Home | History | Annotate | Download | only in lib 
      1 /*
      2  * Copyright 2010-2012, The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *     http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include "Assert.h"
     18 #include "Log.h"
     19 #include "RSTransforms.h"
     20 #include "RSUtils.h"
     21 #include "rsDefines.h"
     22 
     23 #include "bcc/Compiler.h"
     24 #include "bcc/CompilerConfig.h"
     25 #include "bcc/Config.h"
     26 #include "bcc/Script.h"
     27 #include "bcc/Source.h"
     28 #include "bcinfo/MetadataExtractor.h"
     29 
     30 #include <llvm/Analysis/Passes.h>
     31 #include <llvm/Analysis/TargetTransformInfo.h>
     32 #include <llvm/CodeGen/RegAllocRegistry.h>
     33 #include <llvm/IR/LegacyPassManager.h>
     34 #include <llvm/IR/Module.h>
     35 #include <llvm/Support/TargetRegistry.h>
     36 #include <llvm/Support/raw_ostream.h>
     37 #include <llvm/IR/DataLayout.h>
     38 #include <llvm/Target/TargetSubtargetInfo.h>
     39 #include <llvm/Target/TargetMachine.h>
     40 #include <llvm/Transforms/IPO.h>
     41 #include <llvm/Transforms/IPO/PassManagerBuilder.h>
     42 #include <llvm/Transforms/Scalar.h>
     43 #include <llvm/Transforms/Vectorize.h>
     44 
     45 #include <string>
     46 #include <set>
     47 
     48 namespace {
     49 
     50 // Name of metadata node where list of exported types resides
     51 // (should be synced with slang_rs_metadata.h)
     52 static const llvm::StringRef ExportedTypeMetadataName = "#rs_export_type";
     53 
     54 // Every exported struct type must have the same layout according to
     55 // the Module's DataLayout that it does according to the
     56 // TargetMachine's DataLayout -- that is, the front end (represented
     57 // by Module) and back end (represented by TargetMachine) must agree.
     58 bool validateLayoutOfExportedTypes(const llvm::Module &module,
     59                                    const llvm::DataLayout &moduleDataLayout,
     60                                    const llvm::DataLayout &targetDataLayout) {
     61   if (moduleDataLayout == targetDataLayout)
     62     return true;
     63 
     64   const llvm::NamedMDNode *const exportedTypesMD =
     65       module.getNamedMetadata(ExportedTypeMetadataName);
     66   if (!exportedTypesMD)
     67     return true;
     68 
     69   bool allOk = true;
     70   for (const llvm::MDNode *const exportedTypeMD : exportedTypesMD->operands()) {
     71     bccAssert(exportedTypeMD->getNumOperands() == 1);
     72 
     73     // The name of the type in LLVM is the name of the type in the
     74     // metadata with "struct." prepended.
     75     std::string exportedTypeName =
     76         "struct." +
     77         llvm::cast<llvm::MDString>(exportedTypeMD->getOperand(0))->getString().str();
     78 
     79     llvm::StructType *const exportedType = module.getTypeByName(exportedTypeName);
     80 
     81     if (!exportedType) {
     82       // presumably this means the type got optimized away
     83       continue;
     84     }
     85 
     86     const llvm::StructLayout *const moduleStructLayout = moduleDataLayout.getStructLayout(exportedType);
     87     const llvm::StructLayout *const targetStructLayout = targetDataLayout.getStructLayout(exportedType);
     88 
     89     if (moduleStructLayout->getSizeInBits() != targetStructLayout->getSizeInBits()) {
     90       ALOGE("%s: getSizeInBits() does not match (%u, %u)", exportedTypeName.c_str(),
     91             unsigned(moduleStructLayout->getSizeInBits()), unsigned(targetStructLayout->getSizeInBits()));
     92       allOk = false;
     93     }
     94 
     95     // We deliberately do not check alignment of the struct as a whole -- the explicit padding
     96     // from slang doesn't force the alignment.
