Vendor import of stripped llvm trunk r366426 (just before the release_90vendor/llvm/llvm-trunk-r366426

branch point):

https://llvm.org/svn/llvm-project/llvm/trunk@366426

1 files changed, 29 insertions, 22 deletions

diff --git a/lib/Target/ARM/ARMBaseRegisterInfo.cpp b/lib/Target/ARM/ARMBaseRegisterInfo.cpp
index 02b3daf3c6fd..dc99b37742da 100644
--- a/lib/Target/ARM/ARMBaseRegisterInfo.cpp
+++ b/lib/Target/ARM/ARMBaseRegisterInfo.cpp
@@ -1,9 +1,8 @@
 //===-- ARMBaseRegisterInfo.cpp - ARM Register Information ----------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// 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
 //
 //===----------------------------------------------------------------------===//
 //
@@ -150,7 +149,7 @@ ARMBaseRegisterInfo::getTLSCallPreservedMask(const MachineFunction &MF) const {
 const uint32_t *
 ARMBaseRegisterInfo::getSjLjDispatchPreservedMask(const MachineFunction &MF) const {
   const ARMSubtarget &STI = MF.getSubtarget<ARMSubtarget>();
-  if (!STI.useSoftFloat() && STI.hasVFP2() && !STI.isThumb1Only())
+  if (!STI.useSoftFloat() && STI.hasVFP2Base() && !STI.isThumb1Only())
     return CSR_NoRegs_RegMask;
   else
     return CSR_FPRegs_RegMask;
@@ -194,7 +193,7 @@ getReservedRegs(const MachineFunction &MF) const {
   if (STI.isR9Reserved())
     markSuperRegs(Reserved, ARM::R9);
   // Reserve D16-D31 if the subtarget doesn't support them.
-  if (!STI.hasVFP3() || STI.hasD16()) {
+  if (!STI.hasD32()) {
     static_assert(ARM::D31 == ARM::D16 + 15, "Register list not consecutive!");
     for (unsigned R = 0; R < 16; ++R)
       markSuperRegs(Reserved, ARM::D16 + R);
@@ -204,6 +203,8 @@ getReservedRegs(const MachineFunction &MF) const {
     for (MCSubRegIterator SI(Reg, this); SI.isValid(); ++SI)
       if (Reserved.test(*SI))
         markSuperRegs(Reserved, Reg);
+  // For v8.1m architecture
+  markSuperRegs(Reserved, ARM::ZR);
 
   assert(checkAllSuperRegsMarked(Reserved));
   return Reserved;
@@ -369,29 +370,35 @@ bool ARMBaseRegisterInfo::hasBasePointer(const MachineFunction &MF) const {
   const ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
   const ARMFrameLowering *TFI = getFrameLowering(MF);
 
-  // When outgoing call frames are so large that we adjust the stack pointer
-  // around the call, we can no longer use the stack pointer to reach the
-  // emergency spill slot.
+  // If we have stack realignment and VLAs, we have no pointer to use to
+  // access the stack. If we have stack realignment, and a large call frame,
+  // we have no place to allocate the emergency spill slot.
   if (needsStackRealignment(MF) && !TFI->hasReservedCallFrame(MF))
     return true;
 
   // Thumb has trouble with negative offsets from the FP. Thumb2 has a limited
   // negative range for ldr/str (255), and thumb1 is positive offsets only.
+  //
   // It's going to be better to use the SP or Base Pointer instead. When there
   // are variable sized objects, we can't reference off of the SP, so we
   // reserve a Base Pointer.
-  if (AFI->isThumbFunction() && MFI.hasVarSizedObjects()) {
-    // Conservatively estimate whether the negative offset from the frame
-    // pointer will be sufficient to reach. If a function has a smallish
-    // frame, it's less likely to have lots of spills and callee saved
-    // space, so it's all more likely to be within range of the frame pointer.
-    // If it's wrong, the scavenger will still enable access to work, it just
-    // won't be optimal.
-    if (AFI->isThumb2Function() && MFI.getLocalFrameSize() < 128)
-      return false;
+  //
+  // For Thumb2, estimate whether a negative offset from the frame pointer
+  // will be sufficient to reach the whole stack frame. If a function has a
+  // smallish frame, it's less likely to have lots of spills and callee saved
+  // space, so it's all more likely to be within range of the frame pointer.
+  // If it's wrong, the scavenger will still enable access to work, it just
+  // won't be optimal.  (We should always be able to reach the emergency
+  // spill slot from the frame pointer.)
+  if (AFI->isThumb2Function() && MFI.hasVarSizedObjects() &&
+      MFI.getLocalFrameSize() >= 128)
+    return true;
+  // For Thumb1, if sp moves, nothing is in range, so force a base pointer.
+  // This is necessary for correctness in cases where we need an emergency
+  // spill slot. (In Thumb1, we can't use a negative offset from the frame
+  // pointer.)
+  if (AFI->isThumb1OnlyFunction() && !TFI->hasReservedCallFrame(MF))
     return true;
-  }
-
   return false;
 }
 
@@ -425,7 +432,7 @@ cannotEliminateFrame(const MachineFunction &MF) const {
     || needsStackRealignment(MF);
 }
 
-unsigned
+Register
 ARMBaseRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
   const ARMSubtarget &STI = MF.getSubtarget<ARMSubtarget>();
   const ARMFrameLowering *TFI = getFrameLowering(MF);
@@ -785,7 +792,7 @@ ARMBaseRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
   int PIdx = MI.findFirstPredOperandIdx();
   ARMCC::CondCodes Pred = (PIdx == -1)
     ? ARMCC::AL : (ARMCC::CondCodes)MI.getOperand(PIdx).getImm();
-  unsigned PredReg = (PIdx == -1) ? 0 : MI.getOperand(PIdx+1).getReg();
+  Register PredReg = (PIdx == -1) ? Register() : MI.getOperand(PIdx+1).getReg();
   if (Offset == 0)
     // Must be addrmode4/6.
     MI.getOperand(FIOperandNum).ChangeToRegister(FrameReg, false, false, false);