Compiler.cpp revision 9fe081b8bae8a95d903f8fa8dc0a7590ae706606 
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 "bcc/Compiler.h"
18
19#include <llvm/Analysis/Passes.h>
20#include <llvm/CodeGen/RegAllocRegistry.h>
21#include <llvm/IR/Module.h>
22#include <llvm/PassManager.h>
23#include <llvm/Support/TargetRegistry.h>
24#include <llvm/Support/raw_ostream.h>
25#include <llvm/IR/DataLayout.h>
26#include <llvm/Target/TargetSubtargetInfo.h>
27#include <llvm/Target/TargetMachine.h>
28#include <llvm/Transforms/IPO.h>
29#include <llvm/Transforms/IPO/PassManagerBuilder.h>
30#include <llvm/Transforms/Scalar.h>
31#include <llvm/Transforms/Vectorize.h>
32
33#include "bcc/Assert.h"
34#include "bcc/Renderscript/RSScript.h"
35#include "bcc/Renderscript/RSTransforms.h"
36#include "bcc/Script.h"
37#include "bcc/Source.h"
38#include "bcc/Support/CompilerConfig.h"
39#include "bcc/Support/Log.h"
40#include "bcc/Support/OutputFile.h"
41#include "bcinfo/MetadataExtractor.h"
42
43#include <string>
44
45using namespace bcc;
46
47const char *Compiler::GetErrorString(enum ErrorCode pErrCode) {
48  switch (pErrCode) {
49  case kSuccess:
50    return "Successfully compiled.";
51  case kInvalidConfigNoTarget:
52    return "Invalid compiler config supplied (getTarget() returns nullptr.) "
53           "(missing call to CompilerConfig::initialize()?)";
54  case kErrCreateTargetMachine:
55    return "Failed to create llvm::TargetMachine.";
56  case kErrSwitchTargetMachine:
57    return  "Failed to switch llvm::TargetMachine.";
58  case kErrNoTargetMachine:
59    return "Failed to compile the script since there's no available "
60           "TargetMachine. (missing call to Compiler::config()?)";
61  case kErrDataLayoutNoMemory:
62    return "Out of memory when create DataLayout during compilation.";
63  case kErrMaterialization:
64    return "Failed to materialize the module.";
65  case kErrInvalidOutputFileState:
66    return "Supplied output file was invalid (in the error state.)";
67  case kErrPrepareOutput:
68    return "Failed to prepare file for output.";
69  case kPrepareCodeGenPass:
70    return "Failed to construct pass list for code-generation.";
71  case kErrCustomPasses:
72    return "Error occurred while adding custom passes.";
73  case kErrInvalidSource:
74    return "Error loading input bitcode";
75  case kIllegalGlobalFunction:
76    return "Use of undefined external function";
77  }
78
79  // This assert should never be reached as the compiler verifies that the
80  // above switch coveres all enum values.
81  assert(false && "Unknown error code encountered");
82  return  "";
83}
84
85//===----------------------------------------------------------------------===//
86// Instance Methods
87//===----------------------------------------------------------------------===//
88Compiler::Compiler() : mTarget(nullptr), mEnableOpt(true) {
89  return;
90}
91
92Compiler::Compiler(const CompilerConfig &pConfig) : mTarget(nullptr),
93                                                    mEnableOpt(true) {
94  const std::string &triple = pConfig.getTriple();
95
96  enum ErrorCode err = config(pConfig);
97  if (err != kSuccess) {
98    ALOGE("%s (%s, features: %s)", GetErrorString(err),
99          triple.c_str(), pConfig.getFeatureString().c_str());
100    return;
101  }
102
103  return;
104}
105
106enum Compiler::ErrorCode Compiler::config(const CompilerConfig &pConfig) {
107  if (pConfig.getTarget() == nullptr) {
108    return kInvalidConfigNoTarget;
109  }
110
111  llvm::TargetMachine *new_target =
112      (pConfig.getTarget())->createTargetMachine(pConfig.getTriple(),
113                                                 pConfig.getCPU(),
114                                                 pConfig.getFeatureString(),
115                                                 pConfig.getTargetOptions(),
116                                                 pConfig.getRelocationModel(),
117                                                 pConfig.getCodeModel(),
118                                                 pConfig.getOptimizationLevel());
119
120  if (new_target == nullptr) {
121    return ((mTarget != nullptr) ? kErrSwitchTargetMachine :
122                                   kErrCreateTargetMachine);
123  }
124
125  // Replace the old TargetMachine.
126  delete mTarget;
127  mTarget = new_target;
128
129  // Adjust register allocation policy according to the optimization level.
