Subversion Repositories QNX 8.QNX8 LLVM/Clang compiler suite

Rev

Blame | Last modification | View Log | Download | RSS feed

  1. //===- Transforms/Instrumentation.h - Instrumentation passes ----*- C++ -*-===//
  2. //
  3. // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  4. // See https://llvm.org/LICENSE.txt for license information.
  5. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  6. //
  7. //===----------------------------------------------------------------------===//
  8. //
  9. // This file defines constructor functions for instrumentation passes.
  10. //
  11. //===----------------------------------------------------------------------===//
  12.  
  13. #ifndef LLVM_TRANSFORMS_INSTRUMENTATION_H
  14. #define LLVM_TRANSFORMS_INSTRUMENTATION_H
  15.  
  16. #include "llvm/ADT/StringRef.h"
  17. #include "llvm/IR/BasicBlock.h"
  18. #include "llvm/IR/DebugInfoMetadata.h"
  19. #include "llvm/IR/Function.h"
  20. #include "llvm/IR/IRBuilder.h"
  21. #include "llvm/IR/Instruction.h"
  22. #include <cassert>
  23. #include <cstdint>
  24. #include <limits>
  25. #include <string>
  26. #include <vector>
  27.  
  28. namespace llvm {
  29.  
  30. class Triple;
  31. class OptimizationRemarkEmitter;
  32. class Comdat;
  33. class CallBase;
  34.  
  35. /// Instrumentation passes often insert conditional checks into entry blocks.
  36. /// Call this function before splitting the entry block to move instructions
  37. /// that must remain in the entry block up before the split point. Static
  38. /// allocas and llvm.localescape calls, for example, must remain in the entry
  39. /// block.
  40. BasicBlock::iterator PrepareToSplitEntryBlock(BasicBlock &BB,
  41.                                               BasicBlock::iterator IP);
  42.  
  43. // Create a constant for Str so that we can pass it to the run-time lib.
  44. GlobalVariable *createPrivateGlobalForString(Module &M, StringRef Str,
  45.                                              bool AllowMerging,
  46.                                              const char *NamePrefix = "");
  47.  
  48. // Returns F.getComdat() if it exists.
  49. // Otherwise creates a new comdat, sets F's comdat, and returns it.
  50. // Returns nullptr on failure.
  51. Comdat *getOrCreateFunctionComdat(Function &F, Triple &T);
  52.  
  53. // Insert GCOV profiling instrumentation
  54. struct GCOVOptions {
  55.   static GCOVOptions getDefault();
  56.  
  57.   // Specify whether to emit .gcno files.
  58.   bool EmitNotes;
  59.  
  60.   // Specify whether to modify the program to emit .gcda files when run.
  61.   bool EmitData;
  62.  
  63.   // A four-byte version string. The meaning of a version string is described in
  64.   // gcc's gcov-io.h
  65.   char Version[4];
  66.  
  67.   // Add the 'noredzone' attribute to added runtime library calls.
  68.   bool NoRedZone;
  69.  
  70.   // Use atomic profile counter increments.
  71.   bool Atomic = false;
  72.  
  73.   // Regexes separated by a semi-colon to filter the files to instrument.
  74.   std::string Filter;
  75.  
  76.   // Regexes separated by a semi-colon to filter the files to not instrument.
  77.   std::string Exclude;
  78. };
  79.  
  80. // The pgo-specific indirect call promotion function declared below is used by
  81. // the pgo-driven indirect call promotion and sample profile passes. It's a
  82. // wrapper around llvm::promoteCall, et al. that additionally computes !prof
  83. // metadata. We place it in a pgo namespace so it's not confused with the
  84. // generic utilities.
  85. namespace pgo {
  86.  
  87. // Helper function that transforms CB (either an indirect-call instruction, or
  88. // an invoke instruction , to a conditional call to F. This is like:
  89. //     if (Inst.CalledValue == F)
  90. //        F(...);
  91. //     else
  92. //        Inst(...);
  93. //     end
  94. // TotalCount is the profile count value that the instruction executes.
  95. // Count is the profile count value that F is the target function.
