[PowerPC] ELFv2 MC support for .abiversion directive
[oota-llvm.git] / lib / Target / PowerPC / PPCCTRLoops.cpp
index e8760dedea4d0947e6fda8ef26ebdba6d84edc13..ec1e34d91f93b8b158bcab990b6701d14d6b37d5 100644 (file)
 //
 //===----------------------------------------------------------------------===//
 
-#define DEBUG_TYPE "ctrloops"
-
 #include "llvm/Transforms/Scalar.h"
-#include "llvm/ADT/Statistic.h"
+#include "PPC.h"
+#include "PPCTargetMachine.h"
 #include "llvm/ADT/STLExtras.h"
-#include "llvm/Analysis/Dominators.h"
+#include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/ScalarEvolutionExpander.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Dominators.h"
 #include "llvm/IR/InlineAsm.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/Module.h"
+#include "llvm/IR/ValueHandle.h"
 #include "llvm/PassSupport.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
-#include "llvm/Support/ValueHandle.h"
 #include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetLibraryInfo.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
 #include "llvm/Transforms/Utils/Local.h"
-#include "llvm/Target/TargetLibraryInfo.h"
-#include "PPCTargetMachine.h"
-#include "PPC.h"
+#include "llvm/Transforms/Utils/LoopUtils.h"
+
+#ifndef NDEBUG
+#include "llvm/CodeGen/MachineDominators.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#endif
 
 #include <algorithm>
 #include <vector>
 
 using namespace llvm;
 
+#define DEBUG_TYPE "ctrloops"
+
 #ifndef NDEBUG
 static cl::opt<int> CTRLoopLimit("ppc-max-ctrloop", cl::Hidden, cl::init(-1));
 #endif
@@ -61,6 +69,9 @@ STATISTIC(NumCTRLoops, "Number of loops converted to CTR loops");
 
 namespace llvm {
   void initializePPCCTRLoopsPass(PassRegistry&);
+#ifndef NDEBUG
+  void initializePPCCTRLoopsVerifyPass(PassRegistry&);
+#endif
 }
 
 namespace {
@@ -73,37 +84,32 @@ namespace {
   public:
     static char ID;
 
-    PPCCTRLoops() : FunctionPass(ID), TM(0) {
+    PPCCTRLoops() : FunctionPass(ID), TM(nullptr) {
       initializePPCCTRLoopsPass(*PassRegistry::getPassRegistry());
     }
     PPCCTRLoops(PPCTargetMachine &TM) : FunctionPass(ID), TM(&TM) {
       initializePPCCTRLoopsPass(*PassRegistry::getPassRegistry());
     }
 
-    virtual bool runOnFunction(Function &F);
+    bool runOnFunction(Function &F) override;
 
-    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+    void getAnalysisUsage(AnalysisUsage &AU) const override {
       AU.addRequired<LoopInfo>();
       AU.addPreserved<LoopInfo>();
-      AU.addRequired<DominatorTree>();
-      AU.addPreserved<DominatorTree>();
+      AU.addRequired<DominatorTreeWrapperPass>();
+      AU.addPreserved<DominatorTreeWrapperPass>();
       AU.addRequired<ScalarEvolution>();
     }
 
   private:
-    // FIXME: Copied from LoopSimplify.
-    BasicBlock *InsertPreheaderForLoop(Loop *L);
-    void PlaceSplitBlockCarefully(BasicBlock *NewBB,
-                                  SmallVectorImpl<BasicBlock*> &SplitPreds,
-                                  Loop *L);
-
     bool mightUseCTR(const Triple &TT, BasicBlock *BB);
     bool convertToCTRLoop(Loop *L);
+
   private:
     PPCTargetMachine *TM;
     LoopInfo *LI;
     ScalarEvolution *SE;
-    DataLayout *TD;
+    const DataLayout *DL;
     DominatorTree *DT;
     const TargetLibraryInfo *LibInfo;
   };
@@ -112,11 +118,34 @@ namespace {
 #ifndef NDEBUG
   int PPCCTRLoops::Counter = 0;
 #endif
+
+#ifndef NDEBUG
+  struct PPCCTRLoopsVerify : public MachineFunctionPass {
+  public:
+    static char ID;
+
+    PPCCTRLoopsVerify() : MachineFunctionPass(ID) {
+      initializePPCCTRLoopsVerifyPass(*PassRegistry::getPassRegistry());
+    }
+
+    void getAnalysisUsage(AnalysisUsage &AU) const override {
+      AU.addRequired<MachineDominatorTree>();
+      MachineFunctionPass::getAnalysisUsage(AU);
+    }
+
+    bool runOnMachineFunction(MachineFunction &MF) override;
+
+  private:
+    MachineDominatorTree *MDT;
+  };
+
+  char PPCCTRLoopsVerify::ID = 0;
+#endif // NDEBUG
 } // end anonymous namespace
 