130  //  createFastRegisterAllocator: fast but bad quality
131  //  createLinearScanRegisterAllocator: not so fast but good quality
132  if ((pConfig.getOptimizationLevel() == llvm::CodeGenOpt::None)) {
133    llvm::RegisterRegAlloc::setDefault(llvm::createFastRegisterAllocator);
134  } else {
135    llvm::RegisterRegAlloc::setDefault(llvm::createGreedyRegisterAllocator);
136  }
137
138  return kSuccess;
139}
140
141Compiler::~Compiler() {
142  delete mTarget;
143}
144
145
146enum Compiler::ErrorCode Compiler::runPasses(Script &pScript,
147                                             llvm::raw_ostream &pResult) {
148  // Pass manager for link-time optimization
149  llvm::PassManager passes;
150
151  // Empty MCContext.
152  llvm::MCContext *mc_context = nullptr;
153
154  mTarget->addAnalysisPasses(passes);
155
156  // Prepare DataLayout target data from Module
157  llvm::DataLayoutPass *data_layout_pass =
158    new (std::nothrow) llvm::DataLayoutPass();
159
160  if (data_layout_pass == nullptr) {
161    return kErrDataLayoutNoMemory;
162  }
163
164  // Add DataLayout to the pass manager.
165  passes.add(data_layout_pass);
166
167  // Add our custom passes.
168  if (!addCustomPasses(pScript, passes)) {
169    return kErrCustomPasses;
170  }
171
172  if (mTarget->getOptLevel() == llvm::CodeGenOpt::None) {
173    passes.add(llvm::createGlobalOptimizerPass());
174    passes.add(llvm::createConstantMergePass());
175
176  } else {
177    // FIXME: Figure out which passes should be executed.
178    llvm::PassManagerBuilder Builder;
179    Builder.Inliner = llvm::createFunctionInliningPass();
180    Builder.populateLTOPassManager(passes, mTarget);
181
182    // Add vectorization passes after LTO passes are in
183    // additional flag: -unroll-runtime
184    passes.add(llvm::createLoopUnrollPass(-1, 16, 0, 1));
185    // Need to pass appropriate flags here: -scalarize-load-store
186    passes.add(llvm::createScalarizerPass());
187    passes.add(llvm::createCFGSimplificationPass());
188    passes.add(llvm::createScopedNoAliasAAPass());
189    passes.add(llvm::createScalarEvolutionAliasAnalysisPass());
190    // additional flags: -slp-vectorize-hor -slp-vectorize-hor-store (unnecessary?)
191    passes.add(llvm::createSLPVectorizerPass());
192    passes.add(llvm::createDeadCodeEliminationPass());
193    passes.add(llvm::createInstructionCombiningPass());
194  }
195
196  // Add our pass to check for illegal function calls.
197  // This has to come after LTO, since we don't want to examine functions that
198  // are never actually called.
199  passes.add(createRSScreenFunctionsPass());
200  passes.add(createRSIsThreadablePass());
201
202  // RSEmbedInfoPass needs to come after we have scanned for non-threadable
203  // functions.
204  // Script passed to RSCompiler must be a RSScript.
205  RSScript &script = static_cast<RSScript &>(pScript);
206  if (script.getEmbedInfo())
207    passes.add(createRSEmbedInfoPass());
208
209  // Add passes to the pass manager to emit machine code through MC layer.
210  if (mTarget->addPassesToEmitMC(passes, mc_context, pResult,
211                                 /* DisableVerify */false)) {
212    return kPrepareCodeGenPass;
213  }
214
215  // Execute the passes.
216  passes.run(pScript.getSource().getModule());
217
218  return kSuccess;
219}
220
221enum Compiler::ErrorCode Compiler::compile(Script &pScript,
222                                           llvm::raw_ostream &pResult,
223                                           llvm::raw_ostream *IRStream) {
224  llvm::Module &module = pScript.getSource().getModule();
225  enum ErrorCode err;
226
227  if (mTarget == nullptr) {
228    return kErrNoTargetMachine;
229  }
230
231  const std::string &triple = module.getTargetTriple();
232  const llvm::DataLayout *dl = getTargetMachine().getSubtargetImpl()->getDataLayout();
233  unsigned int pointerSize = dl->getPointerSizeInBits();
234  if (triple == "armv7-none-linux-gnueabi") {
235    if (pointerSize != 32) {
236      return kErrInvalidSource;
237    }
238  } else if (triple == "aarch64-none-linux-gnueabi") {
239    if (pointerSize != 64) {
240      return kErrInvalidSource;
241    }
242  } else {
243    return kErrInvalidSource;
244  }
245
246  // Materialize the bitcode module.
247  if (module.getMaterializer() != nullptr) {
248    // A module with non-null materializer means that it is a lazy-load module.
249    // Materialize it now via invoking MaterializeAllPermanently(). This
250    // function returns false when the materialization is successful.
