[llvm] r298282 - [Hexagon] Recognize polynomial-modulo loop idiom again
Vitaly Buka via llvm-commits
llvm-commits at lists.llvm.org
Mon Mar 20 14:58:49 PDT 2017
Could you please take a look?
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/3574/steps/check-llvm%20asan/logs/stdio
Direct leak of 136 byte(s) in 1 object(s) allocated from:
#0 0x98a100 in operator new(unsigned long)
/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/projects/compiler-rt/lib/asan/asan_new_delete.cc:82
#1 0x3d355e5 in allocateFixedOperandUser
/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/lib/IR/User.cpp:128:7
#2 0x3d355e5 in llvm::User::operator new(unsigned long, unsigned
int) /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/lib/IR/User.cpp:146
#3 0x3c3422a in Create
/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/Instructions.h:1962:23
#4 0x3c3422a in llvm::SelectInst::cloneImpl() const
/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/lib/IR/Instructions.cpp:3929
#5 0x3c01f42 in llvm::Instruction::clone() const
/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/Instruction.def:187:1
#6 0x1921b77 in initialize
/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/lib/Target/Hexagon/HexagonLoopIdiomRecognition.cpp:239:28
#7 0x1921b77 in Context
/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/lib/Target/Hexagon/HexagonLoopIdiomRecognition.cpp:154
#8 0x1921b77 in (anonymous
namespace)::PolynomialMultiplyRecognize::recognize()
/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/lib/Target/Hexagon/HexagonLoopIdiomRecognition.cpp:1678
#9 0x191e5b0 in runOnCountableLoop
/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/lib/Target/Hexagon/HexagonLoopIdiomRecognition.cpp:2234:11
#10 0x191e5b0 in (anonymous
namespace)::HexagonLoopIdiomRecognize::runOnLoop(llvm::Loop*,
llvm::LPPassManager&)
/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/lib/Target/Hexagon/HexagonLoopIdiomRecognition.cpp:2291
#11 0x2dcf8bc in
llvm::LPPassManager::runOnFunction(llvm::Function&)
/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/lib/Analysis/LoopPass.cpp:203:23
#12 0x3c7b90d in
llvm::FPPassManager::runOnFunction(llvm::Function&)
/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/lib/IR/LegacyPassManager.cpp:1513:27
#13 0x3c7beb2 in llvm::FPPassManager::runOnModule(llvm::Module&)
/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/lib/IR/LegacyPassManager.cpp:1534:16
#14 0x3c7cd4a in runOnModule
/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/lib/IR/LegacyPassManager.cpp:1590:27
#15 0x3c7cd4a in llvm::legacy::PassManagerImpl::run(llvm::Module&)
/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/lib/IR/LegacyPassManager.cpp:1693
#16 0x9b4feb in main
/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/tools/opt/opt.cpp:722:10
#17 0x7f9b7820482f in __libc_start_main
(/lib/x86_64-linux-gnu/libc.so.6+0x2082f)
On Mon, Mar 20, 2017 at 11:25 AM Krzysztof Parzyszek via llvm-commits <
llvm-commits at lists.llvm.org> wrote:
> Author: kparzysz
> Date: Mon Mar 20 13:12:58 2017
> New Revision: 298282
>
> URL: http://llvm.org/viewvc/llvm-project?rev=298282&view=rev
> Log:
> [Hexagon] Recognize polynomial-modulo loop idiom again
>
> Regain the ability to recognize loops calculating polynomial modulo
> operation. This ability has been lost due to some changes in the
> preceding optimizations. Add code to preprocess the IR to a form
> that the pattern matching code can recognize.
