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diff --git a/llvm/lib/Target/X86/X86InsertPrefetch.cpp b/llvm/lib/Target/X86/X86InsertPrefetch.cpp
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-//===------- X86InsertPrefetch.cpp - Insert cache prefetch hints ----------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This pass applies cache prefetch instructions based on a profile. The pass
-// assumes DiscriminateMemOps ran immediately before, to ensure debug info
-// matches the one used at profile generation time. The profile is encoded in
-// afdo format (text or binary). It contains prefetch hints recommendations.
-// Each recommendation is made in terms of debug info locations, a type (i.e.
-// nta, t{0|1|2}) and a delta. The debug info identifies an instruction with a
-// memory operand (see X86DiscriminateMemOps). The prefetch will be made for
-// a location at that memory operand + the delta specified in the
-// recommendation.
-//
-//===----------------------------------------------------------------------===//
-
-#include "X86.h"
-#include "X86InstrBuilder.h"
-#include "X86InstrInfo.h"
-#include "X86MachineFunctionInfo.h"
-#include "X86Subtarget.h"
-#include "llvm/CodeGen/MachineModuleInfo.h"
-#include "llvm/IR/DebugInfoMetadata.h"
-#include "llvm/ProfileData/SampleProf.h"
-#include "llvm/ProfileData/SampleProfReader.h"
-#include "llvm/Transforms/IPO/SampleProfile.h"
-using namespace llvm;
-using namespace sampleprof;
-
-static cl::opt<std::string>
- PrefetchHintsFile("prefetch-hints-file",
- cl::desc("Path to the prefetch hints profile."),
- cl::Hidden);
-namespace {
-
-class X86InsertPrefetch : public MachineFunctionPass {
- void getAnalysisUsage(AnalysisUsage &AU) const override;
- bool doInitialization(Module &) override;
-
- bool runOnMachineFunction(MachineFunction &MF) override;
- struct PrefetchInfo {
- unsigned InstructionID;
- int64_t Delta;
- };
- typedef SmallVectorImpl<PrefetchInfo> Prefetches;
- bool findPrefetchInfo(const FunctionSamples *Samples, const MachineInstr &MI,
- Prefetches &prefetches) const;
-
-public:
- static char ID;
- X86InsertPrefetch(const std::string &PrefetchHintsFilename);
- StringRef getPassName() const override {
- return "X86 Insert Cache Prefetches";
- }
-
-private:
- std::string Filename;
- std::unique_ptr<SampleProfileReader> Reader;
-};
-
-using PrefetchHints = SampleRecord::CallTargetMap;
-
-// Return any prefetching hints for the specified MachineInstruction. The hints
-// are returned as pairs (name, delta).
-ErrorOr<PrefetchHints> getPrefetchHints(const FunctionSamples *TopSamples,
- const MachineInstr &MI) {
- if (const auto &Loc = MI.getDebugLoc())
- if (const auto *Samples = TopSamples->findFunctionSamples(Loc))
- return Samples->findCallTargetMapAt(FunctionSamples::getOffset(Loc),
- Loc->getBaseDiscriminator());
- return std::error_code();
-}
-
-// The prefetch instruction can't take memory operands involving vector
-// registers.
-bool IsMemOpCompatibleWithPrefetch(const MachineInstr &MI, int Op) {
- unsigned BaseReg = MI.getOperand(Op + X86::AddrBaseReg).getReg();
- unsigned IndexReg = MI.getOperand(Op + X86::AddrIndexReg).getReg();
- return (BaseReg == 0 ||
- X86MCRegisterClasses[X86::GR64RegClassID].contains(BaseReg) ||
- X86MCRegisterClasses[X86::GR32RegClassID].contains(BaseReg)) &&
- (IndexReg == 0 ||
- X86MCRegisterClasses[X86::GR64RegClassID].contains(IndexReg) ||
- X86MCRegisterClasses[X86::GR32RegClassID].contains(IndexReg));
-}
-
-} // end anonymous namespace
-
-//===----------------------------------------------------------------------===//
-// Implementation
-//===----------------------------------------------------------------------===//
-
-char X86InsertPrefetch::ID = 0;
-
-X86InsertPrefetch::X86InsertPrefetch(const std::string &PrefetchHintsFilename)
- : MachineFunctionPass(ID), Filename(PrefetchHintsFilename) {}
-
-/// Return true if the provided MachineInstruction has cache prefetch hints. In
-/// that case, the prefetch hints are stored, in order, in the Prefetches
-/// vector.
-bool X86InsertPrefetch::findPrefetchInfo(const FunctionSamples *TopSamples,
- const MachineInstr &MI,
- Prefetches &Prefetches) const {
- assert(Prefetches.empty() &&
- "Expected caller passed empty PrefetchInfo vector.");
- static const std::pair<const StringRef, unsigned> HintTypes[] = {
- {"_nta_", X86::PREFETCHNTA},
- {"_t0_", X86::PREFETCHT0},
- {"_t1_", X86::PREFETCHT1},
- {"_t2_", X86::PREFETCHT2},
- };
- static const char *SerializedPrefetchPrefix = "__prefetch";
-
- const ErrorOr<PrefetchHints> T = getPrefetchHints(TopSamples, MI);
- if (!T)
- return false;
- int16_t max_index = -1;
- // Convert serialized prefetch hints into PrefetchInfo objects, and populate
- // the Prefetches vector.