     97 
     98     for (unsigned elementCount = exportedType->getNumElements(), elementIdx = 0;
     99          elementIdx < elementCount; ++elementIdx) {
    100       if (moduleStructLayout->getElementOffsetInBits(elementIdx) !=
    101           targetStructLayout->getElementOffsetInBits(elementIdx)) {
    102         ALOGE("%s: getElementOffsetInBits(%u) does not match (%u, %u)",
    103               exportedTypeName.c_str(), elementIdx,
    104               unsigned(moduleStructLayout->getElementOffsetInBits(elementIdx)),
    105               unsigned(targetStructLayout->getElementOffsetInBits(elementIdx)));
    106         allOk = false;
    107       }
    108     }
    109   }
    110 
    111   return allOk;
    112 }
    113 
    114 }  // end unnamed namespace
    115 
    116 using namespace bcc;
    117 
    118 const char *Compiler::GetErrorString(enum ErrorCode pErrCode) {
    119   switch (pErrCode) {
    120   case kSuccess:
    121     return "Successfully compiled.";
    122   case kInvalidConfigNoTarget:
    123     return "Invalid compiler config supplied (getTarget() returns nullptr.) "
    124            "(missing call to CompilerConfig::initialize()?)";
    125   case kErrCreateTargetMachine:
    126     return "Failed to create llvm::TargetMachine.";
    127   case kErrSwitchTargetMachine:
    128     return  "Failed to switch llvm::TargetMachine.";
    129   case kErrNoTargetMachine:
    130     return "Failed to compile the script since there's no available "
    131            "TargetMachine. (missing call to Compiler::config()?)";
    132   case kErrMaterialization:
    133     return "Failed to materialize the module.";
    134   case kErrInvalidOutputFileState:
    135     return "Supplied output file was invalid (in the error state.)";
    136   case kErrPrepareOutput:
    137     return "Failed to prepare file for output.";
    138   case kPrepareCodeGenPass:
    139     return "Failed to construct pass list for code-generation.";
    140   case kErrCustomPasses:
    141     return "Error occurred while adding custom passes.";
    142   case kErrInvalidSource:
    143     return "Error loading input bitcode";
    144   case kIllegalGlobalFunction:
    145     return "Use of undefined external function";
    146   case kErrInvalidTargetMachine:
    147     return "Invalid/unexpected llvm::TargetMachine.";
    148   case kErrInvalidLayout:
    149     return "Invalid layout (RenderScript ABI and native ABI are incompatible)";
    150   }
    151 
    152   // This assert should never be reached as the compiler verifies that the
    153   // above switch coveres all enum values.
    154   bccAssert(false && "Unknown error code encountered");
    155   return  "";
    156 }
    157 
    158 //===----------------------------------------------------------------------===//
    159 // Instance Methods
    160 //===----------------------------------------------------------------------===//
    161 Compiler::Compiler() : mTarget(nullptr), mEnableOpt(true) {
    162   return;
    163 }
    164 
    165 Compiler::Compiler(const CompilerConfig &pConfig) : mTarget(nullptr),
    166                                                     mEnableOpt(true) {
    167   const std::string &triple = pConfig.getTriple();
    168 
    169   enum ErrorCode err = config(pConfig);
    170   if (err != kSuccess) {
    171     ALOGE("%s (%s, features: %s)", GetErrorString(err),
    172           triple.c_str(), pConfig.getFeatureString().c_str());
    173     return;
    174   }
    175 
    176   return;
    177 }
    178 
    179 enum Compiler::ErrorCode Compiler::config(const CompilerConfig &pConfig) {
    180   if (pConfig.getTarget() == nullptr) {
    181     return kInvalidConfigNoTarget;
    182   }
    183 
    184   llvm::TargetMachine *new_target =
    185       (pConfig.getTarget())->createTargetMachine(pConfig.getTriple(),
    186                                                  pConfig.getCPU(),
    187                                                  pConfig.getFeatureString(),
    188                                                  pConfig.getTargetOptions(),
    189                                                  pConfig.getRelocationModel(),
    190                                                  pConfig.getCodeModel(),
    191                                                  pConfig.getOptimizationLevel());
    192 
    193   if (new_target == nullptr) {
    194     return ((mTarget != nullptr) ? kErrSwitchTargetMachine :
    195                                    kErrCreateTargetMachine);
    196   }
    197 
    198   // Replace the old TargetMachine.
    199   delete mTarget;
    200   mTarget = new_target;
    201 
    202   // Adjust register allocation policy according to the optimization level.
    203   //  createFastRegisterAllocator: fast but bad quality
    204   //  createLinearScanRegisterAllocator: not so fast but good quality
    205   if ((pConfig.getOptimizationLevel() == llvm::CodeGenOpt::None)) {
    206     llvm::RegisterRegAlloc::setDefault(llvm::createFastRegisterAllocator);
    207   } else {
    208     llvm::RegisterRegAlloc::setDefault(llvm::createGreedyRegisterAllocator);
    209   }
    210 
    211   return kSuccess;
    212 }
    213 
    214 Compiler::~Compiler() {
    215   delete mTarget;
    216 }
    217 
    218 
    219 // This function has complete responsibility for creating and executing the
    220 // exact list of compiler passes.
