
index 21a18d0955..72593afb22 100644
--- a/contrib/libs/llvm12/lib/Target/X86/X86WinAllocaExpander.cpp
+++ b/contrib/libs/llvm12/lib/Target/X86/X86WinAllocaExpander.cpp
@@ -1,302 +1,302 @@
-//===----- X86WinAllocaExpander.cpp - Expand WinAlloca pseudo instruction -===// 
-// 
-// 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 file defines a pass that expands WinAlloca pseudo-instructions. 
-// 
-// It performs a conservative analysis to determine whether each allocation 
-// falls within a region of the stack that is safe to use, or whether stack 
-// probes must be emitted. 
-// 
-//===----------------------------------------------------------------------===// 
- 
-#include "X86.h" 
-#include "X86InstrBuilder.h" 
-#include "X86InstrInfo.h" 
-#include "X86MachineFunctionInfo.h" 
-#include "X86Subtarget.h" 
-#include "llvm/ADT/MapVector.h" 
-#include "llvm/ADT/PostOrderIterator.h" 
-#include "llvm/CodeGen/MachineFunctionPass.h" 
-#include "llvm/CodeGen/MachineInstrBuilder.h" 
-#include "llvm/CodeGen/MachineRegisterInfo.h" 
-#include "llvm/CodeGen/Passes.h" 
-#include "llvm/CodeGen/TargetInstrInfo.h" 
-#include "llvm/IR/Function.h" 
-#include "llvm/Support/raw_ostream.h" 
- 
-using namespace llvm; 
- 
-namespace { 
- 
-class X86WinAllocaExpander : public MachineFunctionPass { 
-public: 
-  X86WinAllocaExpander() : MachineFunctionPass(ID) {} 
- 
-  bool runOnMachineFunction(MachineFunction &MF) override; 
- 
-private: 
-  /// Strategies for lowering a WinAlloca. 
-  enum Lowering { TouchAndSub, Sub, Probe }; 
- 
-  /// Deterministic-order map from WinAlloca instruction to desired lowering. 
-  typedef MapVector<MachineInstr*, Lowering> LoweringMap; 
- 
-  /// Compute which lowering to use for each WinAlloca instruction. 
-  void computeLowerings(MachineFunction &MF, LoweringMap& Lowerings); 
- 
-  /// Get the appropriate lowering based on current offset and amount. 
-  Lowering getLowering(int64_t CurrentOffset, int64_t AllocaAmount); 
- 
-  /// Lower a WinAlloca instruction. 
-  void lower(MachineInstr* MI, Lowering L); 
- 
-  MachineRegisterInfo *MRI = nullptr; 
-  const X86Subtarget *STI = nullptr; 
-  const TargetInstrInfo *TII = nullptr; 
-  const X86RegisterInfo *TRI = nullptr; 
-  unsigned StackPtr = 0; 
-  unsigned SlotSize = 0; 
-  int64_t StackProbeSize = 0; 
-  bool NoStackArgProbe = false; 
- 
-  StringRef getPassName() const override { return "X86 WinAlloca Expander"; } 
-  static char ID; 
-}; 
- 
-char X86WinAllocaExpander::ID = 0; 
- 
-} // end anonymous namespace 
- 
-FunctionPass *llvm::createX86WinAllocaExpander() { 
-  return new X86WinAllocaExpander(); 
-} 
- 
-/// Return the allocation amount for a WinAlloca instruction, or -1 if unknown. 
-static int64_t getWinAllocaAmount(MachineInstr *MI, MachineRegisterInfo *MRI) { 
-  assert(MI->getOpcode() == X86::WIN_ALLOCA_32 || 
-         MI->getOpcode() == X86::WIN_ALLOCA_64); 
-  assert(MI->getOperand(0).isReg()); 
- 
-  Register AmountReg = MI->getOperand(0).getReg(); 
-  MachineInstr *Def = MRI->getUniqueVRegDef(AmountReg); 
- 
-  if (!Def || 
-      (Def->getOpcode() != X86::MOV32ri && Def->getOpcode() != X86::MOV64ri) || 
-      !Def->getOperand(1).isImm()) 
-    return -1; 
- 
-  return Def->getOperand(1).getImm(); 
-} 
- 
-X86WinAllocaExpander::Lowering 
-X86WinAllocaExpander::getLowering(int64_t CurrentOffset, 
-                                  int64_t AllocaAmount) { 
-  // For a non-constant amount or a large amount, we have to probe. 
