Delete the IPO simplify-libcalls and completely reimplement it as

a FunctionPass.  This makes it simpler, fixes dozens of bugs, adds
a couple of minor features, and shrinks is considerably: from
2214 to 1437 lines.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50520 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 0 insertions, 2214 deletions

diff --git a/lib/Transforms/IPO/SimplifyLibCalls.cpp b/lib/Transforms/IPO/SimplifyLibCalls.cpp
deleted file mode 100644
index cac25c33df..0000000000
--- a/lib/Transforms/IPO/SimplifyLibCalls.cpp
+++ /dev/null
@@ -1,2214 +0,0 @@
-//===- SimplifyLibCalls.cpp - Optimize specific well-known library calls --===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements a module pass that applies a variety of small
-// optimizations for calls to specific well-known function calls (e.g. runtime
-// library functions). For example, a call to the function "exit(3)" that
-// occurs within the main() function can be transformed into a simple "return 3"
-// instruction. Any optimization that takes this form (replace call to library
-// function with simpler code that provides the same result) belongs in this
-// file.
-//
-//===----------------------------------------------------------------------===//
-
-#define DEBUG_TYPE "simplify-libcalls"
-#include "llvm/Constants.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/Instructions.h"
-#include "llvm/Intrinsics.h"
-#include "llvm/Module.h"
-#include "llvm/Pass.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/StringMap.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/Config/config.h"
-#include "llvm/Support/Compiler.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Target/TargetData.h"
-#include "llvm/Transforms/IPO.h"
-#include <cstring>
-using namespace llvm;
-
-/// This statistic keeps track of the total number of library calls that have
-/// been simplified regardless of which call it is.
-STATISTIC(SimplifiedLibCalls, "Number of library calls simplified");
-
-namespace {
-  // Forward declarations
-  class LibCallOptimization;
-  class SimplifyLibCalls;
-  
-/// This list is populated by the constructor for LibCallOptimization class.
-/// Therefore all subclasses are registered here at static initialization time
-/// and this list is what the SimplifyLibCalls pass uses to apply the individual
-/// optimizations to the call sites.
-/// @brief The list of optimizations deriving from LibCallOptimization
-static LibCallOptimization *OptList = 0;
-
-/// This class is the abstract base class for the set of optimizations that
-/// corresponds to one library call. The SimplifyLibCalls pass will call the
-/// ValidateCalledFunction method to ask the optimization if a given Function
-/// is the kind that the optimization can handle. If the subclass returns true,
-/// then SImplifyLibCalls will also call the OptimizeCall method to perform,
-/// or attempt to perform, the optimization(s) for the library call. Otherwise,
-/// OptimizeCall won't be called. Subclasses are responsible for providing the
-/// name of the library call (strlen, strcpy, etc.) to the LibCallOptimization
-/// constructor. This is used to efficiently select which call instructions to
-/// optimize. The criteria for a "lib call" is "anything with well known
-/// semantics", typically a library function that is defined by an international
-/// standard. Because the semantics are well known, the optimizations can
-/// generally short-circuit actually calling the function if there's a simpler
-/// way (e.g. strlen(X) can be reduced to a constant if X is a constant global).
-/// @brief Base class for library call optimizations
-class VISIBILITY_HIDDEN LibCallOptimization {
-  LibCallOptimization **Prev, *Next;
-  const char *FunctionName; ///< Name of the library call we optimize
-#ifndef NDEBUG
-  Statistic occurrences; ///< debug statistic (-debug-only=simplify-libcalls)
-#endif
-public:
-  /// The \p fname argument must be the name of the library function being
-  /// optimized by the subclass.
-  /// @brief Constructor that registers the optimization.
-  LibCallOptimization(const char *FName, const char *Description)
-    : FunctionName(FName) {
-      
-#ifndef NDEBUG
-    occurrences.construct("simplify-libcalls", Description);
-#endif
-    // Register this optimizer in the list of optimizations.
-    Next = OptList;
-    OptList = this;
-    Prev = &OptList;
-    if (Next) Next->Prev = &Next;
-  }
-  
-  /// getNext - All libcall optimizations are chained together into a list,
-  /// return the next one in the list.
-  LibCallOptimization *getNext() { return Next; }
-
-  /// @brief Deregister from the optlist
-  virtual ~LibCallOptimization() {
-    *Prev = Next;
-    if (Next) Next->Prev = Prev;
-  }
-
-  /// The implementation of this function in subclasses should determine if
-  /// \p F is suitable for the optimization. This method is called by
-  /// SimplifyLibCalls::runOnModule to short circuit visiting all the call
-  /// sites of such a function if that function is not suitable in the first
-  /// place.  If the called function is suitabe, this method should return true;
-  /// false, otherwise. This function should also perform any lazy
-  /// initialization that the LibCallOptimization needs to do, if its to return
-  /// true. This avoids doing initialization until the optimizer is actually
-  /// going to be called upon to do some optimization.
-  /// @brief Determine if the function is suitable for optimization
-  virtual bool ValidateCalledFunction(
-    const Function* F,    ///< The function that is the target of call sites
-    SimplifyLibCalls& SLC ///< The pass object invoking us
-  ) = 0;
-
-  /// The implementations of this function in subclasses is the heart of the
-  /// SimplifyLibCalls algorithm. Sublcasses of this class implement
-  /// OptimizeCall to determine if (a) the conditions are right for optimizing
-  /// the call and (b) to perform the optimization. If an action is taken
-  /// against ci, the subclass is responsible for returning true and ensuring
-  /// that ci is erased from its parent.
-  /// @brief Optimize a call, if possible.
-  virtual bool OptimizeCall(
-    CallInst* ci,          ///< The call instruction that should be optimized.
-    SimplifyLibCalls& SLC  ///< The pass object invoking us
-  ) = 0;
-
-  /// @brief Get the name of the library call being optimized
-  const char *getFunctionName() const { return FunctionName; }
-
-  bool ReplaceCallWith(CallInst *CI, Value *V) {
-    if (!CI->use_empty())
-      CI->replaceAllUsesWith(V);
-    CI->eraseFromParent();
-    return true;
-  }
-  
-  /// @brief Called by SimplifyLibCalls to update the occurrences statistic.
-  void succeeded() {
-#ifndef NDEBUG
-    DEBUG(++occurrences);
-#endif
-  }
-};
-
-/// This class is an LLVM Pass that applies each of the LibCallOptimization
-/// instances to all the call sites in a module, relatively efficiently. The
-/// purpose of this pass is to provide optimizations for calls to well-known
-/// functions with well-known semantics, such as those in the c library. The
-/// class provides the basic infrastructure for handling runOnModule.  Whenever
-/// this pass finds a function call, it asks the appropriate optimizer to
-/// validate the call (ValidateLibraryCall). If it is validated, then
-/// the OptimizeCall method is also called.
-/// @brief A ModulePass for optimizing well-known function calls.
-class VISIBILITY_HIDDEN SimplifyLibCalls : public ModulePass {
-public:
-  static char ID; // Pass identification, replacement for typeid
-  SimplifyLibCalls() : ModulePass((intptr_t)&ID) {}
-
-  /// We need some target data for accurate signature details that are
-  /// target dependent. So we require target data in our AnalysisUsage.
-  /// @brief Require TargetData from AnalysisUsage.
-  virtual void getAnalysisUsage(AnalysisUsage& Info) const {
-    // Ask that the TargetData analysis be performed before us so we can use
-    // the target data.
-    Info.addRequired<TargetData>();
-  }
-
-  /// For this pass, process all of the function calls in the module, calling
-  /// ValidateLibraryCall and OptimizeCall as appropriate.
-  /// @brief Run all the lib call optimizations on a Module.
-  virtual bool runOnModule(Module &M) {
-    reset(M);
-
-    bool result = false;
-    StringMap<LibCallOptimization*> OptznMap;
-    for (LibCallOptimization *Optzn = OptList; Optzn; Optzn = Optzn->getNext())
-      OptznMap[Optzn->getFunctionName()] = Optzn;
-
-    // The call optimizations can be recursive. That is, the optimization might
-    // generate a call to another function which can also be optimized. This way
-    // we make the LibCallOptimization instances very specific to the case they
-    // handle. It also means we need to keep running over the function calls in
-    // the module until we don't get any more optimizations possible.
-    bool found_optimization = false;
-    do {
-      found_optimization = false;
-      for (Module::iterator FI = M.begin(), FE = M.end(); FI != FE; ++FI) {
-        // All the "well-known" functions are external and have external linkage
-        // because they live in a runtime library somewhere and were (probably)
-        // not compiled by LLVM.  So, we only act on external functions that
-        // have external or dllimport linkage and non-empty uses.
-        if (!FI->isDeclaration() ||
-            !(FI->hasExternalLinkage() || FI->hasDLLImportLinkage()) ||
-            FI->use_empty())
-          continue;
-
-        // Get the optimization class that pertains to this function
-        StringMap<LibCallOptimization*>::iterator OMI =
-          OptznMap.find(FI->getName());
-        if (OMI == OptznMap.end()) continue;
-        
-        LibCallOptimization *CO = OMI->second;
-
-        // Make sure the called function is suitable for the optimization
-        if (!CO->ValidateCalledFunction(FI, *this))
-          continue;
-
-        // Loop over each of the uses of the function
-        for (Value::use_iterator UI = FI->use_begin(), UE = FI->use_end();
-             UI != UE ; ) {
-          // If the use of the function is a call instruction
-          if (CallInst* CI = dyn_cast<CallInst>(*UI++)) {
-            // Do the optimization on the LibCallOptimization.
-            if (CO->OptimizeCall(CI, *this)) {
-              ++SimplifiedLibCalls;
-              found_optimization = result = true;
-              CO->succeeded();
-            }
-          }
-        }
-      }
-    } while (found_optimization);
-    
-    return result;
-  }
-
-  /// @brief Return the *current* module we're working on.
-  Module* getModule() const { return M; }
-
-  /// @brief Return the *current* target data for the module we're working on.
-  TargetData* getTargetData() const { return TD; }
-
-  /// @brief Return the size_t type -- syntactic shortcut
-  const Type* getIntPtrType() const { return TD->getIntPtrType(); }
-
-  /// @brief Return a Function* for the putchar libcall
-  Constant *get_putchar() {
-    if (!putchar_func)
-      putchar_func = 
-        M->getOrInsertFunction("putchar", Type::Int32Ty, Type::Int32Ty, NULL);
-    return putchar_func;
-  }
-
-  /// @brief Return a Function* for the puts libcall
-  Constant *get_puts() {
-    if (!puts_func)
-      puts_func = M->getOrInsertFunction("puts", Type::Int32Ty,
-                                         PointerType::getUnqual(Type::Int8Ty),
-                                         NULL);
-    return puts_func;
-  }
-
-  /// @brief Return a Function* for the fputc libcall
-  Constant *get_fputc(const Type* FILEptr_type) {
-    if (!fputc_func)
-      fputc_func = M->getOrInsertFunction("fputc", Type::Int32Ty, Type::Int32Ty,
-                                          FILEptr_type, NULL);
-    return fputc_func;
-  }
-
-  /// @brief Return a Function* for the fputs libcall
-  Constant *get_fputs(const Type* FILEptr_type) {
-    if (!fputs_func)
-      fputs_func = M->getOrInsertFunction("fputs", Type::Int32Ty,
-                                          PointerType::getUnqual(Type::Int8Ty),
-                                          FILEptr_type, NULL);
-    return fputs_func;
-  }
-
-  /// @brief Return a Function* for the fwrite libcall
-  Constant *get_fwrite(const Type* FILEptr_type) {
-    if (!fwrite_func)
-      fwrite_func = M->getOrInsertFunction("fwrite", TD->getIntPtrType(),
-                                           PointerType::getUnqual(Type::Int8Ty),
-                                           TD->getIntPtrType(),
-                                           TD->getIntPtrType(),
-                                           FILEptr_type, NULL);
-    return fwrite_func;
-  }
-
-  /// @brief Return a Function* for the sqrt libcall
-  Constant *get_sqrt() {
-    if (!sqrt_func)
-      sqrt_func = M->getOrInsertFunction("sqrt", Type::DoubleTy, 
-                                         Type::DoubleTy, NULL);
-    return sqrt_func;
-  }
-
-  /// @brief Return a Function* for the strcpy libcall
-  Constant *get_strcpy() {
-    if (!strcpy_func)
-      strcpy_func = M->getOrInsertFunction("strcpy",
-                                           PointerType::getUnqual(Type::Int8Ty),
-                                           PointerType::getUnqual(Type::Int8Ty),
-                                           PointerType::getUnqual(Type::Int8Ty),
-                                           NULL);
-    return strcpy_func;
-  }
-
-  /// @brief Return a Function* for the strlen libcall
-  Constant *get_strlen() {
-    if (!strlen_func)
-      strlen_func = M->getOrInsertFunction("strlen", TD->getIntPtrType(),
-                                           PointerType::getUnqual(Type::Int8Ty),
-                                           NULL);
-    return strlen_func;
-  }
-
-  /// @brief Return a Function* for the memchr libcall
-  Constant *get_memchr() {
-    if (!memchr_func)
-      memchr_func = M->getOrInsertFunction("memchr",
-                                           PointerType::getUnqual(Type::Int8Ty),
-                                           PointerType::getUnqual(Type::Int8Ty),
-                                           Type::Int32Ty, TD->getIntPtrType(),
-                                           NULL);
-    return memchr_func;
-  }
-
-  /// @brief Return a Function* for the memcpy libcall
-  Constant *get_memcpy() {
-    if (!memcpy_func) {
-      Intrinsic::ID IID = (TD->getIntPtrType() == Type::Int32Ty) ?
