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      1 //===-- PTXTargetMachine.cpp - Define TargetMachine for PTX ---------------===//
      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 // Top-level implementation for the PTX target.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #include "PTX.h"
     15 #include "PTXTargetMachine.h"
     16 #include "llvm/PassManager.h"
     17 #include "llvm/Analysis/Passes.h"
     18 #include "llvm/Analysis/Verifier.h"
     19 #include "llvm/Assembly/PrintModulePass.h"
     20 #include "llvm/ADT/OwningPtr.h"
     21 #include "llvm/CodeGen/AsmPrinter.h"
     22 #include "llvm/CodeGen/MachineFunctionAnalysis.h"
     23 #include "llvm/CodeGen/MachineModuleInfo.h"
     24 #include "llvm/CodeGen/Passes.h"
     25 #include "llvm/MC/MCAsmInfo.h"
     26 #include "llvm/MC/MCInstrInfo.h"
     27 #include "llvm/MC/MCStreamer.h"
     28 #include "llvm/MC/MCSubtargetInfo.h"
     29 #include "llvm/Support/TargetRegistry.h"
     30 #include "llvm/Support/raw_ostream.h"
     31 #include "llvm/Target/TargetData.h"
     32 #include "llvm/Target/TargetInstrInfo.h"
     33 #include "llvm/Target/TargetLowering.h"
     34 #include "llvm/Target/TargetLoweringObjectFile.h"
     35 #include "llvm/Target/TargetMachine.h"
     36 #include "llvm/Target/TargetOptions.h"
     37 #include "llvm/Target/TargetRegisterInfo.h"
     38 #include "llvm/Target/TargetSubtargetInfo.h"
     39 #include "llvm/Transforms/Scalar.h"
     40 #include "llvm/Support/Debug.h"
     41 #include "llvm/Support/TargetRegistry.h"
     42 
     43 
     44 using namespace llvm;
     45 
     46 namespace llvm {
     47   MCStreamer *createPTXAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS,
     48                                    bool isVerboseAsm, bool useLoc,
     49                                    bool useCFI, bool useDwarfDirectory,
     50                                    MCInstPrinter *InstPrint,
     51                                    MCCodeEmitter *CE,
     52                                    MCAsmBackend *MAB,
     53                                    bool ShowInst);
     54 }
     55 
     56 extern "C" void LLVMInitializePTXTarget() {
     57 
     58   RegisterTargetMachine<PTX32TargetMachine> X(ThePTX32Target);
     59   RegisterTargetMachine<PTX64TargetMachine> Y(ThePTX64Target);
     60 
     61   TargetRegistry::RegisterAsmStreamer(ThePTX32Target, createPTXAsmStreamer);
     62   TargetRegistry::RegisterAsmStreamer(ThePTX64Target, createPTXAsmStreamer);
     63 }
     64 
     65 namespace {
     66   const char* DataLayout32 =
     67     "e-p:32:32-i64:32:32-f64:32:32-v128:32:128-v64:32:64-n32:64";
     68   const char* DataLayout64 =
     69     "e-p:64:64-i64:32:32-f64:32:32-v128:32:128-v64:32:64-n32:64";
     70 
     71   // Copied from LLVMTargetMachine.cpp
     72   void printNoVerify(PassManagerBase &PM, const char *Banner) {
     73     if (PrintMachineCode)
     74       PM.add(createMachineFunctionPrinterPass(dbgs(), Banner));
     75   }
     76 
     77   void printAndVerify(PassManagerBase &PM,
     78                       const char *Banner) {
     79     if (PrintMachineCode)
     80       PM.add(createMachineFunctionPrinterPass(dbgs(), Banner));
     81 
     82     //if (VerifyMachineCode)
     83     //  PM.add(createMachineVerifierPass(Banner));
     84   }
     85 }
     86 
     87 // DataLayout and FrameLowering are filled with dummy data
     88 PTXTargetMachine::PTXTargetMachine(const Target &T,
     89                                    StringRef TT, StringRef CPU, StringRef FS,
     90                                    Reloc::Model RM, CodeModel::Model CM,
     91                                    bool is64Bit)
     92   : LLVMTargetMachine(T, TT, CPU, FS, RM, CM),
     93     DataLayout(is64Bit ? DataLayout64 : DataLayout32),
     94     Subtarget(TT, CPU, FS, is64Bit),
     95     FrameLowering(Subtarget),
     96     InstrInfo(*this),
     97     TSInfo(*this),
     98     TLInfo(*this) {