-  if (AllocaAmount < 0 || AllocaAmount > StackProbeSize) 
-    return Probe; 
- 
-  // If it fits within the safe region of the stack, just subtract. 
-  if (CurrentOffset + AllocaAmount <= StackProbeSize) 
-    return Sub; 
- 
-  // Otherwise, touch the current tip of the stack, then subtract. 
-  return TouchAndSub; 
-} 
- 
-static bool isPushPop(const MachineInstr &MI) { 
-  switch (MI.getOpcode()) { 
-  case X86::PUSH32i8: 
-  case X86::PUSH32r: 
-  case X86::PUSH32rmm: 
-  case X86::PUSH32rmr: 
-  case X86::PUSHi32: 
-  case X86::PUSH64i8: 
-  case X86::PUSH64r: 
-  case X86::PUSH64rmm: 
-  case X86::PUSH64rmr: 
-  case X86::PUSH64i32: 
-  case X86::POP32r: 
-  case X86::POP64r: 
-    return true; 
-  default: 
-    return false; 
-  } 
-} 
- 
-void X86WinAllocaExpander::computeLowerings(MachineFunction &MF, 
-                                            LoweringMap &Lowerings) { 
-  // Do a one-pass reverse post-order walk of the CFG to conservatively estimate 
-  // the offset between the stack pointer and the lowest touched part of the 
-  // stack, and use that to decide how to lower each WinAlloca instruction. 
- 
-  // Initialize OutOffset[B], the stack offset at exit from B, to something big. 
-  DenseMap<MachineBasicBlock *, int64_t> OutOffset; 
-  for (MachineBasicBlock &MBB : MF) 
-    OutOffset[&MBB] = INT32_MAX; 
- 
-  // Note: we don't know the offset at the start of the entry block since the 
-  // prologue hasn't been inserted yet, and how much that will adjust the stack 
-  // pointer depends on register spills, which have not been computed yet. 
- 
-  // Compute the reverse post-order. 
-  ReversePostOrderTraversal<MachineFunction*> RPO(&MF); 
- 
-  for (MachineBasicBlock *MBB : RPO) { 
-    int64_t Offset = -1; 
-    for (MachineBasicBlock *Pred : MBB->predecessors()) 
-      Offset = std::max(Offset, OutOffset[Pred]); 
-    if (Offset == -1) Offset = INT32_MAX; 
- 
-    for (MachineInstr &MI : *MBB) { 
-      if (MI.getOpcode() == X86::WIN_ALLOCA_32 || 
-          MI.getOpcode() == X86::WIN_ALLOCA_64) { 
-        // A WinAlloca moves StackPtr, and potentially touches it. 
-        int64_t Amount = getWinAllocaAmount(&MI, MRI); 
-        Lowering L = getLowering(Offset, Amount); 
-        Lowerings[&MI] = L; 
-        switch (L) { 
-        case Sub: 
-          Offset += Amount; 
-          break; 
-        case TouchAndSub: 
-          Offset = Amount; 
-          break; 
-        case Probe: 
-          Offset = 0; 
-          break; 
-        } 
-      } else if (MI.isCall() || isPushPop(MI)) { 
-        // Calls, pushes and pops touch the tip of the stack. 
-        Offset = 0; 
-      } else if (MI.getOpcode() == X86::ADJCALLSTACKUP32 || 
-                 MI.getOpcode() == X86::ADJCALLSTACKUP64) { 
-        Offset -= MI.getOperand(0).getImm(); 
-      } else if (MI.getOpcode() == X86::ADJCALLSTACKDOWN32 || 
-                 MI.getOpcode() == X86::ADJCALLSTACKDOWN64) { 
-        Offset += MI.getOperand(0).getImm(); 
-      } else if (MI.modifiesRegister(StackPtr, TRI)) { 
-        // Any other modification of SP means we've lost track of it. 
