1 files changed, 0 insertions, 261 deletions

diff --git a/contrib/llvm/lib/Target/WebAssembly/WebAssemblyFrameLowering.cpp b/contrib/llvm/lib/Target/WebAssembly/WebAssemblyFrameLowering.cpp
deleted file mode 100644
index 5299068efdd4..000000000000
--- a/contrib/llvm/lib/Target/WebAssembly/WebAssemblyFrameLowering.cpp
+++ /dev/null
@@ -1,261 +0,0 @@
-//===-- WebAssemblyFrameLowering.cpp - WebAssembly Frame Lowering ----------==//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-///
-/// \file
-/// This file contains the WebAssembly implementation of
-/// TargetFrameLowering class.
-///
-/// On WebAssembly, there aren't a lot of things to do here. There are no
-/// callee-saved registers to save, and no spill slots.
-///
-/// The stack grows downward.
-///
-//===----------------------------------------------------------------------===//
-
-#include "WebAssemblyFrameLowering.h"
-#include "MCTargetDesc/WebAssemblyMCTargetDesc.h"
-#include "WebAssemblyInstrInfo.h"
-#include "WebAssemblyMachineFunctionInfo.h"
-#include "WebAssemblySubtarget.h"
-#include "WebAssemblyTargetMachine.h"
-#include "WebAssemblyUtilities.h"
-#include "llvm/CodeGen/MachineFrameInfo.h"
-#include "llvm/CodeGen/MachineFunction.h"
-#include "llvm/CodeGen/MachineInstrBuilder.h"
-#include "llvm/CodeGen/MachineModuleInfoImpls.h"
-#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/MC/MCAsmInfo.h"
-#include "llvm/Support/Debug.h"
-using namespace llvm;
-
-#define DEBUG_TYPE "wasm-frame-info"
-
-// TODO: wasm64
-// TODO: Emit TargetOpcode::CFI_INSTRUCTION instructions
-
-/// We need a base pointer in the case of having items on the stack that
-/// require stricter alignment than the stack pointer itself.  Because we need
-/// to shift the stack pointer by some unknown amount to force the alignment,
-/// we need to record the value of the stack pointer on entry to the function.
-bool WebAssemblyFrameLowering::hasBP(const MachineFunction &MF) const {
-  const auto *RegInfo =
-      MF.getSubtarget<WebAssemblySubtarget>().getRegisterInfo();
-  return RegInfo->needsStackRealignment(MF);
-}
-
-/// Return true if the specified function should have a dedicated frame pointer
-/// register.
-bool WebAssemblyFrameLowering::hasFP(const MachineFunction &MF) const {
-  const MachineFrameInfo &MFI = MF.getFrameInfo();
-
-  // When we have var-sized objects, we move the stack pointer by an unknown
-  // amount, and need to emit a frame pointer to restore the stack to where we
-  // were on function entry.
-  // If we already need a base pointer, we use that to fix up the stack pointer.
-  // If there are no fixed-size objects, we would have no use of a frame
-  // pointer, and thus should not emit one.
-  bool HasFixedSizedObjects = MFI.getStackSize() > 0;
-  bool NeedsFixedReference = !hasBP(MF) || HasFixedSizedObjects;
-
-  return MFI.isFrameAddressTaken() ||
-         (MFI.hasVarSizedObjects() && NeedsFixedReference) ||
-         MFI.hasStackMap() || MFI.hasPatchPoint();
-}
-
-/// Under normal circumstances, when a frame pointer is not required, we reserve
-/// argument space for call sites in the function immediately on entry to the
-/// current function. This eliminates the need for add/sub sp brackets around
-/// call sites. Returns true if the call frame is included as part of the stack
-/// frame.
-bool WebAssemblyFrameLowering::hasReservedCallFrame(
-    const MachineFunction &MF) const {
-  return !MF.getFrameInfo().hasVarSizedObjects();
-}
-
-// Returns true if this function needs a local user-space stack pointer for its
-// local frame (not for exception handling).
-bool WebAssemblyFrameLowering::needsSPForLocalFrame(
-    const MachineFunction &MF) const {
-  auto &MFI = MF.getFrameInfo();
-  return MFI.getStackSize() || MFI.adjustsStack() || hasFP(MF);
-}
-
-// In function with EH pads, we need to make a copy of the value of
-// __stack_pointer global in SP32 register, in order to use it when restoring
-// __stack_pointer after an exception is caught.
