SimplifyLibCalls.cpp | Explore in Territory

//===------ SimplifyLibCalls.cpp - Library calls simplifier ---------------===//
//
// 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 the library calls simplifier. It does not implement
// any pass, but can't be used by other passes to do simplifications.
//
//===----------------------------------------------------------------------===//

#include "llvm/Transforms/Utils/SimplifyLibCalls.h"
#include "llvm/ADT/APSInt.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/Loads.h"
#include "llvm/Analysis/OptimizationRemarkEmitter.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/AttributeMask.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/KnownBits.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/TargetParser/Triple.h"
#include "llvm/Transforms/Utils/BuildLibCalls.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Transforms/Utils/SizeOpts.h"

#include <cmath>

usingnamespacellvm;
usingnamespacePatternMatch;

static cl::opt<bool>
    EnableUnsafeFPShrink("enable-double-float-shrink", cl::Hidden,
                         cl::init(false),
                         cl::desc("Enable unsafe double to float "
                                  "shrinking for math lib calls"));

// Enable conversion of operator new calls with a MemProf hot or cold hint
// to an operator new call that takes a hot/cold hint. Off by default since
// not all allocators currently support this extension.
static cl::opt<bool>
    OptimizeHotColdNew("optimize-hot-cold-new", cl::Hidden, cl::init(false),
                       cl::desc("Enable hot/cold operator new library calls"));
static cl::opt<bool> OptimizeExistingHotColdNew(
    "optimize-existing-hot-cold-new", cl::Hidden, cl::init(false),
    cl::desc(
        "Enable optimization of existing hot/cold operator new library calls"));

namespace {

// Specialized parser to ensure the hint is an 8 bit value (we can't specify
// uint8_t to opt<> as that is interpreted to mean that we are passing a char
// option with a specific set of values.
struct HotColdHintParser : public cl::parser<unsigned> { … };

} // end anonymous namespace

// Hot/cold operator new takes an 8 bit hotness hint, where 0 is the coldest
// and 255 is the hottest. Default to 1 value away from the coldest and hottest
// hints, so that the compiler hinted allocations are slightly less strong than
// manually inserted hints at the two extremes.
static cl::opt<unsigned, false, HotColdHintParser> ColdNewHintValue(
    "cold-new-hint-value", cl::Hidden, cl::init(1),
    cl::desc("Value to pass to hot/cold operator new for cold allocation"));
static cl::opt<unsigned, false, HotColdHintParser>
    NotColdNewHintValue("notcold-new-hint-value", cl::Hidden, cl::init(128),
                        cl::desc("Value to pass to hot/cold operator new for "
                                 "notcold (warm) allocation"));
static cl::opt<unsigned, false, HotColdHintParser> HotNewHintValue(
    "hot-new-hint-value", cl::Hidden, cl::init(254),
    cl::desc("Value to pass to hot/cold operator new for hot allocation"));

//===----------------------------------------------------------------------===//
// Helper Functions
//===----------------------------------------------------------------------===//

static bool ignoreCallingConv(LibFunc Func) { … }

/// Return true if it is only used in equality comparisons with With.
static bool isOnlyUsedInEqualityComparison(Value *V, Value *With) { … }

static bool callHasFloatingPointArgument(const CallInst *CI) { … }

static bool callHasFP128Argument(const CallInst *CI) { … }

// Convert the entire string Str representing an integer in Base, up to
// the terminating nul if present, to a constant according to the rules
// of strtoul[l] or, when AsSigned is set, of strtol[l].  On success
// return the result, otherwise null.
// The function assumes the string is encoded in ASCII and carefully
// avoids converting sequences (including "") that the corresponding
// library call might fail and set errno for.
static Value *convertStrToInt(CallInst *CI, StringRef &Str, Value *EndPtr,
                              uint64_t Base, bool AsSigned, IRBuilderBase &B) { … }

static bool isOnlyUsedInComparisonWithZero(Value *V) { … }

static bool canTransformToMemCmp(CallInst *CI, Value *Str, uint64_t Len,
                                 const DataLayout &DL) { … }

static void annotateDereferenceableBytes(CallInst *CI,
                                         ArrayRef<unsigned> ArgNos,
                                         uint64_t DereferenceableBytes) { … }

static void annotateNonNullNoUndefBasedOnAccess(CallInst *CI,
                                         ArrayRef<unsigned> ArgNos) { … }

static void annotateNonNullAndDereferenceable(CallInst *CI, ArrayRef<unsigned> ArgNos,
                               Value *Size, const DataLayout &DL) { … }