-        Intrinsic::memcpy_i32 : Intrinsic::memcpy_i64;
-      memcpy_func = Intrinsic::getDeclaration(M, IID);
-    }
-    return memcpy_func;
-  }
-
-  Constant *getUnaryFloatFunction(const char *BaseName, const Type *T = 0) {
-    if (T == 0) T = Type::FloatTy;
-    
-    char NameBuffer[20];
-    const char *Name;
-    if (T == Type::DoubleTy)
-      Name = BaseName;              // floor
-    else {
-      Name = NameBuffer;
-      unsigned NameLen = strlen(BaseName);
-      assert(NameLen < sizeof(NameBuffer)-2 && "Buffer too small");
-      memcpy(NameBuffer, BaseName, NameLen);
-      if (T == Type::FloatTy)
-        NameBuffer[NameLen] = 'f';  // floorf
-      else
-        NameBuffer[NameLen] = 'l';  // floorl
-      NameBuffer[NameLen+1] = 0;
-    }
-    
-    return M->getOrInsertFunction(Name, T, T, NULL);
-  }
-  
-  Constant *get_floorf() { return getUnaryFloatFunction("floor"); }
-  Constant *get_ceilf()  { return getUnaryFloatFunction( "ceil"); }
-  Constant *get_roundf() { return getUnaryFloatFunction("round"); }
-  Constant *get_rintf()  { return getUnaryFloatFunction( "rint"); }
-  Constant *get_nearbyintf() { return getUnaryFloatFunction("nearbyint"); }
-
-  
-  
-private:
-  /// @brief Reset our cached data for a new Module
-  void reset(Module& mod) {
-    M = &mod;
-    TD = &getAnalysis<TargetData>();
-    putchar_func = 0;
-    puts_func = 0;
-    fputc_func = 0;
-    fputs_func = 0;
-    fwrite_func = 0;
-    memcpy_func = 0;
-    memchr_func = 0;
-    sqrt_func   = 0;
-    strcpy_func = 0;
-    strlen_func = 0;
-  }
-
-private:
-  /// Caches for function pointers.
-  Constant *putchar_func, *puts_func;
-  Constant *fputc_func, *fputs_func, *fwrite_func;
-  Constant *memcpy_func, *memchr_func;
-  Constant *sqrt_func;
-  Constant *strcpy_func, *strlen_func;
-  Module *M;             ///< Cached Module
-  TargetData *TD;        ///< Cached TargetData
-};
-
-char SimplifyLibCalls::ID = 0;
-// Register the pass
-RegisterPass<SimplifyLibCalls>
-X("simplify-libcalls", "Simplify well-known library calls");
-
-} // anonymous namespace
-
-// The only public symbol in this file which just instantiates the pass object
-ModulePass *llvm::createSimplifyLibCallsPass() {
-  return new SimplifyLibCalls();
-}
-
-// Forward declare utility functions.
-static bool GetConstantStringInfo(Value *V, std::string &Str);
-static Value *CastToCStr(Value *V, Instruction *IP);
-static uint64_t GetStringLength(Value *V);
-
-
-// Classes below here, in the anonymous namespace, are all subclasses of the
-// LibCallOptimization class, each implementing all optimizations possible for a
-// single well-known library call. Each has a static singleton instance that
-// auto registers it into the "optlist" global above.
-namespace {
-
-/// This LibCallOptimization will find instances of a call to "exit" that occurs
-/// within the "main" function and change it to a simple "ret" instruction with
-/// the same value passed to the exit function. When this is done, it splits the
-/// basic block at the exit(3) call and deletes the call instruction.
-/// @brief Replace calls to exit in main with a simple return
-struct VISIBILITY_HIDDEN ExitInMainOptimization : public LibCallOptimization {
-  ExitInMainOptimization() : LibCallOptimization("exit",
-      "Number of 'exit' calls simplified") {}
-
-  // Make sure the called function looks like exit (int argument, int return
-  // type, external linkage, not varargs).
-  virtual bool ValidateCalledFunction(const Function *F, SimplifyLibCalls &SLC){
-    return F->arg_size() >= 1 && F->arg_begin()->getType()->isInteger();
-  }
-
-  virtual bool OptimizeCall(CallInst* ci, SimplifyLibCalls& SLC) {
-    // To be careful, we check that the call to exit is coming from "main", that
-    // main has external linkage, and the return type of main and the argument
-    // to exit have the same type.
-    Function *from = ci->getParent()->getParent();
-    if (from->hasExternalLinkage())
-      if (from->getReturnType() == ci->getOperand(1)->getType()
-          && !isa<StructType>(from->getReturnType()))
-        if (from->getName() == "main") {
-          // Okay, time to actually do the optimization. First, get the basic
-          // block of the call instruction
-          BasicBlock* bb = ci->getParent();
-
-          // Create a return instruction that we'll replace the call with.
-          // Note that the argument of the return is the argument of the call
-          // instruction.
-          ReturnInst::Create(ci->getOperand(1), ci);
-
-          // Split the block at the call instruction which places it in a new
-          // basic block.
-          bb->splitBasicBlock(ci);
-
-          // The block split caused a branch instruction to be inserted into
-          // the end of the original block, right after the return instruction
-          // that we put there. That's not a valid block, so delete the branch
-          // instruction.
-          bb->getInstList().pop_back();
-
-          // Now we can finally get rid of the call instruction which now lives
-          // in the new basic block.
-          ci->eraseFromParent();
-
-          // Optimization succeeded, return true.
-          return true;
-        }
-    // We didn't pass the criteria for this optimization so return false
-    return false;
-  }
-} ExitInMainOptimizer;
-
-/// This LibCallOptimization will simplify a call to the strcat library
-/// function. The simplification is possible only if the string being
-/// concatenated is a constant array or a constant expression that results in
-/// a constant string. In this case we can replace it with strlen + llvm.memcpy
-/// of the constant string. Both of these calls are further reduced, if possible
-/// on subsequent passes.
-/// @brief Simplify the strcat library function.
-struct VISIBILITY_HIDDEN StrCatOptimization : public LibCallOptimization {
-public:
-  /// @brief Default constructor
-  StrCatOptimization() : LibCallOptimization("strcat",
-      "Number of 'strcat' calls simplified") {}
-
-public:
-
-  /// @brief Make sure that the "strcat" function has the right prototype
-  virtual bool ValidateCalledFunction(const Function *F, SimplifyLibCalls &SLC){
-    const FunctionType *FT = F->getFunctionType();
-    return FT->getNumParams() == 2 &&
-           FT->getReturnType() == PointerType::getUnqual(Type::Int8Ty) &&
-           FT->getParamType(0) == FT->getReturnType() &&
-           FT->getParamType(1) == FT->getReturnType();
-  }
-
-  /// @brief Optimize the strcat library function
-  virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
-    // Extract some information from the instruction
-    Value *Dst = CI->getOperand(1);
-    Value *Src = CI->getOperand(2);
-
-    // See if we can get the length of the input string.
-    uint64_t Len = GetStringLength(Src);
-    if (Len == 0) return false;
-    --Len;  // Unbias length.
-    
-    // Handle the simple, do-nothing case
-    if (Len == 0)
-      return ReplaceCallWith(CI, Dst);
-
-    // We need to find the end of the destination string.  That's where the
-    // memory is to be moved to. We just generate a call to strlen.
-    CallInst *DstLen = CallInst::Create(SLC.get_strlen(), Dst,
-                                        Dst->getName()+".len", CI);
-
-    // Now that we have the destination's length, we must index into the
-    // destination's pointer to get the actual memcpy destination (end of
-    // the string .. we're concatenating).
-    Dst = GetElementPtrInst::Create(Dst, DstLen, Dst->getName()+".indexed", CI);
-
-    // We have enough information to now generate the memcpy call to
-    // do the concatenation for us.
-    Value *Vals[] = {
-      Dst, Src,
-      ConstantInt::get(SLC.getIntPtrType(), Len+1), // copy nul byte.
-      ConstantInt::get(Type::Int32Ty, 1)  // alignment
-    };
-    CallInst::Create(SLC.get_memcpy(), Vals, Vals + 4, "", CI);
-
-    return ReplaceCallWith(CI, Dst);
-  }
-} StrCatOptimizer;
-
-/// This LibCallOptimization will simplify a call to the strchr library
-/// function.  It optimizes out cases where the arguments are both constant
-/// and the result can be determined statically.
-/// @brief Simplify the strcmp library function.
-struct VISIBILITY_HIDDEN StrChrOptimization : public LibCallOptimization {
-public:
-  StrChrOptimization() : LibCallOptimization("strchr",
-      "Number of 'strchr' calls simplified") {}
-
-  /// @brief Make sure that the "strchr" function has the right prototype
-  virtual bool ValidateCalledFunction(const Function *F, SimplifyLibCalls &SLC){
-    const FunctionType *FT = F->getFunctionType();
-    return FT->getNumParams() == 2 &&
-           FT->getReturnType() == PointerType::getUnqual(Type::Int8Ty) &&
-           FT->getParamType(0) == FT->getReturnType() &&
-           isa<IntegerType>(FT->getParamType(1));
-  }
-
-  /// @brief Perform the strchr optimizations
-  virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
-    Value *SrcStr = CI->getOperand(1);
-    // If the second operand is not constant, see if we can compute the length
-    // and turn this into memchr.
-    ConstantInt *CSI = dyn_cast<ConstantInt>(CI->getOperand(2));
-    if (CSI == 0) {
-      uint64_t Len = GetStringLength(SrcStr);
-      if (Len == 0) return false;
-      
-      Value *Args[3] = {
-        CI->getOperand(1),
-        CI->getOperand(2),
-        ConstantInt::get(SLC.getIntPtrType(), Len) // include nul.
-      };
-      return ReplaceCallWith(CI, CallInst::Create(SLC.get_memchr(),
-                                                  Args, Args + 3,
-                                                  CI->getName(), CI));
-    }
-    
-    // Otherwise, the character is a constant, see if the first argument is
-    // a string literal.  If so, we can constant fold.
-    std::string Str;
-    if (!GetConstantStringInfo(SrcStr, Str))
-      return false;
-
-    // strchr can find the nul character.
-    Str += '\0';
-    
-    // Get the character we're looking for
-    char CharValue = CSI->getSExtValue();
-
-    // Compute the offset
-    uint64_t i = 0;
-    while (1) {
-      if (i == Str.size())    // Didn't find the char.  strchr returns null.
-        return ReplaceCallWith(CI, Constant::getNullValue(CI->getType()));
-      // Did we find our match?