  96. // These two values are used to update the branch weight.
  97. // If \p AttachProfToDirectCall is true, a prof metadata is attached to the
  98. // new direct call to contain \p Count.
  99. // Returns the promoted direct call instruction.
  100. CallBase &promoteIndirectCall(CallBase &CB, Function *F, uint64_t Count,
  101.                               uint64_t TotalCount, bool AttachProfToDirectCall,
  102.                               OptimizationRemarkEmitter *ORE);
  103. } // namespace pgo
  104.  
  105. /// Options for the frontend instrumentation based profiling pass.
  106. struct InstrProfOptions {
  107.   // Add the 'noredzone' attribute to added runtime library calls.
  108.   bool NoRedZone = false;
  109.  
  110.   // Do counter register promotion
  111.   bool DoCounterPromotion = false;
  112.  
  113.   // Use atomic profile counter increments.
  114.   bool Atomic = false;
  115.  
  116.   // Use BFI to guide register promotion
  117.   bool UseBFIInPromotion = false;
  118.  
  119.   // Name of the profile file to use as output
  120.   std::string InstrProfileOutput;
  121.  
  122.   InstrProfOptions() = default;
  123. };
  124.  
  125. // Options for sanitizer coverage instrumentation.
  126. struct SanitizerCoverageOptions {
  127.   enum Type {
  128.     SCK_None = 0,
  129.     SCK_Function,
  130.     SCK_BB,
  131.     SCK_Edge
  132.   } CoverageType = SCK_None;
  133.   bool IndirectCalls = false;
  134.   bool TraceBB = false;
  135.   bool TraceCmp = false;
  136.   bool TraceDiv = false;
  137.   bool TraceGep = false;
  138.   bool Use8bitCounters = false;
  139.   bool TracePC = false;
  140.   bool TracePCGuard = false;
  141.   bool Inline8bitCounters = false;
  142.   bool InlineBoolFlag = false;
  143.   bool PCTable = false;
  144.   bool NoPrune = false;
  145.   bool StackDepth = false;
  146.   bool TraceLoads = false;
  147.   bool TraceStores = false;
  148.   bool CollectControlFlow = false;
  149.  
  150.   SanitizerCoverageOptions() = default;
  151. };
  152.  
  153. /// Calculate what to divide by to scale counts.
  154. ///
  155. /// Given the maximum count, calculate a divisor that will scale all the
  156. /// weights to strictly less than std::numeric_limits<uint32_t>::max().
  157. static inline uint64_t calculateCountScale(uint64_t MaxCount) {
  158.   return MaxCount < std::numeric_limits<uint32_t>::max()
  159.              ? 1
  160.              : MaxCount / std::numeric_limits<uint32_t>::max() + 1;
  161. }
  162.  
  163. /// Scale an individual branch count.
  164. ///
  165. /// Scale a 64-bit weight down to 32-bits using \c Scale.
  166. ///
  167. static inline uint32_t scaleBranchCount(uint64_t Count, uint64_t Scale) {
  168.   uint64_t Scaled = Count / Scale;
  169.   assert(Scaled <= std::numeric_limits<uint32_t>::max() && "overflow 32-bits");
  170.   return Scaled;
  171. }
  172.  
  173. // Use to ensure the inserted instrumentation has a DebugLocation; if none is
  174. // attached to the source instruction, try to use a DILocation with offset 0
  175. // scoped to surrounding function (if it has a DebugLocation).
  176. //
  177. // Some non-call instructions may be missing debug info, but when inserting
  178. // instrumentation calls, some builds (e.g. LTO) want calls to have debug info
  179. // if the enclosing function does.
  180. struct InstrumentationIRBuilder : IRBuilder<> {
  181.   static void ensureDebugInfo(IRBuilder<> &IRB, const Function &F) {
  182.     if (IRB.getCurrentDebugLocation())
  183.       return;
  184.     if (DISubprogram *SP = F.getSubprogram())
  185.       IRB.SetCurrentDebugLocation(DILocation::get(SP->getContext(), 0, 0, SP));
  186.   }
  187.  
  188.   explicit InstrumentationIRBuilder(Instruction *IP) : IRBuilder<>(IP) {
  189.     ensureDebugInfo(*this, *IP->getFunction());
  190.   }
  191. };
  192. } // end namespace llvm
  193.  
  194. #endif // LLVM_TRANSFORMS_INSTRUMENTATION_H
  195.