>
> Added:
> llvm/trunk/test/CodeGen/Hexagon/loop-idiom/pmpy-mod.ll
> Modified:
> llvm/trunk/lib/Target/Hexagon/HexagonLoopIdiomRecognition.cpp
>
> Modified: llvm/trunk/lib/Target/Hexagon/HexagonLoopIdiomRecognition.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/Hexagon/HexagonLoopIdiomRecognition.cpp?rev=298282&r1=298281&r2=298282&view=diff
>
> ==============================================================================
> --- llvm/trunk/lib/Target/Hexagon/HexagonLoopIdiomRecognition.cpp
> (original)
> +++ llvm/trunk/lib/Target/Hexagon/HexagonLoopIdiomRecognition.cpp Mon Mar
> 20 13:12:58 2017
> @@ -129,6 +129,342 @@ INITIALIZE_PASS_END(HexagonLoopIdiomReco
> "Recognize Hexagon-specific loop idioms", false, false)
>
>
> +namespace {
> + struct Simplifier {
> + typedef std::function<Value* (Instruction*, LLVMContext&)> Rule;
> +
> + void addRule(const Rule &R) { Rules.push_back(R); }
> +
> + private:
> + typedef std::deque<Value*> WorkListType;
> + typedef std::set<Value*> ValueSetType;
> + std::vector<Rule> Rules;
> +
> + public:
> + struct Context {
> + typedef DenseMap<Value*,Value*> ValueMapType;
> +
> + Value *Root;
> + ValueSetType Used;
> + ValueMapType Clones, Orig;
> + LLVMContext &Ctx;
> +
> + Context(Instruction *Exp)
> + : Ctx(Exp->getParent()->getParent()->getContext()) {
> + initialize(Exp);
> + reset();
> + }
> + ~Context() { cleanup(); }
> + void print(raw_ostream &OS, const Value *V) const;
> +
> + Value *materialize(BasicBlock *B, BasicBlock::iterator At);
> +
> + private:
> + void initialize(Instruction *Exp);
> + void reset();
> + void cleanup();
> + void cleanup(Value *V);
> +
> + bool equal(const Instruction *I, const Instruction *J) const;
> + Value *find(Value *Tree, Value *Sub) const;
> + Value *subst(Value *Tree, Value *OldV, Value *NewV);
> + void replace(Value *OldV, Value *NewV);
> + void link(Instruction *I, BasicBlock *B, BasicBlock::iterator At);
> +
> + friend struct Simplifier;
> + };
> +
> + Value *simplify(Context &C);
> + };
> +
> + struct PE {
> + PE(const Simplifier::Context &c, Value *v = nullptr) : C(c), V(v) {}
> + const Simplifier::Context &C;
> + const Value *V;
> + };
> +
> + raw_ostream &operator<< (raw_ostream &OS, const PE &P)
> LLVM_ATTRIBUTE_USED;
> + raw_ostream &operator<< (raw_ostream &OS, const PE &P) {
> + P.C.print(OS, P.V ? P.V : P.C.Root);
> + return OS;
> + }
> +}
> +
> +
> +void Simplifier::Context::print(raw_ostream &OS, const Value *V) const {
> + const auto *U = dyn_cast<const Instruction>(V);
> + if (!U) {
> + OS << V << '(' << *V << ')';
> + return;
> + }
> +
> + if (U->getParent()) {
> + OS << U << '(';
> + U->printAsOperand(OS, true);
> + OS << ')';
> + return;
> + }
> +
> + unsigned N = U->getNumOperands();
> + if (N != 0)
> + OS << U << '(';
> + OS << U->getOpcodeName();
> + for (const Value *Op : U->operands()) {
> + OS << ' ';
> + print(OS, Op);
> + }
> + if (N != 0)
> + OS << ')';
> +}
> +
> +
> +void Simplifier::Context::initialize(Instruction *Exp) {
> + // Perform a deep clone of the expression, set Root to the root
> + // of the clone, and build a map from the cloned values to the
> + // original ones.
> + BasicBlock *Block = Exp->getParent();
> + WorkListType Q;
> + Q.push_back(Exp);
> +
> + while (!Q.empty()) {
> + Value *V = Q.front();
> + Q.pop_front();
> + if (Clones.find(V) != Clones.end())
> + continue;
> + if (Instruction *U = dyn_cast<Instruction>(V)) {
> + if (isa<PHINode>(U) || U->getParent() != Block)
> + continue;
> + for (Value *Op : U->operands())
> + Q.push_back(Op);
> + Clones.insert({U, U->clone()});
> + }
> + }
> +
> + for (std::pair<Value*,Value*> P : Clones) {
> + Instruction *U = cast<Instruction>(P.second);
> + for (unsigned i = 0, n = U->getNumOperands(); i != n; ++i) {
> + auto F = Clones.find(U->getOperand(i));
> + if (F != Clones.end())
> + U->setOperand(i, F->second);
> + }
> + Orig.insert({P.second, P.first});
> + }
> +
> + auto R = Clones.find(Exp);
> + assert(R != Clones.end());
> + Root = R->second;
> +}
> +
> +
> +void Simplifier::Context::reset() {
> + ValueSetType NewUsed;
> + WorkListType Q;
> + Q.push_back(Root);
> +
> + while (!Q.empty()) {
> + Instruction *U = dyn_cast<Instruction>(Q.front());
> + Q.pop_front();
> + if (!U || U->getParent())
> + continue;
> + NewUsed.insert(U);
> + for (Value *Op : U->operands())
> + Q.push_back(Op);
> + }
> + for (Value *V : Used)
> + if (!NewUsed.count(V))
> + cast<Instruction>(V)->dropAllReferences();
> + Used = NewUsed;
> +}
> +
> +
> +Value *Simplifier::Context::subst(Value *Tree, Value *OldV, Value *NewV) {
> + if (Tree == OldV) {
> + cleanup(OldV);
> + return NewV;
> + }
> +
> + WorkListType Q;
> + Q.push_back(Tree);
> + while (!Q.empty()) {
> + Instruction *U = dyn_cast<Instruction>(Q.front());
> + Q.pop_front();
> + // If U is not an instruction, or it's not a clone, skip it.