// Copy CallInst "flags" like musttail, notail, and tail. Return New param for
// easier chaining. Calls to emit* and B.createCall should probably be wrapped
// in this function when New is created to replace Old. Callers should take
// care to check Old.isMustTailCall() if they aren't replacing Old directly
// with New.
static Value *copyFlags(const CallInst &Old, Value *New) { … }

static Value *mergeAttributesAndFlags(CallInst *NewCI, const CallInst &Old) { … }

// Helper to avoid truncating the length if size_t is 32-bits.
static StringRef substr(StringRef Str, uint64_t Len) { … }

//===----------------------------------------------------------------------===//
// String and Memory Library Call Optimizations
//===----------------------------------------------------------------------===//

Value *LibCallSimplifier::optimizeStrCat(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::emitStrLenMemCpy(Value *Src, Value *Dst, uint64_t Len,
                                           IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeStrNCat(CallInst *CI, IRBuilderBase &B) { … }

// Helper to transform memchr(S, C, N) == S to N && *S == C and, when
// NBytes is null, strchr(S, C) to *S == C.  A precondition of the function
// is that either S is dereferenceable or the value of N is nonzero.
static Value* memChrToCharCompare(CallInst *CI, Value *NBytes,
                                  IRBuilderBase &B, const DataLayout &DL)
{ … }

Value *LibCallSimplifier::optimizeStrChr(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeStrRChr(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeStrCmp(CallInst *CI, IRBuilderBase &B) { … }

// Optimize a memcmp or, when StrNCmp is true, strncmp call CI with constant
// arrays LHS and RHS and nonconstant Size.
static Value *optimizeMemCmpVarSize(CallInst *CI, Value *LHS, Value *RHS,
                                    Value *Size, bool StrNCmp,
                                    IRBuilderBase &B, const DataLayout &DL);

Value *LibCallSimplifier::optimizeStrNCmp(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeStrNDup(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeStrCpy(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeStpCpy(CallInst *CI, IRBuilderBase &B) { … }

// Optimize a call to size_t strlcpy(char*, const char*, size_t).

Value *LibCallSimplifier::optimizeStrLCpy(CallInst *CI, IRBuilderBase &B) { … }

// Optimize a call CI to either stpncpy when RetEnd is true, or to strncpy
// otherwise.
Value *LibCallSimplifier::optimizeStringNCpy(CallInst *CI, bool RetEnd,
                                             IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeStringLength(CallInst *CI, IRBuilderBase &B,
                                               unsigned CharSize,
                                               Value *Bound) { … }

Value *LibCallSimplifier::optimizeStrLen(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeStrNLen(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeWcslen(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeStrPBrk(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeStrTo(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeStrSpn(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeStrCSpn(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeStrStr(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeMemRChr(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeMemChr(CallInst *CI, IRBuilderBase &B) { … }

// Optimize a memcmp or, when StrNCmp is true, strncmp call CI with constant
// arrays LHS and RHS and nonconstant Size.
static Value *optimizeMemCmpVarSize(CallInst *CI, Value *LHS, Value *RHS,
                                    Value *Size, bool StrNCmp,
                                    IRBuilderBase &B, const DataLayout &DL) { … }

// Optimize a memcmp call CI with constant size Len.
static Value *optimizeMemCmpConstantSize(CallInst *CI, Value *LHS, Value *RHS,
                                         uint64_t Len, IRBuilderBase &B,
                                         const DataLayout &DL) { … }

// Most simplifications for memcmp also apply to bcmp.
Value *LibCallSimplifier::optimizeMemCmpBCmpCommon(CallInst *CI,
                                                   IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeMemCmp(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeBCmp(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeMemCpy(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeMemCCpy(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeMemPCpy(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeMemMove(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeMemSet(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeRealloc(CallInst *CI, IRBuilderBase &B) { … }

