Compiler.cpp revision 295e50f60f2c0e27a2e5387400262f9db4477c39 
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
48using namespace bcc;
49
50const char *Compiler::GetErrorString(enum ErrorCode pErrCode) {
51  switch (pErrCode) {
52  case kSuccess:
53    return "Successfully compiled.";
54  case kInvalidConfigNoTarget:
55    return "Invalid compiler config supplied (getTarget() returns nullptr.) "
56           "(missing call to CompilerConfig::initialize()?)";
57  case kErrCreateTargetMachine:
58    return "Failed to create llvm::TargetMachine.";
59  case kErrSwitchTargetMachine:
60    return  "Failed to switch llvm::TargetMachine.";
61  case kErrNoTargetMachine:
62    return "Failed to compile the script since there's no available "
63           "TargetMachine. (missing call to Compiler::config()?)";
64  case kErrMaterialization:
65    return "Failed to materialize the module.";
66  case kErrInvalidOutputFileState:
67    return "Supplied output file was invalid (in the error state.)";
68  case kErrPrepareOutput:
69    return "Failed to prepare file for output.";
70  case kPrepareCodeGenPass:
71    return "Failed to construct pass list for code-generation.";
72  case kErrCustomPasses:
73    return "Error occurred while adding custom passes.";
74  case kErrInvalidSource:
75    return "Error loading input bitcode";
76  case kIllegalGlobalFunction:
77    return "Use of undefined external function";
78  case kErrInvalidTargetMachine:
79    return "Invalid/unexpected llvm::TargetMachine.";
80  }
81
82  // This assert should never be reached as the compiler verifies that the
83  // above switch coveres all enum values.
84  bccAssert(false && "Unknown error code encountered");
85  return  "";
86}
87
88//===----------------------------------------------------------------------===//
89// Instance Methods
90//===----------------------------------------------------------------------===//
91Compiler::Compiler() : mTarget(nullptr), mEnableOpt(true) {
92  return;
93}
94
95Compiler::Compiler(const CompilerConfig &pConfig) : mTarget(nullptr),
96                                                    mEnableOpt(true) {
97  const std::string &triple = pConfig.getTriple();
98
99  enum ErrorCode err = config(pConfig);
100  if (err != kSuccess) {
101    ALOGE("%s (%s, features: %s)", GetErrorString(err),
102          triple.c_str(), pConfig.getFeatureString().c_str());
103    return;
104  }
105
106  return;
107}
108
109enum Compiler::ErrorCode Compiler::config(const CompilerConfig &pConfig) {
110  if (pConfig.getTarget() == nullptr) {
111    return kInvalidConfigNoTarget;
112  }
113
114  llvm::TargetMachine *new_target =
115      (pConfig.getTarget())->createTargetMachine(pConfig.getTriple(),
116                                                 pConfig.getCPU(),
117                                                 pConfig.getFeatureString(),
118                                                 pConfig.getTargetOptions(),
119                                                 pConfig.getRelocationModel(),
120                                                 pConfig.getCodeModel(),
121                                                 pConfig.getOptimizationLevel());
122
123  if (new_target == nullptr) {
124    return ((mTarget != nullptr) ? kErrSwitchTargetMachine :
125                                   kErrCreateTargetMachine);
126  }
127
128  // Replace the old TargetMachine.
129  delete mTarget;
130  mTarget = new_target;
131
132  // Adjust register allocation policy according to the optimization level.
133  //  createFastRegisterAllocator: fast but bad quality
134  //  createLinearScanRegisterAllocator: not so fast but good quality
135  if ((pConfig.getOptimizationLevel() == llvm::CodeGenOpt::None)) {
136    llvm::RegisterRegAlloc::setDefault(llvm::createFastRegisterAllocator);
137  } else {
138    llvm::RegisterRegAlloc::setDefault(llvm::createGreedyRegisterAllocator);
139  }
140
141  return kSuccess;
142}
143
144Compiler::~Compiler() {
145  delete mTarget;
146}
147
148
149// This function has complete responsibility for creating and executing the
150// exact list of compiler passes.