     99 }
    100 
    101 PTX32TargetMachine::PTX32TargetMachine(const Target &T, StringRef TT,
    102                                        StringRef CPU, StringRef FS,
    103                                        Reloc::Model RM, CodeModel::Model CM)
    104   : PTXTargetMachine(T, TT, CPU, FS, RM, CM, false) {
    105 }
    106 
    107 PTX64TargetMachine::PTX64TargetMachine(const Target &T, StringRef TT,
    108                                        StringRef CPU, StringRef FS,
    109                                        Reloc::Model RM, CodeModel::Model CM)
    110   : PTXTargetMachine(T, TT, CPU, FS, RM, CM, true) {
    111 }
    112 
    113 bool PTXTargetMachine::addInstSelector(PassManagerBase &PM,
    114                                        CodeGenOpt::Level OptLevel) {
    115   PM.add(createPTXISelDag(*this, OptLevel));
    116   return false;
    117 }
    118 
    119 bool PTXTargetMachine::addPostRegAlloc(PassManagerBase &PM,
    120                                        CodeGenOpt::Level OptLevel) {
    121   // PTXMFInfoExtract must after register allocation!
    122   //PM.add(createPTXMFInfoExtract(*this, OptLevel));
    123   return false;
    124 }
    125 
    126 bool PTXTargetMachine::addPassesToEmitFile(PassManagerBase &PM,
    127                                            formatted_raw_ostream &Out,
    128                                            CodeGenFileType FileType,
    129                                            CodeGenOpt::Level OptLevel,
    130                                            bool DisableVerify) {
    131   // This is mostly based on LLVMTargetMachine::addPassesToEmitFile
    132 
    133   // Add common CodeGen passes.
    134   MCContext *Context = 0;
    135   if (addCommonCodeGenPasses(PM, OptLevel, DisableVerify, Context))
    136     return true;
    137   assert(Context != 0 && "Failed to get MCContext");
    138 
    139   if (hasMCSaveTempLabels())
    140     Context->setAllowTemporaryLabels(false);
    141 
    142   const MCAsmInfo &MAI = *getMCAsmInfo();
    143   const MCSubtargetInfo &STI = getSubtarget<MCSubtargetInfo>();
    144   OwningPtr<MCStreamer> AsmStreamer;
    145 
    146   switch (FileType) {
    147   default: return true;
    148   case CGFT_AssemblyFile: {
    149     MCInstPrinter *InstPrinter =
    150       getTarget().createMCInstPrinter(MAI.getAssemblerDialect(), MAI, STI);
    151 
    152     // Create a code emitter if asked to show the encoding.
    153     MCCodeEmitter *MCE = 0;
    154     MCAsmBackend *MAB = 0;
    155 
    156     MCStreamer *S = getTarget().createAsmStreamer(*Context, Out,
    157                                                   true, /* verbose asm */
    158                                                   hasMCUseLoc(),
    159                                                   hasMCUseCFI(),
    160                                                   hasMCUseDwarfDirectory(),
    161                                                   InstPrinter,
    162                                                   MCE, MAB,
    163                                                   false /* show MC encoding */);
    164     AsmStreamer.reset(S);
    165     break;
    166   }
    167   case CGFT_ObjectFile: {
    168     llvm_unreachable("Object file emission is not supported with PTX");
    169   }
    170   case CGFT_Null:
    171     // The Null output is intended for use for performance analysis and testing,
    172     // not real users.
    173     AsmStreamer.reset(createNullStreamer(*Context));
    174     break;
    175   }
    176 
    177   // MC Logging
    178   //AsmStreamer.reset(createLoggingStreamer(AsmStreamer.take(), errs()));
    179 
    180   // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
    181   FunctionPass *Printer = getTarget().createAsmPrinter(*this, *AsmStreamer);
    182   if (Printer == 0)
    183     return true;
    184 
    185   // If successful, createAsmPrinter took ownership of AsmStreamer.
