1 files changed, 17 insertions, 57 deletions

diff --git a/llvm/lib/Target/ARM/ARMConstantIslandPass.cpp b/llvm/lib/Target/ARM/ARMConstantIslandPass.cpp
index 634fb89b8e89..195d0a89291b 100644
--- a/llvm/lib/Target/ARM/ARMConstantIslandPass.cpp
+++ b/llvm/lib/Target/ARM/ARMConstantIslandPass.cpp
@@ -206,10 +206,6 @@ namespace {
     /// T2JumpTables - Keep track of all the Thumb2 jumptable instructions.
     SmallVector<MachineInstr*, 4> T2JumpTables;
 
-    /// HasFarJump - True if any far jump instruction has been emitted during
-    /// the branch fix up pass.
-    bool HasFarJump;
-
     MachineFunction *MF;
     MachineConstantPool *MCP;
     const ARMBaseInstrInfo *TII;
@@ -270,7 +266,6 @@ namespace {
     bool fixupImmediateBr(ImmBranch &Br);
     bool fixupConditionalBr(ImmBranch &Br);
     bool fixupUnconditionalBr(ImmBranch &Br);
-    bool undoLRSpillRestore();
     bool optimizeThumb2Instructions();
     bool optimizeThumb2Branches();
     bool reorderThumb2JumpTables();
@@ -330,8 +325,8 @@ void ARMConstantIslands::verify() {
 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 /// print block size and offset information - debugging
 LLVM_DUMP_METHOD void ARMConstantIslands::dumpBBs() {
-  BBInfoVector &BBInfo = BBUtils->getBBInfo();
   LLVM_DEBUG({
+    BBInfoVector &BBInfo = BBUtils->getBBInfo();
     for (unsigned J = 0, E = BBInfo.size(); J !=E; ++J) {
       const BasicBlockInfo &BBI = BBInfo[J];
       dbgs() << format("%08x %bb.%u\t", BBI.Offset, J)
@@ -350,7 +345,7 @@ bool ARMConstantIslands::runOnMachineFunction(MachineFunction &mf) {
 
   LLVM_DEBUG(dbgs() << "***** ARMConstantIslands: "
                     << MCP->getConstants().size() << " CP entries, aligned to "
-                    << MCP->getConstantPoolAlignment() << " bytes *****\n");
+                    << MCP->getConstantPoolAlign().value() << " bytes *****\n");
 
   STI = &static_cast<const ARMSubtarget &>(MF->getSubtarget());
   TII = STI->getInstrInfo();
@@ -363,7 +358,6 @@ bool ARMConstantIslands::runOnMachineFunction(MachineFunction &mf) {
   isThumb1 = AFI->isThumb1OnlyFunction();
   isThumb2 = AFI->isThumb2Function();
 
-  HasFarJump = false;
   bool GenerateTBB = isThumb2 || (isThumb1 && SynthesizeThumb1TBB);
 
   // Renumber all of the machine basic blocks in the function, guaranteeing that
@@ -456,11 +450,6 @@ bool ARMConstantIslands::runOnMachineFunction(MachineFunction &mf) {
   // After a while, this might be made debug-only, but it is not expensive.
   verify();
 
-  // If LR has been forced spilled and no far jump (i.e. BL) has been issued,
-  // undo the spill / restore of LR if possible.
-  if (isThumb && !HasFarJump && AFI->isLRSpilledForFarJump())
-    MadeChange |= undoLRSpillRestore();
-
   // Save the mapping between original and cloned constpool entries.
   for (unsigned i = 0, e = CPEntries.size(); i != e; ++i) {
     for (unsigned j = 0, je = CPEntries[i].size(); j != je; ++j) {
@@ -494,7 +483,7 @@ ARMConstantIslands::doInitialConstPlacement(std::vector<MachineInstr*> &CPEMIs)
   MF->push_back(BB);
 
   // MachineConstantPool measures alignment in bytes.
-  const Align MaxAlign(MCP->getConstantPoolAlignment());
+  const Align MaxAlign = MCP->getConstantPoolAlign();
   const unsigned MaxLogAlign = Log2(MaxAlign);
 