-        Offset = INT32_MAX; 
-      } 
-    } 
- 
-    OutOffset[MBB] = Offset; 
-  } 
-} 
- 
-static unsigned getSubOpcode(bool Is64Bit, int64_t Amount) { 
-  if (Is64Bit) 
-    return isInt<8>(Amount) ? X86::SUB64ri8 : X86::SUB64ri32; 
-  return isInt<8>(Amount) ? X86::SUB32ri8 : X86::SUB32ri; 
-} 
- 
-void X86WinAllocaExpander::lower(MachineInstr* MI, Lowering L) { 
-  DebugLoc DL = MI->getDebugLoc(); 
-  MachineBasicBlock *MBB = MI->getParent(); 
-  MachineBasicBlock::iterator I = *MI; 
- 
-  int64_t Amount = getWinAllocaAmount(MI, MRI); 
-  if (Amount == 0) { 
-    MI->eraseFromParent(); 
-    return; 
-  } 
- 
-  // These two variables differ on x32, which is a 64-bit target with a 
-  // 32-bit alloca. 
-  bool Is64Bit = STI->is64Bit(); 
-  bool Is64BitAlloca = MI->getOpcode() == X86::WIN_ALLOCA_64; 
-  assert(SlotSize == 4 || SlotSize == 8); 
- 
-  switch (L) { 
-  case TouchAndSub: { 
-    assert(Amount >= SlotSize); 
- 
-    // Use a push to touch the top of the stack. 
-    unsigned RegA = Is64Bit ? X86::RAX : X86::EAX; 
-    BuildMI(*MBB, I, DL, TII->get(Is64Bit ? X86::PUSH64r : X86::PUSH32r)) 
-        .addReg(RegA, RegState::Undef); 
-    Amount -= SlotSize; 
-    if (!Amount) 
-      break; 
- 
-    // Fall through to make any remaining adjustment. 
-    LLVM_FALLTHROUGH; 
-  } 
-  case Sub: 
-    assert(Amount > 0); 
-    if (Amount == SlotSize) { 
-      // Use push to save size. 
-      unsigned RegA = Is64Bit ? X86::RAX : X86::EAX; 
-      BuildMI(*MBB, I, DL, TII->get(Is64Bit ? X86::PUSH64r : X86::PUSH32r)) 
-          .addReg(RegA, RegState::Undef); 
-    } else { 
-      // Sub. 
-      BuildMI(*MBB, I, DL, 
-              TII->get(getSubOpcode(Is64BitAlloca, Amount)), StackPtr) 
-          .addReg(StackPtr) 
-          .addImm(Amount); 
-    } 
-    break; 
-  case Probe: 
-    if (!NoStackArgProbe) { 
-      // The probe lowering expects the amount in RAX/EAX. 
-      unsigned RegA = Is64BitAlloca ? X86::RAX : X86::EAX; 
-      BuildMI(*MBB, MI, DL, TII->get(TargetOpcode::COPY), RegA) 
-          .addReg(MI->getOperand(0).getReg()); 
- 
-      // Do the probe. 
-      STI->getFrameLowering()->emitStackProbe(*MBB->getParent(), *MBB, MI, DL, 
-                                              /*InProlog=*/false); 
-    } else { 
-      // Sub 
-      BuildMI(*MBB, I, DL, 
-              TII->get(Is64BitAlloca ? X86::SUB64rr : X86::SUB32rr), StackPtr) 
-          .addReg(StackPtr) 
-          .addReg(MI->getOperand(0).getReg()); 
-    } 
-    break; 
-  } 
- 
-  Register AmountReg = MI->getOperand(0).getReg(); 
-  MI->eraseFromParent(); 
- 
-  // Delete the definition of AmountReg. 