    186   AsmStreamer.take();
    187 
    188   PM.add(Printer);
    189 
    190   PM.add(createGCInfoDeleter());
    191   return false;
    192 }
    193 
    194 bool PTXTargetMachine::addCommonCodeGenPasses(PassManagerBase &PM,
    195                                               CodeGenOpt::Level OptLevel,
    196                                               bool DisableVerify,
    197                                               MCContext *&OutContext) {
    198   // Add standard LLVM codegen passes.
    199   // This is derived from LLVMTargetMachine::addCommonCodeGenPasses, with some
    200   // modifications for the PTX target.
    201 
    202   // Standard LLVM-Level Passes.
    203 
    204   // Basic AliasAnalysis support.
    205   // Add TypeBasedAliasAnalysis before BasicAliasAnalysis so that
    206   // BasicAliasAnalysis wins if they disagree. This is intended to help
    207   // support "obvious" type-punning idioms.
    208   PM.add(createTypeBasedAliasAnalysisPass());
    209   PM.add(createBasicAliasAnalysisPass());
    210 
    211   // Before running any passes, run the verifier to determine if the input
    212   // coming from the front-end and/or optimizer is valid.
    213   if (!DisableVerify)
    214     PM.add(createVerifierPass());
    215 
    216   // Run loop strength reduction before anything else.
    217   if (OptLevel != CodeGenOpt::None) {
    218     PM.add(createLoopStrengthReducePass(getTargetLowering()));
    219     //PM.add(createPrintFunctionPass("\n\n*** Code after LSR ***\n", &dbgs()));
    220   }
    221 
    222   PM.add(createGCLoweringPass());
    223 
    224   // Make sure that no unreachable blocks are instruction selected.
    225   PM.add(createUnreachableBlockEliminationPass());
    226 
    227   PM.add(createLowerInvokePass(getTargetLowering()));
    228   // The lower invoke pass may create unreachable code. Remove it.
    229   PM.add(createUnreachableBlockEliminationPass());
    230 
    231   if (OptLevel != CodeGenOpt::None)
    232     PM.add(createCodeGenPreparePass(getTargetLowering()));
    233 
    234   PM.add(createStackProtectorPass(getTargetLowering()));
    235 
    236   addPreISel(PM, OptLevel);
    237 
    238   //PM.add(createPrintFunctionPass("\n\n"
    239   //                               "*** Final LLVM Code input to ISel ***\n",
    240   //                               &dbgs()));
    241 
    242   // All passes which modify the LLVM IR are now complete; run the verifier
    243   // to ensure that the IR is valid.
    244   if (!DisableVerify)
    245     PM.add(createVerifierPass());
    246 
    247   // Standard Lower-Level Passes.
    248 
    249   // Install a MachineModuleInfo class, which is an immutable pass that holds
    250   // all the per-module stuff we're generating, including MCContext.
    251   MachineModuleInfo *MMI = new MachineModuleInfo(*getMCAsmInfo(),
    252                                                  *getRegisterInfo(),
    253                                     &getTargetLowering()->getObjFileLowering());
    254   PM.add(MMI);
    255   OutContext = &MMI->getContext(); // Return the MCContext specifically by-ref.
    256 
    257   // Set up a MachineFunction for the rest of CodeGen to work on.
    258   PM.add(new MachineFunctionAnalysis(*this, OptLevel));
    259 
    260   // Ask the target for an isel.
    261   if (addInstSelector(PM, OptLevel))
    262     return true;
    263 
    264   // Print the instruction selected machine code...
    265   printAndVerify(PM, "After Instruction Selection");
    266 
    267   // Expand pseudo-instructions emitted by ISel.
    268   PM.add(createExpandISelPseudosPass());
    269 
    270   // Pre-ra tail duplication.
    271   if (OptLevel != CodeGenOpt::None) {
    272     PM.add(createTailDuplicatePass(true));
    273     printAndVerify(PM, "After Pre-RegAlloc TailDuplicate");
    274   }
    275 
    276   // Optimize PHIs before DCE: removing dead PHI cycles may make more
    277   // instructions dead.
    278   if (OptLevel != CodeGenOpt::None)
    279     PM.add(createOptimizePHIsPass());
    280 
    281   // If the target requests it, assign local variables to stack slots relative
    282   // to one another and simplify frame index references where possible.
