+void LibCallSimplifier::replaceTrigInsts(SmallVectorImpl<CallInst *> &Calls,
+ Value *Res) {
+ for (SmallVectorImpl<CallInst *>::iterator I = Calls.begin(), E = Calls.end();
+ I != E; ++I) {
+ replaceAllUsesWith(*I, Res);
+ }
+}
+
+void insertSinCosCall(IRBuilder<> &B, Function *OrigCallee, Value *Arg,
+ bool UseFloat, Value *&Sin, Value *&Cos, Value *&SinCos) {
+ Type *ArgTy = Arg->getType();
+ Type *ResTy;
+ StringRef Name;
+
+ Triple T(OrigCallee->getParent()->getTargetTriple());
+ if (UseFloat) {
+ Name = "__sincospif_stret";
+
+ assert(T.getArch() != Triple::x86 && "x86 messy and unsupported for now");
+ // x86_64 can't use {float, float} since that would be returned in both
+ // xmm0 and xmm1, which isn't what a real struct would do.
+ ResTy = T.getArch() == Triple::x86_64
+ ? static_cast<Type *>(VectorType::get(ArgTy, 2))
+ : static_cast<Type *>(StructType::get(ArgTy, ArgTy, nullptr));
+ } else {
+ Name = "__sincospi_stret";
+ ResTy = StructType::get(ArgTy, ArgTy, nullptr);
+ }
+
+ Module *M = OrigCallee->getParent();
+ Value *Callee = M->getOrInsertFunction(Name, OrigCallee->getAttributes(),
+ ResTy, ArgTy, nullptr);
+
+ if (Instruction *ArgInst = dyn_cast<Instruction>(Arg)) {
+ // If the argument is an instruction, it must dominate all uses so put our
+ // sincos call there.
+ BasicBlock::iterator Loc = ArgInst;
+ B.SetInsertPoint(ArgInst->getParent(), ++Loc);
+ } else {
+ // Otherwise (e.g. for a constant) the beginning of the function is as
+ // good a place as any.
+ BasicBlock &EntryBB = B.GetInsertBlock()->getParent()->getEntryBlock();
+ B.SetInsertPoint(&EntryBB, EntryBB.begin());
+ }
+
+ SinCos = B.CreateCall(Callee, Arg, "sincospi");
+
+ if (SinCos->getType()->isStructTy()) {
+ Sin = B.CreateExtractValue(SinCos, 0, "sinpi");
+ Cos = B.CreateExtractValue(SinCos, 1, "cospi");
+ } else {
+ Sin = B.CreateExtractElement(SinCos, ConstantInt::get(B.getInt32Ty(), 0),
+ "sinpi");
+ Cos = B.CreateExtractElement(SinCos, ConstantInt::get(B.getInt32Ty(), 1),
+ "cospi");
+ }
+}
+
+//===----------------------------------------------------------------------===//
+// Integer Library Call Optimizations
+//===----------------------------------------------------------------------===//
+
+Value *LibCallSimplifier::optimizeFFS(CallInst *CI, IRBuilder<> &B) {
+ Function *Callee = CI->getCalledFunction();
+ FunctionType *FT = Callee->getFunctionType();
+ // Just make sure this has 2 arguments of the same FP type, which match the
+ // result type.
+ if (FT->getNumParams() != 1 || !FT->getReturnType()->isIntegerTy(32) ||
+ !FT->getParamType(0)->isIntegerTy())
+ return nullptr;
+
+ Value *Op = CI->getArgOperand(0);
+
+ // Constant fold.
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(Op)) {
+ if (CI->isZero()) // ffs(0) -> 0.