> + if (!U || U->getParent())
> + continue;
> + for (unsigned i = 0, n = U->getNumOperands(); i != n; ++i) {
> + Value *Op = U->getOperand(i);
> + if (Op == OldV) {
> + cleanup(OldV);
> + U->setOperand(i, NewV);
> + } else {
> + Q.push_back(Op);
> + }
> + }
> + }
> + return Tree;
> +}
> +
> +
> +void Simplifier::Context::replace(Value *OldV, Value *NewV) {
> + if (Root == OldV) {
> + Root = NewV;
> + reset();
> + return;
> + }
> +
> + // NewV may be a complex tree that has just been created by one of the
> + // transformation rules. We need to make sure that it is commoned with
> + // the existing Root to the maximum extent possible.
> + // Identify all subtrees of NewV (including NewV itself) that have
> + // equivalent counterparts in Root, and replace those subtrees with
> + // these counterparts.
> + WorkListType Q;
> + Q.push_back(NewV);
> + while (!Q.empty()) {
> + Value *V = Q.front();
> + Q.pop_front();
> + Instruction *U = dyn_cast<Instruction>(V);
> + if (!U || U->getParent())
> + continue;
> + if (Value *DupV = find(Root, V)) {
> + if (DupV != V)
> + NewV = subst(NewV, V, DupV);
> + } else {
> + for (Value *Op : U->operands())
> + Q.push_back(Op);
> + }
> + }
> +
> + // Now, simply replace OldV with NewV in Root.
> + Root = subst(Root, OldV, NewV);
> + reset();
> +}
> +
> +
> +void Simplifier::Context::cleanup() {
> + for (Value *V : Used) {
> + Instruction *U = cast<Instruction>(V);
> + if (!U->getParent())
> + U->dropAllReferences();
> + }
> +}
> +
> +
> +void Simplifier::Context::cleanup(Value *V) {
> + if (!isa<Instruction>(V) || cast<Instruction>(V)->getParent() !=
> nullptr)
> + return;
> + WorkListType Q;
> + Q.push_back(V);
> + while (!Q.empty()) {
> + Instruction *U = dyn_cast<Instruction>(Q.front());
> + Q.pop_front();
> + if (!U || U->getParent() || Used.count(U))
> + continue;
> + for (Value *Op : U->operands())
> + Q.push_back(Op);
> + U->dropAllReferences();
> + }
> +}
> +
> +
> +bool Simplifier::Context::equal(const Instruction *I,
> + const Instruction *J) const {
> + if (I == J)
> + return true;
> + if (!I->isSameOperationAs(J))
> + return false;
> + if (isa<PHINode>(I))
> + return I->isIdenticalTo(J);
> +
> + for (unsigned i = 0, n = I->getNumOperands(); i != n; ++i) {
> + Value *OpI = I->getOperand(i), *OpJ = J->getOperand(i);
> + if (OpI == OpJ)
> + continue;
> + auto *InI = dyn_cast<const Instruction>(OpI);
> + auto *InJ = dyn_cast<const Instruction>(OpJ);
> + if (InI && InJ) {
> + if (!equal(InI, InJ))
> + return false;
> + } else if (InI != InJ || !InI)
> + return false;
> + }
> + return true;
> +}
> +
> +
> +Value *Simplifier::Context::find(Value *Tree, Value *Sub) const {
> + Instruction *SubI = dyn_cast<Instruction>(Sub);
> + WorkListType Q;
> + Q.push_back(Tree);
> +
> + while (!Q.empty()) {
> + Value *V = Q.front();
> + Q.pop_front();
> + if (V == Sub)
> + return V;
> + Instruction *U = dyn_cast<Instruction>(V);
> + if (!U || U->getParent())
> + continue;
> + if (SubI && equal(SubI, U))
> + return U;
> + assert(!isa<PHINode>(U));
> + for (Value *Op : U->operands())
> + Q.push_back(Op);
> + }
> + return nullptr;
> +}
> +
> +
> +void Simplifier::Context::link(Instruction *I, BasicBlock *B,
> + BasicBlock::iterator At) {
> + if (I->getParent())
> + return;
> +
> + for (Value *Op : I->operands()) {
> + if (Instruction *OpI = dyn_cast<Instruction>(Op))
> + link(OpI, B, At);
> + }
> +
> + B->getInstList().insert(At, I);
> +}
> +
> +
> +Value *Simplifier::Context::materialize(BasicBlock *B,
> + BasicBlock::iterator At) {
> + if (Instruction *RootI = dyn_cast<Instruction>(Root))
> + link(RootI, B, At);
> + return Root;
> +}
> +
> +
> +Value *Simplifier::simplify(Context &C) {
> + WorkListType Q;
> + Q.push_back(C.Root);
> +
> + while (!Q.empty()) {
> + Instruction *U = dyn_cast<Instruction>(Q.front());
> + Q.pop_front();
> + if (!U || U->getParent() || !C.Used.count(U))
> + continue;
> + bool Changed = false;
> + for (Rule &R : Rules) {
> + Value *W = R(U, C.Ctx);
> + if (!W)
> + continue;
> + Changed = true;
> + C.replace(U, W);
> + Q.push_back(C.Root);
> + break;
> + }
> + if (!Changed) {