-      if (Str[i] == CharValue)
-        break;
-      ++i;
-    }
-
-    // strchr(s+n,c)  -> gep(s+n+i,c)
-    //    (if c is a constant integer and s is a constant string)
-    Value *Idx = ConstantInt::get(Type::Int64Ty, i);
-    Value *GEP = GetElementPtrInst::Create(CI->getOperand(1), Idx, 
-                                           CI->getOperand(1)->getName() +
-                                           ".strchr", CI);
-    return ReplaceCallWith(CI, GEP);
-  }
-} StrChrOptimizer;
-
-/// This LibCallOptimization will simplify a call to the strcmp library
-/// function.  It optimizes out cases where one or both arguments are constant
-/// and the result can be determined statically.
-/// @brief Simplify the strcmp library function.
-struct VISIBILITY_HIDDEN StrCmpOptimization : public LibCallOptimization {
-public:
-  StrCmpOptimization() : LibCallOptimization("strcmp",
-      "Number of 'strcmp' calls simplified") {}
-
-  /// @brief Make sure that the "strcmp" function has the right prototype
-  virtual bool ValidateCalledFunction(const Function *F, SimplifyLibCalls &SLC){
-    const FunctionType *FT = F->getFunctionType();
-    return FT->getReturnType() == Type::Int32Ty && FT->getNumParams() == 2 &&
-           FT->getParamType(0) == FT->getParamType(1) &&
-           FT->getParamType(0) == PointerType::getUnqual(Type::Int8Ty);
-  }
-
-  /// @brief Perform the strcmp optimization
-  virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
-    // First, check to see if src and destination are the same. If they are,
-    // then the optimization is to replace the CallInst with a constant 0
-    // because the call is a no-op.
-    Value *Str1P = CI->getOperand(1);
-    Value *Str2P = CI->getOperand(2);
-    if (Str1P == Str2P)      // strcmp(x,x)  -> 0
-      return ReplaceCallWith(CI, ConstantInt::get(CI->getType(), 0));
-
-    std::string Str1;
-    if (!GetConstantStringInfo(Str1P, Str1))
-      return false;
-    if (Str1.empty()) {
-      // strcmp("", x) -> *x
-      Value *V = new LoadInst(Str2P, CI->getName()+".load", CI);
-      V = new ZExtInst(V, CI->getType(), CI->getName()+".int", CI);
-      return ReplaceCallWith(CI, V);
-    }
-
-    std::string Str2;
-    if (!GetConstantStringInfo(Str2P, Str2))
-      return false;
-    if (Str2.empty()) {
-      // strcmp(x,"") -> *x
-      Value *V = new LoadInst(Str1P, CI->getName()+".load", CI);
-      V = new ZExtInst(V, CI->getType(), CI->getName()+".int", CI);
-      return ReplaceCallWith(CI, V);
-    }
-
-    // strcmp(x, y)  -> cnst  (if both x and y are constant strings)
-    int R = strcmp(Str1.c_str(), Str2.c_str());
-    return ReplaceCallWith(CI, ConstantInt::get(CI->getType(), R));
-  }
-} StrCmpOptimizer;
-
-/// This LibCallOptimization will simplify a call to the strncmp library
-/// function.  It optimizes out cases where one or both arguments are constant
-/// and the result can be determined statically.
-/// @brief Simplify the strncmp library function.
-struct VISIBILITY_HIDDEN StrNCmpOptimization : public LibCallOptimization {
-public:
-  StrNCmpOptimization() : LibCallOptimization("strncmp",
-      "Number of 'strncmp' calls simplified") {}
-
-  /// @brief Make sure that the "strncmp" function has the right prototype
-  virtual bool ValidateCalledFunction(const Function *F, SimplifyLibCalls &SLC){
-    const FunctionType *FT = F->getFunctionType();
-    return FT->getReturnType() == Type::Int32Ty && FT->getNumParams() == 3 &&
-           FT->getParamType(0) == FT->getParamType(1) &&
-           FT->getParamType(0) == PointerType::getUnqual(Type::Int8Ty) &&
-           isa<IntegerType>(FT->getParamType(2));
-    return false;
-  }
-
-  /// @brief Perform the strncmp optimization
-  virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
-    // First, check to see if src and destination are the same. If they are,
-    // then the optimization is to replace the CallInst with a constant 0
-    // because the call is a no-op.
-    Value *Str1P = CI->getOperand(1);
-    Value *Str2P = CI->getOperand(2);
-    if (Str1P == Str2P)  // strncmp(x,x, n)  -> 0
-      return ReplaceCallWith(CI, ConstantInt::get(CI->getType(), 0));
-    
-    // Check the length argument, if it is Constant zero then the strings are
-    // considered equal.
-    uint64_t Length;
-    if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(CI->getOperand(3)))
-      Length = LengthArg->getZExtValue();
-    else
-      return false;
-    
-    if (Length == 0) // strncmp(x,y,0)   -> 0
-      return ReplaceCallWith(CI, ConstantInt::get(CI->getType(), 0));
-    
-    std::string Str1;
-    if (!GetConstantStringInfo(Str1P, Str1))
-      return false;
-    if (Str1.empty()) {
-      // strncmp("", x, n) -> *x
-      Value *V = new LoadInst(Str2P, CI->getName()+".load", CI);
-      V = new ZExtInst(V, CI->getType(), CI->getName()+".int", CI);
-      return ReplaceCallWith(CI, V);
-    }
-    
-    std::string Str2;
-    if (!GetConstantStringInfo(Str2P, Str2))
-      return false;
-    if (Str2.empty()) {
-      // strncmp(x, "", n) -> *x
-      Value *V = new LoadInst(Str1P, CI->getName()+".load", CI);
-      V = new ZExtInst(V, CI->getType(), CI->getName()+".int", CI);
-      return ReplaceCallWith(CI, V);
-    }
-    
-    // strncmp(x, y, n)  -> cnst  (if both x and y are constant strings)
-    int R = strncmp(Str1.c_str(), Str2.c_str(), Length);
-    return ReplaceCallWith(CI, ConstantInt::get(CI->getType(), R));
-  }
-} StrNCmpOptimizer;
-
-/// This LibCallOptimization will simplify a call to the strcpy library
-/// function.  Two optimizations are possible:
-/// (1) If src and dest are the same and not volatile, just return dest
-/// (2) If the src is a constant then we can convert to llvm.memmove
-/// @brief Simplify the strcpy library function.
-struct VISIBILITY_HIDDEN StrCpyOptimization : public LibCallOptimization {
-public:
-  StrCpyOptimization() : LibCallOptimization("strcpy",
-      "Number of 'strcpy' calls simplified") {}
-
-  /// @brief Make sure that the "strcpy" function has the right prototype
-  virtual bool ValidateCalledFunction(const Function *F, SimplifyLibCalls &SLC){
-    const FunctionType *FT = F->getFunctionType();
-    return FT->getNumParams() == 2 &&
-           FT->getParamType(0) == FT->getParamType(1) &&
-           FT->getReturnType() == FT->getParamType(0) &&
-           FT->getParamType(0) == PointerType::getUnqual(Type::Int8Ty);
-  }
-
-  /// @brief Perform the strcpy optimization
-  virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
-    // First, check to see if src and destination are the same. If they are,
-    // then the optimization is to replace the CallInst with the destination
-    // because the call is a no-op. Note that this corresponds to the
-    // degenerate strcpy(X,X) case which should have "undefined" results
-    // according to the C specification. However, it occurs sometimes and
-    // we optimize it as a no-op.
-    Value *Dst = CI->getOperand(1);
-    Value *Src = CI->getOperand(2);
-    if (Dst == Src) {
-      // strcpy(x, x) -> x
-      return ReplaceCallWith(CI, Dst);
-    }
-    
-    // See if we can get the length of the input string.
-    uint64_t Len = GetStringLength(Src);
-    if (Len == 0) return false;
-    --Len;  // Unbias length.
-    
-    // If the constant string's length is zero we can optimize this by just
-    // doing a store of 0 at the first byte of the destination.
-    if (Len == 0) {
-      new StoreInst(ConstantInt::get(Type::Int8Ty, 0), Dst, CI);
-      return ReplaceCallWith(CI, Dst);
-    }
-
-    // We have enough information to now generate the memcpy call to
-    // do the concatenation for us.
-    Value *MemcpyOps[] = {
-      Dst, Src,
-      ConstantInt::get(SLC.getIntPtrType(), Len+1),// Length including nul byte.
-      ConstantInt::get(Type::Int32Ty, 1) // alignment
-    };
-    CallInst::Create(SLC.get_memcpy(), MemcpyOps, MemcpyOps + 4, "", CI);
-
-    return ReplaceCallWith(CI, Dst);
-  }
-} StrCpyOptimizer;
-
-/// This LibCallOptimization will simplify a call to the strlen library
-/// function by replacing it with a constant value if the string provided to
-/// it is a constant array.
-/// @brief Simplify the strlen library function.
-struct VISIBILITY_HIDDEN StrLenOptimization : public LibCallOptimization {
-  StrLenOptimization() : LibCallOptimization("strlen",
-      "Number of 'strlen' calls simplified") {}
-
-  /// @brief Make sure that the "strlen" function has the right prototype
-  virtual bool ValidateCalledFunction(const Function *F, SimplifyLibCalls &SLC){
-    const FunctionType *FT = F->getFunctionType();
-    return FT->getNumParams() == 1 &&
-           FT->getParamType(0) == PointerType::getUnqual(Type::Int8Ty) &&
-           isa<IntegerType>(FT->getReturnType());
-  }
-
-  /// @brief Perform the strlen optimization
-  virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
-    // Make sure we're dealing with an sbyte* here.
-    Value *Src = CI->getOperand(1);
-
-    // Does the call to strlen have exactly one use?
-    if (CI->hasOneUse()) {
-      // Is that single use a icmp operator?
-      if (ICmpInst *Cmp = dyn_cast<ICmpInst>(CI->use_back()))
-        // Is it compared against a constant integer?
-        if (ConstantInt *Cst = dyn_cast<ConstantInt>(Cmp->getOperand(1))) {
-          // If its compared against length 0 with == or !=
-          if (Cst->getZExtValue() == 0 && Cmp->isEquality()) {
-            // strlen(x) != 0 -> *x != 0
-            // strlen(x) == 0 -> *x == 0
-            Value *V = new LoadInst(Src, Src->getName()+".first", CI);
-            V = new ICmpInst(Cmp->getPredicate(), V, 
-                             ConstantInt::get(Type::Int8Ty, 0),
-                             Cmp->getName()+".strlen", CI);
-            Cmp->replaceAllUsesWith(V);
-            Cmp->eraseFromParent();
-            return ReplaceCallWith(CI, 0);  // no uses.
-          }
-        }
-    }
-
-    // Get the length of the constant string operand
-    // strlen("xyz") -> 3 (for example)
-    if (uint64_t Len = GetStringLength(Src))
-      return ReplaceCallWith(CI, ConstantInt::get(CI->getType(), Len-1));
-    return false;
-  }
-} StrLenOptimizer;
-
-/// IsOnlyUsedInEqualsComparison - Return true if it only matters that the value
-/// is equal or not-equal to zero. 
-static bool IsOnlyUsedInEqualsZeroComparison(Instruction *I) {
-  for (Value::use_iterator UI = I->use_begin(), E = I->use_end();
-       UI != E; ++UI) {
-    if (ICmpInst *IC = dyn_cast<ICmpInst>(*UI))
-      if (IC->isEquality())
-        if (Constant *C = dyn_cast<Constant>(IC->getOperand(1)))
-          if (C->isNullValue())
-            continue;
-    // Unknown instruction.
-    return false;
-  }
-  return true;
-}
-
-/// This memcmpOptimization will simplify a call to the memcmp library
-/// function.
-struct VISIBILITY_HIDDEN memcmpOptimization : public LibCallOptimization {
-  /// @brief Default Constructor
-  memcmpOptimization()
-    : LibCallOptimization("memcmp", "Number of 'memcmp' calls simplified") {}
-  
-  /// @brief Make sure that the "memcmp" function has the right prototype
-  virtual bool ValidateCalledFunction(const Function *F, SimplifyLibCalls &TD) {
-    Function::const_arg_iterator AI = F->arg_begin();
-    if (F->arg_size() != 3 || !isa<PointerType>(AI->getType())) return false;
-    if (!isa<PointerType>((++AI)->getType())) return false;
-    if (!(++AI)->getType()->isInteger()) return false;
-    if (!F->getReturnType()->isInteger()) return false;
-    return true;
-  }
-  
-  /// Because of alignment and instruction information that we don't have, we
-  /// leave the bulk of this to the code generators.