151enum Compiler::ErrorCode Compiler::runPasses(Script &script,
152                                             llvm::raw_pwrite_stream &pResult) {
153  // Pass manager for link-time optimization
154  llvm::legacy::PassManager transformPasses;
155
156  // Empty MCContext.
157  llvm::MCContext *mc_context = nullptr;
158
159  transformPasses.add(
160      createTargetTransformInfoWrapperPass(mTarget->getTargetIRAnalysis()));
161
162  // Add some initial custom passes.
163  addInvokeHelperPass(transformPasses);
164  addExpandKernelPass(transformPasses);
165  addDebugInfoPass(script, transformPasses);
166  addInvariantPass(transformPasses);
167  if (mTarget->getOptLevel() != llvm::CodeGenOpt::None) {
168    if (!addInternalizeSymbolsPass(script, transformPasses))
169      return kErrCustomPasses;
170  }
171  addGlobalInfoPass(script, transformPasses);
172
173  if (mTarget->getOptLevel() == llvm::CodeGenOpt::None) {
174    transformPasses.add(llvm::createGlobalOptimizerPass());
175    transformPasses.add(llvm::createConstantMergePass());
176
177  } else {
178    // FIXME: Figure out which passes should be executed.
179    llvm::PassManagerBuilder Builder;
180    Builder.Inliner = llvm::createFunctionInliningPass();
181    Builder.populateLTOPassManager(transformPasses);
182
183    /* FIXME: Reenable autovectorization after rebase.
184       bug 19324423
185    // Add vectorization passes after LTO passes are in
186    // additional flag: -unroll-runtime
187    transformPasses.add(llvm::createLoopUnrollPass(-1, 16, 0, 1));
188    // Need to pass appropriate flags here: -scalarize-load-store
189    transformPasses.add(llvm::createScalarizerPass());
190    transformPasses.add(llvm::createCFGSimplificationPass());
191    transformPasses.add(llvm::createScopedNoAliasAAPass());
192    transformPasses.add(llvm::createScalarEvolutionAliasAnalysisPass());
193    // additional flags: -slp-vectorize-hor -slp-vectorize-hor-store (unnecessary?)
194    transformPasses.add(llvm::createSLPVectorizerPass());
195    transformPasses.add(llvm::createDeadCodeEliminationPass());
196    transformPasses.add(llvm::createInstructionCombiningPass());
197    */
198  }
199
200  // These passes have to come after LTO, since we don't want to examine
201  // functions that are never actually called.
202  if (llvm::Triple(getTargetMachine().getTargetTriple()).getArch() == llvm::Triple::x86_64)
203    transformPasses.add(createRSX86_64CallConvPass());  // Add pass to correct calling convention for X86-64.
204  transformPasses.add(createRSIsThreadablePass());      // Add pass to mark script as threadable.
205
206  // RSEmbedInfoPass needs to come after we have scanned for non-threadable
207  // functions.
208  if (script.getEmbedInfo())
209    transformPasses.add(createRSEmbedInfoPass());
210
211  // Execute the passes.
212  transformPasses.run(script.getSource().getModule());
213
214  // Run backend separately to avoid interference between debug metadata
215  // generation and backend initialization.
216  llvm::legacy::PassManager codeGenPasses;
217
218  // Add passes to the pass manager to emit machine code through MC layer.
219  if (mTarget->addPassesToEmitMC(codeGenPasses, mc_context, pResult,
220                                 /* DisableVerify */false)) {
221    return kPrepareCodeGenPass;
222  }
223
224  // Execute the passes.
225  codeGenPasses.run(script.getSource().getModule());
226
227  return kSuccess;
228}
229
230enum Compiler::ErrorCode Compiler::compile(Script &script,
231                                           llvm::raw_pwrite_stream &pResult,
232                                           llvm::raw_ostream *IRStream) {
233  llvm::Module &module = script.getSource().getModule();
234  enum ErrorCode err;
235
236  if (mTarget == nullptr) {
237    return kErrNoTargetMachine;
238  }
239
240  const std::string &triple = module.getTargetTriple();
241  const llvm::DataLayout dl = getTargetMachine().createDataLayout();
242  unsigned int pointerSize = dl.getPointerSizeInBits();
243  if (triple == "armv7-none-linux-gnueabi") {
244    if (pointerSize != 32) {
245      return kErrInvalidSource;
246    }
247  } else if (triple == "aarch64-none-linux-gnueabi") {
248    if (pointerSize != 64) {
249      return kErrInvalidSource;
250    }
251  } else {
252    return kErrInvalidSource;
253  }
254
255  if (getTargetMachine().getTargetTriple().getArch() == llvm::Triple::x86) {
256    // Detect and fail if TargetMachine datalayout is different than what we
257    // expect.  This is to detect changes in default target layout for x86 and
258    // update X86_CUSTOM_DL_STRING in include/bcc/Config/Config.h appropriately.