- for (const auto &S_V : *T) {
- StringRef Name = S_V.getKey();
- if (Name.consume_front(SerializedPrefetchPrefix)) {
- int64_t D = static_cast<int64_t>(S_V.second);
- unsigned IID = 0;
- for (const auto &HintType : HintTypes) {
- if (Name.startswith(HintType.first)) {
- Name = Name.drop_front(HintType.first.size());
- IID = HintType.second;
- break;
- }
- }
- if (IID == 0)
- return false;
- uint8_t index = 0;
- Name.consumeInteger(10, index);
-
- if (index >= Prefetches.size())
- Prefetches.resize(index + 1);
- Prefetches[index] = {IID, D};
- max_index = std::max(max_index, static_cast<int16_t>(index));
- }
- }
- assert(max_index + 1 >= 0 &&
- "Possible overflow: max_index + 1 should be positive.");
- assert(static_cast<size_t>(max_index + 1) == Prefetches.size() &&
- "The number of prefetch hints received should match the number of "
- "PrefetchInfo objects returned");
- return !Prefetches.empty();
-}
-
-bool X86InsertPrefetch::doInitialization(Module &M) {
- if (Filename.empty())
- return false;
-
- LLVMContext &Ctx = M.getContext();
- ErrorOr<std::unique_ptr<SampleProfileReader>> ReaderOrErr =
- SampleProfileReader::create(Filename, Ctx);
- if (std::error_code EC = ReaderOrErr.getError()) {
- std::string Msg = "Could not open profile: " + EC.message();
- Ctx.diagnose(DiagnosticInfoSampleProfile(Filename, Msg,
- DiagnosticSeverity::DS_Warning));
- return false;
- }
- Reader = std::move(ReaderOrErr.get());
- Reader->read();
- return true;
-}
-
-void X86InsertPrefetch::getAnalysisUsage(AnalysisUsage &AU) const {
- AU.setPreservesAll();
- AU.addRequired<MachineModuleInfo>();
-}
-
-bool X86InsertPrefetch::runOnMachineFunction(MachineFunction &MF) {
- if (!Reader)
- return false;
- const FunctionSamples *Samples = Reader->getSamplesFor(MF.getFunction());
- if (!Samples)
- return false;
-
- bool Changed = false;
-
- const TargetInstrInfo *TII = MF.getSubtarget().getInstrInfo();
- SmallVector<PrefetchInfo, 4> Prefetches;
- for (auto &MBB : MF) {
- for (auto MI = MBB.instr_begin(); MI != MBB.instr_end();) {
- auto Current = MI;
- ++MI;
-
- int Offset = X86II::getMemoryOperandNo(Current->getDesc().TSFlags);
- if (Offset < 0)
- continue;
- unsigned Bias = X86II::getOperandBias(Current->getDesc());
- int MemOpOffset = Offset + Bias;
- // FIXME(mtrofin): ORE message when the recommendation cannot be taken.
- if (!IsMemOpCompatibleWithPrefetch(*Current, MemOpOffset))
- continue;
- Prefetches.clear();
- if (!findPrefetchInfo(Samples, *Current, Prefetches))
- continue;
- assert(!Prefetches.empty() &&
- "The Prefetches vector should contain at least a value if "
- "findPrefetchInfo returned true.");
- for (auto &PrefInfo : Prefetches) {
- unsigned PFetchInstrID = PrefInfo.InstructionID;
- int64_t Delta = PrefInfo.Delta;
- const MCInstrDesc &Desc = TII->get(PFetchInstrID);
- MachineInstr *PFetch =
- MF.CreateMachineInstr(Desc, Current->getDebugLoc(), true);
- MachineInstrBuilder MIB(MF, PFetch);
-
- assert(X86::AddrBaseReg == 0 && X86::AddrScaleAmt == 1 &&
- X86::AddrIndexReg == 2 && X86::AddrDisp == 3 &&
- X86::AddrSegmentReg == 4 &&
- "Unexpected change in X86 operand offset order.");
-
- // This assumes X86::AddBaseReg = 0, {...}ScaleAmt = 1, etc.
- // FIXME(mtrofin): consider adding a:
- // MachineInstrBuilder::set(unsigned offset, op).
- MIB.addReg(Current->getOperand(MemOpOffset + X86::AddrBaseReg).getReg())
- .addImm(
- Current->getOperand(MemOpOffset + X86::AddrScaleAmt).getImm())
- .addReg(
- Current->getOperand(MemOpOffset + X86::AddrIndexReg).getReg())
- .addImm(Current->getOperand(MemOpOffset + X86::AddrDisp).getImm() +
- Delta)
- .addReg(Current->getOperand(MemOpOffset + X86::AddrSegmentReg)
- .getReg());
-
- if (!Current->memoperands_empty()) {
- MachineMemOperand *CurrentOp = *(Current->memoperands_begin());
- MIB.addMemOperand(MF.getMachineMemOperand(
- CurrentOp, CurrentOp->getOffset() + Delta, CurrentOp->getSize()));
- }
-
- // Insert before Current. This is because Current may clobber some of
- // the registers used to describe the input memory operand.
- MBB.insert(Current, PFetch);
- Changed = true;
- }
- }
- }
- return Changed;
-}
-
-FunctionPass *llvm::createX86InsertPrefetchPass() {
- return new X86InsertPrefetch(PrefetchHintsFile);
-}
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