 INITIALIZE_PASS_BEGIN(PPCCTRLoops, "ppc-ctr-loops", "PowerPC CTR Loops",
                       false, false)
-INITIALIZE_PASS_DEPENDENCY(DominatorTree)
+INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(LoopInfo)
 INITIALIZE_PASS_DEPENDENCY(ScalarEvolution)
 INITIALIZE_PASS_END(PPCCTRLoops, "ppc-ctr-loops", "PowerPC CTR Loops",
@@ -126,11 +155,24 @@ FunctionPass *llvm::createPPCCTRLoops(PPCTargetMachine &TM) {
   return new PPCCTRLoops(TM);
 }
 
+#ifndef NDEBUG
+INITIALIZE_PASS_BEGIN(PPCCTRLoopsVerify, "ppc-ctr-loops-verify",
+                      "PowerPC CTR Loops Verify", false, false)
+INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
+INITIALIZE_PASS_END(PPCCTRLoopsVerify, "ppc-ctr-loops-verify",
+                    "PowerPC CTR Loops Verify", false, false)
+
+FunctionPass *llvm::createPPCCTRLoopsVerify() {
+  return new PPCCTRLoopsVerify();
+}
+#endif // NDEBUG
+
 bool PPCCTRLoops::runOnFunction(Function &F) {
   LI = &getAnalysis<LoopInfo>();
   SE = &getAnalysis<ScalarEvolution>();
-  DT = &getAnalysis<DominatorTree>();
-  TD = getAnalysisIfAvailable<DataLayout>();
+  DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
+  DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
+  DL = DLP ? &DLP->getDataLayout() : nullptr;
   LibInfo = getAnalysisIfAvailable<TargetLibraryInfo>();
 
   bool MadeChange = false;
@@ -145,6 +187,13 @@ bool PPCCTRLoops::runOnFunction(Function &F) {
   return MadeChange;
 }
 
+static bool isLargeIntegerTy(bool Is32Bit, Type *Ty) {
+  if (IntegerType *ITy = dyn_cast<IntegerType>(Ty))
+    return ITy->getBitWidth() > (Is32Bit ? 32U : 64U);
+
+  return false;
+}
+
 bool PPCCTRLoops::mightUseCTR(const Triple &TT, BasicBlock *BB) {
   for (BasicBlock::iterator J = BB->begin(), JE = BB->end();
        J != JE; ++J) {
@@ -192,6 +241,13 @@ bool PPCCTRLoops::mightUseCTR(const Triple &TT, BasicBlock *BB) {
 #endif
 
           case Intrinsic::longjmp:
+
+          // Exclude eh_sjlj_setjmp; we don't need to exclude eh_sjlj_longjmp
+          // because, although it does clobber the counter register, the
+          // control can't then return to inside the loop unless there is also
+          // an eh_sjlj_setjmp.
+          case Intrinsic::eh_sjlj_setjmp:
+
           case Intrinsic::memcpy:
           case Intrinsic::memmove:
           case Intrinsic::memset:
@@ -205,12 +261,19 @@ bool PPCCTRLoops::mightUseCTR(const Triple &TT, BasicBlock *BB) {
           case Intrinsic::sin:
           case Intrinsic::cos:
             return true;
+          case Intrinsic::copysign:
+            if (CI->getArgOperand(0)->getType()->getScalarType()->
+                isPPC_FP128Ty())
+              return true;
+            else
+              continue; // ISD::FCOPYSIGN is never a library call.
           case Intrinsic::sqrt:      Opcode = ISD::FSQRT;      break;
           case Intrinsic::floor:     Opcode = ISD::FFLOOR;     break;
           case Intrinsic::ceil:      Opcode = ISD::FCEIL;      break;
           case Intrinsic::trunc:     Opcode = ISD::FTRUNC;     break;
           case Intrinsic::rint:      Opcode = ISD::FRINT;      break;
           case Intrinsic::nearbyint: Opcode = ISD::FNEARBYINT; break;
+          case Intrinsic::round:     Opcode = ISD::FROUND;     break;
           }
         }
 