259    if (dl.getStringRepresentation().compare(X86_DEFAULT_DL_STRING) != 0) {
260      return kErrInvalidTargetMachine;
261    }
262  }
263
264  // Sanitize module's target information.
265  module.setTargetTriple(getTargetMachine().getTargetTriple().str());
266  module.setDataLayout(getTargetMachine().createDataLayout());
267
268  // Materialize the bitcode module.
269  if (module.getMaterializer() != nullptr) {
270    // A module with non-null materializer means that it is a lazy-load module.
271    // Materialize it now.  This function returns false when the materialization
272    // is successful.
273    std::error_code ec = module.materializeAll();
274    if (ec) {
275      ALOGE("Failed to materialize the module `%s'! (%s)",
276            module.getModuleIdentifier().c_str(), ec.message().c_str());
277      return kErrMaterialization;
278    }
279  }
280
281  if ((err = runPasses(script, pResult)) != kSuccess) {
282    return err;
283  }
284
285  if (IRStream) {
286    *IRStream << module;
287  }
288
289  return kSuccess;
290}
291
292bool Compiler::addInternalizeSymbolsPass(Script &script, llvm::legacy::PassManager &pPM) {
293  // Add a pass to internalize the symbols that don't need to have global
294  // visibility.
295  llvm::Module &module = script.getSource().getModule();
296  bcinfo::MetadataExtractor me(&module);
297  if (!me.extract()) {
298    bccAssert(false && "Could not extract metadata for module!");
299    return false;
300  }
301
302  // Set of symbols that should not be internalized.
303  std::set<std::string> export_symbols;
304
305  const char *sf[] = {
306    kRoot,               // Graphics drawing function or compute kernel.
307    kInit,               // Initialization routine called implicitly on startup.
308    kRsDtor,             // Static global destructor for a script instance.
309    kRsInfo,             // Variable containing string of RS metadata info.
310    kRsGlobalEntries,    // Optional number of global variables.
311    kRsGlobalNames,      // Optional global variable name info.
312    kRsGlobalAddresses,  // Optional global variable address info.
313    kRsGlobalSizes,      // Optional global variable size info.
314    kRsGlobalProperties, // Optional global variable properties.
315    nullptr              // Must be nullptr-terminated.
316  };
317  const char **special_functions = sf;
318  // Special RS functions should always be global symbols.
319  while (*special_functions != nullptr) {
320    export_symbols.insert(*special_functions);
321    special_functions++;
322  }
323
324  // Visibility of symbols appeared in rs_export_var and rs_export_func should
325  // also be preserved.
326  size_t exportVarCount = me.getExportVarCount();
327  size_t exportFuncCount = me.getExportFuncCount();
328  size_t exportForEachCount = me.getExportForEachSignatureCount();
329  size_t exportReduceCount = me.getExportReduceCount();
330  const char **exportVarNameList = me.getExportVarNameList();
331  const char **exportFuncNameList = me.getExportFuncNameList();
332  const char **exportForEachNameList = me.getExportForEachNameList();
333  const bcinfo::MetadataExtractor::Reduce *exportReduceList = me.getExportReduceList();
334  size_t i;
335
336  for (i = 0; i < exportVarCount; ++i) {
337    export_symbols.insert(exportVarNameList[i]);
338  }
339
340  for (i = 0; i < exportFuncCount; ++i) {
341    export_symbols.insert(exportFuncNameList[i]);
342  }
343
344  // Expanded foreach functions should not be internalized; nor should
345  // general reduction initializer, combiner, and outconverter
346  // functions. keep_funcs keeps the names of these functions around
347  // until createInternalizePass() is finished making its own copy of
348  // the visible symbols.
