InstCount.cpp

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//===-- InstCount.cpp - Collects the count of all instructions ------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This pass collects the count of all instructions and reports them
//
//===----------------------------------------------------------------------===//
 
#include "llvm/Analysis/InstCount.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/InstVisitor.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
 
#define DEBUG_TYPE "instcount"
 
STATISTIC(TotalInsts, "Number of instructions (of all types)");
STATISTIC(TotalBlocks, "Number of basic blocks");
STATISTIC(TotalFuncs, "Number of non-external functions");
STATISTIC(LargestFunctionSize,
          "Largest number of instructions in a single function");
STATISTIC(LargestFunctionBBCount,
          "Largest number of basic blocks in a single function");
 
#define HANDLE_INST(N, OPCODE, CLASS)                                          \
  STATISTIC(Num##OPCODE##Inst, "Number of " #OPCODE " insts");
 
#include "llvm/IR/Instruction.def"
 
namespace {
class InstCount : public InstVisitor<InstCount> {
  friend class InstVisitor<InstCount>;
 
  void visitFunction(Function &F) {
    ++TotalFuncs;
    LargestFunctionSize.updateMax(F.getInstructionCount());
    LargestFunctionBBCount.updateMax(F.size());
  }
  void visitBasicBlock(BasicBlock &BB) { ++TotalBlocks; }
 
#define HANDLE_INST(N, OPCODE, CLASS)                                          \
  void visit##OPCODE(CLASS &) {                                                \
    ++Num##OPCODE##Inst;                                                       \
    ++TotalInsts;                                                              \
  }
 
#include "llvm/IR/Instruction.def"
 
  void visitInstruction(Instruction &I) {
    errs() << "Instruction Count does not know about " << I;
    llvm_unreachable(nullptr);
  }
};
} // namespace
 
PreservedAnalyses InstCountPass::run(Function &F,
                                     FunctionAnalysisManager &FAM) {
  LLVM_DEBUG(dbgs() << "INSTCOUNT: running on function " << F.getName()
                    << "\n");
  InstCount().visit(F);
 
  return PreservedAnalyses::all();
}