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authorDimitry Andric <dim@FreeBSD.org>2019-08-21 18:13:02 +0000
committerDimitry Andric <dim@FreeBSD.org>2019-08-21 18:13:02 +0000
commit54db30ce18663e6c2991958f3b5d18362e8e93c4 (patch)
tree4aa6442802570767398cc83ba484e97b1309bdc2 /contrib/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp
parent35284c22e9c8348159b7ce032ea45f2cdeb65298 (diff)
parente6d1592492a3a379186bfb02bd0f4eda0669c0d5 (diff)
Merge llvm trunk r366426, resolve conflicts, and update FREEBSD-Xlist.
Notes
Notes: svn path=/projects/clang900-import/; revision=351344
Diffstat (limited to 'contrib/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp')
-rw-r--r--contrib/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp449
1 files changed, 423 insertions, 26 deletions
diff --git a/contrib/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp b/contrib/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp
index bc9bcab83a0a..ff3dfbfaca05 100644
--- a/contrib/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp
+++ b/contrib/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp
@@ -1,17 +1,18 @@
//===-- PPCTargetTransformInfo.cpp - PPC specific TTI ---------------------===//
//
-// 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
//
//===----------------------------------------------------------------------===//
#include "PPCTargetTransformInfo.h"
+#include "llvm/Analysis/CodeMetrics.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/CodeGen/BasicTTIImpl.h"
#include "llvm/CodeGen/CostTable.h"
#include "llvm/CodeGen/TargetLowering.h"
+#include "llvm/CodeGen/TargetSchedule.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
using namespace llvm;
@@ -32,6 +33,13 @@ EnablePPCColdCC("ppc-enable-coldcc", cl::Hidden, cl::init(false),
cl::desc("Enable using coldcc calling conv for cold "
"internal functions"));
+// The latency of mtctr is only justified if there are more than 4
+// comparisons that will be removed as a result.
+static cl::opt<unsigned>
+SmallCTRLoopThreshold("min-ctr-loop-threshold", cl::init(4), cl::Hidden,
+ cl::desc("Loops with a constant trip count smaller than "
+ "this value will not use the count register."));
+
//===----------------------------------------------------------------------===//
//
// PPC cost model.
@@ -205,6 +213,341 @@ unsigned PPCTTIImpl::getUserCost(const User *U,
return BaseT::getUserCost(U, Operands);
}
+bool PPCTTIImpl::mightUseCTR(BasicBlock *BB,
+ TargetLibraryInfo *LibInfo) {
+ const PPCTargetMachine &TM = ST->getTargetMachine();
+
+ // Loop through the inline asm constraints and look for something that
+ // clobbers ctr.
+ auto asmClobbersCTR = [](InlineAsm *IA) {
+ 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;
+ }
+ return false;
+ };
+
+ // Determining the address of a TLS variable results in a function call in
+ // certain TLS models.
+ std::function<bool(const Value*)> memAddrUsesCTR =
+ [&memAddrUsesCTR, &TM](const Value *MemAddr) -> bool {
+ const auto *GV = dyn_cast<GlobalValue>(MemAddr);
+ if (!GV) {
+ // Recurse to check for constants that refer to TLS global variables.
+ if (const auto *CV = dyn_cast<Constant>(MemAddr))
+ for (const auto &CO : CV->operands())
+ if (memAddrUsesCTR(CO))
+ return true;
+
+ return false;
+ }
+
+ if (!GV->isThreadLocal())
+ return false;
+ TLSModel::Model Model = TM.getTLSModel(GV);
+ return Model == TLSModel::GeneralDynamic ||
+ Model == TLSModel::LocalDynamic;
+ };
+
+ auto isLargeIntegerTy = [](bool Is32Bit, Type *Ty) {
+ if (IntegerType *ITy = dyn_cast<IntegerType>(Ty))
+ return ITy->getBitWidth() > (Is32Bit ? 32U : 64U);
+
+ return false;
+ };
+
+ for (BasicBlock::iterator J = BB->begin(), JE = BB->end();
+ J != JE; ++J) {
+ if (CallInst *CI = dyn_cast<CallInst>(J)) {
+ // Inline ASM is okay, unless it clobbers the ctr register.
+ if (InlineAsm *IA = dyn_cast<InlineAsm>(CI->getCalledValue())) {
+ if (asmClobbersCTR(IA))
+ return true;
+ continue;
+ }
+
+ 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 = 0;
+ if (F->getIntrinsicID() != Intrinsic::not_intrinsic) {
+ switch (F->getIntrinsicID()) {
+ default: continue;
+ // If we have a call to ppc_is_decremented_ctr_nonzero, or ppc_mtctr
+ // we're definitely using CTR.