-bool WebAssemblyFrameLowering::needsPrologForEH(
-    const MachineFunction &MF) const {
-  auto EHType = MF.getTarget().getMCAsmInfo()->getExceptionHandlingType();
-  return EHType == ExceptionHandling::Wasm &&
-         MF.getFunction().hasPersonalityFn() && MF.getFrameInfo().hasCalls();
-}
-
-/// Returns true if this function needs a local user-space stack pointer.
-/// Unlike a machine stack pointer, the wasm user stack pointer is a global
-/// variable, so it is loaded into a register in the prolog.
-bool WebAssemblyFrameLowering::needsSP(const MachineFunction &MF) const {
-  return needsSPForLocalFrame(MF) || needsPrologForEH(MF);
-}
-
-/// Returns true if the local user-space stack pointer needs to be written back
-/// to __stack_pointer global by this function (this is not meaningful if
-/// needsSP is false). If false, the stack red zone can be used and only a local
-/// SP is needed.
-bool WebAssemblyFrameLowering::needsSPWriteback(
-    const MachineFunction &MF) const {
-  auto &MFI = MF.getFrameInfo();
-  assert(needsSP(MF));
-  // When we don't need a local stack pointer for its local frame but only to
-  // support EH, we don't need to write SP back in the epilog, because we don't
-  // bump down the stack pointer in the prolog. We need to write SP back in the
-  // epilog only if
-  // 1. We need SP not only for EH support but also because we actually use
-  // stack or we have a frame address taken.
-  // 2. We cannot use the red zone.
-  bool CanUseRedZone = MFI.getStackSize() <= RedZoneSize && !MFI.hasCalls() &&
-                       !MF.getFunction().hasFnAttribute(Attribute::NoRedZone);
-  return needsSPForLocalFrame(MF) && !CanUseRedZone;
-}
-
-void WebAssemblyFrameLowering::writeSPToGlobal(
-    unsigned SrcReg, MachineFunction &MF, MachineBasicBlock &MBB,
-    MachineBasicBlock::iterator &InsertStore, const DebugLoc &DL) const {
-  const auto *TII = MF.getSubtarget<WebAssemblySubtarget>().getInstrInfo();
-
-  const char *ES = "__stack_pointer";
-  auto *SPSymbol = MF.createExternalSymbolName(ES);
-  BuildMI(MBB, InsertStore, DL, TII->get(WebAssembly::GLOBAL_SET_I32))
-      .addExternalSymbol(SPSymbol)
-      .addReg(SrcReg);
-}
-
-MachineBasicBlock::iterator
-WebAssemblyFrameLowering::eliminateCallFramePseudoInstr(
-    MachineFunction &MF, MachineBasicBlock &MBB,
-    MachineBasicBlock::iterator I) const {
-  assert(!I->getOperand(0).getImm() && (hasFP(MF) || hasBP(MF)) &&
-         "Call frame pseudos should only be used for dynamic stack adjustment");
-  const auto *TII = MF.getSubtarget<WebAssemblySubtarget>().getInstrInfo();
-  if (I->getOpcode() == TII->getCallFrameDestroyOpcode() &&
-      needsSPWriteback(MF)) {
-    DebugLoc DL = I->getDebugLoc();
-    writeSPToGlobal(WebAssembly::SP32, MF, MBB, I, DL);
-  }
-  return MBB.erase(I);
-}
-
-void WebAssemblyFrameLowering::emitPrologue(MachineFunction &MF,
-                                            MachineBasicBlock &MBB) const {
-  // TODO: Do ".setMIFlag(MachineInstr::FrameSetup)" on emitted instructions
-  auto &MFI = MF.getFrameInfo();
-  assert(MFI.getCalleeSavedInfo().empty() &&
-         "WebAssembly should not have callee-saved registers");
-
-  if (!needsSP(MF))
-    return;
-  uint64_t StackSize = MFI.getStackSize();
-
-  const auto *TII = MF.getSubtarget<WebAssemblySubtarget>().getInstrInfo();
-  auto &MRI = MF.getRegInfo();
-
-  auto InsertPt = MBB.begin();
-  while (InsertPt != MBB.end() &&
-         WebAssembly::isArgument(InsertPt->getOpcode()))
-    ++InsertPt;
-  DebugLoc DL;
-
-  const TargetRegisterClass *PtrRC =