+ return B.getInt32(0);
+ // ffs(c) -> cttz(c)+1
+ return B.getInt32(CI->getValue().countTrailingZeros() + 1);
+ }
+
+ // ffs(x) -> x != 0 ? (i32)llvm.cttz(x)+1 : 0
+ Type *ArgType = Op->getType();
+ Value *F =
+ Intrinsic::getDeclaration(Callee->getParent(), Intrinsic::cttz, ArgType);
+ Value *V = B.CreateCall2(F, Op, B.getFalse(), "cttz");
+ V = B.CreateAdd(V, ConstantInt::get(V->getType(), 1));
+ V = B.CreateIntCast(V, B.getInt32Ty(), false);
+
+ Value *Cond = B.CreateICmpNE(Op, Constant::getNullValue(ArgType));
+ return B.CreateSelect(Cond, V, B.getInt32(0));
+}
+
+Value *LibCallSimplifier::optimizeAbs(CallInst *CI, IRBuilder<> &B) {
+ Function *Callee = CI->getCalledFunction();
+ FunctionType *FT = Callee->getFunctionType();
+ // We require integer(integer) where the types agree.
+ if (FT->getNumParams() != 1 || !FT->getReturnType()->isIntegerTy() ||
+ FT->getParamType(0) != FT->getReturnType())
+ return nullptr;
+
+ // abs(x) -> x >s -1 ? x : -x
+ Value *Op = CI->getArgOperand(0);
+ Value *Pos =
+ B.CreateICmpSGT(Op, Constant::getAllOnesValue(Op->getType()), "ispos");
+ Value *Neg = B.CreateNeg(Op, "neg");
+ return B.CreateSelect(Pos, Op, Neg);
+}
+
+Value *LibCallSimplifier::optimizeIsDigit(CallInst *CI, IRBuilder<> &B) {
+ Function *Callee = CI->getCalledFunction();
+ FunctionType *FT = Callee->getFunctionType();
+ // We require integer(i32)
+ if (FT->getNumParams() != 1 || !FT->getReturnType()->isIntegerTy() ||
+ !FT->getParamType(0)->isIntegerTy(32))
+ return nullptr;
+
+ // isdigit(c) -> (c-'0') <u 10
+ Value *Op = CI->getArgOperand(0);
+ Op = B.CreateSub(Op, B.getInt32('0'), "isdigittmp");
+ Op = B.CreateICmpULT(Op, B.getInt32(10), "isdigit");
+ return B.CreateZExt(Op, CI->getType());
+}
+
+Value *LibCallSimplifier::optimizeIsAscii(CallInst *CI, IRBuilder<> &B) {
+ Function *Callee = CI->getCalledFunction();
+ FunctionType *FT = Callee->getFunctionType();
+ // We require integer(i32)
+ if (FT->getNumParams() != 1 || !FT->getReturnType()->isIntegerTy() ||
+ !FT->getParamType(0)->isIntegerTy(32))
+ return nullptr;
+
+ // isascii(c) -> c <u 128
+ Value *Op = CI->getArgOperand(0);
+ Op = B.CreateICmpULT(Op, B.getInt32(128), "isascii");
+ return B.CreateZExt(Op, CI->getType());
+}
+
+Value *LibCallSimplifier::optimizeToAscii(CallInst *CI, IRBuilder<> &B) {
+ Function *Callee = CI->getCalledFunction();
+ FunctionType *FT = Callee->getFunctionType();
+ // We require i32(i32)
+ if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
+ !FT->getParamType(0)->isIntegerTy(32))
+ return nullptr;
+
+ // toascii(c) -> c & 0x7f
+ return B.CreateAnd(CI->getArgOperand(0),
+ ConstantInt::get(CI->getType(), 0x7F));
+}
+
+//===----------------------------------------------------------------------===//
+// Formatting and IO Library Call Optimizations
+//===----------------------------------------------------------------------===//
+
+static bool isReportingError(Function *Callee, CallInst *CI, int StreamArg);
+
+Value *LibCallSimplifier::optimizeErrorReporting(CallInst *CI, IRBuilder<> &B,
+ int StreamArg) {
+ // Error reporting calls should be cold, mark them as such.
+ // This applies even to non-builtin calls: it is only a hint and applies to
+ // functions that the frontend might not understand as builtins.