+ case Intrinsic::set_loop_iterations:
+ case Intrinsic::loop_decrement:
+ return true;
+
+// 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;
+ case Intrinsic::minnum: Opcode = ISD::FMINNUM; break;
+ case Intrinsic::maxnum: Opcode = ISD::FMAXNUM; break;
+ case Intrinsic::umul_with_overflow: Opcode = ISD::UMULO; break;
+ case Intrinsic::smul_with_overflow: Opcode = ISD::SMULO; 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;
+ 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;
+ case LibFunc_fmin:
+ case LibFunc_fminf:
+ case LibFunc_fminl:
+ Opcode = ISD::FMINNUM; break;
+ case LibFunc_fmax:
+ case LibFunc_fmaxf:
+ case LibFunc_fmaxl:
+ Opcode = ISD::FMAXNUM; break;
+ }
+ }
+
+ if (Opcode) {
+ EVT EVTy =
+ TLI->getValueType(DL, CI->getArgOperand(0)->getType(), true);
+
+ if (EVTy == MVT::Other)
+ return true;
+
+ if (TLI->isOperationLegalOrCustom(Opcode, EVTy))
+ continue;
+ else if (EVTy.isVector() &&
+ TLI->isOperationLegalOrCustom(Opcode, EVTy.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(!TM.isPPC64(), CI->getSrcTy()->getScalarType()) ||
+ isLargeIntegerTy(!TM.isPPC64(), CI->getDestTy()->getScalarType()))
+ return true;
+ } else if (isLargeIntegerTy(!TM.isPPC64(),
+ J->getType()->getScalarType()) &&
+ (J->getOpcode() == Instruction::UDiv ||
+ J->getOpcode() == Instruction::SDiv ||
+ J->getOpcode() == Instruction::URem ||
+ J->getOpcode() == Instruction::SRem)) {
+ return true;
+ } else if (!TM.isPPC64() &&
+ 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 (SI->getNumCases() + 1 >= (unsigned)TLI->getMinimumJumpTableEntries())
+ return true;
+ }
+
+ // FREM is always a call.
+ if (J->getOpcode() == Instruction::FRem)
+ return true;
+
+ if (ST->useSoftFloat()) {
+ switch(J->getOpcode()) {
+ case Instruction::FAdd:
+ case Instruction::FSub:
+ case Instruction::FMul:
+ case Instruction::FDiv:
+ case Instruction::FPTrunc:
+ case Instruction::FPExt:
+ case Instruction::FPToUI:
+ case Instruction::FPToSI:
+ case Instruction::UIToFP:
+ case Instruction::SIToFP:
+ case Instruction::FCmp:
+ return true;
+ }
+ }
+
+ for (Value *Operand : J->operands())
+ if (memAddrUsesCTR(Operand))
+ return true;
+ }
+
+ return false;
+}
+
+bool PPCTTIImpl::isHardwareLoopProfitable(Loop *L, ScalarEvolution &SE,
+ AssumptionCache &AC,
+ TargetLibraryInfo *LibInfo,
+ HardwareLoopInfo &HWLoopInfo) {
+ const PPCTargetMachine &TM = ST->getTargetMachine();
+ TargetSchedModel SchedModel;
+ SchedModel.init(ST);
+
+ // Do not convert small short loops to CTR loop.
+ unsigned ConstTripCount = SE.getSmallConstantTripCount(L);
+ if (ConstTripCount && ConstTripCount < SmallCTRLoopThreshold) {
+ SmallPtrSet<const Value *, 32> EphValues;
+ CodeMetrics::collectEphemeralValues(L, &AC, EphValues);
+ CodeMetrics Metrics;
+ for (BasicBlock *BB : L->blocks())
+ Metrics.analyzeBasicBlock(BB, *this, EphValues);
+ // 6 is an approximate latency for the mtctr instruction.
+ if (Metrics.NumInsts <= (6 * SchedModel.getIssueWidth()))
+ return 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)
+ if (mightUseCTR(*I, LibInfo))
+ return false;
+
+ SmallVector<BasicBlock*, 4> ExitingBlocks;
+ L->getExitingBlocks(ExitingBlocks);
+
+ // If there is an exit edge known to be frequently taken,
+ // we should not transform this loop.
+ for (auto &BB : ExitingBlocks) {
+ Instruction *TI = BB->getTerminator();
+ if (!TI) continue;
+
+ if (BranchInst *BI = dyn_cast<BranchInst>(TI)) {
+ uint64_t TrueWeight = 0, FalseWeight = 0;
+ if (!BI->isConditional() ||
+ !BI->extractProfMetadata(TrueWeight, FalseWeight))
+ continue;
+
+ // If the exit path is more frequent than the loop path,
+ // we return here without further analysis for this loop.