> + for (Value *Op : U->operands())
> + Q.push_back(Op);
> + }
> + }
> + return C.Root;
> +}
> +
> +
>
> //===----------------------------------------------------------------------===//
> //
> // Implementation of PolynomialMultiplyRecognize
> @@ -147,6 +483,14 @@ namespace {
> private:
> typedef SetVector<Value*> ValueSeq;
>
> + IntegerType *getPmpyType() const {
> + LLVMContext &Ctx = CurLoop->getHeader()->getParent()->getContext();
> + return IntegerType::get(Ctx, 32);
> + }
> + bool isPromotableTo(Value *V, IntegerType *Ty);
> + void promoteTo(Instruction *In, IntegerType *DestTy, BasicBlock
> *LoopB);
> + bool promoteTypes(BasicBlock *LoopB, BasicBlock *ExitB);
> +
> Value *getCountIV(BasicBlock *BB);
> bool findCycle(Value *Out, Value *In, ValueSeq &Cycle);
> void classifyCycle(Instruction *DivI, ValueSeq &Cycle, ValueSeq
> &Early,
> @@ -176,6 +520,9 @@ namespace {
> unsigned getInverseMxN(unsigned QP);
> Value *generate(BasicBlock::iterator At, ParsedValues &PV);
>
> + void setupSimplifier();
> +
> + Simplifier Simp;
> Loop *CurLoop;
> const DataLayout &DL;
> const DominatorTree &DT;
> @@ -425,7 +772,6 @@ bool PolynomialMultiplyRecognize::scanSe
> BasicBlock *LoopB, BasicBlock *PrehB, Value *CIV, ParsedValues &PV,
> bool PreScan) {
> using namespace PatternMatch;
> -
> // The basic pattern for R = P.Q is:
> // for i = 0..31
> // R = phi (0, R')
> @@ -529,6 +875,150 @@ bool PolynomialMultiplyRecognize::scanSe
> }
>
>
> +bool PolynomialMultiplyRecognize::isPromotableTo(Value *Val,
> + IntegerType *DestTy) {
> + IntegerType *T = dyn_cast<IntegerType>(Val->getType());
> + if (!T || T->getBitWidth() > DestTy->getBitWidth())
> + return false;
> + if (T->getBitWidth() == DestTy->getBitWidth())
> + return true;
> + // Non-instructions are promotable. The reason why an instruction may
> not
> + // be promotable is that it may produce a different result if its
> operands
> + // and the result are promoted, for example, it may produce more
> non-zero
> + // bits. While it would still be possible to represent the proper result
> + // in a wider type, it may require adding additional instructions (which
> + // we don't want to do).
> + Instruction *In = dyn_cast<Instruction>(Val);
> + if (!In)
> + return true;
> + // The bitwidth of the source type is smaller than the destination.
> + // Check if the individual operation can be promoted.
> + switch (In->getOpcode()) {
> + case Instruction::PHI:
> + case Instruction::ZExt:
> + case Instruction::And:
> + case Instruction::Or:
> + case Instruction::Xor:
> + case Instruction::LShr: // Shift right is ok.
> + case Instruction::Select:
> + return true;
> + case Instruction::ICmp:
> + if (CmpInst *CI = cast<CmpInst>(In))
> + return CI->isEquality() || CI->isUnsigned();
> + llvm_unreachable("Cast failed unexpectedly");
> + case Instruction::Add:
> + return In->hasNoSignedWrap() && In->hasNoUnsignedWrap();
> + }
> + return false;
> +}
> +
> +
> +void PolynomialMultiplyRecognize::promoteTo(Instruction *In,
> + IntegerType *DestTy, BasicBlock *LoopB) {
> + // Leave boolean values alone.
> + if (!In->getType()->isIntegerTy(1))
> + In->mutateType(DestTy);
> + unsigned DestBW = DestTy->getBitWidth();
> +
> + // Handle PHIs.
> + if (PHINode *P = dyn_cast<PHINode>(In)) {
> + unsigned N = P->getNumIncomingValues();
> + for (unsigned i = 0; i != N; ++i) {
> + BasicBlock *InB = P->getIncomingBlock(i);
> + if (InB == LoopB)
> + continue;
> + Value *InV = P->getIncomingValue(i);
> + IntegerType *Ty = cast<IntegerType>(InV->getType());
> + // Do not promote values in PHI nodes of type i1.
> + if (Ty != P->getType()) {
> + // If the value type does not match the PHI type, the PHI type
> + // must have been promoted.
> + assert(Ty->getBitWidth() < DestBW);
> + InV = IRBuilder<>(InB->getTerminator()).CreateZExt(InV, DestTy);
> + P->setIncomingValue(i, InV);
> + }
> + }
> + } else if (ZExtInst *Z = dyn_cast<ZExtInst>(In)) {
> + Value *Op = Z->getOperand(0);
> + if (Op->getType() == Z->getType())
> + Z->replaceAllUsesWith(Op);
> + Z->eraseFromParent();
> + return;
> + }
> +
> + // Promote immediates.