-  ///
-  /// Note that we could do much more if we could force alignment on otherwise
-  /// small aligned allocas, or if we could indicate that loads have a small
-  /// alignment.
-  virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &TD) {
-    Value *LHS = CI->getOperand(1), *RHS = CI->getOperand(2);
-
-    // If the two operands are the same, return zero.
-    if (LHS == RHS) {
-      // memcmp(s,s,x) -> 0
-      return ReplaceCallWith(CI, Constant::getNullValue(CI->getType()));
-    }
-    
-    // Make sure we have a constant length.
-    ConstantInt *LenC = dyn_cast<ConstantInt>(CI->getOperand(3));
-    if (!LenC) return false;
-    uint64_t Len = LenC->getZExtValue();
-      
-    // If the length is zero, this returns 0.
-    switch (Len) {
-    case 0:
-      // memcmp(s1,s2,0) -> 0
-      return ReplaceCallWith(CI, Constant::getNullValue(CI->getType()));
-    case 1: {
-      // memcmp(S1,S2,1) -> *(ubyte*)S1 - *(ubyte*)S2
-      const Type *UCharPtr = PointerType::getUnqual(Type::Int8Ty);
-      CastInst *Op1Cast = CastInst::create(
-          Instruction::BitCast, LHS, UCharPtr, LHS->getName(), CI);
-      CastInst *Op2Cast = CastInst::create(
-          Instruction::BitCast, RHS, UCharPtr, RHS->getName(), CI);
-      Value *S1V = new LoadInst(Op1Cast, LHS->getName()+".val", CI);
-      Value *S2V = new LoadInst(Op2Cast, RHS->getName()+".val", CI);
-      Value *RV = BinaryOperator::createSub(S1V, S2V, CI->getName()+".diff",CI);
-      if (RV->getType() != CI->getType())
-        RV = CastInst::createIntegerCast(RV, CI->getType(), false, 
-                                         RV->getName(), CI);
-      return ReplaceCallWith(CI, RV);
-    }
-    case 2:
-      if (IsOnlyUsedInEqualsZeroComparison(CI)) {
-        // TODO: IF both are aligned, use a short load/compare.
-      
-        // memcmp(S1,S2,2) -> S1[0]-S2[0] | S1[1]-S2[1] iff only ==/!= 0 matters
-        const Type *UCharPtr = PointerType::getUnqual(Type::Int8Ty);
-        CastInst *Op1Cast = CastInst::create(
-            Instruction::BitCast, LHS, UCharPtr, LHS->getName(), CI);
-        CastInst *Op2Cast = CastInst::create(
-            Instruction::BitCast, RHS, UCharPtr, RHS->getName(), CI);
-        Value *S1V1 = new LoadInst(Op1Cast, LHS->getName()+".val1", CI);
-        Value *S2V1 = new LoadInst(Op2Cast, RHS->getName()+".val1", CI);
-        Value *D1 = BinaryOperator::createSub(S1V1, S2V1,
-                                              CI->getName()+".d1", CI);
-        Constant *One = ConstantInt::get(Type::Int32Ty, 1);
-        Value *G1 = GetElementPtrInst::Create(Op1Cast, One, "next1v", CI);
-        Value *G2 = GetElementPtrInst::Create(Op2Cast, One, "next2v", CI);
-        Value *S1V2 = new LoadInst(G1, LHS->getName()+".val2", CI);
-        Value *S2V2 = new LoadInst(G2, RHS->getName()+".val2", CI);
-        Value *D2 = BinaryOperator::createSub(S1V2, S2V2,
-                                              CI->getName()+".d1", CI);
-        Value *Or = BinaryOperator::createOr(D1, D2, CI->getName()+".res", CI);
-        if (Or->getType() != CI->getType())
-          Or = CastInst::createIntegerCast(Or, CI->getType(), false /*ZExt*/, 
-                                           Or->getName(), CI);
-        return ReplaceCallWith(CI, Or);
-      }
-      break;
-    default:
-      break;
-    }
-    
-    return false;
-  }
-} memcmpOptimizer;
-
-/// This LibCallOptimization will simplify a call to the memcpy library
-/// function.  It simply converts them into calls to llvm.memcpy.*;
-/// the resulting call should be optimized later.
-/// @brief Simplify the memcpy library function.
-struct VISIBILITY_HIDDEN MemCpyOptimization : public LibCallOptimization {
-public:
-  MemCpyOptimization() : LibCallOptimization("memcpy",
-      "Number of 'memcpy' calls simplified") {}
-
-  /// @brief Make sure that the "memcpy" function has the right prototype
-  virtual bool ValidateCalledFunction(const Function *F, SimplifyLibCalls &SLC){
-    const FunctionType *FT = F->getFunctionType();
-    const Type* voidPtr = PointerType::getUnqual(Type::Int8Ty);
-    return FT->getReturnType() == voidPtr && FT->getNumParams() == 3 &&
-           FT->getParamType(0) == voidPtr &&
-           FT->getParamType(1) == voidPtr &&
-           FT->getParamType(2) == SLC.getIntPtrType();
-  }
-
-  /// @brief Perform the memcpy optimization
-  virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
-    Value *MemcpyOps[] = {
-      CI->getOperand(1), CI->getOperand(2), CI->getOperand(3),
-      ConstantInt::get(Type::Int32Ty, 1)   // align = 1 always.
-    };
-    CallInst::Create(SLC.get_memcpy(), MemcpyOps, MemcpyOps + 4, "", CI);
-    // memcpy always returns the destination
-    return ReplaceCallWith(CI, CI->getOperand(1));
-  }
-} MemCpyOptimizer;
-
-/// This LibCallOptimization will simplify a call to the memcpy library
-/// function by expanding it out to a single store of size 0, 1, 2, 4, or 8
-/// bytes depending on the length of the string and the alignment. Additional
-/// optimizations are possible in code generation (sequence of immediate store)
-/// @brief Simplify the memcpy library function.
-struct VISIBILITY_HIDDEN LLVMMemCpyMoveOptzn : public LibCallOptimization {
-  LLVMMemCpyMoveOptzn(const char* fname, const char* desc)
-  : LibCallOptimization(fname, desc) {}
-
-  /// @brief Make sure that the "memcpy" function has the right prototype
-  virtual bool ValidateCalledFunction(const Function* f, SimplifyLibCalls& TD) {
-    // Just make sure this has 4 arguments per LLVM spec.
-    return (f->arg_size() == 4);
-  }
-
-  /// Because of alignment and instruction information that we don't have, we
-  /// leave the bulk of this to the code generators. The optimization here just
-  /// deals with a few degenerate cases where the length of the string and the
-  /// alignment match the sizes of our intrinsic types so we can do a load and
-  /// store instead of the memcpy call.
-  /// @brief Perform the memcpy optimization.
-  virtual bool OptimizeCall(CallInst* ci, SimplifyLibCalls& TD) {
-    // Make sure we have constant int values to work with
-    ConstantInt* LEN = dyn_cast<ConstantInt>(ci->getOperand(3));
-    if (!LEN)
-      return false;
-    ConstantInt* ALIGN = dyn_cast<ConstantInt>(ci->getOperand(4));
-    if (!ALIGN)
-      return false;
-
-    // If the length is larger than the alignment, we can't optimize
-    uint64_t len = LEN->getZExtValue();
-    uint64_t alignment = ALIGN->getZExtValue();
-    if (alignment == 0)
-      alignment = 1; // Alignment 0 is identity for alignment 1
-    if (len > alignment)
-      return false;
-
-    // Get the type we will cast to, based on size of the string
-    Value* dest = ci->getOperand(1);
-    Value* src = ci->getOperand(2);
-    const Type* castType = 0;
-    switch (len) {
-      case 0:
-        // memcpy(d,s,0,a) -> d
-        return ReplaceCallWith(ci, 0);
-      case 1: castType = Type::Int8Ty; break;
-      case 2: castType = Type::Int16Ty; break;
-      case 4: castType = Type::Int32Ty; break;
-      case 8: castType = Type::Int64Ty; break;
-      default:
-        return false;
-    }
-
-    // Cast source and dest to the right sized primitive and then load/store
-    CastInst* SrcCast = CastInst::create(Instruction::BitCast,
-        src, PointerType::getUnqual(castType), src->getName()+".cast", ci);
-    CastInst* DestCast = CastInst::create(Instruction::BitCast,
-        dest, PointerType::getUnqual(castType),dest->getName()+".cast", ci);
-    LoadInst* LI = new LoadInst(SrcCast,SrcCast->getName()+".val",ci);
-    new StoreInst(LI, DestCast, ci);
-    return ReplaceCallWith(ci, 0);
-  }
-};
-
-/// This LibCallOptimization will simplify a call to the memcpy/memmove library
-/// functions.
-LLVMMemCpyMoveOptzn LLVMMemCpyOptimizer32("llvm.memcpy.i32",
-                                    "Number of 'llvm.memcpy' calls simplified");
-LLVMMemCpyMoveOptzn LLVMMemCpyOptimizer64("llvm.memcpy.i64",
-                                   "Number of 'llvm.memcpy' calls simplified");
-LLVMMemCpyMoveOptzn LLVMMemMoveOptimizer32("llvm.memmove.i32",
-                                   "Number of 'llvm.memmove' calls simplified");
-LLVMMemCpyMoveOptzn LLVMMemMoveOptimizer64("llvm.memmove.i64",
-                                   "Number of 'llvm.memmove' calls simplified");
-
-/// This LibCallOptimization will simplify a call to the memset library
-/// function by expanding it out to a single store of size 0, 1, 2, 4, or 8
-/// bytes depending on the length argument.
-struct VISIBILITY_HIDDEN LLVMMemSetOptimization : public LibCallOptimization {
-  /// @brief Default Constructor
-  LLVMMemSetOptimization(const char *Name) : LibCallOptimization(Name,
-      "Number of 'llvm.memset' calls simplified") {}
-
-  /// @brief Make sure that the "memset" function has the right prototype
-  virtual bool ValidateCalledFunction(const Function *F, SimplifyLibCalls &TD) {
-    // Just make sure this has 3 arguments per LLVM spec.
-    return F->arg_size() == 4;
-  }
-
-  /// Because of alignment and instruction information that we don't have, we
-  /// leave the bulk of this to the code generators. The optimization here just
-  /// deals with a few degenerate cases where the length parameter is constant
-  /// and the alignment matches the sizes of our intrinsic types so we can do
-  /// store instead of the memcpy call. Other calls are transformed into the
-  /// llvm.memset intrinsic.
-  /// @brief Perform the memset optimization.
-  virtual bool OptimizeCall(CallInst *ci, SimplifyLibCalls &TD) {
-    // Make sure we have constant int values to work with
-    ConstantInt* LEN = dyn_cast<ConstantInt>(ci->getOperand(3));
-    if (!LEN)
-      return false;
-    ConstantInt* ALIGN = dyn_cast<ConstantInt>(ci->getOperand(4));
-    if (!ALIGN)
-      return false;
-
-    // Extract the length and alignment
-    uint64_t len = LEN->getZExtValue();
-    uint64_t alignment = ALIGN->getZExtValue();
-
-    // Alignment 0 is identity for alignment 1
-    if (alignment == 0)
-      alignment = 1;
-
-    // If the length is zero, this is a no-op
-    if (len == 0) {
-      // memset(d,c,0,a) -> noop
-      return ReplaceCallWith(ci, 0);
-    }
-
-    // If the length is larger than the alignment, we can't optimize
-    if (len > alignment)
-      return false;
-
-    // Make sure we have a constant ubyte to work with so we can extract
-    // the value to be filled.