@@ -235,8 +298,9 @@ bool PPCCTRLoops::mightUseCTR(const Triple &TT, BasicBlock *BB) {
           default: return true;
           case LibFunc::copysign:
           case LibFunc::copysignf:
-          case LibFunc::copysignl:
             continue; // ISD::FCOPYSIGN is never a library call.
+          case LibFunc::copysignl:
+            return true;
           case LibFunc::fabs:
           case LibFunc::fabsf:
           case LibFunc::fabsl:
@@ -261,6 +325,10 @@ bool PPCCTRLoops::mightUseCTR(const Triple &TT, BasicBlock *BB) {
           case LibFunc::rintf:
           case LibFunc::rintl:
             Opcode = ISD::FRINT; break;
+          case LibFunc::round:
+          case LibFunc::roundf:
+          case LibFunc::roundl:
+            Opcode = ISD::FROUND; break;
           case LibFunc::trunc:
           case LibFunc::truncf:
           case LibFunc::truncl:
@@ -292,11 +360,24 @@ bool PPCCTRLoops::mightUseCTR(const Triple &TT, BasicBlock *BB) {
       CastInst *CI = cast<CastInst>(J);
       if (CI->getSrcTy()->getScalarType()->isPPC_FP128Ty() ||
           CI->getDestTy()->getScalarType()->isPPC_FP128Ty() ||
-          (TT.isArch32Bit() &&
-           (CI->getSrcTy()->getScalarType()->isIntegerTy(64) ||
-            CI->getDestTy()->getScalarType()->isIntegerTy(64))
-          ))
+          isLargeIntegerTy(TT.isArch32Bit(), CI->getSrcTy()->getScalarType()) ||
+          isLargeIntegerTy(TT.isArch32Bit(), CI->getDestTy()->getScalarType()))
         return true;
+    } else if (isLargeIntegerTy(TT.isArch32Bit(),
+                                J->getType()->getScalarType()) &&
+               (J->getOpcode() == Instruction::UDiv ||
+                J->getOpcode() == Instruction::SDiv ||
+                J->getOpcode() == Instruction::URem ||
+                J->getOpcode() == Instruction::SRem)) {
+      return true;
+    } else if (TT.isArch32Bit() &&
+               isLargeIntegerTy(false, J->getType()->getScalarType()) &&
+               (J->getOpcode() == Instruction::Shl ||
+                J->getOpcode() == Instruction::AShr ||
+                J->getOpcode() == Instruction::LShr)) {
+      // Only on PPC32, for 128-bit integers (specifically not 64-bit
+      // integers), these might be runtime calls.
+      return true;
     } else if (isa<IndirectBrInst>(J) || isa<InvokeInst>(J)) {
       // On PowerPC, indirect jumps use the counter register.
       return true;
@@ -351,10 +432,10 @@ bool PPCCTRLoops::convertToCTRLoop(Loop *L) {
   SmallVector<BasicBlock*, 4> ExitingBlocks;
   L->getExitingBlocks(ExitingBlocks);
 
-  BasicBlock *CountedExitBlock = 0;
-  const SCEV *ExitCount = 0;
-  BranchInst *CountedExitBranch = 0;
-  for (SmallVector<BasicBlock*, 4>::iterator I = ExitingBlocks.begin(),
+  BasicBlock *CountedExitBlock = nullptr;
+  const SCEV *ExitCount = nullptr;
+  BranchInst *CountedExitBranch = nullptr;
+  for (SmallVectorImpl<BasicBlock *>::iterator I = ExitingBlocks.begin(),
        IE = ExitingBlocks.end(); I != IE; ++I) {
     const SCEV *EC = SE->getExitCount(L, *I);
     DEBUG(dbgs() << "Exit Count for " << *L << " from block " <<
@@ -367,6 +448,9 @@ bool PPCCTRLoops::convertToCTRLoop(Loop *L) {
     } else if (!SE->isLoopInvariant(EC, L))
       continue;
 