// When enabled, replace operator new() calls marked with a hot or cold memprof
// attribute with an operator new() call that takes a __hot_cold_t parameter.
// Currently this is supported by the open source version of tcmalloc, see:
// https://github.com/google/tcmalloc/blob/master/tcmalloc/new_extension.h
Value *LibCallSimplifier::optimizeNew(CallInst *CI, IRBuilderBase &B,
                                      LibFunc &Func) { … }

//===----------------------------------------------------------------------===//
// Math Library Optimizations
//===----------------------------------------------------------------------===//

// Replace a libcall \p CI with a call to intrinsic \p IID
static Value *replaceUnaryCall(CallInst *CI, IRBuilderBase &B,
                               Intrinsic::ID IID) { … }

/// Return a variant of Val with float type.
/// Currently this works in two cases: If Val is an FPExtension of a float
/// value to something bigger, simply return the operand.
/// If Val is a ConstantFP but can be converted to a float ConstantFP without
/// loss of precision do so.
static Value *valueHasFloatPrecision(Value *Val) { … }

/// Shrink double -> float functions.
static Value *optimizeDoubleFP(CallInst *CI, IRBuilderBase &B,
                               bool isBinary, const TargetLibraryInfo *TLI,
                               bool isPrecise = false) { … }

/// Shrink double -> float for unary functions.
static Value *optimizeUnaryDoubleFP(CallInst *CI, IRBuilderBase &B,
                                    const TargetLibraryInfo *TLI,
                                    bool isPrecise = false) { … }

/// Shrink double -> float for binary functions.
static Value *optimizeBinaryDoubleFP(CallInst *CI, IRBuilderBase &B,
                                     const TargetLibraryInfo *TLI,
                                     bool isPrecise = false) { … }

// cabs(z) -> sqrt((creal(z)*creal(z)) + (cimag(z)*cimag(z)))
Value *LibCallSimplifier::optimizeCAbs(CallInst *CI, IRBuilderBase &B) { … }

// Return a properly extended integer (DstWidth bits wide) if the operation is
// an itofp.
static Value *getIntToFPVal(Value *I2F, IRBuilderBase &B, unsigned DstWidth) { … }

/// Use exp{,2}(x * y) for pow(exp{,2}(x), y);
/// ldexp(1.0, x) for pow(2.0, itofp(x)); exp2(n * x) for pow(2.0 ** n, x);
/// exp10(x) for pow(10.0, x); exp2(log2(n) * x) for pow(n, x).
Value *LibCallSimplifier::replacePowWithExp(CallInst *Pow, IRBuilderBase &B) { … }

static Value *getSqrtCall(Value *V, AttributeList Attrs, bool NoErrno,
                          Module *M, IRBuilderBase &B,
                          const TargetLibraryInfo *TLI) { … }

/// Use square root in place of pow(x, +/-0.5).
Value *LibCallSimplifier::replacePowWithSqrt(CallInst *Pow, IRBuilderBase &B) { … }

static Value *createPowWithIntegerExponent(Value *Base, Value *Expo, Module *M,
                                           IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizePow(CallInst *Pow, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeExp2(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeFMinFMax(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeLog(CallInst *Log, IRBuilderBase &B) { … }

// sqrt(exp(X)) -> exp(X * 0.5)
Value *LibCallSimplifier::mergeSqrtToExp(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeSqrt(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeFMod(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeTrigInversionPairs(CallInst *CI,
                                                     IRBuilderBase &B) { … }

static bool isTrigLibCall(CallInst *CI) { … }

static bool insertSinCosCall(IRBuilderBase &B, Function *OrigCallee, Value *Arg,
                             bool UseFloat, Value *&Sin, Value *&Cos,
                             Value *&SinCos, const TargetLibraryInfo *TLI) { … }

static Value *optimizeSymmetricCall(CallInst *CI, bool IsEven,
                                    IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeSymmetric(CallInst *CI, LibFunc Func,
                                            IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeSinCosPi(CallInst *CI, bool IsSin, IRBuilderBase &B) { … }

void LibCallSimplifier::classifyArgUse(
    Value *Val, Function *F, bool IsFloat,
    SmallVectorImpl<CallInst *> &SinCalls,
    SmallVectorImpl<CallInst *> &CosCalls,
    SmallVectorImpl<CallInst *> &SinCosCalls) { … }