    221 enum Compiler::ErrorCode Compiler::runPasses(Script &script,
    222                                              llvm::raw_pwrite_stream &pResult) {
    223   // Pass manager for link-time optimization
    224   llvm::legacy::PassManager transformPasses;
    225 
    226   // Empty MCContext.
    227   llvm::MCContext *mc_context = nullptr;
    228 
    229   transformPasses.add(
    230       createTargetTransformInfoWrapperPass(mTarget->getTargetIRAnalysis()));
    231 
    232   // Add some initial custom passes.
    233   addInvokeHelperPass(transformPasses);
    234   addExpandKernelPass(transformPasses);
    235   addDebugInfoPass(script, transformPasses);
    236   addInvariantPass(transformPasses);
    237   if (mTarget->getOptLevel() != llvm::CodeGenOpt::None) {
    238     if (!addInternalizeSymbolsPass(script, transformPasses))
    239       return kErrCustomPasses;
    240   }
    241   addGlobalInfoPass(script, transformPasses);
    242 
    243   if (mTarget->getOptLevel() == llvm::CodeGenOpt::None) {
    244     transformPasses.add(llvm::createGlobalOptimizerPass());
    245     transformPasses.add(llvm::createConstantMergePass());
    246 
    247   } else {
    248     // FIXME: Figure out which passes should be executed.
    249     llvm::PassManagerBuilder Builder;
    250     Builder.Inliner = llvm::createFunctionInliningPass();
    251     Builder.populateLTOPassManager(transformPasses);
    252 
    253     /* FIXME: Reenable autovectorization after rebase.
    254        bug 19324423
    255     // Add vectorization passes after LTO passes are in
    256     // additional flag: -unroll-runtime
    257     transformPasses.add(llvm::createLoopUnrollPass(-1, 16, 0, 1));
    258     // Need to pass appropriate flags here: -scalarize-load-store
    259     transformPasses.add(llvm::createScalarizerPass());
    260     transformPasses.add(llvm::createCFGSimplificationPass());
    261     transformPasses.add(llvm::createScopedNoAliasAAPass());
    262     transformPasses.add(llvm::createScalarEvolutionAliasAnalysisPass());
    263     // additional flags: -slp-vectorize-hor -slp-vectorize-hor-store (unnecessary?)
    264     transformPasses.add(llvm::createSLPVectorizerPass());
    265     transformPasses.add(llvm::createDeadCodeEliminationPass());
    266     transformPasses.add(llvm::createInstructionCombiningPass());
    267     */
    268   }
    269 
    270   // These passes have to come after LTO, since we don't want to examine
    271   // functions that are never actually called.
    272   if (llvm::Triple(getTargetMachine().getTargetTriple()).getArch() == llvm::Triple::x86_64)
    273     transformPasses.add(createRSX86_64CallConvPass());  // Add pass to correct calling convention for X86-64.
    274   transformPasses.add(createRSIsThreadablePass());      // Add pass to mark script as threadable.
    275 
    276   // RSEmbedInfoPass needs to come after we have scanned for non-threadable
    277   // functions.
    278   if (script.getEmbedInfo())
    279     transformPasses.add(createRSEmbedInfoPass());
    280 
    281   // Execute the passes.
    282   transformPasses.run(script.getSource().getModule());
    283 
    284   // Run backend separately to avoid interference between debug metadata
    285   // generation and backend initialization.
    286   llvm::legacy::PassManager codeGenPasses;
    287 
    288   // Add passes to the pass manager to emit machine code through MC layer.
    289   if (mTarget->addPassesToEmitMC(codeGenPasses, mc_context, pResult,
    290                                  /* DisableVerify */false)) {
    291     return kPrepareCodeGenPass;
    292   }
    293 
    294   // Execute the passes.
    295   codeGenPasses.run(script.getSource().getModule());
    296 
    297   return kSuccess;
    298 }
    299 
    300 enum Compiler::ErrorCode Compiler::compile(Script &script,
    301                                            llvm::raw_pwrite_stream &pResult,
    302                                            llvm::raw_ostream *IRStream) {
    303   llvm::Module &module = script.getSource().getModule();
    304   enum ErrorCode err;
    305 
    306   if (mTarget == nullptr) {
    307     return kErrNoTargetMachine;
    308   }
    309 
    310   const std::string &triple = module.getTargetTriple();
    311   const llvm::DataLayout dl = getTargetMachine().createDataLayout();
    312   unsigned int pointerSize = dl.getPointerSizeInBits();
    313   if (triple == "armv7-none-linux-gnueabi") {
    314     if (pointerSize != 32) {
    315       return kErrInvalidSource;
    316     }
    317   } else if (triple == "aarch64-none-linux-gnueabi") {
    318     if (pointerSize != 64) {
    319       return kErrInvalidSource;
    320     }
    321   } else {
    322     return kErrInvalidSource;
    323   }
    324 
    325   if (script.isStructExplicitlyPaddedBySlang()) {
    326     if (!validateLayoutOfExportedTypes(module, module.getDataLayout(), dl))
    327       return kErrInvalidLayout;
    328   } else {
    329     if (getTargetMachine().getTargetTriple().getArch() == llvm::Triple::x86) {
    330       // Detect and fail if TargetMachine datalayout is different than what we
    331       // expect.  This is to detect changes in default target layout for x86 and
    332       // update X86_CUSTOM_DL_STRING in include/bcc/Config/Config.h appropriately.