+
+ // This heuristic was suggested in:
+ // Improving Static Branch Prediction in a Compiler
+ // Brian L. Deitrich, Ben-Chung Cheng, Wen-mei W. Hwu
+ // Proceedings of PACT'98, Oct. 1998, IEEE
+ Function *Callee = CI->getCalledFunction();
+
+ if (!CI->hasFnAttr(Attribute::Cold) &&
+ isReportingError(Callee, CI, StreamArg)) {
+ CI->addAttribute(AttributeSet::FunctionIndex, Attribute::Cold);
+ }
+
+ return nullptr;
+}
+
+static bool isReportingError(Function *Callee, CallInst *CI, int StreamArg) {
+ if (!ColdErrorCalls)
+ return false;
+
+ if (!Callee || !Callee->isDeclaration())
+ return false;
+
+ if (StreamArg < 0)
+ return true;
+
+ // These functions might be considered cold, but only if their stream
+ // argument is stderr.
+
+ if (StreamArg >= (int)CI->getNumArgOperands())
+ return false;
+ LoadInst *LI = dyn_cast<LoadInst>(CI->getArgOperand(StreamArg));
+ if (!LI)
+ return false;
+ GlobalVariable *GV = dyn_cast<GlobalVariable>(LI->getPointerOperand());
+ if (!GV || !GV->isDeclaration())
+ return false;
+ return GV->getName() == "stderr";
+}
+
+Value *LibCallSimplifier::optimizePrintFString(CallInst *CI, IRBuilder<> &B) {
+ // Check for a fixed format string.
+ StringRef FormatStr;
+ if (!getConstantStringInfo(CI->getArgOperand(0), FormatStr))
+ return nullptr;
+
+ // Empty format string -> noop.
+ if (FormatStr.empty()) // Tolerate printf's declared void.
+ return CI->use_empty() ? (Value *)CI : ConstantInt::get(CI->getType(), 0);
+
+ // Do not do any of the following transformations if the printf return value
+ // is used, in general the printf return value is not compatible with either
+ // putchar() or puts().
+ if (!CI->use_empty())
+ return nullptr;
+
+ // printf("x") -> putchar('x'), even for '%'.
+ if (FormatStr.size() == 1) {
+ Value *Res = EmitPutChar(B.getInt32(FormatStr[0]), B, DL, TLI);
+ if (CI->use_empty() || !Res)
+ return Res;
+ return B.CreateIntCast(Res, CI->getType(), true);
+ }
+
+ // printf("foo\n") --> puts("foo")
+ if (FormatStr[FormatStr.size() - 1] == '\n' &&
+ FormatStr.find('%') == StringRef::npos) { // No format characters.
+ // 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 = FormatStr.drop_back();
+ Value *GV = B.CreateGlobalString(FormatStr, "str");
+ Value *NewCI = EmitPutS(GV, B, DL, TLI);
+ return (CI->use_empty() || !NewCI)
+ ? NewCI
+ : ConstantInt::get(CI->getType(), FormatStr.size() + 1);
+ }
+
+ // Optimize specific format strings.
+ // printf("%c", chr) --> putchar(chr)
+ if (FormatStr == "%c" && CI->getNumArgOperands() > 1 &&
+ CI->getArgOperand(1)->getType()->isIntegerTy()) {
+ Value *Res = EmitPutChar(CI->getArgOperand(1), B, DL, TLI);
+
+ if (CI->use_empty() || !Res)
+ return Res;
+ return B.CreateIntCast(Res, CI->getType(), true);
+ }
+
+ // printf("%s\n", str) --> puts(str)
+ if (FormatStr == "%s\n" && CI->getNumArgOperands() > 1 &&
+ CI->getArgOperand(1)->getType()->isPointerTy()) {
+ return EmitPutS(CI->getArgOperand(1), B, DL, TLI);
+ }
+ return nullptr;
+}
+
+Value *LibCallSimplifier::optimizePrintF(CallInst *CI, IRBuilder<> &B) {
+
+ Function *Callee = CI->getCalledFunction();
+ // Require one fixed pointer argument and an integer/void result.