+ bool TrueIsExit = !L->contains(BI->getSuccessor(0));
+ if (( TrueIsExit && FalseWeight < TrueWeight) ||
+ (!TrueIsExit && FalseWeight > TrueWeight))
+ return false;
+ }
+ }
+
+ LLVMContext &C = L->getHeader()->getContext();
+ HWLoopInfo.CountType = TM.isPPC64() ?
+ Type::getInt64Ty(C) : Type::getInt32Ty(C);
+ HWLoopInfo.LoopDecrement = ConstantInt::get(HWLoopInfo.CountType, 1);
+ return true;
+}
+
void PPCTTIImpl::getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
TTI::UnrollingPreferences &UP) {
if (ST->getDarwinDirective() == PPC::DIR_A2) {
@@ -239,17 +582,12 @@ bool PPCTTIImpl::enableAggressiveInterleaving(bool LoopHasReductions) {
return LoopHasReductions;
}
-const PPCTTIImpl::TTI::MemCmpExpansionOptions *
-PPCTTIImpl::enableMemCmpExpansion(bool IsZeroCmp) const {
- static const auto Options = []() {
- TTI::MemCmpExpansionOptions Options;
- Options.LoadSizes.push_back(8);
- Options.LoadSizes.push_back(4);
- Options.LoadSizes.push_back(2);
- Options.LoadSizes.push_back(1);
- return Options;
- }();
- return &Options;
+PPCTTIImpl::TTI::MemCmpExpansionOptions
+PPCTTIImpl::enableMemCmpExpansion(bool OptSize, bool IsZeroCmp) const {
+ TTI::MemCmpExpansionOptions Options;
+ Options.LoadSizes = {8, 4, 2, 1};
+ Options.MaxNumLoads = TLI->getMaxExpandSizeMemcmp(OptSize);
+ return Options;
}
bool PPCTTIImpl::enableInterleavedAccessVectorization() {
@@ -324,6 +662,33 @@ unsigned PPCTTIImpl::getMaxInterleaveFactor(unsigned VF) {
return 2;
}
+// Adjust the cost of vector instructions on targets which there is overlap
+// between the vector and scalar units, thereby reducing the overall throughput
+// of vector code wrt. scalar code.
+int PPCTTIImpl::vectorCostAdjustment(int Cost, unsigned Opcode, Type *Ty1,
+ Type *Ty2) {
+ if (!ST->vectorsUseTwoUnits() || !Ty1->isVectorTy())
+ return Cost;
+
+ std::pair<int, MVT> LT1 = TLI->getTypeLegalizationCost(DL, Ty1);
+ // If type legalization involves splitting the vector, we don't want to
+ // double the cost at every step - only the last step.
+ if (LT1.first != 1 || !LT1.second.isVector())
+ return Cost;
+
+ int ISD = TLI->InstructionOpcodeToISD(Opcode);
+ if (TLI->isOperationExpand(ISD, LT1.second))
+ return Cost;
+
+ if (Ty2) {
+ std::pair<int, MVT> LT2 = TLI->getTypeLegalizationCost(DL, Ty2);
+ if (LT2.first != 1 || !LT2.second.isVector())
+ return Cost;
+ }
+
+ return Cost * 2;
+}
+
int PPCTTIImpl::getArithmeticInstrCost(
unsigned Opcode, Type *Ty, TTI::OperandValueKind Op1Info,
TTI::OperandValueKind Op2Info, TTI::OperandValueProperties Opd1PropInfo,
@@ -331,8 +696,9 @@ int PPCTTIImpl::getArithmeticInstrCost(
assert(TLI->InstructionOpcodeToISD(Opcode) && "Invalid opcode");
// Fallback to the default implementation.
- return BaseT::getArithmeticInstrCost(Opcode, Ty, Op1Info, Op2Info,
- Opd1PropInfo, Opd2PropInfo);
+ int Cost = BaseT::getArithmeticInstrCost(Opcode, Ty, Op1Info, Op2Info,
+ Opd1PropInfo, Opd2PropInfo);
+ return vectorCostAdjustment(Cost, Opcode, Ty, nullptr);
}
int PPCTTIImpl::getShuffleCost(TTI::ShuffleKind Kind, Type *Tp, int Index,
@@ -345,19 +711,22 @@ int PPCTTIImpl::getShuffleCost(TTI::ShuffleKind Kind, Type *Tp, int Index,
// instruction). We need one such shuffle instruction for each actual
// register (this is not true for arbitrary shuffles, but is true for the
// structured types of shuffles covered by TTI::ShuffleKind).