    333       if (dl.getStringRepresentation().compare(X86_DEFAULT_DL_STRING) != 0) {
    334         return kErrInvalidTargetMachine;
    335       }
    336     }
    337   }
    338 
    339   // Sanitize module's target information.
    340   module.setTargetTriple(getTargetMachine().getTargetTriple().str());
    341   module.setDataLayout(getTargetMachine().createDataLayout());
    342 
    343   // Materialize the bitcode module.
    344   if (module.getMaterializer() != nullptr) {
    345     // A module with non-null materializer means that it is a lazy-load module.
    346     // Materialize it now.  This function returns false when the materialization
    347     // is successful.
    348     std::error_code ec = module.materializeAll();
    349     if (ec) {
    350       ALOGE("Failed to materialize the module `%s'! (%s)",
    351             module.getModuleIdentifier().c_str(), ec.message().c_str());
    352       return kErrMaterialization;
    353     }
    354   }
    355 
    356   if ((err = runPasses(script, pResult)) != kSuccess) {
    357     return err;
    358   }
    359 
    360   if (IRStream) {
    361     *IRStream << module;
    362   }
    363 
    364   return kSuccess;
    365 }
    366 
    367 bool Compiler::addInternalizeSymbolsPass(Script &script, llvm::legacy::PassManager &pPM) {
    368   // Add a pass to internalize the symbols that don't need to have global
    369   // visibility.
    370   llvm::Module &module = script.getSource().getModule();
    371   bcinfo::MetadataExtractor me(&module);
    372   if (!me.extract()) {
    373     bccAssert(false && "Could not extract metadata for module!");
    374     return false;
    375   }
    376 
    377   // Set of symbols that should not be internalized.
    378   std::set<std::string> export_symbols;
    379 
    380   const char *sf[] = {
    381     kRoot,               // Graphics drawing function or compute kernel.
    382     kInit,               // Initialization routine called implicitly on startup.
    383     kRsDtor,             // Static global destructor for a script instance.
    384     kRsInfo,             // Variable containing string of RS metadata info.
    385     kRsGlobalEntries,    // Optional number of global variables.
    386     kRsGlobalNames,      // Optional global variable name info.
    387     kRsGlobalAddresses,  // Optional global variable address info.
    388     kRsGlobalSizes,      // Optional global variable size info.
    389     kRsGlobalProperties, // Optional global variable properties.
    390     nullptr              // Must be nullptr-terminated.
    391   };
    392   const char **special_functions = sf;
    393   // Special RS functions should always be global symbols.
    394   while (*special_functions != nullptr) {
    395     export_symbols.insert(*special_functions);
    396     special_functions++;
    397   }
    398 
    399   // Visibility of symbols appeared in rs_export_var and rs_export_func should
    400   // also be preserved.
    401   size_t exportVarCount = me.getExportVarCount();
    402   size_t exportFuncCount = me.getExportFuncCount();
    403   size_t exportForEachCount = me.getExportForEachSignatureCount();
    404   size_t exportReduceCount = me.getExportReduceCount();
    405   const char **exportVarNameList = me.getExportVarNameList();
    406   const char **exportFuncNameList = me.getExportFuncNameList();
    407   const char **exportForEachNameList = me.getExportForEachNameList();
    408   const bcinfo::MetadataExtractor::Reduce *exportReduceList = me.getExportReduceList();
    409   size_t i;
    410 
    411   for (i = 0; i < exportVarCount; ++i) {
    412     export_symbols.insert(exportVarNameList[i]);
    413   }
    414 
    415   for (i = 0; i < exportFuncCount; ++i) {
    416     export_symbols.insert(exportFuncNameList[i]);
    417   }
    418 
    419   // Expanded foreach functions should not be internalized; nor should
    420   // general reduction initializer, combiner, and outconverter
    421   // functions. keep_funcs keeps the names of these functions around
    422   // until createInternalizePass() is finished making its own copy of
    423   // the visible symbols.
