llvm/llvm/lib/Transforms/IPO/SCCP.cpp

//===-- SCCP.cpp ----------------------------------------------------------===//
//
// 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 file implements Interprocedural Sparse Conditional Constant Propagation.
//
//===----------------------------------------------------------------------===//

#include "llvm/Transforms/IPO/SCCP.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/BlockFrequencyInfo.h"
#include "llvm/Analysis/PostDominators.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/Analysis/ValueLattice.h"
#include "llvm/Analysis/ValueLatticeUtils.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/AttributeMask.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DIBuilder.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ModRef.h"
#include "llvm/Transforms/IPO.h"
#include "llvm/Transforms/IPO/FunctionSpecialization.h"
#include "llvm/Transforms/Scalar/SCCP.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Transforms/Utils/SCCPSolver.h"

usingnamespacellvm;

#define DEBUG_TYPE …

STATISTIC(NumInstRemoved, "Number of instructions removed");
STATISTIC(NumArgsElimed ,"Number of arguments constant propagated");
STATISTIC(NumGlobalConst, "Number of globals found to be constant");
STATISTIC(NumDeadBlocks , "Number of basic blocks unreachable");
STATISTIC(NumInstReplaced,
          "Number of instructions replaced with (simpler) instruction");

static cl::opt<unsigned> FuncSpecMaxIters(
    "funcspec-max-iters", cl::init(10), cl::Hidden, cl::desc(
    "The maximum number of iterations function specialization is run"));

static void findReturnsToZap(Function &F,
                             SmallVector<ReturnInst *, 8> &ReturnsToZap,
                             SCCPSolver &Solver) { … }

static bool runIPSCCP(
    Module &M, const DataLayout &DL, FunctionAnalysisManager *FAM,
    std::function<const TargetLibraryInfo &(Function &)> GetTLI,
    std::function<TargetTransformInfo &(Function &)> GetTTI,
    std::function<AssumptionCache &(Function &)> GetAC,
    std::function<DominatorTree &(Function &)> GetDT,
    std::function<BlockFrequencyInfo &(Function &)> GetBFI,
    bool IsFuncSpecEnabled) { … }

PreservedAnalyses IPSCCPPass::run(Module &M, ModuleAnalysisManager &AM) { … }