/// Constant folds remquo
Value *LibCallSimplifier::optimizeRemquo(CallInst *CI, IRBuilderBase &B) { … }

//===----------------------------------------------------------------------===//
// Integer Library Call Optimizations
//===----------------------------------------------------------------------===//

Value *LibCallSimplifier::optimizeFFS(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeFls(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeAbs(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeIsDigit(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeIsAscii(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeToAscii(CallInst *CI, IRBuilderBase &B) { … }

// Fold calls to atoi, atol, and atoll.
Value *LibCallSimplifier::optimizeAtoi(CallInst *CI, IRBuilderBase &B) { … }

// Fold calls to strtol, strtoll, strtoul, and strtoull.
Value *LibCallSimplifier::optimizeStrToInt(CallInst *CI, IRBuilderBase &B,
                                           bool AsSigned) { … }

//===----------------------------------------------------------------------===//
// Formatting and IO Library Call Optimizations
//===----------------------------------------------------------------------===//

static bool isReportingError(Function *Callee, CallInst *CI, int StreamArg);

Value *LibCallSimplifier::optimizeErrorReporting(CallInst *CI, IRBuilderBase &B,
                                                 int StreamArg) { … }

static bool isReportingError(Function *Callee, CallInst *CI, int StreamArg) { … }

Value *LibCallSimplifier::optimizePrintFString(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizePrintF(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeSPrintFString(CallInst *CI,
                                                IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeSPrintF(CallInst *CI, IRBuilderBase &B) { … }

// Transform an snprintf call CI with the bound N to format the string Str
// either to a call to memcpy, or to single character a store, or to nothing,
// and fold the result to a constant.  A nonnull StrArg refers to the string
// argument being formatted.  Otherwise the call is one with N < 2 and
// the "%c" directive to format a single character.
Value *LibCallSimplifier::emitSnPrintfMemCpy(CallInst *CI, Value *StrArg,
                                             StringRef Str, uint64_t N,
                                             IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeSnPrintFString(CallInst *CI,
                                                 IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeSnPrintF(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeFPrintFString(CallInst *CI,
                                                IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeFPrintF(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeFWrite(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeFPuts(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizePuts(CallInst *CI, IRBuilderBase &B) { … }

Value *LibCallSimplifier::optimizeExit(CallInst *CI) { … }

Value *LibCallSimplifier::optimizeBCopy(CallInst *CI, IRBuilderBase &B) { … }

bool LibCallSimplifier::hasFloatVersion(const Module *M, StringRef FuncName) { … }

Value *LibCallSimplifier::optimizeStringMemoryLibCall(CallInst *CI,
                                                      IRBuilderBase &Builder) { … }

/// Constant folding nan/nanf/nanl.
static Value *optimizeNaN(CallInst *CI) { … }

Value *LibCallSimplifier::optimizeFloatingPointLibCall(CallInst *CI,
                                                       LibFunc Func,
                                                       IRBuilderBase &Builder) { … }

Value *LibCallSimplifier::optimizeCall(CallInst *CI, IRBuilderBase &Builder) { … }

LibCallSimplifier::LibCallSimplifier(
    const DataLayout &DL, const TargetLibraryInfo *TLI, DominatorTree *DT,
    DomConditionCache *DC, AssumptionCache *AC, OptimizationRemarkEmitter &ORE,
    BlockFrequencyInfo *BFI, ProfileSummaryInfo *PSI,
    function_ref<void(Instruction *, Value *)> Replacer,
    function_ref<void(Instruction *)> Eraser)
    : … { … }