-  if (MRI->use_empty(AmountReg)) 
-    if (MachineInstr *AmountDef = MRI->getUniqueVRegDef(AmountReg)) 
-      AmountDef->eraseFromParent(); 
-} 
- 
-bool X86WinAllocaExpander::runOnMachineFunction(MachineFunction &MF) { 
-  if (!MF.getInfo<X86MachineFunctionInfo>()->hasWinAlloca()) 
-    return false; 
- 
-  MRI = &MF.getRegInfo(); 
-  STI = &MF.getSubtarget<X86Subtarget>(); 
-  TII = STI->getInstrInfo(); 
-  TRI = STI->getRegisterInfo(); 
-  StackPtr = TRI->getStackRegister(); 
-  SlotSize = TRI->getSlotSize(); 
- 
-  StackProbeSize = 4096; 
-  if (MF.getFunction().hasFnAttribute("stack-probe-size")) { 
-    MF.getFunction() 
-        .getFnAttribute("stack-probe-size") 
-        .getValueAsString() 
-        .getAsInteger(0, StackProbeSize); 
-  } 
-  NoStackArgProbe = MF.getFunction().hasFnAttribute("no-stack-arg-probe"); 
-  if (NoStackArgProbe) 
-    StackProbeSize = INT64_MAX; 
- 
-  LoweringMap Lowerings; 
-  computeLowerings(MF, Lowerings); 
-  for (auto &P : Lowerings) 
-    lower(P.first, P.second); 
- 
-  return true; 
-} 
+//===----- X86WinAllocaExpander.cpp - Expand WinAlloca pseudo instruction -===//
+//
+// 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 file defines a pass that expands WinAlloca pseudo-instructions.
+//
+// It performs a conservative analysis to determine whether each allocation
+// falls within a region of the stack that is safe to use, or whether stack
+// probes must be emitted.
+//
+//===----------------------------------------------------------------------===//
+
+#include "X86.h"
+#include "X86InstrBuilder.h"
+#include "X86InstrInfo.h"
+#include "X86MachineFunctionInfo.h"
+#include "X86Subtarget.h"
+#include "llvm/ADT/MapVector.h"
+#include "llvm/ADT/PostOrderIterator.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/CodeGen/TargetInstrInfo.h"
+#include "llvm/IR/Function.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+namespace {
+
+class X86WinAllocaExpander : public MachineFunctionPass {
+public:
+  X86WinAllocaExpander() : MachineFunctionPass(ID) {}
+
+  bool runOnMachineFunction(MachineFunction &MF) override;
+
+private:
+  /// Strategies for lowering a WinAlloca.
+  enum Lowering { TouchAndSub, Sub, Probe };
+
+  /// Deterministic-order map from WinAlloca instruction to desired lowering.
+  typedef MapVector<MachineInstr*, Lowering> LoweringMap;
+
+  /// Compute which lowering to use for each WinAlloca instruction.
+  void computeLowerings(MachineFunction &MF, LoweringMap& Lowerings);
+
+  /// Get the appropriate lowering based on current offset and amount.
+  Lowering getLowering(int64_t CurrentOffset, int64_t AllocaAmount);
+
+  /// Lower a WinAlloca instruction.
+  void lower(MachineInstr* MI, Lowering L);
+
+  MachineRegisterInfo *MRI = nullptr;
+  const X86Subtarget *STI = nullptr;
+  const TargetInstrInfo *TII = nullptr;
+  const X86RegisterInfo *TRI = nullptr;
+  unsigned StackPtr = 0;
+  unsigned SlotSize = 0;
+  int64_t StackProbeSize = 0;
+  bool NoStackArgProbe = false;
+
+  StringRef getPassName() const override { return "X86 WinAlloca Expander"; }
+  static char ID;
+};
+
+char X86WinAllocaExpander::ID = 0;
+
+} // end anonymous namespace
+
+FunctionPass *llvm::createX86WinAllocaExpander() {
+  return new X86WinAllocaExpander();
+}
+
+/// Return the allocation amount for a WinAlloca instruction, or -1 if unknown.
+static int64_t getWinAllocaAmount(MachineInstr *MI, MachineRegisterInfo *MRI) {
+  assert(MI->getOpcode() == X86::WIN_ALLOCA_32 ||
+         MI->getOpcode() == X86::WIN_ALLOCA_64);
+  assert(MI->getOperand(0).isReg());
+
+  Register AmountReg = MI->getOperand(0).getReg();
+  MachineInstr *Def = MRI->getUniqueVRegDef(AmountReg);
+
+  if (!Def ||
+      (Def->getOpcode() != X86::MOV32ri && Def->getOpcode() != X86::MOV64ri) ||
+      !Def->getOperand(1).isImm())
+    return -1;
+
+  return Def->getOperand(1).getImm();
+}
+
+X86WinAllocaExpander::Lowering
+X86WinAllocaExpander::getLowering(int64_t CurrentOffset,
+                                  int64_t AllocaAmount) {
+  // For a non-constant amount or a large amount, we have to probe.