-    ConstantInt* FILL = dyn_cast<ConstantInt>(ci->getOperand(2));
-    if (!FILL)
-      return false;
-    if (FILL->getType() != Type::Int8Ty)
-      return false;
-
-    // memset(s,c,n) -> store s, c (for n=1,2,4,8)
-
-    // Extract the fill character
-    uint64_t fill_char = FILL->getZExtValue();
-    uint64_t fill_value = fill_char;
-
-    // Get the type we will cast to, based on size of memory area to fill, and
-    // and the value we will store there.
-    Value* dest = ci->getOperand(1);
-    const Type* castType = 0;
-    switch (len) {
-      case 1:
-        castType = Type::Int8Ty;
-        break;
-      case 2:
-        castType = Type::Int16Ty;
-        fill_value |= fill_char << 8;
-        break;
-      case 4:
-        castType = Type::Int32Ty;
-        fill_value |= fill_char << 8 | fill_char << 16 | fill_char << 24;
-        break;
-      case 8:
-        castType = Type::Int64Ty;
-        fill_value |= fill_char << 8 | fill_char << 16 | fill_char << 24;
-        fill_value |= fill_char << 32 | fill_char << 40 | fill_char << 48;
-        fill_value |= fill_char << 56;
-        break;
-      default:
-        return false;
-    }
-
-    // Cast dest to the right sized primitive and then load/store
-    CastInst* DestCast = new BitCastInst(dest, PointerType::getUnqual(castType), 
-                                         dest->getName()+".cast", ci);
-    new StoreInst(ConstantInt::get(castType,fill_value),DestCast, ci);
-    return ReplaceCallWith(ci, 0);
-  }
-};
-
-LLVMMemSetOptimization MemSet32Optimizer("llvm.memset.i32");
-LLVMMemSetOptimization MemSet64Optimizer("llvm.memset.i64");
-
-
-/// This LibCallOptimization will simplify calls to the "pow" library
-/// function. It looks for cases where the result of pow is well known and
-/// substitutes the appropriate value.
-/// @brief Simplify the pow library function.
-struct VISIBILITY_HIDDEN PowOptimization : public LibCallOptimization {
-public:
-  /// @brief Default Constructor
-  PowOptimization(const char *Name) : LibCallOptimization(Name,
-      "Number of 'pow' calls simplified") {}
-
-  /// @brief Make sure that the "pow" function has the right prototype
-  virtual bool ValidateCalledFunction(const Function *F, SimplifyLibCalls &SLC){
-    // Just make sure this has 2 arguments of the same FP type, which match the
-    // result type.
-    const FunctionType *FT = F->getFunctionType();
-    return FT->getNumParams() == 2 && 
-          FT->getParamType(0) == FT->getParamType(1) &&
-          FT->getParamType(0) == FT->getReturnType() &&
-          FT->getParamType(0)->isFloatingPoint();
-  }
-
-  /// @brief Perform the pow optimization.
-  virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
-    Value *Op1 = CI->getOperand(1);
-    Value *Op2 = CI->getOperand(2);
-    if (ConstantFP *Op1C = dyn_cast<ConstantFP>(Op1)) {
-      if (Op1C->isExactlyValue(1.0)) // pow(1.0, x) -> 1.0
-        return ReplaceCallWith(CI, Op1C);
-      if (Op1C->isExactlyValue(2.0)) {// pow(2.0, x) -> exp2(x)
-        Value *Exp2 = SLC.getUnaryFloatFunction("exp2", CI->getType());
-        Value *Res = CallInst::Create(Exp2, Op2, CI->getName()+"exp2", CI);
-        return ReplaceCallWith(CI, Res);
-      }
-    }
-    
-    ConstantFP *Op2C = dyn_cast<ConstantFP>(Op2);
-    if (Op2C == 0) return false;
-    
-    if (Op2C->getValueAPF().isZero()) {
-      // pow(x, 0.0) -> 1.0
-      return ReplaceCallWith(CI, ConstantFP::get(CI->getType(), 1.0));
-    } else if (Op2C->isExactlyValue(0.5)) {
-      // FIXME: This is not safe for -0.0 and -inf.  This can only be done when
-      // 'unsafe' math optimizations are allowed.
-      // x    pow(x, 0.5)  sqrt(x)
-      // ---------------------------------------------
-      // -0.0    +0.0       -0.0
-      // -inf    +inf       NaN
-#if 0
-      // pow(x, 0.5) -> sqrt(x)
-      Value *Sqrt = CallInst::Create(SLC.get_sqrt(), Op1, "sqrt", CI);
-      return ReplaceCallWith(CI, Sqrt);
-#endif
-    } else if (Op2C->isExactlyValue(1.0)) {
-      // pow(x, 1.0) -> x
-      return ReplaceCallWith(CI, Op1);
-    } else if (Op2C->isExactlyValue(2.0)) {
-      // pow(x, 2.0) -> x*x
-      Value *Sq = BinaryOperator::createMul(Op1, Op1, "pow2", CI);
-      return ReplaceCallWith(CI, Sq);
-    } else if (Op2C->isExactlyValue(-1.0)) {
-      // pow(x, -1.0) -> 1.0/x
-      Value *R = BinaryOperator::createFDiv(ConstantFP::get(CI->getType(), 1.0),
-                                            Op1, CI->getName()+".pow", CI);
-      return ReplaceCallWith(CI, R);
-    }
-    return false; // opt failed
-  }
-};
-
-PowOptimization PowFOptimizer("powf");
-PowOptimization PowOptimizer("pow");
-PowOptimization PowLOptimizer("powl");
- 
-  
-/// This LibCallOptimization will simplify calls to the "printf" library
-/// function. It looks for cases where the result of printf is not used and the
-/// operation can be reduced to something simpler.
-/// @brief Simplify the printf library function.
-struct VISIBILITY_HIDDEN PrintfOptimization : public LibCallOptimization {
-public:
-  /// @brief Default Constructor
-  PrintfOptimization() : LibCallOptimization("printf",
-      "Number of 'printf' calls simplified") {}
-
-  /// @brief Make sure that the "printf" function has the right prototype
-  virtual bool ValidateCalledFunction(const Function *F, SimplifyLibCalls &SLC){
-    // Just make sure this has at least 1 argument and returns an integer or
-    // void type.
-    const FunctionType *FT = F->getFunctionType();
-    return FT->getNumParams() >= 1 &&
-          (isa<IntegerType>(FT->getReturnType()) ||
-           FT->getReturnType() == Type::VoidTy);
-  }
-
-  /// @brief Perform the printf optimization.
-  virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
-    // All the optimizations depend on the length of the first argument and the
-    // fact that it is a constant string array. Check that now
-    std::string FormatStr;
-    if (!GetConstantStringInfo(CI->getOperand(1), FormatStr))
-      return false;
-    
-    // If this is a simple constant string with no format specifiers that ends
-    // with a \n, turn it into a puts call.
-    if (FormatStr.empty()) {
-      // Tolerate printf's declared void.
-      if (CI->use_empty()) return ReplaceCallWith(CI, 0);
-      return ReplaceCallWith(CI, ConstantInt::get(CI->getType(), 0));
-    }
-    
-    if (FormatStr.size() == 1) {
-      // Turn this into a putchar call, even if it is a %.
-      Value *V = ConstantInt::get(Type::Int32Ty, FormatStr[0]);
-      CallInst::Create(SLC.get_putchar(), V, "", CI);
-      if (CI->use_empty()) return ReplaceCallWith(CI, 0);
-      return ReplaceCallWith(CI, ConstantInt::get(CI->getType(), 1));
-    }
-
-    // Check to see if the format str is something like "foo\n", in which case
-    // we convert it to a puts call.  We don't allow it to contain any format
-    // characters.
-    if (FormatStr[FormatStr.size()-1] == '\n' &&
-        FormatStr.find('%') == std::string::npos) {
-      // Create a string literal with no \n on it.  We expect the constant merge
-      // pass to be run after this pass, to merge duplicate strings.
-      FormatStr.erase(FormatStr.end()-1);
-      Constant *Init = ConstantArray::get(FormatStr, true);
-      Constant *GV = new GlobalVariable(Init->getType(), true,
-                                        GlobalVariable::InternalLinkage,
-                                        Init, "str",
-                                     CI->getParent()->getParent()->getParent());
-      // Cast GV to be a pointer to char.
-      GV = ConstantExpr::getBitCast(GV, PointerType::getUnqual(Type::Int8Ty));
-      CallInst::Create(SLC.get_puts(), GV, "", CI);
-
-      if (CI->use_empty()) return ReplaceCallWith(CI, 0);
-      // The return value from printf includes the \n we just removed, so +1.
-      return ReplaceCallWith(CI,
-                             ConstantInt::get(CI->getType(), 
-                                              FormatStr.size()+1));
-    }
-    
-    
-    // Only support %c or "%s\n" for now.
-    if (FormatStr.size() < 2 || FormatStr[0] != '%')
-      return false;
-
-    // Get the second character and switch on its value
-    switch (FormatStr[1]) {
-    default:  return false;
-    case 's':
-      if (FormatStr != "%s\n" || CI->getNumOperands() < 3 ||
-          // TODO: could insert strlen call to compute string length.
-          !CI->use_empty())
-        return false;
-
-      // printf("%s\n",str) -> puts(str)
-      CallInst::Create(SLC.get_puts(), CastToCStr(CI->getOperand(2), CI),
-                       CI->getName(), CI);
-      return ReplaceCallWith(CI, 0);
-    case 'c': {
-      // printf("%c",c) -> putchar(c)
-      if (FormatStr.size() != 2 || CI->getNumOperands() < 3)
-        return false;
-      
-      Value *V = CI->getOperand(2);
-      if (!isa<IntegerType>(V->getType()) ||
-          cast<IntegerType>(V->getType())->getBitWidth() > 32)
-        return false;
-
-      V = CastInst::createZExtOrBitCast(V, Type::Int32Ty, CI->getName()+".int",
-                                        CI);
-      CallInst::Create(SLC.get_putchar(), V, "", CI);
-      return ReplaceCallWith(CI, ConstantInt::get(CI->getType(), 1));
-    }
-    }
-  }
-} PrintfOptimizer;
-
-/// This LibCallOptimization will simplify calls to the "fprintf" library
-/// function. It looks for cases where the result of fprintf is not used and the
-/// operation can be reduced to something simpler.
-/// @brief Simplify the fprintf library function.
-struct VISIBILITY_HIDDEN FPrintFOptimization : public LibCallOptimization {
-public:
-  /// @brief Default Constructor
-  FPrintFOptimization() : LibCallOptimization("fprintf",
-      "Number of 'fprintf' calls simplified") {}
-
-  /// @brief Make sure that the "fprintf" function has the right prototype
-  virtual bool ValidateCalledFunction(const Function *F, SimplifyLibCalls &SLC){
-    const FunctionType *FT = F->getFunctionType();
-    return FT->getNumParams() == 2 &&  // two fixed arguments.
-           FT->getParamType(1) == PointerType::getUnqual(Type::Int8Ty) &&
-           isa<PointerType>(FT->getParamType(0)) &&
-           isa<IntegerType>(FT->getReturnType());
-  }
-
-  /// @brief Perform the fprintf optimization.
-  virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
-    // If the call has more than 3 operands, we can't optimize it
-    if (CI->getNumOperands() != 3 && CI->getNumOperands() != 4)
-      return false;
-
-    // All the optimizations depend on the format string.
-    std::string FormatStr;
-    if (!GetConstantStringInfo(CI->getOperand(2), FormatStr))
-      return false;
-
-    // If this is just a format string, turn it into fwrite.
-    if (CI->getNumOperands() == 3) {
-      for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
-        if (FormatStr[i] == '%')
-          return false; // we found a format specifier
-
-      // fprintf(file,fmt) -> fwrite(fmt,strlen(fmt),file)
-      const Type *FILEty = CI->getOperand(1)->getType();
-
-      Value *FWriteArgs[] = {
-        CI->getOperand(2),
-        ConstantInt::get(SLC.getIntPtrType(), FormatStr.size()),
-        ConstantInt::get(SLC.getIntPtrType(), 1),
-        CI->getOperand(1)
-      };
-      CallInst::Create(SLC.get_fwrite(FILEty), FWriteArgs, FWriteArgs + 4, CI->getName(), CI);
-      return ReplaceCallWith(CI, ConstantInt::get(CI->getType(), 
-                                                  FormatStr.size()));
-    }
-    
-    // The remaining optimizations require the format string to be length 2:
-    // "%s" or "%c".