> + for (unsigned i = 0, n = In->getNumOperands(); i != n; ++i) {
> + if (ConstantInt *CI = dyn_cast<ConstantInt>(In->getOperand(i)))
> + if (CI->getType()->getBitWidth() < DestBW)
> + In->setOperand(i, ConstantInt::get(DestTy, CI->getZExtValue()));
> + }
> +}
> +
> +
> +bool PolynomialMultiplyRecognize::promoteTypes(BasicBlock *LoopB,
> + BasicBlock *ExitB) {
> + assert(LoopB);
> + // Skip loops where the exit block has more than one predecessor. The
> values
> + // coming from the loop block will be promoted to another type, and so
> the
> + // values coming into the exit block from other predecessors would also
> have
> + // to be promoted.
> + if (!ExitB || (ExitB->getSinglePredecessor() != LoopB))
> + return false;
> + IntegerType *DestTy = getPmpyType();
> + // Check if the exit values have types that are no wider than the type
> + // that we want to promote to.
> + unsigned DestBW = DestTy->getBitWidth();
> + for (Instruction &In : *ExitB) {
> + PHINode *P = dyn_cast<PHINode>(&In);
> + if (!P)
> + break;
> + if (P->getNumIncomingValues() != 1)
> + return false;
> + assert(P->getIncomingBlock(0) == LoopB);
> + IntegerType *T = dyn_cast<IntegerType>(P->getType());
> + if (!T || T->getBitWidth() > DestBW)
> + return false;
> + }
> +
> + // Check all instructions in the loop.
> + for (Instruction &In : *LoopB)
> + if (!In.isTerminator() && !isPromotableTo(&In, DestTy))
> + return false;
> +
> + // Perform the promotion.
> + std::vector<Instruction*> LoopIns;
> + std::transform(LoopB->begin(), LoopB->end(),
> std::back_inserter(LoopIns),
> + [](Instruction &In) { return &In; });
> + for (Instruction *In : LoopIns)
> + promoteTo(In, DestTy, LoopB);
> +
> + // Fix up the PHI nodes in the exit block.
> + Instruction *EndI = ExitB->getFirstNonPHI();
> + BasicBlock::iterator End = EndI ? EndI->getIterator() : ExitB->end();
> + for (auto I = ExitB->begin(); I != End; ++I) {
> + PHINode *P = dyn_cast<PHINode>(I);
> + if (!P)
> + break;
> + Type *Ty0 = P->getIncomingValue(0)->getType();
> + Type *PTy = P->getType();
> + if (PTy != Ty0) {
> + assert(Ty0 == DestTy);
> + // In order to create the trunc, P must have the promoted type.
> + P->mutateType(Ty0);
> + Value *T = IRBuilder<>(ExitB, End).CreateTrunc(P, PTy);
> + // In order for the RAUW to work, the types of P and T must match.
> + P->mutateType(PTy);
> + P->replaceAllUsesWith(T);
> + // Final update of the P's type.
> + P->mutateType(Ty0);
> + cast<Instruction>(T)->setOperand(0, P);
> + }
> + }
> +
> + return true;
> +}
> +
> +
> bool PolynomialMultiplyRecognize::findCycle(Value *Out, Value *In,
> ValueSeq &Cycle) {
> // Out = ..., In, ...
> @@ -699,6 +1189,7 @@ bool PolynomialMultiplyRecognize::keepsH
> case Instruction::Select:
> case Instruction::ICmp:
> case Instruction::PHI:
> + case Instruction::ZExt:
> return true;
> }
> }
> @@ -985,13 +1476,170 @@ Value *PolynomialMultiplyRecognize::gene
> }
>
>
> +void PolynomialMultiplyRecognize::setupSimplifier() {
> + Simp.addRule(
> + // Sink zext past bitwise operations.