   // Mark the basic block as required by the const-pool.
@@ -518,14 +507,13 @@ ARMConstantIslands::doInitialConstPlacement(std::vector<MachineInstr*> &CPEMIs)
   const DataLayout &TD = MF->getDataLayout();
   for (unsigned i = 0, e = CPs.size(); i != e; ++i) {
     unsigned Size = TD.getTypeAllocSize(CPs[i].getType());
-    unsigned Align = CPs[i].getAlignment();
-    assert(isPowerOf2_32(Align) && "Invalid alignment");
+    Align Alignment = CPs[i].getAlign();
     // Verify that all constant pool entries are a multiple of their alignment.
     // If not, we would have to pad them out so that instructions stay aligned.
-    assert((Size % Align) == 0 && "CP Entry not multiple of 4 bytes!");
+    assert(isAligned(Alignment, Size) && "CP Entry not multiple of 4 bytes!");
 
     // Insert CONSTPOOL_ENTRY before entries with a smaller alignment.
-    unsigned LogAlign = Log2_32(Align);
+    unsigned LogAlign = Log2(Alignment);
     MachineBasicBlock::iterator InsAt = InsPoint[LogAlign];
     MachineInstr *CPEMI =
       BuildMI(*BB, InsAt, DebugLoc(), TII->get(ARM::CONSTPOOL_ENTRY))
@@ -542,7 +530,7 @@ ARMConstantIslands::doInitialConstPlacement(std::vector<MachineInstr*> &CPEMIs)
     CPEntries.emplace_back(1, CPEntry(CPEMI, i));
     ++NumCPEs;
     LLVM_DEBUG(dbgs() << "Moved CPI#" << i << " to end of function, size = "
-                      << Size << ", align = " << Align << '\n');
+                      << Size << ", align = " << Alignment.value() << '\n');
   }
   LLVM_DEBUG(BB->dump());
 }
@@ -668,7 +656,7 @@ Align ARMConstantIslands::getCPEAlign(const MachineInstr *CPEMI) {
 
   unsigned CPI = getCombinedIndex(CPEMI);
   assert(CPI < MCP->getConstants().size() && "Invalid constant pool index.");
-  return Align(MCP->getConstants()[CPI].getAlignment());
+  return MCP->getConstants()[CPI].getAlign();
 }
 
 /// scanFunctionJumpTables - Do a scan of the function, building up
@@ -1364,8 +1352,8 @@ void ARMConstantIslands::createNewWater(unsigned CPUserIndex,
     //   displacement.
     MachineBasicBlock::iterator I = UserMI;
     ++I;
-    for (unsigned Offset = UserOffset + TII->getInstSizeInBytes(*UserMI),
-                  PredReg = 0;
+    Register PredReg;
+    for (unsigned Offset = UserOffset + TII->getInstSizeInBytes(*UserMI);
          I->getOpcode() != ARM::t2IT &&
          getITInstrPredicate(*I, PredReg) != ARMCC::AL;
          Offset += TII->getInstSizeInBytes(*I), I = std::next(I)) {
@@ -1410,7 +1398,7 @@ void ARMConstantIslands::createNewWater(unsigned CPUserIndex,
 
   // Avoid splitting an IT block.
   if (LastIT) {
-    unsigned PredReg = 0;
+    Register PredReg;
     ARMCC::CondCodes CC = getITInstrPredicate(*MI, PredReg);
     if (CC != ARMCC::AL)
       MI = LastIT;
@@ -1434,7 +1422,7 @@ void ARMConstantIslands::createNewWater(unsigned CPUserIndex,
 
   // We really must not split an IT block.
 #ifndef NDEBUG
-  unsigned PredReg;
+  Register PredReg;
   assert(!isThumb || getITInstrPredicate(*MI, PredReg) == ARMCC::AL);
 #endif
   NewMBB = splitBlockBeforeInstr(&*MI);
@@ -1566,7 +1554,7 @@ void ARMConstantIslands::removeDeadCPEMI(MachineInstr *CPEMI) {
     BBInfo[CPEBB->getNumber()].Size = 0;
 