-    if (FormatStr.size() != 2 || FormatStr[0] != '%')
-      return false;
-
-    // Get the second character and switch on its value
-    switch (FormatStr[1]) {
-    case 'c': {
-      // fprintf(file,"%c",c) -> fputc(c,file)
-      const Type *FILETy = CI->getOperand(1)->getType();
-      Value *C = CastInst::createZExtOrBitCast(CI->getOperand(3), Type::Int32Ty,
-                                               CI->getName()+".int", CI);
-      SmallVector<Value *, 2> Args;
-      Args.push_back(C);
-      Args.push_back(CI->getOperand(1));
-      CallInst::Create(SLC.get_fputc(FILETy), Args.begin(), Args.end(), "", CI);
-      return ReplaceCallWith(CI, ConstantInt::get(CI->getType(), 1));
-    }
-    case 's': {
-      const Type *FILETy = CI->getOperand(1)->getType();
-      
-      // If the result of the fprintf call is used, we can't do this.
-      // TODO: we should insert a strlen call.
-      if (!CI->use_empty() || !isa<PointerType>(CI->getOperand(3)->getType()))
-        return false;
-      
-      // fprintf(file,"%s",str) -> fputs(str,file)
-      SmallVector<Value *, 2> Args;
-      Args.push_back(CastToCStr(CI->getOperand(3), CI));
-      Args.push_back(CI->getOperand(1));
-      CallInst::Create(SLC.get_fputs(FILETy), Args.begin(),
-                       Args.end(), CI->getName(), CI);
-      return ReplaceCallWith(CI, 0);
-    }
-    default:
-      return false;
-    }
-  }
-} FPrintFOptimizer;
-
-/// This LibCallOptimization will simplify calls to the "sprintf" library
-/// function. It looks for cases where the result of sprintf is not used and the
-/// operation can be reduced to something simpler.
-/// @brief Simplify the sprintf library function.
-struct VISIBILITY_HIDDEN SPrintFOptimization : public LibCallOptimization {
-public:
-  /// @brief Default Constructor
-  SPrintFOptimization() : LibCallOptimization("sprintf",
-      "Number of 'sprintf' calls simplified") {}
-
-  /// @brief Make sure that the "sprintf" function has the right prototype
-  virtual bool ValidateCalledFunction(const Function *F, SimplifyLibCalls &SLC){
-    const FunctionType *FT = F->getFunctionType();
-    return FT->getNumParams() == 2 &&  // two fixed arguments.
-           FT->getParamType(1) == PointerType::getUnqual(Type::Int8Ty) &&
-           FT->getParamType(0) == FT->getParamType(1) &&
-           isa<IntegerType>(FT->getReturnType());
-  }
-
-  /// @brief Perform the sprintf optimization.
-  virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
-    // If the call has more than 3 operands, we can't optimize it
-    if (CI->getNumOperands() != 3 && CI->getNumOperands() != 4)
-      return false;
-
-    std::string FormatStr;
-    if (!GetConstantStringInfo(CI->getOperand(2), FormatStr))
-      return false;
-    
-    if (CI->getNumOperands() == 3) {
-      // Make sure there's no % in the constant array
-      for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
-        if (FormatStr[i] == '%')
-          return false; // we found a format specifier
-      
-      // sprintf(str,fmt) -> llvm.memcpy(str,fmt,strlen(fmt),1)
-      Value *MemCpyArgs[] = {
-        CI->getOperand(1), CI->getOperand(2),
-        ConstantInt::get(SLC.getIntPtrType(), 
-                         FormatStr.size()+1), // Copy the nul byte.
-        ConstantInt::get(Type::Int32Ty, 1)
-      };
-      CallInst::Create(SLC.get_memcpy(), MemCpyArgs, MemCpyArgs + 4, "", CI);
-      return ReplaceCallWith(CI, ConstantInt::get(CI->getType(), 
-                                                  FormatStr.size()));
-    }
-
-    // The remaining optimizations require the format string to be "%s" or "%c".
-    if (FormatStr.size() != 2 || FormatStr[0] != '%')
-      return false;
-
-    // Get the second character and switch on its value
-    switch (FormatStr[1]) {
-    case 'c': {
-      // sprintf(dest,"%c",chr) -> store chr, dest
-      Value *V = CastInst::createTruncOrBitCast(CI->getOperand(3),
-                                                Type::Int8Ty, "char", CI);
-      new StoreInst(V, CI->getOperand(1), CI);
-      Value *Ptr = GetElementPtrInst::Create(CI->getOperand(1),
-                                             ConstantInt::get(Type::Int32Ty, 1),
-                                             CI->getOperand(1)->getName()+".end",
-                                             CI);
-      new StoreInst(ConstantInt::get(Type::Int8Ty,0), Ptr, CI);
-      return ReplaceCallWith(CI, ConstantInt::get(Type::Int32Ty, 1));
-    }
-    case 's': {
-      // sprintf(dest,"%s",str) -> llvm.memcpy(dest, str, strlen(str)+1, 1)
-      Value *Len = CallInst::Create(SLC.get_strlen(),
-                                    CastToCStr(CI->getOperand(3), CI),
-                                    CI->getOperand(3)->getName()+".len", CI);
-      Value *UnincLen = Len;
-      Len = BinaryOperator::createAdd(Len, ConstantInt::get(Len->getType(), 1),
-                                      Len->getName()+"1", CI);
-      Value *MemcpyArgs[4] = {
-        CI->getOperand(1),
-        CastToCStr(CI->getOperand(3), CI),
-        Len,
-        ConstantInt::get(Type::Int32Ty, 1)
-      };
-      CallInst::Create(SLC.get_memcpy(), MemcpyArgs, MemcpyArgs + 4, "", CI);
-      
-      // The strlen result is the unincremented number of bytes in the string.
-      if (!CI->use_empty()) {
-        if (UnincLen->getType() != CI->getType())
-          UnincLen = CastInst::createIntegerCast(UnincLen, CI->getType(), false, 
-                                                 Len->getName(), CI);
-        CI->replaceAllUsesWith(UnincLen);
-      }
-      return ReplaceCallWith(CI, 0);
-    }
-    }
-    return false;
-  }
-} SPrintFOptimizer;
-
-/// This LibCallOptimization will simplify calls to the "fputs" library
-/// function. It looks for cases where the result of fputs is not used and the
-/// operation can be reduced to something simpler.
-/// @brief Simplify the fputs library function.
-struct VISIBILITY_HIDDEN FPutsOptimization : public LibCallOptimization {
-public:
-  /// @brief Default Constructor
-  FPutsOptimization() : LibCallOptimization("fputs",
-      "Number of 'fputs' calls simplified") {}
-
-  /// @brief Make sure that the "fputs" function has the right prototype
-  virtual bool ValidateCalledFunction(const Function *F, SimplifyLibCalls &SLC){
-    // Just make sure this has 2 arguments
-    return F->arg_size() == 2;
-  }
-
-  /// @brief Perform the fputs optimization.
-  virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
-    // If the result is used, none of these optimizations work.
-    if (!CI->use_empty())
-      return false;
-
-    // All the optimizations depend on the length of the first argument.
-    uint64_t Len = GetStringLength(CI->getOperand(1));
-    if (!Len) return false;
-    
-    const Type *FILETy = CI->getOperand(2)->getType();
-    // fputs(s,F)  -> fwrite(s,1,strlen(s),F)
-    Value *Ops[4] = {
-      CI->getOperand(1),
-      ConstantInt::get(SLC.getIntPtrType(), Len-1),
-      ConstantInt::get(SLC.getIntPtrType(), 1),
-      CI->getOperand(2)
-    };
-    CallInst::Create(SLC.get_fwrite(FILETy), Ops, Ops + 4, "", CI);
-    return ReplaceCallWith(CI, 0);  // Known to have no uses (see above).
-  }
-} FPutsOptimizer;
-
-/// This LibCallOptimization will simplify calls to the "fwrite" function.
-struct VISIBILITY_HIDDEN FWriteOptimization : public LibCallOptimization {
-public:
-  /// @brief Default Constructor
-  FWriteOptimization() : LibCallOptimization("fwrite",
-                                       "Number of 'fwrite' calls simplified") {}
-  
-  /// @brief Make sure that the "fputs" function has the right prototype
-  virtual bool ValidateCalledFunction(const Function *F, SimplifyLibCalls &SLC){
-    const FunctionType *FT = F->getFunctionType();
-    return FT->getNumParams() == 4 && 
-           FT->getParamType(0) == PointerType::getUnqual(Type::Int8Ty) &&
-           FT->getParamType(1) == FT->getParamType(2) &&
-           isa<IntegerType>(FT->getParamType(1)) &&
-           isa<PointerType>(FT->getParamType(3)) &&
-           isa<IntegerType>(FT->getReturnType());
-  }
-  
-  virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
-    // Get the element size and count.
-    uint64_t EltSize, EltCount;
-    if (ConstantInt *C = dyn_cast<ConstantInt>(CI->getOperand(2)))
-      EltSize = C->getZExtValue();
-    else
-      return false;
-    if (ConstantInt *C = dyn_cast<ConstantInt>(CI->getOperand(3)))
-      EltCount = C->getZExtValue();
-    else
-      return false;
-    
-    // If this is writing zero records, remove the call (it's a noop).
-    if (EltSize * EltCount == 0)
-      return ReplaceCallWith(CI, ConstantInt::get(CI->getType(), 0));
-    
-    // If this is writing one byte, turn it into fputc.
-    if (EltSize == 1 && EltCount == 1) {
-      SmallVector<Value *, 2> Args;
-      // fwrite(s,1,1,F) -> fputc(s[0],F)
-      Value *Ptr = CI->getOperand(1);
-      Value *Val = new LoadInst(Ptr, Ptr->getName()+".byte", CI);
-      Args.push_back(new ZExtInst(Val, Type::Int32Ty, Val->getName()+".int", CI));
-      Args.push_back(CI->getOperand(4));
-      const Type *FILETy = CI->getOperand(4)->getType();
-      CallInst::Create(SLC.get_fputc(FILETy), Args.begin(), Args.end(), "", CI);
-      return ReplaceCallWith(CI, ConstantInt::get(CI->getType(), 1));
-    }
-    return false;
-  }
-} FWriteOptimizer;
-
-/// This LibCallOptimization will simplify calls to the "isdigit" library
-/// function. It simply does range checks the parameter explicitly.
-/// @brief Simplify the isdigit library function.
-struct VISIBILITY_HIDDEN isdigitOptimization : public LibCallOptimization {
-public:
-  isdigitOptimization() : LibCallOptimization("isdigit",
-      "Number of 'isdigit' calls simplified") {}
-
-  /// @brief Make sure that the "isdigit" function has the right prototype
-  virtual bool ValidateCalledFunction(const Function* f, SimplifyLibCalls& SLC){
-    // Just make sure this has 1 argument
-    return (f->arg_size() == 1);
-  }
-
-  /// @brief Perform the toascii optimization.
-  virtual bool OptimizeCall(CallInst *ci, SimplifyLibCalls &SLC) {
-    if (ConstantInt* CI = dyn_cast<ConstantInt>(ci->getOperand(1))) {
-      // isdigit(c)   -> 0 or 1, if 'c' is constant
-      uint64_t val = CI->getZExtValue();
-      if (val >= '0' && val <= '9')
-        return ReplaceCallWith(ci, ConstantInt::get(Type::Int32Ty, 1));
-      else
-        return ReplaceCallWith(ci, ConstantInt::get(Type::Int32Ty, 0));
-    }
-
-    // isdigit(c)   -> (unsigned)c - '0' <= 9
-    CastInst* cast = CastInst::createIntegerCast(ci->getOperand(1),
-        Type::Int32Ty, false/*ZExt*/, ci->getOperand(1)->getName()+".uint", ci);
-    BinaryOperator* sub_inst = BinaryOperator::createSub(cast,
-        ConstantInt::get(Type::Int32Ty,0x30),
-        ci->getOperand(1)->getName()+".sub",ci);
-    ICmpInst* setcond_inst = new ICmpInst(ICmpInst::ICMP_ULE,sub_inst,
-        ConstantInt::get(Type::Int32Ty,9),
-        ci->getOperand(1)->getName()+".cmp",ci);
-    CastInst* c2 = new ZExtInst(setcond_inst, Type::Int32Ty, 
-        ci->getOperand(1)->getName()+".isdigit", ci);
-    return ReplaceCallWith(ci, c2);
-  }
-} isdigitOptimizer;
-
-struct VISIBILITY_HIDDEN isasciiOptimization : public LibCallOptimization {
-public:
-  isasciiOptimization()
-    : LibCallOptimization("isascii", "Number of 'isascii' calls simplified") {}
-  
-  virtual bool ValidateCalledFunction(const Function *F, SimplifyLibCalls &SLC){
-    return F->arg_size() == 1 && F->arg_begin()->getType()->isInteger() && 
-           F->getReturnType()->isInteger();
-  }
-  
-  /// @brief Perform the isascii optimization.