> + [](Instruction *I, LLVMContext &Ctx) -> Value* {
> + if (I->getOpcode() != Instruction::ZExt)
> + return nullptr;
> + Instruction *T = dyn_cast<Instruction>(I->getOperand(0));
> + if (!T)
> + return nullptr;
> + switch (T->getOpcode()) {
> + case Instruction::And:
> + case Instruction::Or:
> + case Instruction::Xor:
> + break;
> + default:
> + return nullptr;
> + }
> + IRBuilder<> B(Ctx);
> + return B.CreateBinOp(cast<BinaryOperator>(T)->getOpcode(),
> + B.CreateZExt(T->getOperand(0), I->getType()),
> + B.CreateZExt(T->getOperand(1), I->getType()));
> + });
> + Simp.addRule(
> + // (xor (and x a) (and y a)) -> (and (xor x y) a)
> + [](Instruction *I, LLVMContext &Ctx) -> Value* {
> + if (I->getOpcode() != Instruction::Xor)
> + return nullptr;
> + Instruction *And0 = dyn_cast<Instruction>(I->getOperand(0));
> + Instruction *And1 = dyn_cast<Instruction>(I->getOperand(1));
> + if (!And0 || !And1)
> + return nullptr;
> + if (And0->getOpcode() != Instruction::And ||
> + And1->getOpcode() != Instruction::And)
> + return nullptr;
> + if (And0->getOperand(1) != And1->getOperand(1))
> + return nullptr;
> + IRBuilder<> B(Ctx);
> + return B.CreateAnd(B.CreateXor(And0->getOperand(0),
> And1->getOperand(0)),
> + And0->getOperand(1));
> + });
> + Simp.addRule(
> + // (Op (select c x y) z) -> (select c (Op x z) (Op y z))
> + // (Op x (select c y z)) -> (select c (Op x y) (Op x z))
> + [](Instruction *I, LLVMContext &Ctx) -> Value* {
> + BinaryOperator *BO = dyn_cast<BinaryOperator>(I);
> + if (!BO)
> + return nullptr;
> + Instruction::BinaryOps Op = BO->getOpcode();
> + if (SelectInst *Sel = dyn_cast<SelectInst>(BO->getOperand(0))) {
> + IRBuilder<> B(Ctx);
> + Value *X = Sel->getTrueValue(), *Y = Sel->getFalseValue();
> + Value *Z = BO->getOperand(1);
> + return B.CreateSelect(Sel->getCondition(),
> + B.CreateBinOp(Op, X, Z),
> + B.CreateBinOp(Op, Y, Z));
> + }
> + if (SelectInst *Sel = dyn_cast<SelectInst>(BO->getOperand(1))) {
> + IRBuilder<> B(Ctx);
> + Value *X = BO->getOperand(0);
> + Value *Y = Sel->getTrueValue(), *Z = Sel->getFalseValue();
> + return B.CreateSelect(Sel->getCondition(),
> + B.CreateBinOp(Op, X, Y),
> + B.CreateBinOp(Op, X, Z));
> + }
> + return nullptr;
> + });
> + Simp.addRule(
> + // (select c (select c x y) z) -> (select c x z)
> + // (select c x (select c y z)) -> (select c x z)
> + [](Instruction *I, LLVMContext &Ctx) -> Value* {
> + SelectInst *Sel = dyn_cast<SelectInst>(I);
> + if (!Sel)
> + return nullptr;
> + IRBuilder<> B(Ctx);
> + Value *C = Sel->getCondition();
> + if (SelectInst *Sel0 = dyn_cast<SelectInst>(Sel->getTrueValue())) {
> + if (Sel0->getCondition() == C)
> + return B.CreateSelect(C, Sel0->getTrueValue(),
> Sel->getFalseValue());
> + }
> + if (SelectInst *Sel1 = dyn_cast<SelectInst>(Sel->getFalseValue())) {
> + if (Sel1->getCondition() == C)
> + return B.CreateSelect(C, Sel->getTrueValue(),
> Sel1->getFalseValue());
> + }
> + return nullptr;
> + });
> + Simp.addRule(
> + // (or (lshr x 1) 0x800.0) -> (xor (lshr x 1) 0x800.0)
> + [](Instruction *I, LLVMContext &Ctx) -> Value* {
> + if (I->getOpcode() != Instruction::Or)
> + return nullptr;
> + Instruction *LShr = dyn_cast<Instruction>(I->getOperand(0));
> + if (!LShr || LShr->getOpcode() != Instruction::LShr)
> + return nullptr;
> + ConstantInt *One = dyn_cast<ConstantInt>(LShr->getOperand(1));
> + if (!One || One->getZExtValue() != 1)
> + return nullptr;
> + ConstantInt *Msb = dyn_cast<ConstantInt>(I->getOperand(1));
> + if (!Msb || Msb->getZExtValue() != Msb->getType()->getSignBit())
> + return nullptr;
> + return IRBuilder<>(Ctx).CreateXor(LShr, Msb);
> + });
> + Simp.addRule(
> + // (lshr (BitOp x y) c) -> (BitOp (lshr x c) (lshr y c))
> + [](Instruction *I, LLVMContext &Ctx) -> Value* {
> + if (I->getOpcode() != Instruction::LShr)
> + return nullptr;
> + BinaryOperator *BitOp = dyn_cast<BinaryOperator>(I->getOperand(0));
> + if (!BitOp)
> + return nullptr;
> + switch (BitOp->getOpcode()) {
> + case Instruction::And:
> + case Instruction::Or:
> + case Instruction::Xor:
> + break;
> + default:
> + return nullptr;
> + }
> + IRBuilder<> B(Ctx);
> + Value *S = I->getOperand(1);
> + return B.CreateBinOp(BitOp->getOpcode(),
> + B.CreateLShr(BitOp->getOperand(0), S),
> + B.CreateLShr(BitOp->getOperand(1), S));
> + });
> + Simp.addRule(
> + // (BitOp1 (BitOp2 x a) b) -> (BitOp2 x (BitOp1 a b))
> + [](Instruction *I, LLVMContext &Ctx) -> Value* {
> + auto IsBitOp = [](unsigned Op) -> bool {
> + switch (Op) {
> + case Instruction::And:
> + case Instruction::Or:
> + case Instruction::Xor:
> + return true;
> + }
> + return false;
> + };
> + BinaryOperator *BitOp1 = dyn_cast<BinaryOperator>(I);
> + if (!BitOp1 || !IsBitOp(BitOp1->getOpcode()))
> + return nullptr;
> + BinaryOperator *BitOp2 =
> dyn_cast<BinaryOperator>(BitOp1->getOperand(0));
> + if (!BitOp2 || !IsBitOp(BitOp2->getOpcode()))
> + return nullptr;
> + ConstantInt *CA = dyn_cast<ConstantInt>(BitOp2->getOperand(1));
> + ConstantInt *CB = dyn_cast<ConstantInt>(BitOp1->getOperand(1));
> + if (!CA || !CB)
> + return nullptr;
> + IRBuilder<> B(Ctx);
> + Value *X = BitOp2->getOperand(0);
> + return B.CreateBinOp(BitOp2->getOpcode(), X,
> + B.CreateBinOp(BitOp1->getOpcode(), CA, CB));
> + });
> +}
> +
> +
> bool PolynomialMultiplyRecognize::recognize() {
> + DEBUG(dbgs() << "Starting PolynomialMultiplyRecognize on loop\n"
> + << *CurLoop << '\n');
> // Restrictions:
> // - The loop must consist of a single block.