+  if (AllocaAmount < 0 || AllocaAmount > StackProbeSize)
+    return Probe;
+
+  // If it fits within the safe region of the stack, just subtract.
+  if (CurrentOffset + AllocaAmount <= StackProbeSize)
+    return Sub;
+
+  // Otherwise, touch the current tip of the stack, then subtract.
+  return TouchAndSub;
+}
+
+static bool isPushPop(const MachineInstr &MI) {
+  switch (MI.getOpcode()) {
+  case X86::PUSH32i8:
+  case X86::PUSH32r:
+  case X86::PUSH32rmm:
+  case X86::PUSH32rmr:
+  case X86::PUSHi32:
+  case X86::PUSH64i8:
+  case X86::PUSH64r:
+  case X86::PUSH64rmm:
+  case X86::PUSH64rmr:
+  case X86::PUSH64i32:
+  case X86::POP32r:
+  case X86::POP64r:
+    return true;
+  default:
+    return false;
+  }
+}
+
+void X86WinAllocaExpander::computeLowerings(MachineFunction &MF,
+                                            LoweringMap &Lowerings) {
+  // Do a one-pass reverse post-order walk of the CFG to conservatively estimate
+  // the offset between the stack pointer and the lowest touched part of the
+  // stack, and use that to decide how to lower each WinAlloca instruction.
+
+  // Initialize OutOffset[B], the stack offset at exit from B, to something big.
+  DenseMap<MachineBasicBlock *, int64_t> OutOffset;
+  for (MachineBasicBlock &MBB : MF)
+    OutOffset[&MBB] = INT32_MAX;
+
+  // Note: we don't know the offset at the start of the entry block since the
+  // prologue hasn't been inserted yet, and how much that will adjust the stack
+  // pointer depends on register spills, which have not been computed yet.
+
+  // Compute the reverse post-order.
+  ReversePostOrderTraversal<MachineFunction*> RPO(&MF);
+
+  for (MachineBasicBlock *MBB : RPO) {
+    int64_t Offset = -1;
+    for (MachineBasicBlock *Pred : MBB->predecessors())
+      Offset = std::max(Offset, OutOffset[Pred]);
+    if (Offset == -1) Offset = INT32_MAX;
+
+    for (MachineInstr &MI : *MBB) {
+      if (MI.getOpcode() == X86::WIN_ALLOCA_32 ||
+          MI.getOpcode() == X86::WIN_ALLOCA_64) {
+        // A WinAlloca moves StackPtr, and potentially touches it.
+        int64_t Amount = getWinAllocaAmount(&MI, MRI);
+        Lowering L = getLowering(Offset, Amount);
+        Lowerings[&MI] = L;
+        switch (L) {
+        case Sub:
+          Offset += Amount;
+          break;
+        case TouchAndSub:
+          Offset = Amount;
+          break;
+        case Probe:
+          Offset = 0;
+          break;
+        }
+      } else if (MI.isCall() || isPushPop(MI)) {
+        // Calls, pushes and pops touch the tip of the stack.
+        Offset = 0;
+      } else if (MI.getOpcode() == X86::ADJCALLSTACKUP32 ||
+                 MI.getOpcode() == X86::ADJCALLSTACKUP64) {
+        Offset -= MI.getOperand(0).getImm();
+      } else if (MI.getOpcode() == X86::ADJCALLSTACKDOWN32 ||
+                 MI.getOpcode() == X86::ADJCALLSTACKDOWN64) {
+        Offset += MI.getOperand(0).getImm();
+      } else if (MI.modifiesRegister(StackPtr, TRI)) {
+        // Any other modification of SP means we've lost track of it.
+        Offset = INT32_MAX;
+      }
+    }
+
+    OutOffset[MBB] = Offset;
+  }
+}
+
+static unsigned getSubOpcode(bool Is64Bit, int64_t Amount) {
+  if (Is64Bit)
+    return isInt<8>(Amount) ? X86::SUB64ri8 : X86::SUB64ri32;
+  return isInt<8>(Amount) ? X86::SUB32ri8 : X86::SUB32ri;
+}
+
+void X86WinAllocaExpander::lower(MachineInstr* MI, Lowering L) {
+  DebugLoc DL = MI->getDebugLoc();
+  MachineBasicBlock *MBB = MI->getParent();
+  MachineBasicBlock::iterator I = *MI;
+
+  int64_t Amount = getWinAllocaAmount(MI, MRI);
+  if (Amount == 0) {
+    MI->eraseFromParent();
+    return;
+  }
+
+  // These two variables differ on x32, which is a 64-bit target with a
+  // 32-bit alloca.
