//
//===----------------------------------------------------------------------===//
-#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
namespace llvm {
void initializePPCCTRLoopsPass(PassRegistry&);
+#ifndef NDEBUG
+ void initializePPCCTRLoopsVerifyPass(PassRegistry&);
+#endif
}
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;
};
#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",
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;
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) {
+ if (CallInst *CI = dyn_cast<CallInst>(J)) {
+ if (InlineAsm *IA = dyn_cast<InlineAsm>(CI->getCalledValue())) {
+ // Inline ASM is okay, unless it clobbers the ctr register.
+ InlineAsm::ConstraintInfoVector CIV = IA->ParseConstraints();
+ for (unsigned i = 0, ie = CIV.size(); i < ie; ++i) {
+ InlineAsm::ConstraintInfo &C = CIV[i];
+ if (C.Type != InlineAsm::isInput)
+ for (unsigned j = 0, je = C.Codes.size(); j < je; ++j)
+ if (StringRef(C.Codes[j]).equals_lower("{ctr}"))
+ return true;
+ }
+
+ continue;
+ }
+
+ if (!TM)
+ return true;
+ const TargetLowering *TLI = TM->getTargetLowering();
+
+ if (Function *F = CI->getCalledFunction()) {
+ // Most intrinsics don't become function calls, but some might.
+ // sin, cos, exp and log are always calls.
+ unsigned Opcode;
+ if (F->getIntrinsicID() != Intrinsic::not_intrinsic) {
+ switch (F->getIntrinsicID()) {
+ default: continue;
+
+// VisualStudio defines setjmp as _setjmp
+#if defined(_MSC_VER) && defined(setjmp) && \
+ !defined(setjmp_undefined_for_msvc)
+# pragma push_macro("setjmp")
+# undef setjmp
+# define setjmp_undefined_for_msvc
+#endif
+
+ case Intrinsic::setjmp:
+
+#if defined(_MSC_VER) && defined(setjmp_undefined_for_msvc)
+ // let's return it to _setjmp state
+# pragma pop_macro("setjmp")
+# undef setjmp_undefined_for_msvc
+#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:
+ case Intrinsic::powi:
+ case Intrinsic::log:
+ case Intrinsic::log2:
+ case Intrinsic::log10:
+ case Intrinsic::exp:
+ case Intrinsic::exp2:
+ case Intrinsic::pow:
+ 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;
+ }
+ }
+
+ // PowerPC does not use [US]DIVREM or other library calls for
+ // operations on regular types which are not otherwise library calls
+ // (i.e. soft float or atomics). If adapting for targets that do,
+ // additional care is required here.
+
+ LibFunc::Func Func;
+ if (!F->hasLocalLinkage() && F->hasName() && LibInfo &&
+ LibInfo->getLibFunc(F->getName(), Func) &&
+ LibInfo->hasOptimizedCodeGen(Func)) {
+ // Non-read-only functions are never treated as intrinsics.
+ if (!CI->onlyReadsMemory())
+ return true;
+
+ // Conversion happens only for FP calls.
+ if (!CI->getArgOperand(0)->getType()->isFloatingPointTy())
+ return true;
+
+ switch (Func) {
+ default: return true;
+ case LibFunc::copysign:
+ case LibFunc::copysignf:
+ continue; // ISD::FCOPYSIGN is never a library call.
+ case LibFunc::copysignl:
+ return true;
+ case LibFunc::fabs:
+ case LibFunc::fabsf:
+ case LibFunc::fabsl:
+ continue; // ISD::FABS is never a library call.