+ FunctionType *FT = Callee->getFunctionType();
+ if (FT->getNumParams() < 1 || !FT->getParamType(0)->isPointerTy() ||
+ !(FT->getReturnType()->isIntegerTy() || FT->getReturnType()->isVoidTy()))
+ return nullptr;
+
+ if (Value *V = optimizePrintFString(CI, B)) {
+ return V;
+ }
+
+ // printf(format, ...) -> iprintf(format, ...) if no floating point
+ // arguments.
+ if (TLI->has(LibFunc::iprintf) && !callHasFloatingPointArgument(CI)) {
+ Module *M = B.GetInsertBlock()->getParent()->getParent();
+ Constant *IPrintFFn =
+ M->getOrInsertFunction("iprintf", FT, Callee->getAttributes());
+ CallInst *New = cast<CallInst>(CI->clone());
+ New->setCalledFunction(IPrintFFn);
+ B.Insert(New);
+ return New;
+ }
+ return nullptr;
+}
+
+Value *LibCallSimplifier::optimizeSPrintFString(CallInst *CI, IRBuilder<> &B) {
+ // Check for a fixed format string.
+ StringRef FormatStr;
+ if (!getConstantStringInfo(CI->getArgOperand(1), FormatStr))
+ return nullptr;
+
+ // If we just have a format string (nothing else crazy) transform it.
+ if (CI->getNumArgOperands() == 2) {
+ // Make sure there's no % in the constant array. We could try to handle
+ // %% -> % in the future if we cared.
+ for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
+ if (FormatStr[i] == '%')
+ return nullptr; // we found a format specifier, bail out.
+
+ // These optimizations require DataLayout.
+ if (!DL)
+ return nullptr;
+
+ // sprintf(str, fmt) -> llvm.memcpy(str, fmt, strlen(fmt)+1, 1)
+ B.CreateMemCpy(
+ CI->getArgOperand(0), CI->getArgOperand(1),
+ ConstantInt::get(DL->getIntPtrType(CI->getContext()),
+ FormatStr.size() + 1),
+ 1); // Copy the null byte.
+ return ConstantInt::get(CI->getType(), FormatStr.size());
+ }
+
+ // The remaining optimizations require the format string to be "%s" or "%c"
+ // and have an extra operand.
+ if (FormatStr.size() != 2 || FormatStr[0] != '%' ||
+ CI->getNumArgOperands() < 3)
+ return nullptr;
+
+ // Decode the second character of the format string.
+ if (FormatStr[1] == 'c') {
+ // sprintf(dst, "%c", chr) --> *(i8*)dst = chr; *((i8*)dst+1) = 0
+ if (!CI->getArgOperand(2)->getType()->isIntegerTy())
+ return nullptr;
+ Value *V = B.CreateTrunc(CI->getArgOperand(2), B.getInt8Ty(), "char");
+ Value *Ptr = CastToCStr(CI->getArgOperand(0), B);
+ B.CreateStore(V, Ptr);
+ Ptr = B.CreateGEP(Ptr, B.getInt32(1), "nul");
+ B.CreateStore(B.getInt8(0), Ptr);
+
+ return ConstantInt::get(CI->getType(), 1);
+ }
+
+ if (FormatStr[1] == 's') {
+ // These optimizations require DataLayout.
+ if (!DL)
+ return nullptr;
+
+ // sprintf(dest, "%s", str) -> llvm.memcpy(dest, str, strlen(str)+1, 1)
+ if (!CI->getArgOperand(2)->getType()->isPointerTy())
+ return nullptr;
+
+ Value *Len = EmitStrLen(CI->getArgOperand(2), B, DL, TLI);
+ if (!Len)
+ return nullptr;
+ Value *IncLen =
+ B.CreateAdd(Len, ConstantInt::get(Len->getType(), 1), "leninc");
+ B.CreateMemCpy(CI->getArgOperand(0), CI->getArgOperand(2), IncLen, 1);
+
+ // The sprintf result is the unincremented number of bytes in the string.
+ return B.CreateIntCast(Len, CI->getType(), false);
+ }
+ return nullptr;
+}