return true;
}
+static bool callHasFloatingPointArgument(const CallInst *CI) {
+ for (CallInst::const_op_iterator it = CI->op_begin(), e = CI->op_end();
+ it != e; ++it) {
+ if ((*it)->getType()->isFloatingPointTy())
+ return true;
+ }
+ return false;
+}
+
//===----------------------------------------------------------------------===//
// Fortified Library Call Optimizations
//===----------------------------------------------------------------------===//
!FT->getParamType(0)->isIntegerTy(32))
return 0;
- // isascii(c) -> c & 0x7f
+ // toascii(c) -> c & 0x7f
return B.CreateAnd(CI->getArgOperand(0),
ConstantInt::get(CI->getType(),0x7F));
}
};
+//===----------------------------------------------------------------------===//
+// Formatting and IO Library Call Optimizations
+//===----------------------------------------------------------------------===//
+
+struct PrintFOpt : public LibCallOptimization {
+ Value *optimizeFixedFormatString(Function *Callee, CallInst *CI,
+ IRBuilder<> &B) {
+ // Check for a fixed format string.
+ StringRef FormatStr;
+ if (!getConstantStringInfo(CI->getArgOperand(0), FormatStr))
+ return 0;
+
+ // 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 0;
+
+ // printf("x") -> putchar('x'), even for '%'.
+ if (FormatStr.size() == 1) {
+ Value *Res = EmitPutChar(B.getInt32(FormatStr[0]), B, TD, 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('%') == std::string::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, TD, 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, TD, 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, TD, TLI);
+ }
+ return 0;
+ }
+
+ virtual Value *callOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
+ // 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 0;
+
+ if (Value *V = optimizeFixedFormatString(Callee, 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 0;
+ }
+};
+
+struct SPrintFOpt : public LibCallOptimization {
+ Value *OptimizeFixedFormatString(Function *Callee, CallInst *CI,
+ IRBuilder<> &B) {
+ // Check for a fixed format string.
+ StringRef FormatStr;
+ if (!getConstantStringInfo(CI->getArgOperand(1), FormatStr))
+ return 0;
+
+ // 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 0; // we found a format specifier, bail out.
+
+ // These optimizations require DataLayout.
+ if (!TD) return 0;
+
+ // sprintf(str, fmt) -> llvm.memcpy(str, fmt, strlen(fmt)+1, 1)
+ B.CreateMemCpy(CI->getArgOperand(0), CI->getArgOperand(1),
+ ConstantInt::get(TD->getIntPtrType(*Context), // Copy the
+ FormatStr.size() + 1), 1); // nul 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 0;
+
+ // 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 0;
+ 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 (!TD) return 0;
+
+ // sprintf(dest, "%s", str) -> llvm.memcpy(dest, str, strlen(str)+1, 1)
+ if (!CI->getArgOperand(2)->getType()->isPointerTy()) return 0;
+
+ Value *Len = EmitStrLen(CI->getArgOperand(2), B, TD, TLI);
+ if (!Len)
+ return 0;
+ 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 0;
+ }
+
+ virtual Value *callOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
+ // Require two fixed pointer arguments and an integer result.
+ FunctionType *FT = Callee->getFunctionType();
+ if (FT->getNumParams() != 2 || !FT->getParamType(0)->isPointerTy() ||
+ !FT->getParamType(1)->isPointerTy() ||
+ !FT->getReturnType()->isIntegerTy())
+ return 0;
+
+ if (Value *V = OptimizeFixedFormatString(Callee, CI, B)) {
+ return V;
+ }
+
+ // sprintf(str, format, ...) -> siprintf(str, format, ...) if no floating
+ // point arguments.
+ if (TLI->has(LibFunc::siprintf) && !callHasFloatingPointArgument(CI)) {
+ Module *M = B.GetInsertBlock()->getParent()->getParent();
+ Constant *SIPrintFFn =
+ M->getOrInsertFunction("siprintf", FT, Callee->getAttributes());
+ CallInst *New = cast<CallInst>(CI->clone());
+ New->setCalledFunction(SIPrintFFn);
+ B.Insert(New);
+ return New;
+ }
+ return 0;
+ }
+};
+
+struct FPrintFOpt : public LibCallOptimization {
+ Value *optimizeFixedFormatString(Function *Callee, CallInst *CI,
+ IRBuilder<> &B) {
+ // All the optimizations depend on the format string.
+ StringRef FormatStr;
+ if (!getConstantStringInfo(CI->getArgOperand(1), FormatStr))
+ return 0;
+
+ // fprintf(F, "foo") --> fwrite("foo", 3, 1, F)
+ if (CI->getNumArgOperands() == 2) {
+ for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
+ if (FormatStr[i] == '%') // Could handle %% -> % if we cared.
+ return 0; // We found a format specifier.
+
+ // These optimizations require DataLayout.