251    std::error_code ec = module.materializeAllPermanently();
252    if (ec) {
253      ALOGE("Failed to materialize the module `%s'! (%s)",
254            module.getModuleIdentifier().c_str(), ec.message().c_str());
255      return kErrMaterialization;
256    }
257  }
258
259  if ((err = runPasses(pScript, pResult)) != kSuccess) {
260    return err;
261  }
262
263  if (IRStream) {
264    *IRStream << module;
265  }
266
267  return kSuccess;
268}
269
270enum Compiler::ErrorCode Compiler::compile(Script &pScript,
271                                           OutputFile &pResult,
272                                           llvm::raw_ostream *IRStream) {
273  // Check the state of the specified output file.
274  if (pResult.hasError()) {
275    return kErrInvalidOutputFileState;
276  }
277
278  // Open the output file decorated in llvm::raw_ostream.
279  llvm::raw_ostream *out = pResult.dup();
280  if (out == nullptr) {
281    return kErrPrepareOutput;
282  }
283
284  // Delegate the request.
285  enum Compiler::ErrorCode err = compile(pScript, *out, IRStream);
286
287  // Close the output before return.
288  delete out;
289
290  return err;
291}
292
293bool Compiler::addInternalizeSymbolsPass(Script &pScript, llvm::PassManager &pPM) {
294  // Add a pass to internalize the symbols that don't need to have global
295  // visibility.
296  RSScript &script = static_cast<RSScript &>(pScript);
297  llvm::Module &module = script.getSource().getModule();
298  bcinfo::MetadataExtractor me(&module);
299  if (!me.extract()) {
300    bccAssert(false && "Could not extract metadata for module!");
301    return false;
302  }
303
304  // The vector contains the symbols that should not be internalized.
305  std::vector<const char *> export_symbols;
306
307  const char *sf[] = {
308    "root",      // Graphics drawing function or compute kernel.
309    "init",      // Initialization routine called implicitly on startup.
310    ".rs.dtor",  // Static global destructor for a script instance.
311    ".rs.info",  // Variable containing string of RS metadata info.
312    nullptr         // Must be nullptr-terminated.
313  };
314  const char **special_functions = sf;
315  // Special RS functions should always be global symbols.
316  while (*special_functions != nullptr) {
317    export_symbols.push_back(*special_functions);
318    special_functions++;
319  }
320
321  // Visibility of symbols appeared in rs_export_var and rs_export_func should
322  // also be preserved.
323  size_t exportVarCount = me.getExportVarCount();
324  size_t exportFuncCount = me.getExportFuncCount();
325  size_t exportForEachCount = me.getExportForEachSignatureCount();
326  const char **exportVarNameList = me.getExportVarNameList();
327  const char **exportFuncNameList = me.getExportFuncNameList();
328  const char **exportForEachNameList = me.getExportForEachNameList();
329  size_t i;
330
331  for (i = 0; i < exportVarCount; ++i) {
332    export_symbols.push_back(exportVarNameList[i]);
333  }
334
335  for (i = 0; i < exportFuncCount; ++i) {
336    export_symbols.push_back(exportFuncNameList[i]);
337  }
338
339  // Expanded foreach functions should not be internalized, too.
340  // expanded_foreach_funcs keeps the .expand version of the kernel names
341  // around until createInternalizePass() is finished making its own
342  // copy of the visible symbols.
343  std::vector<std::string> expanded_foreach_funcs;
344  for (i = 0; i < exportForEachCount; ++i) {
345    expanded_foreach_funcs.push_back(
346        std::string(exportForEachNameList[i]) + ".expand");
347  }
348
349  for (i = 0; i < exportForEachCount; i++) {
350      export_symbols.push_back(expanded_foreach_funcs[i].c_str());
351  }
352
353  pPM.add(llvm::createInternalizePass(export_symbols));
354
355  return true;
356}
357
358bool Compiler::addInvokeHelperPass(llvm::PassManager &pPM) {
359  llvm::Triple arch(getTargetMachine().getTargetTriple());
360  if (arch.isArch64Bit()) {
361    pPM.add(createRSInvokeHelperPass());
362  }
363  return true;
364}
365
366bool Compiler::addExpandForEachPass(Script &pScript, llvm::PassManager &pPM) {
367  // Expand ForEach on CPU path to reduce launch overhead.
368  bool pEnableStepOpt = true;
369  pPM.add(createRSForEachExpandPass(pEnableStepOpt));
370
371  return true;
372}
373
374bool Compiler::addCustomPasses(Script &pScript, llvm::PassManager &pPM) {
375  if (!addInvokeHelperPass(pPM))
376    return false;
377
378  if (!addExpandForEachPass(pScript, pPM))
379    return false;
380
381  if (!addInternalizeSymbolsPass(pScript, pPM))
382    return false;
383
384  return true;
385}
386