    424   std::vector<std::string> keep_funcs;
    425   keep_funcs.reserve(exportForEachCount + exportReduceCount*4);
    426 
    427   for (i = 0; i < exportForEachCount; ++i) {
    428     keep_funcs.push_back(std::string(exportForEachNameList[i]) + ".expand");
    429   }
    430   auto keepFuncsPushBackIfPresent = [&keep_funcs](const char *Name) {
    431     if (Name) keep_funcs.push_back(Name);
    432   };
    433   for (i = 0; i < exportReduceCount; ++i) {
    434     keep_funcs.push_back(std::string(exportReduceList[i].mAccumulatorName) + ".expand");
    435     keepFuncsPushBackIfPresent(exportReduceList[i].mInitializerName);
    436     if (exportReduceList[i].mCombinerName != nullptr) {
    437       keep_funcs.push_back(exportReduceList[i].mCombinerName);
    438     } else {
    439       keep_funcs.push_back(nameReduceCombinerFromAccumulator(exportReduceList[i].mAccumulatorName));
    440     }
    441     keepFuncsPushBackIfPresent(exportReduceList[i].mOutConverterName);
    442   }
    443 
    444   for (auto &symbol_name : keep_funcs) {
    445     export_symbols.insert(symbol_name);
    446   }
    447 
    448   auto IsExportedSymbol = [=](const llvm::GlobalValue &GV) {
    449     return export_symbols.count(GV.getName()) > 0;
    450   };
    451 
    452   pPM.add(llvm::createInternalizePass(IsExportedSymbol));
    453 
    454   return true;
    455 }
    456 
    457 void Compiler::addInvokeHelperPass(llvm::legacy::PassManager &pPM) {
    458   llvm::Triple arch(getTargetMachine().getTargetTriple());
    459   if (arch.isArch64Bit()) {
    460     pPM.add(createRSInvokeHelperPass());
    461   }
    462 }
    463 
    464 void Compiler::addDebugInfoPass(Script &script, llvm::legacy::PassManager &pPM) {
    465   if (script.getSource().getDebugInfoEnabled())
    466     pPM.add(createRSAddDebugInfoPass());
    467 }
    468 
    469 void Compiler::addExpandKernelPass(llvm::legacy::PassManager &pPM) {
    470   // Expand ForEach and reduce on CPU path to reduce launch overhead.
    471   bool pEnableStepOpt = true;
    472   pPM.add(createRSKernelExpandPass(pEnableStepOpt));
    473 }
    474 
    475 void Compiler::addGlobalInfoPass(Script &script, llvm::legacy::PassManager &pPM) {
    476   // Add additional information about RS global variables inside the Module.
    477   if (script.getEmbedGlobalInfo()) {
    478     pPM.add(createRSGlobalInfoPass(script.getEmbedGlobalInfoSkipConstant()));
    479   }
    480 }
    481 
    482 void Compiler::addInvariantPass(llvm::legacy::PassManager &pPM) {
    483   // Mark Loads from RsExpandKernelDriverInfo as "load.invariant".
    484   // Should run after ExpandForEach and before inlining.
    485   pPM.add(createRSInvariantPass());
    486 }
    487 
    488 enum Compiler::ErrorCode Compiler::screenGlobalFunctions(Script &script) {
    489   llvm::Module &module = script.getSource().getModule();
    490 
    491   // Materialize the bitcode module in case this is a lazy-load module.  Do not
    492   // clear the materializer by calling materializeAllPermanently since the
    493   // runtime library has not been merged into the module yet.
    494   if (module.getMaterializer() != nullptr) {
    495     std::error_code ec = module.materializeAll();
    496     if (ec) {
    497       ALOGE("Failed to materialize module `%s' when screening globals! (%s)",
    498             module.getModuleIdentifier().c_str(), ec.message().c_str());
    499       return kErrMaterialization;
    500     }
    501   }
    502 
    503   // Add pass to check for illegal function calls.
    504   llvm::legacy::PassManager pPM;
    505   pPM.add(createRSScreenFunctionsPass());
    506   pPM.run(module);
    507 
    508   return kSuccess;
    509 
    510 }
    511 
    512 void Compiler::translateGEPs(Script &script) {
    513   llvm::legacy::PassManager pPM;
    514   pPM.add(createRSX86TranslateGEPPass());
    515 
    516   // Materialization done in screenGlobalFunctions above.
    517   pPM.run(script.getSource().getModule());
    518 }
    519