    283   PM.add(createLocalStackSlotAllocationPass());
    284 
    285   if (OptLevel != CodeGenOpt::None) {
    286     // With optimization, dead code should already be eliminated. However
    287     // there is one known exception: lowered code for arguments that are only
    288     // used by tail calls, where the tail calls reuse the incoming stack
    289     // arguments directly (see t11 in test/CodeGen/X86/sibcall.ll).
    290     PM.add(createDeadMachineInstructionElimPass());
    291     printAndVerify(PM, "After codegen DCE pass");
    292 
    293     PM.add(createMachineLICMPass());
    294     PM.add(createMachineCSEPass());
    295     PM.add(createMachineSinkingPass());
    296     printAndVerify(PM, "After Machine LICM, CSE and Sinking passes");
    297 
    298     PM.add(createPeepholeOptimizerPass());
    299     printAndVerify(PM, "After codegen peephole optimization pass");
    300   }
    301 
    302   // Run pre-ra passes.
    303   if (addPreRegAlloc(PM, OptLevel))
    304     printAndVerify(PM, "After PreRegAlloc passes");
    305 
    306   // Perform register allocation.
    307   PM.add(createPTXRegisterAllocator());
    308   printAndVerify(PM, "After Register Allocation");
    309 
    310   // Perform stack slot coloring and post-ra machine LICM.
    311   if (OptLevel != CodeGenOpt::None) {
    312     // FIXME: Re-enable coloring with register when it's capable of adding
    313     // kill markers.
    314     PM.add(createStackSlotColoringPass(false));
    315 
    316     // FIXME: Post-RA LICM has asserts that fire on virtual registers.
    317     // Run post-ra machine LICM to hoist reloads / remats.
    318     //if (!DisablePostRAMachineLICM)
    319     //  PM.add(createMachineLICMPass(false));
    320 
    321     printAndVerify(PM, "After StackSlotColoring and postra Machine LICM");
    322   }
    323 
    324   // Run post-ra passes.
    325   if (addPostRegAlloc(PM, OptLevel))
    326     printAndVerify(PM, "After PostRegAlloc passes");
    327 
    328   PM.add(createExpandPostRAPseudosPass());
    329   printAndVerify(PM, "After ExpandPostRAPseudos");
    330 
    331   // Insert prolog/epilog code.  Eliminate abstract frame index references...
    332   PM.add(createPrologEpilogCodeInserter());
    333   printAndVerify(PM, "After PrologEpilogCodeInserter");
    334 
    335   // Run pre-sched2 passes.
    336   if (addPreSched2(PM, OptLevel))
    337     printAndVerify(PM, "After PreSched2 passes");
    338 
    339   // Second pass scheduler.
    340   if (OptLevel != CodeGenOpt::None) {
    341     PM.add(createPostRAScheduler(OptLevel));
    342     printAndVerify(PM, "After PostRAScheduler");
    343   }
    344 
    345   // Branch folding must be run after regalloc and prolog/epilog insertion.
    346   if (OptLevel != CodeGenOpt::None) {
    347     PM.add(createBranchFoldingPass(getEnableTailMergeDefault()));
    348     printNoVerify(PM, "After BranchFolding");
    349   }
    350 
    351   // Tail duplication.
    352   if (OptLevel != CodeGenOpt::None) {
    353     PM.add(createTailDuplicatePass(false));
    354     printNoVerify(PM, "After TailDuplicate");
    355   }
    356 
    357   PM.add(createGCMachineCodeAnalysisPass());
    358 
    359   //if (PrintGCInfo)
    360   //  PM.add(createGCInfoPrinter(dbgs()));
    361 
    362   if (OptLevel != CodeGenOpt::None) {
    363     PM.add(createCodePlacementOptPass());
    364     printNoVerify(PM, "After CodePlacementOpt");
    365   }
    366 
    367   if (addPreEmitPass(PM, OptLevel))
    368     printNoVerify(PM, "After PreEmit passes");
    369 
    370   PM.add(createPTXMFInfoExtract(*this, OptLevel));
    371   PM.add(createPTXFPRoundingModePass(*this, OptLevel));
    372 
    373   return false;
    374 }
    375