Compiler.cpp revision 94350549959ebc4c9ec70803a418bec09ad27378 
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
48namespace {
49
50// Name of metadata node where list of exported types resides
51// (should be synced with slang_rs_metadata.h)
52static 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.
58bool 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
116using namespace bcc;
117
118const 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//===----------------------------------------------------------------------===//
161Compiler::Compiler() : mTarget(nullptr), mEnableOpt(true) {
162  return;
163}
164
165Compiler::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
179enum 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
214Compiler::~Compiler() {
215  delete mTarget;
216}
217
218
219// This function has complete responsibility for creating and executing the
220// exact list of compiler passes.
221enum 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
300enum 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
367bool 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
457void Compiler::addInvokeHelperPass(llvm::legacy::PassManager &pPM) {
458  llvm::Triple arch(getTargetMachine().getTargetTriple());
459  if (arch.isArch64Bit()) {
460    pPM.add(createRSInvokeHelperPass());
461  }
462}
463
464void Compiler::addDebugInfoPass(Script &script, llvm::legacy::PassManager &pPM) {
465  if (script.getSource().getDebugInfoEnabled())
466    pPM.add(createRSAddDebugInfoPass());
467}
468
469void 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
475void 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
482void 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
488enum 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
512void 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