> // - The iteration count must be known at compile-time.
> // - The loop must have an induction variable starting from 0, and
> // incremented in each iteration of the loop.
> BasicBlock *LoopB = CurLoop->getHeader();
> + DEBUG(dbgs() << "Loop header:\n" << *LoopB);
> +
> if (LoopB != CurLoop->getLoopLatch())
> return false;
> BasicBlock *ExitB = CurLoop->getExitBlock();
> @@ -1011,30 +1659,65 @@ bool PolynomialMultiplyRecognize::recogn
> Value *CIV = getCountIV(LoopB);
> ParsedValues PV;
> PV.IterCount = IterCount;
> + DEBUG(dbgs() << "Loop IV: " << *CIV << "\nIterCount: " << IterCount <<
> '\n');
>
> - // Test function to see if a given select instruction is a part of the
> - // pmpy pattern. The argument PreScan set to "true" indicates that only
> - // a preliminary scan is needed, "false" indicated an exact match.
> - auto CouldBePmpy = [this, LoopB, EntryB, CIV, &PV] (bool PreScan)
> - -> std::function<bool (Instruction &I)> {
> - return [this, LoopB, EntryB, CIV, &PV, PreScan] (Instruction &I) ->
> bool {
> - if (auto *SelI = dyn_cast<SelectInst>(&I))
> - return scanSelect(SelI, LoopB, EntryB, CIV, PV, PreScan);
> - return false;
> - };
> - };
> - auto PreF = std::find_if(LoopB->begin(), LoopB->end(),
> CouldBePmpy(true));
> - if (PreF == LoopB->end())
> + setupSimplifier();
> +
> + // Perform a preliminary scan of select instructions to see if any of
> them
> + // looks like a generator of the polynomial multiply steps. Assume that
> a
> + // loop can only contain a single transformable operation, so stop the
> + // traversal after the first reasonable candidate was found.
> + // XXX: Currently this approach can modify the loop before being 100%
> sure
> + // that the transformation can be carried out.
> + bool FoundPreScan = false;
> + for (Instruction &In : *LoopB) {
> + SelectInst *SI = dyn_cast<SelectInst>(&In);
> + if (!SI)
> + continue;
> +
> + Simplifier::Context C(SI);
> + Value *T = Simp.simplify(C);
> + SelectInst *SelI = (T && isa<SelectInst>(T)) ? cast<SelectInst>(T) :
> SI;
> + DEBUG(dbgs() << "scanSelect(pre-scan): " << PE(C, SelI) << '\n');
> + if (scanSelect(SelI, LoopB, EntryB, CIV, PV, true)) {
> + FoundPreScan = true;
> + if (SelI != SI) {
> + Value *NewSel = C.materialize(LoopB, SI->getIterator());
> + SI->replaceAllUsesWith(NewSel);
> + RecursivelyDeleteTriviallyDeadInstructions(SI, &TLI);
> + }
> + break;
> + }
> + }
> +
> + if (!FoundPreScan) {
> + DEBUG(dbgs() << "Have not found candidates for pmpy\n");
> return false;
> + }
>
> if (!PV.Left) {
> + // The right shift version actually only returns the higher bits of
> + // the result (each iteration discards the LSB). If we want to
> convert it
> + // to a left-shifting loop, the working data type must be at least as
> + // wide as the target's pmpy instruction.
> + if (!promoteTypes(LoopB, ExitB))
> + return false;
> convertShiftsToLeft(LoopB, ExitB, IterCount);
> cleanupLoopBody(LoopB);
> }
>
> - auto PostF = std::find_if(LoopB->begin(), LoopB->end(),
> CouldBePmpy(false));
> - if (PostF == LoopB->end())
> - return false;
> + // Scan the loop again, find the generating select instruction.