- return LT.first;
+ return vectorCostAdjustment(LT.first, Instruction::ShuffleVector, Tp,
+ nullptr);
}
int PPCTTIImpl::getCastInstrCost(unsigned Opcode, Type *Dst, Type *Src,
const Instruction *I) {
assert(TLI->InstructionOpcodeToISD(Opcode) && "Invalid opcode");
- return BaseT::getCastInstrCost(Opcode, Dst, Src);
+ int Cost = BaseT::getCastInstrCost(Opcode, Dst, Src);
+ return vectorCostAdjustment(Cost, Opcode, Dst, Src);
}
int PPCTTIImpl::getCmpSelInstrCost(unsigned Opcode, Type *ValTy, Type *CondTy,
const Instruction *I) {
- return BaseT::getCmpSelInstrCost(Opcode, ValTy, CondTy, I);
+ int Cost = BaseT::getCmpSelInstrCost(Opcode, ValTy, CondTy, I);
+ return vectorCostAdjustment(Cost, Opcode, ValTy, nullptr);
}
int PPCTTIImpl::getVectorInstrCost(unsigned Opcode, Type *Val, unsigned Index) {
@@ -366,18 +735,23 @@ int PPCTTIImpl::getVectorInstrCost(unsigned Opcode, Type *Val, unsigned Index) {
int ISD = TLI->InstructionOpcodeToISD(Opcode);
assert(ISD && "Invalid opcode");
+ int Cost = BaseT::getVectorInstrCost(Opcode, Val, Index);
+ Cost = vectorCostAdjustment(Cost, Opcode, Val, nullptr);
+
if (ST->hasVSX() && Val->getScalarType()->isDoubleTy()) {
- // Double-precision scalars are already located in index #0.
- if (Index == 0)
+ // Double-precision scalars are already located in index #0 (or #1 if LE).
+ if (ISD == ISD::EXTRACT_VECTOR_ELT &&
+ Index == (ST->isLittleEndian() ? 1 : 0))
return 0;
- return BaseT::getVectorInstrCost(Opcode, Val, Index);
+ return Cost;
+
} else if (ST->hasQPX() && Val->getScalarType()->isFloatingPointTy()) {
// Floating point scalars are already located in index #0.
if (Index == 0)
return 0;
- return BaseT::getVectorInstrCost(Opcode, Val, Index);
+ return Cost;
}
// Estimated cost of a load-hit-store delay. This was obtained
@@ -394,9 +768,9 @@ int PPCTTIImpl::getVectorInstrCost(unsigned Opcode, Type *Val, unsigned Index) {
// these need to be estimated as very costly.
if (ISD == ISD::EXTRACT_VECTOR_ELT ||
ISD == ISD::INSERT_VECTOR_ELT)
- return LHSPenalty + BaseT::getVectorInstrCost(Opcode, Val, Index);
+ return LHSPenalty + Cost;
- return BaseT::getVectorInstrCost(Opcode, Val, Index);
+ return Cost;
}
int PPCTTIImpl::getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
@@ -407,6 +781,7 @@ int PPCTTIImpl::getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
"Invalid Opcode");
int Cost = BaseT::getMemoryOpCost(Opcode, Src, Alignment, AddressSpace);
+ Cost = vectorCostAdjustment(Cost, Opcode, Src, nullptr);
bool IsAltivecType = ST->hasAltivec() &&
(LT.second == MVT::v16i8 || LT.second == MVT::v8i16 ||
@@ -500,3 +875,25 @@ int PPCTTIImpl::getInterleavedMemoryOpCost(unsigned Opcode, Type *VecTy,
return Cost;
}
+bool PPCTTIImpl::canSaveCmp(Loop *L, BranchInst **BI, ScalarEvolution *SE,
+ LoopInfo *LI, DominatorTree *DT,
+ AssumptionCache *AC, TargetLibraryInfo *LibInfo) {
+ // Process nested loops first.
+ for (Loop::iterator I = L->begin(), E = L->end(); I != E; ++I)
+ if (canSaveCmp(*I, BI, SE, LI, DT, AC, LibInfo))
+ return false; // Stop search.
+
+ HardwareLoopInfo HWLoopInfo(L);
+
+ if (!HWLoopInfo.canAnalyze(*LI))
+ return false;
+
+ if (!isHardwareLoopProfitable(L, *SE, *AC, LibInfo, HWLoopInfo))
+ return false;
+
+ if (!HWLoopInfo.isHardwareLoopCandidate(*SE, *LI, *DT))
+ return false;
+
+ *BI = HWLoopInfo.ExitBranch;
+ return true;
+}