+ if (!TD) return 0;
+
+ Value *NewCI = EmitFWrite(CI->getArgOperand(1),
+ ConstantInt::get(TD->getIntPtrType(*Context),
+ FormatStr.size()),
+ CI->getArgOperand(0), B, TD, TLI);
+ return NewCI ? ConstantInt::get(CI->getType(), FormatStr.size()) : 0;
+ }
+
+ // 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 0;
+
+ // Decode the second character of the format string.
+ if (FormatStr[1] == 'c') {
+ // fprintf(F, "%c", chr) --> fputc(chr, F)
+ if (!CI->getArgOperand(2)->getType()->isIntegerTy()) return 0;
+ Value *NewCI = EmitFPutC(CI->getArgOperand(2), CI->getArgOperand(0), B,
+ TD, TLI);
+ return NewCI ? ConstantInt::get(CI->getType(), 1) : 0;
+ }
+
+ if (FormatStr[1] == 's') {
+ // fprintf(F, "%s", str) --> fputs(str, F)
+ if (!CI->getArgOperand(2)->getType()->isPointerTy() || !CI->use_empty())
+ return 0;
+ return EmitFPutS(CI->getArgOperand(2), CI->getArgOperand(0), B, TD, TLI);
+ }
+ return 0;
+ }
+
+ virtual Value *callOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
+ // Require two fixed paramters as pointers and integer result.
+ FunctionType *FT = Callee->getFunctionType();
+ if (FT->getNumParams() != 2 || !FT->getParamType(0)->isPointerTy() ||
+ !FT->getParamType(1)->isPointerTy() ||
+ !FT->getReturnType()->isIntegerTy())
+ return 0;
+
+ if (Value *V = optimizeFixedFormatString(Callee, CI, B)) {
+ return V;
+ }
+
+ // fprintf(stream, format, ...) -> fiprintf(stream, format, ...) if no
+ // floating point arguments.
+ if (TLI->has(LibFunc::fiprintf) && !callHasFloatingPointArgument(CI)) {
+ Module *M = B.GetInsertBlock()->getParent()->getParent();
+ Constant *FIPrintFFn =
+ M->getOrInsertFunction("fiprintf", FT, Callee->getAttributes());
+ CallInst *New = cast<CallInst>(CI->clone());
+ New->setCalledFunction(FIPrintFFn);
+ B.Insert(New);
+ return New;
+ }
+ return 0;
+ }
+};
+
+struct FWriteOpt : public LibCallOptimization {
+ virtual Value *callOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
+ // Require a pointer, an integer, an integer, a pointer, returning integer.
+ FunctionType *FT = Callee->getFunctionType();
+ if (FT->getNumParams() != 4 || !FT->getParamType(0)->isPointerTy() ||
+ !FT->getParamType(1)->isIntegerTy() ||
+ !FT->getParamType(2)->isIntegerTy() ||
+ !FT->getParamType(3)->isPointerTy() ||
+ !FT->getReturnType()->isIntegerTy())
+ return 0;
+
+ // Get the element size and count.
+ ConstantInt *SizeC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
+ ConstantInt *CountC = dyn_cast<ConstantInt>(CI->getArgOperand(2));
+ if (!SizeC || !CountC) return 0;
+ uint64_t Bytes = SizeC->getZExtValue()*CountC->getZExtValue();
+
+ // If this is writing zero records, remove the call (it's a noop).
+ if (Bytes == 0)
+ return ConstantInt::get(CI->getType(), 0);
+
+ // If this is writing one byte, turn it into fputc.
+ // This optimisation is only valid, if the return value is unused.
+ if (Bytes == 1 && CI->use_empty()) { // fwrite(S,1,1,F) -> fputc(S[0],F)
+ Value *Char = B.CreateLoad(CastToCStr(CI->getArgOperand(0), B), "char");
+ Value *NewCI = EmitFPutC(Char, CI->getArgOperand(3), B, TD, TLI);
+ return NewCI ? ConstantInt::get(CI->getType(), 1) : 0;
+ }
+
+ return 0;
+ }
+};
+
} // End anonymous namespace.
namespace llvm {
IsAsciiOpt IsAscii;
ToAsciiOpt ToAscii;
+ // Formatting and IO library call optimizations.
+ PrintFOpt PrintF;
+ SPrintFOpt SPrintF;
+ FPrintFOpt FPrintF;
+ FWriteOpt FWrite;
+
void initOptimizations();
void addOpt(LibFunc::Func F, LibCallOptimization* Opt);
void addOpt(LibFunc::Func F1, LibFunc::Func F2, LibCallOptimization* Opt);
addOpt(LibFunc::isdigit, &IsDigit);
addOpt(LibFunc::isascii, &IsAscii);
addOpt(LibFunc::toascii, &ToAscii);
+
+ // Formatting and IO library call optimizations.
+ addOpt(LibFunc::printf, &PrintF);
+ addOpt(LibFunc::sprintf, &SPrintF);
+ addOpt(LibFunc::fprintf, &FPrintF);
+ addOpt(LibFunc::fwrite, &FWrite);
}
Value *LibCallSimplifierImpl::optimizeCall(CallInst *CI) {
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