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      1 //===-- MCSubtargetInfo.cpp - Subtarget Information -----------------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 
     10 #include "llvm/MC/MCSubtargetInfo.h"
     11 #include "llvm/ADT/StringRef.h"
     12 #include "llvm/ADT/Triple.h"
     13 #include "llvm/MC/MCInstrItineraries.h"
     14 #include "llvm/MC/SubtargetFeature.h"
     15 #include "llvm/Support/raw_ostream.h"
     16 #include <algorithm>
     17 
     18 using namespace llvm;
     19 
     20 MCSchedModel MCSchedModel::DefaultSchedModel; // For unknown processors.
     21 
     22 /// InitMCProcessorInfo - Set or change the CPU (optionally supplemented
     23 /// with feature string). Recompute feature bits and scheduling model.
     24 void
     25 MCSubtargetInfo::InitMCProcessorInfo(StringRef CPU, StringRef FS) {
     26   SubtargetFeatures Features(FS);
     27   FeatureBits = Features.getFeatureBits(CPU, ProcDesc, NumProcs,
     28                                         ProcFeatures, NumFeatures);
     29 
     30   if (!CPU.empty())
     31     CPUSchedModel = getSchedModelForCPU(CPU);
     32   else
     33     CPUSchedModel = &MCSchedModel::DefaultSchedModel;
     34 }
     35 
     36 void
     37 MCSubtargetInfo::InitMCSubtargetInfo(StringRef TT, StringRef CPU, StringRef FS,
     38                                      const SubtargetFeatureKV *PF,
     39                                      const SubtargetFeatureKV *PD,
     40                                      const SubtargetInfoKV *ProcSched,
     41                                      const MCWriteProcResEntry *WPR,
     42                                      const MCWriteLatencyEntry *WL,
     43                                      const MCReadAdvanceEntry *RA,
     44                                      const InstrStage *IS,
     45                                      const unsigned *OC,
     46                                      const unsigned *FP,
     47                                      unsigned NF, unsigned NP) {
     48   TargetTriple = TT;
     49   ProcFeatures = PF;
     50   ProcDesc = PD;
     51   ProcSchedModels = ProcSched;
     52   WriteProcResTable = WPR;
     53   WriteLatencyTable = WL;
     54   ReadAdvanceTable = RA;
     55 
     56   Stages = IS;
     57   OperandCycles = OC;
     58   ForwardingPaths = FP;
     59   NumFeatures = NF;
     60   NumProcs = NP;
     61 
     62   InitMCProcessorInfo(CPU, FS);
     63 }
     64 
     65 /// ToggleFeature - Toggle a feature and returns the re-computed feature
     66 /// bits. This version does not change the implied bits.
     67 uint64_t MCSubtargetInfo::ToggleFeature(uint64_t FB) {
     68   FeatureBits ^= FB;
     69   return FeatureBits;
     70 }
     71 
     72 /// ToggleFeature - Toggle a feature and returns the re-computed feature
     73 /// bits. This version will also change all implied bits.
     74 uint64_t MCSubtargetInfo::ToggleFeature(StringRef FS) {
     75   SubtargetFeatures Features;
     76   FeatureBits = Features.ToggleFeature(FeatureBits, FS,
     77                                        ProcFeatures, NumFeatures);
     78   return FeatureBits;
     79 }
     80 
     81 
     82 const MCSchedModel *
     83 MCSubtargetInfo::getSchedModelForCPU(StringRef CPU) const {
     84   assert(ProcSchedModels && "Processor machine model not available!");
     85 
     86 #ifndef NDEBUG
     87   for (size_t i = 1; i < NumProcs; i++) {
     88     assert(strcmp(ProcSchedModels[i - 1].Key, ProcSchedModels[i].Key) < 0 &&
     89            "Processor machine model table is not sorted");
     90   }
     91 #endif
     92 
     93   // Find entry
     94   SubtargetInfoKV KV;
     95   KV.Key = CPU.data();
     96   const SubtargetInfoKV *Found =
     97     std::lower_bound(ProcSchedModels, ProcSchedModels+NumProcs, KV);
     98   if (Found == ProcSchedModels+NumProcs || StringRef(Found->Key) != CPU) {
     99     errs() << "'" << CPU
    100            << "' is not a recognized processor for this target"
    101            << " (ignoring processor)\n";
    102     return &MCSchedModel::DefaultSchedModel;
    103   }
    104   assert(Found->Value && "Missing processor SchedModel value");
    105   return (const MCSchedModel *)Found->Value;
    106 }
    107 
    108 InstrItineraryData
    109 MCSubtargetInfo::getInstrItineraryForCPU(StringRef CPU) const {
    110   const MCSchedModel *SchedModel = getSchedModelForCPU(CPU);
    111   return InstrItineraryData(SchedModel, Stages, OperandCycles, ForwardingPaths);
    112 }
    113 
    114 /// Initialize an InstrItineraryData instance.
    115 void MCSubtargetInfo::initInstrItins(InstrItineraryData &InstrItins) const {
    116   InstrItins =
    117     InstrItineraryData(CPUSchedModel, Stages, OperandCycles, ForwardingPaths);
    118 }
    119