-  virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
-    // isascii(c)   -> (unsigned)c < 128
-    Value *V = CI->getOperand(1);
-    Value *Cmp = new ICmpInst(ICmpInst::ICMP_ULT, V, 
-                              ConstantInt::get(V->getType(), 128), 
-                              V->getName()+".isascii", CI);
-    if (Cmp->getType() != CI->getType())
-      Cmp = new ZExtInst(Cmp, CI->getType(), Cmp->getName(), CI);
-    return ReplaceCallWith(CI, Cmp);
-  }
-} isasciiOptimizer;
-
-
-/// This LibCallOptimization will simplify calls to the "toascii" library
-/// function. It simply does the corresponding and operation to restrict the
-/// range of values to the ASCII character set (0-127).
-/// @brief Simplify the toascii library function.
-struct VISIBILITY_HIDDEN ToAsciiOptimization : public LibCallOptimization {
-public:
-  /// @brief Default Constructor
-  ToAsciiOptimization() : LibCallOptimization("toascii",
-      "Number of 'toascii' calls simplified") {}
-
-  /// @brief Make sure that the "fputs" function has the right prototype
-  virtual bool ValidateCalledFunction(const Function* f, SimplifyLibCalls& SLC){
-    // Just make sure this has 2 arguments
-    return (f->arg_size() == 1);
-  }
-
-  /// @brief Perform the toascii optimization.
-  virtual bool OptimizeCall(CallInst *ci, SimplifyLibCalls &SLC) {
-    // toascii(c)   -> (c & 0x7f)
-    Value *chr = ci->getOperand(1);
-    Value *and_inst = BinaryOperator::createAnd(chr,
-        ConstantInt::get(chr->getType(),0x7F),ci->getName()+".toascii",ci);
-    return ReplaceCallWith(ci, and_inst);
-  }
-} ToAsciiOptimizer;
-
-/// This LibCallOptimization will simplify calls to the "ffs" library
-/// calls which find the first set bit in an int, long, or long long. The
-/// optimization is to compute the result at compile time if the argument is
-/// a constant.
-/// @brief Simplify the ffs library function.
-struct VISIBILITY_HIDDEN FFSOptimization : public LibCallOptimization {
-protected:
-  /// @brief Subclass Constructor
-  FFSOptimization(const char* funcName, const char* description)
-    : LibCallOptimization(funcName, description) {}
-
-public:
-  /// @brief Default Constructor
-  FFSOptimization() : LibCallOptimization("ffs",
-      "Number of 'ffs' calls simplified") {}
-
-  /// @brief Make sure that the "ffs" function has the right prototype
-  virtual bool ValidateCalledFunction(const Function *F, SimplifyLibCalls &SLC){
-    // Just make sure this has 2 arguments
-    return F->arg_size() == 1 && F->getReturnType() == Type::Int32Ty;
-  }
-
-  /// @brief Perform the ffs optimization.
-  virtual bool OptimizeCall(CallInst *TheCall, SimplifyLibCalls &SLC) {
-    if (ConstantInt *CI = dyn_cast<ConstantInt>(TheCall->getOperand(1))) {
-      // ffs(cnst)  -> bit#
-      // ffsl(cnst) -> bit#
-      // ffsll(cnst) -> bit#
-      uint64_t val = CI->getZExtValue();
-      int result = 0;
-      if (val) {
-        ++result;
-        while ((val & 1) == 0) {
-          ++result;
-          val >>= 1;
-        }
-      }
-      return ReplaceCallWith(TheCall, ConstantInt::get(Type::Int32Ty, result));
-    }
-
-    // ffs(x)   -> x == 0 ? 0 : llvm.cttz(x)+1
-    // ffsl(x)  -> x == 0 ? 0 : llvm.cttz(x)+1
-    // ffsll(x) -> x == 0 ? 0 : llvm.cttz(x)+1
-    const Type *ArgType = TheCall->getOperand(1)->getType();
-    assert(ArgType->getTypeID() == Type::IntegerTyID &&
-           "llvm.cttz argument is not an integer?");
-    Constant *F = Intrinsic::getDeclaration(SLC.getModule(),
-                                            Intrinsic::cttz, &ArgType, 1);
-
-    Value *V = CastInst::createIntegerCast(TheCall->getOperand(1), ArgType, 
-                                           false/*ZExt*/, "tmp", TheCall);
-    Value *V2 = CallInst::Create(F, V, "tmp", TheCall);
-    V2 = CastInst::createIntegerCast(V2, Type::Int32Ty, false/*ZExt*/, 
-                                     "tmp", TheCall);
-    V2 = BinaryOperator::createAdd(V2, ConstantInt::get(Type::Int32Ty, 1),
-                                   "tmp", TheCall);
-    Value *Cond = new ICmpInst(ICmpInst::ICMP_EQ, V, 
-                               Constant::getNullValue(V->getType()), "tmp", 
-                               TheCall);
-    V2 = SelectInst::Create(Cond, ConstantInt::get(Type::Int32Ty, 0), V2,
-                            TheCall->getName(), TheCall);
-    return ReplaceCallWith(TheCall, V2);
-  }
-} FFSOptimizer;
-
-/// This LibCallOptimization will simplify calls to the "ffsl" library
-/// calls. It simply uses FFSOptimization for which the transformation is
-/// identical.
-/// @brief Simplify the ffsl library function.
-struct VISIBILITY_HIDDEN FFSLOptimization : public FFSOptimization {
-public:
-  /// @brief Default Constructor
-  FFSLOptimization() : FFSOptimization("ffsl",
-      "Number of 'ffsl' calls simplified") {}
-
-} FFSLOptimizer;
-
-/// This LibCallOptimization will simplify calls to the "ffsll" library
-/// calls. It simply uses FFSOptimization for which the transformation is
-/// identical.
-/// @brief Simplify the ffsl library function.
-struct VISIBILITY_HIDDEN FFSLLOptimization : public FFSOptimization {
-public:
-  /// @brief Default Constructor
-  FFSLLOptimization() : FFSOptimization("ffsll",
-      "Number of 'ffsll' calls simplified") {}
-
-} FFSLLOptimizer;
-
-/// This optimizes unary functions that take and return doubles.
-struct UnaryDoubleFPOptimizer : public LibCallOptimization {
-  UnaryDoubleFPOptimizer(const char *Fn, const char *Desc)
-  : LibCallOptimization(Fn, Desc) {}
-  
-  // Make sure that this function has the right prototype
-  virtual bool ValidateCalledFunction(const Function *F, SimplifyLibCalls &SLC){
-    return F->arg_size() == 1 && F->arg_begin()->getType() == Type::DoubleTy &&
-           F->getReturnType() == Type::DoubleTy;
-  }
-
-  /// ShrinkFunctionToFloatVersion - If the input to this function is really a
-  /// float, strength reduce this to a float version of the function,
-  /// e.g. floor((double)FLT) -> (double)floorf(FLT).  This can only be called
-  /// when the target supports the destination function and where there can be
-  /// no precision loss.
-  static bool ShrinkFunctionToFloatVersion(CallInst *CI, SimplifyLibCalls &SLC,
-                                           Constant *(SimplifyLibCalls::*FP)()){
-    if (FPExtInst *Cast = dyn_cast<FPExtInst>(CI->getOperand(1)))
-      if (Cast->getOperand(0)->getType() == Type::FloatTy) {
-        Value *New = CallInst::Create((SLC.*FP)(), Cast->getOperand(0),
-                                      CI->getName(), CI);
-        New = new FPExtInst(New, Type::DoubleTy, CI->getName(), CI);
-        CI->replaceAllUsesWith(New);
-        CI->eraseFromParent();
-        if (Cast->use_empty())
-          Cast->eraseFromParent();
-        return true;
-      }
-    return false;
-  }
-};
-
-
-struct VISIBILITY_HIDDEN FloorOptimization : public UnaryDoubleFPOptimizer {
-  FloorOptimization()
-    : UnaryDoubleFPOptimizer("floor", "Number of 'floor' calls simplified") {}
-  
-  virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
-#ifdef HAVE_FLOORF
-    // If this is a float argument passed in, convert to floorf.
-    if (ShrinkFunctionToFloatVersion(CI, SLC, &SimplifyLibCalls::get_floorf))
-      return true;
-#endif
-    return false; // opt failed
-  }
-} FloorOptimizer;
-
-struct VISIBILITY_HIDDEN CeilOptimization : public UnaryDoubleFPOptimizer {
-  CeilOptimization()
-  : UnaryDoubleFPOptimizer("ceil", "Number of 'ceil' calls simplified") {}
-  
-  virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
-#ifdef HAVE_CEILF
-    // If this is a float argument passed in, convert to ceilf.
-    if (ShrinkFunctionToFloatVersion(CI, SLC, &SimplifyLibCalls::get_ceilf))
-      return true;
-#endif
-    return false; // opt failed
-  }
-} CeilOptimizer;
-
-struct VISIBILITY_HIDDEN RoundOptimization : public UnaryDoubleFPOptimizer {
-  RoundOptimization()
-  : UnaryDoubleFPOptimizer("round", "Number of 'round' calls simplified") {}
-  
-  virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
-#ifdef HAVE_ROUNDF
-    // If this is a float argument passed in, convert to roundf.
-    if (ShrinkFunctionToFloatVersion(CI, SLC, &SimplifyLibCalls::get_roundf))
-      return true;
-#endif
-    return false; // opt failed
-  }
-} RoundOptimizer;
-
-struct VISIBILITY_HIDDEN RintOptimization : public UnaryDoubleFPOptimizer {
-  RintOptimization()
-  : UnaryDoubleFPOptimizer("rint", "Number of 'rint' calls simplified") {}
-  
-  virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
-#ifdef HAVE_RINTF
-    // If this is a float argument passed in, convert to rintf.
-    if (ShrinkFunctionToFloatVersion(CI, SLC, &SimplifyLibCalls::get_rintf))
-      return true;
-#endif
-    return false; // opt failed
-  }
-} RintOptimizer;
-
-struct VISIBILITY_HIDDEN NearByIntOptimization : public UnaryDoubleFPOptimizer {
-  NearByIntOptimization()
-  : UnaryDoubleFPOptimizer("nearbyint",
-                           "Number of 'nearbyint' calls simplified") {}
-  
-  virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
-#ifdef HAVE_NEARBYINTF
-    // If this is a float argument passed in, convert to nearbyintf.
-    if (ShrinkFunctionToFloatVersion(CI, SLC,&SimplifyLibCalls::get_nearbyintf))
-      return true;
-#endif
-    return false; // opt failed
-  }
-} NearByIntOptimizer;
-} // end anon namespace
-
-/// GetConstantStringInfo - This function computes the length of a
-/// null-terminated constant array of integers.  This function can't rely on the
-/// size of the constant array because there could be a null terminator in the
-/// middle of the array.
-///
-/// We also have to bail out if we find a non-integer constant initializer
-/// of one of the elements or if there is no null-terminator. The logic
-/// below checks each of these conditions and will return true only if all
-/// conditions are met.  If the conditions aren't met, this returns false.
-///
-/// If successful, the \p Array param is set to the constant array being
-/// indexed, the \p Length parameter is set to the length of the null-terminated
-/// string pointed to by V, the \p StartIdx value is set to the first
-/// element of the Array that V points to, and true is returned.