void LibCallSimplifier::replaceAllUsesWith(Instruction *I, Value *With) { … }

void LibCallSimplifier::eraseFromParent(Instruction *I) { … }

// TODO:
//   Additional cases that we need to add to this file:
//
// cbrt:
//   * cbrt(expN(X))  -> expN(x/3)
//   * cbrt(sqrt(x))  -> pow(x,1/6)
//   * cbrt(cbrt(x))  -> pow(x,1/9)
//
// exp, expf, expl:
//   * exp(log(x))  -> x
//
// log, logf, logl:
//   * log(exp(x))   -> x
//   * log(exp(y))   -> y*log(e)
//   * log(exp10(y)) -> y*log(10)
//   * log(sqrt(x))  -> 0.5*log(x)
//
// pow, powf, powl:
//   * pow(sqrt(x),y) -> pow(x,y*0.5)
//   * pow(pow(x,y),z)-> pow(x,y*z)
//
// signbit:
//   * signbit(cnst) -> cnst'
//   * signbit(nncst) -> 0 (if pstv is a non-negative constant)
//
// sqrt, sqrtf, sqrtl:
//   * sqrt(expN(x))  -> expN(x*0.5)
//   * sqrt(Nroot(x)) -> pow(x,1/(2*N))
//   * sqrt(pow(x,y)) -> pow(|x|,y*0.5)
//

//===----------------------------------------------------------------------===//
// Fortified Library Call Optimizations
//===----------------------------------------------------------------------===//

bool FortifiedLibCallSimplifier::isFortifiedCallFoldable(
    CallInst *CI, unsigned ObjSizeOp, std::optional<unsigned> SizeOp,
    std::optional<unsigned> StrOp, std::optional<unsigned> FlagOp) { … }

Value *FortifiedLibCallSimplifier::optimizeMemCpyChk(CallInst *CI,
                                                     IRBuilderBase &B) { … }

Value *FortifiedLibCallSimplifier::optimizeMemMoveChk(CallInst *CI,
                                                      IRBuilderBase &B) { … }

Value *FortifiedLibCallSimplifier::optimizeMemSetChk(CallInst *CI,
                                                     IRBuilderBase &B) { … }

Value *FortifiedLibCallSimplifier::optimizeMemPCpyChk(CallInst *CI,
                                                      IRBuilderBase &B) { … }

Value *FortifiedLibCallSimplifier::optimizeStrpCpyChk(CallInst *CI,
                                                      IRBuilderBase &B,
                                                      LibFunc Func) { … }

Value *FortifiedLibCallSimplifier::optimizeStrLenChk(CallInst *CI,
                                                     IRBuilderBase &B) { … }

Value *FortifiedLibCallSimplifier::optimizeStrpNCpyChk(CallInst *CI,
                                                       IRBuilderBase &B,
                                                       LibFunc Func) { … }

Value *FortifiedLibCallSimplifier::optimizeMemCCpyChk(CallInst *CI,
                                                      IRBuilderBase &B) { … }

Value *FortifiedLibCallSimplifier::optimizeSNPrintfChk(CallInst *CI,
                                                       IRBuilderBase &B) { … }

Value *FortifiedLibCallSimplifier::optimizeSPrintfChk(CallInst *CI,
                                                      IRBuilderBase &B) { … }

Value *FortifiedLibCallSimplifier::optimizeStrCatChk(CallInst *CI,
                                                     IRBuilderBase &B) { … }

Value *FortifiedLibCallSimplifier::optimizeStrLCat(CallInst *CI,
                                                   IRBuilderBase &B) { … }

Value *FortifiedLibCallSimplifier::optimizeStrNCatChk(CallInst *CI,
                                                      IRBuilderBase &B) { … }

Value *FortifiedLibCallSimplifier::optimizeStrLCpyChk(CallInst *CI,
                                                      IRBuilderBase &B) { … }

Value *FortifiedLibCallSimplifier::optimizeVSNPrintfChk(CallInst *CI,
                                                        IRBuilderBase &B) { … }

Value *FortifiedLibCallSimplifier::optimizeVSPrintfChk(CallInst *CI,
                                                       IRBuilderBase &B) { … }

Value *FortifiedLibCallSimplifier::optimizeCall(CallInst *CI,
                                                IRBuilderBase &Builder) { … }

FortifiedLibCallSimplifier::FortifiedLibCallSimplifier(
    const TargetLibraryInfo *TLI, bool OnlyLowerUnknownSize)
    : … { … }
llvm/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