     // This block no longer needs to be aligned.
-    CPEBB->setAlignment(Align::None());
+    CPEBB->setAlignment(Align(1));
   } else {
     // Entries are sorted by descending alignment, so realign from the front.
     CPEBB->setAlignment(getCPEAlign(&*CPEBB->begin()));
@@ -1633,7 +1621,6 @@ ARMConstantIslands::fixupUnconditionalBr(ImmBranch &Br) {
   BBInfoVector &BBInfo = BBUtils->getBBInfo();
   BBInfo[MBB->getNumber()].Size += 2;
   BBUtils->adjustBBOffsetsAfter(MBB);
-  HasFarJump = true;
   ++NumUBrFixed;
 
   LLVM_DEBUG(dbgs() << "  Changed B to long jump " << *MI);
@@ -1735,34 +1722,6 @@ ARMConstantIslands::fixupConditionalBr(ImmBranch &Br) {
   return true;
 }
 
-/// undoLRSpillRestore - Remove Thumb push / pop instructions that only spills
-/// LR / restores LR to pc. FIXME: This is done here because it's only possible
-/// to do this if tBfar is not used.
-bool ARMConstantIslands::undoLRSpillRestore() {
-  bool MadeChange = false;
-  for (unsigned i = 0, e = PushPopMIs.size(); i != e; ++i) {
-    MachineInstr *MI = PushPopMIs[i];
-    // First two operands are predicates.
-    if (MI->getOpcode() == ARM::tPOP_RET &&
-        MI->getOperand(2).getReg() == ARM::PC &&
-        MI->getNumExplicitOperands() == 3) {
-      // Create the new insn and copy the predicate from the old.
-      BuildMI(MI->getParent(), MI->getDebugLoc(), TII->get(ARM::tBX_RET))
-          .add(MI->getOperand(0))
-          .add(MI->getOperand(1));
-      MI->eraseFromParent();
-      MadeChange = true;
-    } else if (MI->getOpcode() == ARM::tPUSH &&
-               MI->getOperand(2).getReg() == ARM::LR &&
-               MI->getNumExplicitOperands() == 3) {
-      // Just remove the push.
-      MI->eraseFromParent();
-      MadeChange = true;
-    }
-  }
-  return MadeChange;
-}
-
 bool ARMConstantIslands::optimizeThumb2Instructions() {
   bool MadeChange = false;
 
@@ -1868,7 +1827,7 @@ bool ARMConstantIslands::optimizeThumb2Branches() {
     if (!Br.MI->killsRegister(ARM::CPSR))
       return false;
 
-    unsigned PredReg = 0;
+    Register PredReg;
     unsigned NewOpc = 0;
     ARMCC::CondCodes Pred = getInstrPredicate(*Br.MI, PredReg);
     if (Pred == ARMCC::EQ)
@@ -2402,6 +2361,7 @@ adjustJTTargetBlockForward(MachineBasicBlock *BB, MachineBasicBlock *JTBB) {
   SmallVector<MachineOperand, 4> CondPrior;
   MachineFunction::iterator BBi = BB->getIterator();
   MachineFunction::iterator OldPrior = std::prev(BBi);
+  MachineFunction::iterator OldNext = std::next(BBi);
 
   // If the block terminator isn't analyzable, don't try to move the block
   bool B = TII->analyzeBranch(*BB, TBB, FBB, Cond);
@@ -2412,8 +2372,8 @@ adjustJTTargetBlockForward(MachineBasicBlock *BB, MachineBasicBlock *JTBB) {
   if (!B && Cond.empty() && BB != &MF->front() &&
       !TII->analyzeBranch(*OldPrior, TBB, FBB, CondPrior)) {
     BB->moveAfter(JTBB);
-    OldPrior->updateTerminator();
-    BB->updateTerminator();
+    OldPrior->updateTerminator(BB);
+    BB->updateTerminator(OldNext != MF->end() ? &*OldNext : nullptr);
     // Update numbering to account for the block being moved.
     MF->RenumberBlocks();
     ++NumJTMoved;