-      MRI.getTargetRegisterInfo()->getPointerRegClass(MF);
-  unsigned SPReg = WebAssembly::SP32;
-  if (StackSize)
-    SPReg = MRI.createVirtualRegister(PtrRC);
-
-  const char *ES = "__stack_pointer";
-  auto *SPSymbol = MF.createExternalSymbolName(ES);
-  BuildMI(MBB, InsertPt, DL, TII->get(WebAssembly::GLOBAL_GET_I32), SPReg)
-      .addExternalSymbol(SPSymbol);
-
-  bool HasBP = hasBP(MF);
-  if (HasBP) {
-    auto FI = MF.getInfo<WebAssemblyFunctionInfo>();
-    unsigned BasePtr = MRI.createVirtualRegister(PtrRC);
-    FI->setBasePointerVreg(BasePtr);
-    BuildMI(MBB, InsertPt, DL, TII->get(WebAssembly::COPY), BasePtr)
-        .addReg(SPReg);
-  }
-  if (StackSize) {
-    // Subtract the frame size
-    unsigned OffsetReg = MRI.createVirtualRegister(PtrRC);
-    BuildMI(MBB, InsertPt, DL, TII->get(WebAssembly::CONST_I32), OffsetReg)
-        .addImm(StackSize);
-    BuildMI(MBB, InsertPt, DL, TII->get(WebAssembly::SUB_I32),
-            WebAssembly::SP32)
-        .addReg(SPReg)
-        .addReg(OffsetReg);
-  }
-  if (HasBP) {
-    unsigned BitmaskReg = MRI.createVirtualRegister(PtrRC);
-    unsigned Alignment = MFI.getMaxAlignment();
-    assert((1u << countTrailingZeros(Alignment)) == Alignment &&
-           "Alignment must be a power of 2");
-    BuildMI(MBB, InsertPt, DL, TII->get(WebAssembly::CONST_I32), BitmaskReg)
-        .addImm((int)~(Alignment - 1));
-    BuildMI(MBB, InsertPt, DL, TII->get(WebAssembly::AND_I32),
-            WebAssembly::SP32)
-        .addReg(WebAssembly::SP32)
-        .addReg(BitmaskReg);
-  }
-  if (hasFP(MF)) {
-    // Unlike most conventional targets (where FP points to the saved FP),
-    // FP points to the bottom of the fixed-size locals, so we can use positive
-    // offsets in load/store instructions.
-    BuildMI(MBB, InsertPt, DL, TII->get(WebAssembly::COPY), WebAssembly::FP32)
-        .addReg(WebAssembly::SP32);
-  }
-  if (StackSize && needsSPWriteback(MF)) {
-    writeSPToGlobal(WebAssembly::SP32, MF, MBB, InsertPt, DL);
-  }
-}
-
-void WebAssemblyFrameLowering::emitEpilogue(MachineFunction &MF,
-                                            MachineBasicBlock &MBB) const {
-  uint64_t StackSize = MF.getFrameInfo().getStackSize();
-  if (!needsSP(MF) || !needsSPWriteback(MF))
-    return;
-  const auto *TII = MF.getSubtarget<WebAssemblySubtarget>().getInstrInfo();
-  auto &MRI = MF.getRegInfo();
-  auto InsertPt = MBB.getFirstTerminator();
-  DebugLoc DL;
-
-  if (InsertPt != MBB.end())
-    DL = InsertPt->getDebugLoc();
-
-  // Restore the stack pointer. If we had fixed-size locals, add the offset
-  // subtracted in the prolog.
-  unsigned SPReg = 0;
-  if (hasBP(MF)) {
-    auto FI = MF.getInfo<WebAssemblyFunctionInfo>();
-    SPReg = FI->getBasePointerVreg();
-  } else if (StackSize) {
-    const TargetRegisterClass *PtrRC =
-        MRI.getTargetRegisterInfo()->getPointerRegClass(MF);
-    unsigned OffsetReg = MRI.createVirtualRegister(PtrRC);
-    BuildMI(MBB, InsertPt, DL, TII->get(WebAssembly::CONST_I32), OffsetReg)
-        .addImm(StackSize);
-    // In the epilog we don't need to write the result back to the SP32 physreg
-    // because it won't be used again. We can use a stackified register instead.
-    SPReg = MRI.createVirtualRegister(PtrRC);
-    BuildMI(MBB, InsertPt, DL, TII->get(WebAssembly::ADD_I32), SPReg)
-        .addReg(hasFP(MF) ? WebAssembly::FP32 : WebAssembly::SP32)
-        .addReg(OffsetReg);
-  } else {
-    SPReg = hasFP(MF) ? WebAssembly::FP32 : WebAssembly::SP32;
-  }
-
-  writeSPToGlobal(SPReg, MF, MBB, InsertPt, DL);
-}