+  bool Is64Bit = STI->is64Bit();
+  bool Is64BitAlloca = MI->getOpcode() == X86::WIN_ALLOCA_64;
+  assert(SlotSize == 4 || SlotSize == 8);
+
+  switch (L) {
+  case TouchAndSub: {
+    assert(Amount >= SlotSize);
+
+    // Use a push to touch the top of the stack.
+    unsigned RegA = Is64Bit ? X86::RAX : X86::EAX;
+    BuildMI(*MBB, I, DL, TII->get(Is64Bit ? X86::PUSH64r : X86::PUSH32r))
+        .addReg(RegA, RegState::Undef);
+    Amount -= SlotSize;
+    if (!Amount)
+      break;
+
+    // Fall through to make any remaining adjustment.
+    LLVM_FALLTHROUGH;
+  }
+  case Sub:
+    assert(Amount > 0);
+    if (Amount == SlotSize) {
+      // Use push to save size.
+      unsigned RegA = Is64Bit ? X86::RAX : X86::EAX;
+      BuildMI(*MBB, I, DL, TII->get(Is64Bit ? X86::PUSH64r : X86::PUSH32r))
+          .addReg(RegA, RegState::Undef);
+    } else {
+      // Sub.
+      BuildMI(*MBB, I, DL,
+              TII->get(getSubOpcode(Is64BitAlloca, Amount)), StackPtr)
+          .addReg(StackPtr)
+          .addImm(Amount);
+    }
+    break;
+  case Probe:
+    if (!NoStackArgProbe) {
+      // The probe lowering expects the amount in RAX/EAX.
+      unsigned RegA = Is64BitAlloca ? X86::RAX : X86::EAX;
+      BuildMI(*MBB, MI, DL, TII->get(TargetOpcode::COPY), RegA)
+          .addReg(MI->getOperand(0).getReg());
+
+      // Do the probe.
+      STI->getFrameLowering()->emitStackProbe(*MBB->getParent(), *MBB, MI, DL,
+                                              /*InProlog=*/false);
+    } else {
+      // Sub
+      BuildMI(*MBB, I, DL,
+              TII->get(Is64BitAlloca ? X86::SUB64rr : X86::SUB32rr), StackPtr)
+          .addReg(StackPtr)
+          .addReg(MI->getOperand(0).getReg());
+    }
+    break;
+  }
+
+  Register AmountReg = MI->getOperand(0).getReg();
+  MI->eraseFromParent();
+
+  // Delete the definition of AmountReg.
+  if (MRI->use_empty(AmountReg))
+    if (MachineInstr *AmountDef = MRI->getUniqueVRegDef(AmountReg))
+      AmountDef->eraseFromParent();
+}
+
+bool X86WinAllocaExpander::runOnMachineFunction(MachineFunction &MF) {
+  if (!MF.getInfo<X86MachineFunctionInfo>()->hasWinAlloca())
+    return false;
+
+  MRI = &MF.getRegInfo();
+  STI = &MF.getSubtarget<X86Subtarget>();
+  TII = STI->getInstrInfo();
+  TRI = STI->getRegisterInfo();
+  StackPtr = TRI->getStackRegister();
+  SlotSize = TRI->getSlotSize();
+
+  StackProbeSize = 4096;
+  if (MF.getFunction().hasFnAttribute("stack-probe-size")) {
+    MF.getFunction()
+        .getFnAttribute("stack-probe-size")
+        .getValueAsString()
+        .getAsInteger(0, StackProbeSize);
+  }
+  NoStackArgProbe = MF.getFunction().hasFnAttribute("no-stack-arg-probe");
+  if (NoStackArgProbe)
+    StackProbeSize = INT64_MAX;
+
+  LoweringMap Lowerings;
+  computeLowerings(MF, Lowerings);
+  for (auto &P : Lowerings)
+    lower(P.first, P.second);
+
+  return true;
+}