+    if (SE->getTypeSizeInBits(EC->getType()) > (TT.isArch64Bit() ? 64 : 32))
+      continue;
+
     // We now have a loop-invariant count of loop iterations (which is not the
     // constant zero) for which we know that this loop will not exit via this
     // exisiting block.
@@ -419,7 +503,7 @@ bool PPCCTRLoops::convertToCTRLoop(Loop *L) {
   // the CTR register because some such uses might be reordered by the
   // selection DAG after the mtctr instruction).
   if (!Preheader || mightUseCTR(TT, Preheader))
-    Preheader = InsertPreheaderForLoop(L);
+    Preheader = InsertPreheaderForLoop(L, this);
   if (!Preheader)
     return MadeChange;
 
@@ -467,81 +551,113 @@ bool PPCCTRLoops::convertToCTRLoop(Loop *L) {
   return MadeChange;
 }
 
-// FIXME: Copied from LoopSimplify.
-BasicBlock *PPCCTRLoops::InsertPreheaderForLoop(Loop *L) {
-  BasicBlock *Header = L->getHeader();
-
-  // Compute the set of predecessors of the loop that are not in the loop.
-  SmallVector<BasicBlock*, 8> OutsideBlocks;
-  for (pred_iterator PI = pred_begin(Header), PE = pred_end(Header);
-       PI != PE; ++PI) {
-    BasicBlock *P = *PI;
-    if (!L->contains(P)) {         // Coming in from outside the loop?
-      // If the loop is branched to from an indirect branch, we won't
-      // be able to fully transform the loop, because it prohibits
-      // edge splitting.
-      if (isa<IndirectBrInst>(P->getTerminator())) return 0;
-
-      // Keep track of it.
-      OutsideBlocks.push_back(P);
+#ifndef NDEBUG
+static bool clobbersCTR(const MachineInstr *MI) {
+  for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+    const MachineOperand &MO = MI->getOperand(i);
+    if (MO.isReg()) {
+      if (MO.isDef() && (MO.getReg() == PPC::CTR || MO.getReg() == PPC::CTR8))
+        return true;
+    } else if (MO.isRegMask()) {
+      if (MO.clobbersPhysReg(PPC::CTR) || MO.clobbersPhysReg(PPC::CTR8))
+        return true;
     }
   }
 
-  // Split out the loop pre-header.
-  BasicBlock *PreheaderBB;
-  if (!Header->isLandingPad()) {
-    PreheaderBB = SplitBlockPredecessors(Header, OutsideBlocks, ".preheader",
-                                         this);
-  } else {
-    SmallVector<BasicBlock*, 2> NewBBs;
-    SplitLandingPadPredecessors(Header, OutsideBlocks, ".preheader",
-                                ".split-lp", this, NewBBs);
-    PreheaderBB = NewBBs[0];
+  return false;
+}
+
+static bool verifyCTRBranch(MachineBasicBlock *MBB,
+                            MachineBasicBlock::iterator I) {
+  MachineBasicBlock::iterator BI = I;
+  SmallSet<MachineBasicBlock *, 16>   Visited;
+  SmallVector<MachineBasicBlock *, 8> Preds;
+  bool CheckPreds;
+
+  if (I == MBB->begin()) {
+    Visited.insert(MBB);
+    goto queue_preds;
+  } else
+    --I;
+
+check_block:
+  Visited.insert(MBB);
+  if (I == MBB->end())
+    goto queue_preds;
+
+  CheckPreds = true;
+  for (MachineBasicBlock::iterator IE = MBB->begin();; --I) {
+    unsigned Opc = I->getOpcode();
+    if (Opc == PPC::MTCTRloop || Opc == PPC::MTCTR8loop) {
+      CheckPreds = false;
+      break;
+    }
+
+    if (I != BI && clobbersCTR(I)) {
+      DEBUG(dbgs() << "BB#" << MBB->getNumber() << " (" <<
+                      MBB->getFullName() << ") instruction " << *I <<
+                      " clobbers CTR, invalidating " << "BB#" <<
+                      BI->getParent()->getNumber() << " (" <<
+                      BI->getParent()->getFullName() << ") instruction " <<
+                      *BI << "\n");
+      return false;
+    }
+
+    if (I == IE)
+      break;
   }
 