> + bool FoundScan = false;
> + for (Instruction &In : *LoopB) {
> + SelectInst *SelI = dyn_cast<SelectInst>(&In);
> + if (!SelI)
> + continue;
> + DEBUG(dbgs() << "scanSelect: " << *SelI << '\n');
> + FoundScan = scanSelect(SelI, LoopB, EntryB, CIV, PV, false);
> + if (FoundScan)
> + break;
> + }
> + assert(FoundScan);
>
> DEBUG({
> StringRef PP = (PV.M ? "(P+M)" : "P");
>
> Added: llvm/trunk/test/CodeGen/Hexagon/loop-idiom/pmpy-mod.ll
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/Hexagon/loop-idiom/pmpy-mod.ll?rev=298282&view=auto
>
> ==============================================================================
> --- llvm/trunk/test/CodeGen/Hexagon/loop-idiom/pmpy-mod.ll (added)
> +++ llvm/trunk/test/CodeGen/Hexagon/loop-idiom/pmpy-mod.ll Mon Mar 20
> 13:12:58 2017
> @@ -0,0 +1,84 @@
> +; Run -O2 to make sure that all the usual optimizations do happen before
> +; the Hexagon loop idiom recognition runs. This is to check that we still
> +; get this opportunity regardless of what happens before.
> +
> +; RUN: opt -O2 -march=hexagon -S < %s | FileCheck %s
> +
> +target triple = "hexagon"
> +target datalayout =
> "e-m:e-p:32:32:32-a:0-n16:32-i64:64:64-i32:32:32-i16:16:16-i1:8:8-f32:32:32-f64:64:64-v32:32:32-v64:64:64-v512:512:512-v1024:1024:1024-v2048:2048:2048"
> +
> +; CHECK-LABEL: define zeroext i16 @pmpy_mod_lsr
> +; There need to be two pmpy instructions.
> +; CHECK: call i64 @llvm.hexagon.M4.pmpyw
> +; CHECK: call i64 @llvm.hexagon.M4.pmpyw
> +
> +define zeroext i16 @pmpy_mod_lsr(i8 zeroext %a0, i16 zeroext %a1) #0 {
> +b2:
> + br label %b3
> +
> +b3: ; preds = %b44, %b2
> + %v4 = phi i8 [ %a0, %b2 ], [ %v19, %b44 ]
> + %v5 = phi i16 [ %a1, %b2 ], [ %v43, %b44 ]
> + %v6 = phi i8 [ 0, %b2 ], [ %v45, %b44 ]
> + %v7 = zext i8 %v6 to i32
> + %v8 = icmp slt i32 %v7, 8
> + br i1 %v8, label %b9, label %b46
> +
> +b9: ; preds = %b3
> + %v10 = zext i8 %v4 to i32
> + %v11 = and i32 %v10, 1
> + %v12 = trunc i16 %v5 to i8
> + %v13 = zext i8 %v12 to i32
> + %v14 = and i32 %v13, 1
> + %v15 = xor i32 %v11, %v14
> + %v16 = trunc i32 %v15 to i8
> + %v17 = zext i8 %v4 to i32
> + %v18 = ashr i32 %v17, 1
> + %v19 = trunc i32 %v18 to i8
> + %v20 = zext i8 %v16 to i32
> + %v21 = icmp eq i32 %v20, 1
> + br i1 %v21, label %b22, label %b26
> +
> +b22: ; preds = %b9
> + %v23 = zext i16 %v5 to i32
> + %v24 = xor i32 %v23, 16386
> + %v25 = trunc i32 %v24 to i16
> + br label %b27
> +
> +b26: ; preds = %b9
> + br label %b27
> +
> +b27: ; preds = %b26, %b22
> + %v28 = phi i16 [ %v25, %b22 ], [ %v5, %b26 ]
> + %v29 = phi i8 [ 1, %b22 ], [ 0, %b26 ]
> + %v30 = zext i16 %v28 to i32
> + %v31 = ashr i32 %v30, 1
> + %v32 = trunc i32 %v31 to i16
> + %v33 = icmp ne i8 %v29, 0
> + br i1 %v33, label %b34, label %b38
> +
> +b34: ; preds = %b27
> + %v35 = zext i16 %v32 to i32
> + %v36 = or i32 %v35, 32768
> + %v37 = trunc i32 %v36 to i16
> + br label %b42
> +
> +b38: ; preds = %b27
> + %v39 = zext i16 %v32 to i32
> + %v40 = and i32 %v39, 32767
> + %v41 = trunc i32 %v40 to i16
> + br label %b42
> +
> +b42: ; preds = %b38, %b34
> + %v43 = phi i16 [ %v37, %b34 ], [ %v41, %b38 ]
> + br label %b44
> +
> +b44: ; preds = %b42
> + %v45 = add i8 %v6, 1
> + br label %b3
> +
> +b46: ; preds = %b3
> + ret i16 %v5
> +}
> +
> +attributes #0 = { noinline nounwind "target-cpu"="hexagonv5"
> "target-features"="-hvx,-hvx-double,-long-calls" }
>
>
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