+ case LibFunc::sqrt:
+ case LibFunc::sqrtf:
+ case LibFunc::sqrtl:
+ Opcode = ISD::FSQRT; break;
+ case LibFunc::floor:
+ case LibFunc::floorf:
+ case LibFunc::floorl:
+ Opcode = ISD::FFLOOR; break;
+ case LibFunc::nearbyint:
+ case LibFunc::nearbyintf:
+ case LibFunc::nearbyintl:
+ Opcode = ISD::FNEARBYINT; break;
+ case LibFunc::ceil:
+ case LibFunc::ceilf:
+ case LibFunc::ceill:
+ Opcode = ISD::FCEIL; break;
+ case LibFunc::rint:
+ 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:
+ Opcode = ISD::FTRUNC; break;
+ }
+
+ MVT VTy =
+ TLI->getSimpleValueType(CI->getArgOperand(0)->getType(), true);
+ if (VTy == MVT::Other)
+ return true;
+
+ if (TLI->isOperationLegalOrCustom(Opcode, VTy))
+ continue;
+ else if (VTy.isVector() &&
+ TLI->isOperationLegalOrCustom(Opcode, VTy.getScalarType()))
+ continue;
+
+ return true;
+ }
+ }
+
+ return true;
+ } else if (isa<BinaryOperator>(J) &&
+ J->getType()->getScalarType()->isPPC_FP128Ty()) {
+ // Most operations on ppc_f128 values become calls.
+ return true;
+ } else if (isa<UIToFPInst>(J) || isa<SIToFPInst>(J) ||
+ isa<FPToUIInst>(J) || isa<FPToSIInst>(J)) {
+ CastInst *CI = cast<CastInst>(J);
+ if (CI->getSrcTy()->getScalarType()->isPPC_FP128Ty() ||
+ CI->getDestTy()->getScalarType()->isPPC_FP128Ty() ||
+ 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;
+ } else if (SwitchInst *SI = dyn_cast<SwitchInst>(J)) {
+ if (!TM)
+ return true;
+ const TargetLowering *TLI = TM->getTargetLowering();
+
+ if (TLI->supportJumpTables() &&
+ SI->getNumCases()+1 >= (unsigned) TLI->getMinimumJumpTableEntries())
+ return true;
+ }
+ }
+
+ return false;
+}
+
bool PPCCTRLoops::convertToCTRLoop(Loop *L) {
bool MadeChange = false;
// We don't want to spill/restore the counter register, and so we don't
// want to use the counter register if the loop contains calls.
for (Loop::block_iterator I = L->block_begin(), IE = L->block_end();
- I != IE; ++I) {
- for (BasicBlock::iterator J = (*I)->begin(), JE = (*I)->end();
- J != JE; ++J) {
- if (CallInst *CI = dyn_cast<CallInst>(J)) {
- if (!TM)
- return MadeChange;
- const TargetLowering *TLI = TM->getTargetLowering();
-
- if (Function *F = CI->getCalledFunction()) {
- // Most intrinsics don't become function calls, but some might.
- // sin, cos, exp and log are always calls.
- unsigned Opcode;
- if (F->getIntrinsicID() != Intrinsic::not_intrinsic) {
- switch (F->getIntrinsicID()) {
- default: continue;
-
-// VisualStudio defines setjmp as _setjmp
-#if defined(_MSC_VER) && defined(setjmp) && \
- !defined(setjmp_undefined_for_msvc)
-# pragma push_macro("setjmp")
-# undef setjmp
-# define setjmp_undefined_for_msvc
-#endif
-
- case Intrinsic::setjmp:
-
-#if defined(_MSC_VER) && defined(setjmp_undefined_for_msvc)
- // let's return it to _setjmp state
-# pragma pop_macro("setjmp")
-# undef setjmp_undefined_for_msvc
-#endif
-
- case Intrinsic::longjmp:
- case Intrinsic::memcpy:
- case Intrinsic::memmove:
- case Intrinsic::memset:
- case Intrinsic::powi:
- case Intrinsic::log:
- case Intrinsic::log2:
- case Intrinsic::log10:
- case Intrinsic::exp:
- case Intrinsic::exp2:
- case Intrinsic::pow:
- case Intrinsic::sin:
- case Intrinsic::cos:
- return MadeChange;
- 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;
- }
- }
-
- // PowerPC does not use [US]DIVREM or other library calls for
- // operations on regular types which are not otherwise library calls
- // (i.e. soft float or atomics). If adapting for targets that do,
- // additional care is required here.
-
- LibFunc::Func Func;
- if (!F->hasLocalLinkage() && F->hasName() && LibInfo &&
- LibInfo->getLibFunc(F->getName(), Func) &&
- LibInfo->hasOptimizedCodeGen(Func)) {
- // Non-read-only functions are never treated as intrinsics.