349  std::vector<std::string> keep_funcs;
350  keep_funcs.reserve(exportForEachCount + exportReduceCount*4);
351
352  for (i = 0; i < exportForEachCount; ++i) {
353    keep_funcs.push_back(std::string(exportForEachNameList[i]) + ".expand");
354  }
355  auto keepFuncsPushBackIfPresent = [&keep_funcs](const char *Name) {
356    if (Name) keep_funcs.push_back(Name);
357  };
358  for (i = 0; i < exportReduceCount; ++i) {
359    keep_funcs.push_back(std::string(exportReduceList[i].mAccumulatorName) + ".expand");
360    keepFuncsPushBackIfPresent(exportReduceList[i].mInitializerName);
361    if (exportReduceList[i].mCombinerName != nullptr) {
362      keep_funcs.push_back(exportReduceList[i].mCombinerName);
363    } else {
364      keep_funcs.push_back(nameReduceCombinerFromAccumulator(exportReduceList[i].mAccumulatorName));
365    }
366    keepFuncsPushBackIfPresent(exportReduceList[i].mOutConverterName);
367  }
368
369  for (auto &symbol_name : keep_funcs) {
370    export_symbols.insert(symbol_name);
371  }
372
373  auto IsExportedSymbol = [=](const llvm::GlobalValue &GV) {
374    return export_symbols.count(GV.getName()) > 0;
375  };
376
377  pPM.add(llvm::createInternalizePass(IsExportedSymbol));
378
379  return true;
380}
381
382void Compiler::addInvokeHelperPass(llvm::legacy::PassManager &pPM) {
383  llvm::Triple arch(getTargetMachine().getTargetTriple());
384  if (arch.isArch64Bit()) {
385    pPM.add(createRSInvokeHelperPass());
386  }
387}
388
389void Compiler::addDebugInfoPass(Script &script, llvm::legacy::PassManager &pPM) {
390  if (script.getSource().getDebugInfoEnabled())
391    pPM.add(createRSAddDebugInfoPass());
392}
393
394void Compiler::addExpandKernelPass(llvm::legacy::PassManager &pPM) {
395  // Expand ForEach and reduce on CPU path to reduce launch overhead.
396  bool pEnableStepOpt = true;
397  pPM.add(createRSKernelExpandPass(pEnableStepOpt));
398}
399
400void Compiler::addGlobalInfoPass(Script &script, llvm::legacy::PassManager &pPM) {
401  // Add additional information about RS global variables inside the Module.
402  if (script.getEmbedGlobalInfo()) {
403    pPM.add(createRSGlobalInfoPass(script.getEmbedGlobalInfoSkipConstant()));
404  }
405}
406
407void Compiler::addInvariantPass(llvm::legacy::PassManager &pPM) {
408  // Mark Loads from RsExpandKernelDriverInfo as "load.invariant".
409  // Should run after ExpandForEach and before inlining.
410  pPM.add(createRSInvariantPass());
411}
412
413enum Compiler::ErrorCode Compiler::screenGlobalFunctions(Script &script) {
414  llvm::Module &module = script.getSource().getModule();
415
416  // Materialize the bitcode module in case this is a lazy-load module.  Do not
417  // clear the materializer by calling materializeAllPermanently since the
418  // runtime library has not been merged into the module yet.
419  if (module.getMaterializer() != nullptr) {
420    std::error_code ec = module.materializeAll();
421    if (ec) {
422      ALOGE("Failed to materialize module `%s' when screening globals! (%s)",
423            module.getModuleIdentifier().c_str(), ec.message().c_str());
424      return kErrMaterialization;
425    }
426  }
427
428  // Add pass to check for illegal function calls.
429  llvm::legacy::PassManager pPM;
430  pPM.add(createRSScreenFunctionsPass());
431  pPM.run(module);
432
433  return kSuccess;
434
435}
436
437void Compiler::translateGEPs(Script &script) {
438  llvm::legacy::PassManager pPM;
439  pPM.add(createRSX86TranslateGEPPass());
440
441  // Materialization done in screenGlobalFunctions above.
442  pPM.run(script.getSource().getModule());
443}
444