-static bool GetConstantStringInfo(Value *V, std::string &Str) {
-  // Look through noop bitcast instructions.
-  if (BitCastInst *BCI = dyn_cast<BitCastInst>(V)) {
-    if (BCI->getType() == BCI->getOperand(0)->getType())
-      return GetConstantStringInfo(BCI->getOperand(0), Str);
-    return false;
-  }
-  
-  // If the value is not a GEP instruction nor a constant expression with a
-  // GEP instruction, then return false because ConstantArray can't occur
-  // any other way
-  User *GEP = 0;
-  if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(V)) {
-    GEP = GEPI;
-  } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
-    if (CE->getOpcode() != Instruction::GetElementPtr)
-      return false;
-    GEP = CE;
-  } else {
-    return false;
-  }
-
-  // Make sure the GEP has exactly three arguments.
-  if (GEP->getNumOperands() != 3)
-    return false;
-
-  // Check to make sure that the first operand of the GEP is an integer and
-  // has value 0 so that we are sure we're indexing into the initializer.
-  if (ConstantInt *Idx = dyn_cast<ConstantInt>(GEP->getOperand(1))) {
-    if (!Idx->isZero())
-      return false;
-  } else
-    return false;
-
-  // If the second index isn't a ConstantInt, then this is a variable index
-  // into the array.  If this occurs, we can't say anything meaningful about
-  // the string.
-  uint64_t StartIdx = 0;
-  if (ConstantInt *CI = dyn_cast<ConstantInt>(GEP->getOperand(2)))
-    StartIdx = CI->getZExtValue();
-  else
-    return false;
-
-  // The GEP instruction, constant or instruction, must reference a global
-  // variable that is a constant and is initialized. The referenced constant
-  // initializer is the array that we'll use for optimization.
-  GlobalVariable* GV = dyn_cast<GlobalVariable>(GEP->getOperand(0));
-  if (!GV || !GV->isConstant() || !GV->hasInitializer())
-    return false;
-  Constant *GlobalInit = GV->getInitializer();
-
-  // Handle the ConstantAggregateZero case
-  if (isa<ConstantAggregateZero>(GlobalInit)) {
-    // This is a degenerate case. The initializer is constant zero so the
-    // length of the string must be zero.
-    Str.clear();
-    return true;
-  }
-
-  // Must be a Constant Array
-  ConstantArray *Array = dyn_cast<ConstantArray>(GlobalInit);
-  if (!Array) return false;
-
-  // Get the number of elements in the array
-  uint64_t NumElts = Array->getType()->getNumElements();
-
-  // Traverse the constant array from StartIdx (derived above) which is
-  // the place the GEP refers to in the array.
-  for (unsigned i = StartIdx; i < NumElts; ++i) {
-    Constant *Elt = Array->getOperand(i);
-    ConstantInt *CI = dyn_cast<ConstantInt>(Elt);
-    if (!CI) // This array isn't suitable, non-int initializer.
-      return false;
-    if (CI->isZero())
-      return true; // we found end of string, success!
-    Str += (char)CI->getZExtValue();
-  }
-  
-  return false; // The array isn't null terminated.
-}
-
-/// GetStringLengthH - If we can compute the length of the string pointed to by
-/// the specified pointer, return 'len+1'.  If we can't, return 0.
-static uint64_t GetStringLengthH(Value *V, SmallPtrSet<PHINode*, 32> &PHIs) {
-  // Look through noop bitcast instructions.
-  if (BitCastInst *BCI = dyn_cast<BitCastInst>(V))
-    return GetStringLengthH(BCI->getOperand(0), PHIs);
-  
-  // If this is a PHI node, there are two cases: either we have already seen it
-  // or we haven't.
-  if (PHINode *PN = dyn_cast<PHINode>(V)) {
-    if (!PHIs.insert(PN))
-      return ~0ULL;  // already in the set.
-
-    // If it was new, see if all the input strings are the same length.
-    uint64_t LenSoFar = ~0ULL;
-    for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
-      uint64_t Len = GetStringLengthH(PN->getIncomingValue(i), PHIs);
-      if (Len == 0) return 0; // Unknown length -> unknown.
-      
-      if (Len == ~0ULL) continue;
-      
-      if (Len != LenSoFar && LenSoFar != ~0ULL)
-        return 0;    // Disagree -> unknown.
-      LenSoFar = Len;
-    }
-    
-    // Success, all agree.
-    return LenSoFar;
-  }
-  
-  // strlen(select(c,x,y)) -> strlen(x) ^ strlen(y)
-  if (SelectInst *SI = dyn_cast<SelectInst>(V)) {
-    uint64_t Len1 = GetStringLengthH(SI->getTrueValue(), PHIs);
-    if (Len1 == 0) return 0;
-    uint64_t Len2 = GetStringLengthH(SI->getFalseValue(), PHIs);
-    if (Len2 == 0) return 0;
-    if (Len1 == ~0ULL) return Len2;
-    if (Len2 == ~0ULL) return Len1;
-    if (Len1 != Len2) return 0;
-    return Len1;
-  }
-  
-  // If the value is not a GEP instruction nor a constant expression with a
-  // GEP instruction, then return unknown.
-  User *GEP = 0;
-  if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(V)) {
-    GEP = GEPI;
-  } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
-    if (CE->getOpcode() != Instruction::GetElementPtr)
-      return 0;
-    GEP = CE;
-  } else {
-    return 0;
-  }
-  
-  // Make sure the GEP has exactly three arguments.
-  if (GEP->getNumOperands() != 3)
-    return 0;
-  
-  // Check to make sure that the first operand of the GEP is an integer and
-  // has value 0 so that we are sure we're indexing into the initializer.
-  if (ConstantInt *Idx = dyn_cast<ConstantInt>(GEP->getOperand(1))) {
-    if (!Idx->isZero())
-      return 0;
-  } else
-    return 0;
-  
-  // If the second index isn't a ConstantInt, then this is a variable index
-  // into the array.  If this occurs, we can't say anything meaningful about
-  // the string.
-  uint64_t StartIdx = 0;
-  if (ConstantInt *CI = dyn_cast<ConstantInt>(GEP->getOperand(2)))
-    StartIdx = CI->getZExtValue();
-  else
-    return 0;
-  
-  // The GEP instruction, constant or instruction, must reference a global
-  // variable that is a constant and is initialized. The referenced constant
-  // initializer is the array that we'll use for optimization.
-  GlobalVariable* GV = dyn_cast<GlobalVariable>(GEP->getOperand(0));
-  if (!GV || !GV->isConstant() || !GV->hasInitializer())
-    return 0;
-  Constant *GlobalInit = GV->getInitializer();
-  
-  // Handle the ConstantAggregateZero case, which is a degenerate case. The
-  // initializer is constant zero so the length of the string must be zero.
-  if (isa<ConstantAggregateZero>(GlobalInit))
-    return 1;  // Len = 0 offset by 1.
-  
-  // Must be a Constant Array
-  ConstantArray *Array = dyn_cast<ConstantArray>(GlobalInit);
-  if (!Array || Array->getType()->getElementType() != Type::Int8Ty)
-    return false;
-  
-  // Get the number of elements in the array
-  uint64_t NumElts = Array->getType()->getNumElements();
-  
-  // Traverse the constant array from StartIdx (derived above) which is
-  // the place the GEP refers to in the array.
-  for (unsigned i = StartIdx; i != NumElts; ++i) {
-    Constant *Elt = Array->getOperand(i);
-    ConstantInt *CI = dyn_cast<ConstantInt>(Elt);
-    if (!CI) // This array isn't suitable, non-int initializer.
-      return 0;
-    if (CI->isZero())
-      return i-StartIdx+1; // We found end of string, success!
-  }
-  
-  return 0; // The array isn't null terminated, conservatively return 'unknown'.
-}
-  
-/// GetStringLength - If we can compute the length of the string pointed to by
-/// the specified pointer, return 'len+1'.  If we can't, return 0.
-static uint64_t GetStringLength(Value *V) {
-  if (!isa<PointerType>(V->getType())) return 0;
-
-  SmallPtrSet<PHINode*, 32> PHIs;
-  uint64_t Len = GetStringLengthH(V, PHIs);
-  // If Len is ~0ULL, we had an infinite phi cycle: this is dead code, so return
-  // an empty string as a length.
-  return Len == ~0ULL ? 1 : Len;
-}
-
-  
-  
-/// CastToCStr - Return V if it is an sbyte*, otherwise cast it to sbyte*,
-/// inserting the cast before IP, and return the cast.
-/// @brief Cast a value to a "C" string.
-static Value *CastToCStr(Value *V, Instruction *IP) {
-  assert(isa<PointerType>(V->getType()) && 
-         "Can't cast non-pointer type to C string type");
-  const Type *SBPTy = PointerType::getUnqual(Type::Int8Ty);
-  if (V->getType() != SBPTy)
-    return new BitCastInst(V, SBPTy, V->getName(), IP);
-  return V;
-}
-
-// 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(sqrt(x))  -> pow(x,1/9)
-//
-// cos, cosf, cosl:
-//   * cos(-x)  -> cos(x)
-//
-// exp, expf, expl:
-//   * exp(log(x))  -> x
-//
-// log, logf, logl:
-//   * log(exp(x))   -> x
-//   * log(x**y)     -> y*log(x)
-//   * log(exp(y))   -> y*log(e)
-//   * log(exp2(y))  -> y*log(2)
-//   * log(exp10(y)) -> y*log(10)
-//   * log(sqrt(x))  -> 0.5*log(x)
-//   * log(pow(x,y)) -> y*log(x)
-//
-// lround, lroundf, lroundl:
-//   * lround(cnst) -> cnst'
-//
-// memcmp:
-//   * memcmp(x,y,l)   -> cnst
-//      (if all arguments are constant and strlen(x) <= l and strlen(y) <= l)
-//
-// memmove:
-//   * memmove(d,s,l,a) -> memcpy(d,s,l,a)
-//       (if s is a global constant array)
-//
-// pow, powf, powl:
-//   * pow(exp(x),y)  -> exp(x*y)
-//   * pow(sqrt(x),y) -> pow(x,y*0.5)
-//   * pow(pow(x,y),z)-> pow(x,y*z)
-//
-// puts:
-//   * puts("") -> putchar("\n")
-//
-// round, roundf, roundl:
-//   * round(cnst) -> cnst'
-//
-// 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)
-//
-// stpcpy:
-//   * stpcpy(str, "literal") ->
-//           llvm.memcpy(str,"literal",strlen("literal")+1,1)
-// strrchr:
-//   * strrchr(s,c) -> reverse_offset_of_in(c,s)
-//      (if c is a constant integer and s is a constant string)
-//   * strrchr(s1,0) -> strchr(s1,0)
-//
-// strncat:
-//   * strncat(x,y,0) -> x
-//   * strncat(x,y,0) -> x (if strlen(y) = 0)
-//   * strncat(x,y,l) -> strcat(x,y) (if y and l are constants an l > strlen(y))
-//
-// strncpy:
-//   * strncpy(d,s,0) -> d
-//   * strncpy(d,s,l) -> memcpy(d,s,l,1)
-//      (if s and l are constants)
-//
-// strpbrk:
-//   * strpbrk(s,a) -> offset_in_for(s,a)
-//      (if s and a are both constant strings)
-//   * strpbrk(s,"") -> 0
-//   * strpbrk(s,a) -> strchr(s,a[0]) (if a is constant string of length 1)
-//
-// strspn, strcspn:
-//   * strspn(s,a)   -> const_int (if both args are constant)
-//   * strspn("",a)  -> 0
-//   * strspn(s,"")  -> 0
-//   * strcspn(s,a)  -> const_int (if both args are constant)
-//   * strcspn("",a) -> 0
-//   * strcspn(s,"") -> strlen(a)
-//
-// strstr:
-//   * strstr(x,x)  -> x
-//   * strstr(s1,s2) -> offset_of_s2_in(s1)
-//       (if s1 and s2 are constant strings)
-//
-// tan, tanf, tanl:
-//   * tan(atan(x)) -> x
-//
-// trunc, truncf, truncl:
-//   * trunc(cnst) -> cnst'
-//
-//