- if (!CI->onlyReadsMemory())
- return MadeChange;
-
- // Conversion happens only for FP calls.
- if (!CI->getArgOperand(0)->getType()->isFloatingPointTy())
- return MadeChange;
-
- switch (Func) {
- default: return MadeChange;
- case LibFunc::copysign:
- case LibFunc::copysignf:
- case LibFunc::copysignl:
- continue; // ISD::FCOPYSIGN is never a library call.
- case LibFunc::fabs:
- case LibFunc::fabsf:
- case LibFunc::fabsl:
- continue; // ISD::FABS is never a library call.
- case LibFunc::sqrt:
- case LibFunc::sqrtf:
- case LibFunc::sqrtl:
- Opcode = ISD::FSQRT; break;
- case LibFunc::floor:
- case LibFunc::floorf:
- case LibFunc::floorl:
- Opcode = ISD::FFLOOR; break;
- case LibFunc::nearbyint:
- case LibFunc::nearbyintf:
- case LibFunc::nearbyintl:
- Opcode = ISD::FNEARBYINT; break;
- case LibFunc::ceil:
- case LibFunc::ceilf:
- case LibFunc::ceill:
- Opcode = ISD::FCEIL; break;
- case LibFunc::rint:
- case LibFunc::rintf:
- case LibFunc::rintl:
- Opcode = ISD::FRINT; break;
- case LibFunc::trunc:
- case LibFunc::truncf:
- case LibFunc::truncl:
- Opcode = ISD::FTRUNC; break;
- }
-
- MVT VTy =
- TLI->getSimpleValueType(CI->getArgOperand(0)->getType(), true);
- if (VTy == MVT::Other)
- return MadeChange;
-
- if (TLI->isOperationLegalOrCustom(Opcode, VTy))
- continue;
- else if (VTy.isVector() &&
- TLI->isOperationLegalOrCustom(Opcode, VTy.getScalarType()))
- continue;
-
- return MadeChange;
- }
- }
-
- return MadeChange;
- } else if (isa<BinaryOperator>(J) &&
- J->getType()->getScalarType()->isPPC_FP128Ty()) {
- // Most operations on ppc_f128 values become calls.
- return MadeChange;
- } else if (isa<UIToFPInst>(J) || isa<SIToFPInst>(J) ||
- isa<FPToUIInst>(J) || isa<FPToSIInst>(J)) {
- 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))
- ))
- return MadeChange;
- } else if (isa<IndirectBrInst>(J) || isa<InvokeInst>(J)) {
- // On PowerPC, indirect jumps use the counter register.
- return MadeChange;
- } else if (SwitchInst *SI = dyn_cast<SwitchInst>(J)) {
- if (!TM)
- return MadeChange;
- const TargetLowering *TLI = TM->getTargetLowering();
-
- if (TLI->supportJumpTables() &&
- SI->getNumCases()+1 >= (unsigned) TLI->getMinimumJumpTableEntries())
- return MadeChange;
- }
- }
- }
+ I != IE; ++I)
+ if (mightUseCTR(TT, *I))
+ return MadeChange;
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 " <<
} 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.
return MadeChange;
BasicBlock *Preheader = L->getLoopPreheader();
- if (!Preheader)
- Preheader = InsertPreheaderForLoop(L);
+
+ // If we don't have a preheader, then insert one. If we already have a
+ // preheader, then we can use it (except if the preheader contains a use of
+ // 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, this);
if (!Preheader)
return MadeChange;
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;
- // Make sure that NewBB is put someplace intelligent, which doesn't mess up
- // code layout too horribly.
- PlaceSplitBlockCarefully(PreheaderBB, OutsideBlocks, L);
+ 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);
+ }
- return PreheaderBB;
+ do {
+ MBB = Preds.pop_back_val();
+ if (!Visited.count(MBB)) {
+ I = MBB->getLastNonDebugInstr();
+ goto check_block;
+ }
+ } while (!Preds.empty());
+
+ 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
projects / oota-llvm.git / blobdiff