-  PreheaderBB->getTerminator()->setDebugLoc(
-                                      Header->getFirstNonPHI()->getDebugLoc());
-  DEBUG(dbgs() << "Creating pre-header "
-               << PreheaderBB->getName() << "\n");
+  if (!CheckPreds && Preds.empty())
+    return true;
+
+  if (CheckPreds) {
+queue_preds:
+    if (MachineFunction::iterator(MBB) == MBB->getParent()->begin()) {
+      DEBUG(dbgs() << "Unable to find a MTCTR instruction for BB#" <<
+                      BI->getParent()->getNumber() << " (" <<
+                      BI->getParent()->getFullName() << ") instruction " <<
+                      *BI << "\n");
+      return false;
+    }
+
+    for (MachineBasicBlock::pred_iterator PI = MBB->pred_begin(),
+         PIE = MBB->pred_end(); PI != PIE; ++PI)
+      Preds.push_back(*PI);
+  }
 
-  // Make sure that NewBB is put someplace intelligent, which doesn't mess up
-  // code layout too horribly.
-  PlaceSplitBlockCarefully(PreheaderBB, OutsideBlocks, L);
+  do {
+    MBB = Preds.pop_back_val();
+    if (!Visited.count(MBB)) {
+      I = MBB->getLastNonDebugInstr();
+      goto check_block;
+    }
+  } while (!Preds.empty());
 
-  return PreheaderBB;
+  return true;
 }
 
-void PPCCTRLoops::PlaceSplitBlockCarefully(BasicBlock *NewBB,
-                                       SmallVectorImpl<BasicBlock*> &SplitPreds,
-                                            Loop *L) {
-  // Check to see if NewBB is already well placed.
-  Function::iterator BBI = NewBB; --BBI;
-  for (unsigned i = 0, e = SplitPreds.size(); i != e; ++i) {
-    if (&*BBI == SplitPreds[i])
-      return;
-  }
+bool PPCCTRLoopsVerify::runOnMachineFunction(MachineFunction &MF) {
+  MDT = &getAnalysis<MachineDominatorTree>();
 
-  // If it isn't already after an outside block, move it after one.  This is
-  // always good as it makes the uncond branch from the outside block into a
-  // fall-through.
-
-  // Figure out *which* outside block to put this after.  Prefer an outside
-  // block that neighbors a BB actually in the loop.
-  BasicBlock *FoundBB = 0;
-  for (unsigned i = 0, e = SplitPreds.size(); i != e; ++i) {
-    Function::iterator BBI = SplitPreds[i];
-    if (++BBI != NewBB->getParent()->end() &&
-        L->contains(BBI)) {
-      FoundBB = SplitPreds[i];
-      break;
+  // Verify that all bdnz/bdz instructions are dominated by a loop mtctr before
+  // any other instructions that might clobber the ctr register.
+  for (MachineFunction::iterator I = MF.begin(), IE = MF.end();
+       I != IE; ++I) {
+    MachineBasicBlock *MBB = I;
+    if (!MDT->isReachableFromEntry(MBB))
+      continue;
+
+    for (MachineBasicBlock::iterator MII = MBB->getFirstTerminator(),
+      MIIE = MBB->end(); MII != MIIE; ++MII) {
+      unsigned Opc = MII->getOpcode();
+      if (Opc == PPC::BDNZ8 || Opc == PPC::BDNZ ||
+          Opc == PPC::BDZ8  || Opc == PPC::BDZ)
+        if (!verifyCTRBranch(MBB, MII))
+          llvm_unreachable("Invalid PPC CTR loop!");
     }
   }
 
-  // If our heuristic for a *good* bb to place this after doesn't find
-  // anything, just pick something.  It's likely better than leaving it within
-  // the loop.
-  if (!FoundBB)
-    FoundBB = SplitPreds[0];
-  NewBB->moveAfter(FoundBB);
+  return false;
 }
+#endif // NDEBUG