//
// The LLVM Compiler Infrastructure
//
-// This file was developed by Reid Spencer and is distributed under the
-// University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
#include "llvm/Instructions.h"
#include "llvm/Module.h"
#include "llvm/Pass.h"
-#include "llvm/ADT/hash_map"
+#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
/// 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 LibCallOptimization {
+class VISIBILITY_HIDDEN LibCallOptimization {
LibCallOptimization **Prev, *Next;
const char *FunctionName; ///< Name of the library call we optimize
#ifndef NDEBUG
/// @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
/// 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 SimplifyLibCalls : public ModulePass {
+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.
reset(M);
bool result = false;
- hash_map<std::string, LibCallOptimization*> OptznMap;
+ StringMap<LibCallOptimization*> OptznMap;
for (LibCallOptimization *Optzn = OptList; Optzn; Optzn = Optzn->getNext())
OptznMap[Optzn->getFunctionName()] = Optzn;
// 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->isExternal() ||
+ if (!FI->isDeclaration() ||
!(FI->hasExternalLinkage() || FI->hasDLLImportLinkage()) ||
FI->use_empty())
continue;
// Get the optimization class that pertains to this function
- hash_map<std::string, LibCallOptimization*>::iterator OMI =
+ StringMap<LibCallOptimization*>::iterator OMI =
OptznMap.find(FI->getName());
if (OMI == OptznMap.end()) continue;
Constant *get_puts() {
if (!puts_func)
puts_func = M->getOrInsertFunction("puts", Type::Int32Ty,
- PointerType::get(Type::Int8Ty),
+ PointerType::getUnqual(Type::Int8Ty),
NULL);
return puts_func;
}
Constant *get_fputs(const Type* FILEptr_type) {
if (!fputs_func)
fputs_func = M->getOrInsertFunction("fputs", Type::Int32Ty,
- PointerType::get(Type::Int8Ty),
+ PointerType::getUnqual(Type::Int8Ty),
FILEptr_type, NULL);
return fputs_func;
}
Constant *get_fwrite(const Type* FILEptr_type) {
if (!fwrite_func)
fwrite_func = M->getOrInsertFunction("fwrite", TD->getIntPtrType(),
- PointerType::get(Type::Int8Ty),
+ PointerType::getUnqual(Type::Int8Ty),
TD->getIntPtrType(),
TD->getIntPtrType(),
FILEptr_type, NULL);
return sqrt_func;
}
- /// @brief Return a Function* for the strlen libcall
+ /// @brief Return a Function* for the strcpy libcall
Constant *get_strcpy() {
if (!strcpy_func)
strcpy_func = M->getOrInsertFunction("strcpy",
- PointerType::get(Type::Int8Ty),
- PointerType::get(Type::Int8Ty),
- PointerType::get(Type::Int8Ty),
+ PointerType::getUnqual(Type::Int8Ty),
+ PointerType::getUnqual(Type::Int8Ty),
+ PointerType::getUnqual(Type::Int8Ty),
NULL);
return strcpy_func;
}
Constant *get_strlen() {
if (!strlen_func)
strlen_func = M->getOrInsertFunction("strlen", TD->getIntPtrType(),
- PointerType::get(Type::Int8Ty),
+ PointerType::getUnqual(Type::Int8Ty),
NULL);
return strlen_func;
}
Constant *get_memchr() {
if (!memchr_func)
memchr_func = M->getOrInsertFunction("memchr",
- PointerType::get(Type::Int8Ty),
- PointerType::get(Type::Int8Ty),
+ 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) {
- const Type *SBP = PointerType::get(Type::Int8Ty);
+ const Type *SBP = PointerType::getUnqual(Type::Int8Ty);
const char *N = TD->getIntPtrType() == Type::Int32Ty ?
"llvm.memcpy.i32" : "llvm.memcpy.i64";
memcpy_func = M->getOrInsertFunction(N, Type::VoidTy, SBP, SBP,
TargetData *TD; ///< Cached TargetData
};
+char SimplifyLibCalls::ID = 0;
// Register the pass
RegisterPass<SimplifyLibCalls>
X("simplify-libcalls", "Simplify well-known library calls");
namespace {
// Forward declare utility functions.
-bool getConstantStringLength(Value* V, uint64_t& len, ConstantArray** A = 0 );
-Value *CastToCStr(Value *V, Instruction &IP);
+static bool GetConstantStringInfo(Value *V, std::string &Str);
+static Value *CastToCStr(Value *V, Instruction *IP);
/// 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 ExitInMainOptimization : public LibCallOptimization {
+struct VISIBILITY_HIDDEN ExitInMainOptimization : public LibCallOptimization {
ExitInMainOptimization() : LibCallOptimization("exit",
"Number of 'exit' calls simplified") {}
// to exit have the same type.
Function *from = ci->getParent()->getParent();
if (from->hasExternalLinkage())
- if (from->getReturnType() == ci->getOperand(1)->getType())
+ 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
// 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.
- new ReturnInst(ci->getOperand(1), ci);
+ ReturnInst::Create(ci->getOperand(1), ci);
// Split the block at the call instruction which places it in a new
// basic block.
/// of the constant string. Both of these calls are further reduced, if possible
/// on subsequent passes.
/// @brief Simplify the strcat library function.
-struct StrCatOptimization : public LibCallOptimization {
+struct VISIBILITY_HIDDEN StrCatOptimization : public LibCallOptimization {
public:
/// @brief Default constructor
StrCatOptimization() : LibCallOptimization("strcat",
public:
/// @brief Make sure that the "strcat" function has the right prototype
- virtual bool ValidateCalledFunction(const Function* f, SimplifyLibCalls& SLC){
- if (f->getReturnType() == PointerType::get(Type::Int8Ty))
- if (f->arg_size() == 2)
- {
- Function::const_arg_iterator AI = f->arg_begin();
- if (AI++->getType() == PointerType::get(Type::Int8Ty))
- if (AI->getType() == PointerType::get(Type::Int8Ty))
- {
- // Indicate this is a suitable call type.
- return true;
- }
- }
- return false;
+ 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) {
+ virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
// Extract some information from the instruction
- Value* dest = ci->getOperand(1);
- Value* src = ci->getOperand(2);
+ Value *Dst = CI->getOperand(1);
+ Value *Src = CI->getOperand(2);
// Extract the initializer (while making numerous checks) from the
- // source operand of the call to strcat. If we get null back, one of
- // a variety of checks in get_GVInitializer failed
- uint64_t len = 0;
- if (!getConstantStringLength(src,len))
+ // source operand of the call to strcat.
+ std::string SrcStr;
+ if (!GetConstantStringInfo(Src, SrcStr))
return false;
// Handle the simple, do-nothing case
- if (len == 0) {
- ci->replaceAllUsesWith(dest);
- ci->eraseFromParent();
- return true;
- }
-
- // Increment the length because we actually want to memcpy the null
- // terminator as well.
- len++;
+ if (SrcStr.empty())
+ 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 (further
- // optimized in another pass). Note that the SLC.get_strlen() call
- // caches the Function* for us.
- CallInst* strlen_inst =
- new CallInst(SLC.get_strlen(), dest, dest->getName()+".len",ci);
+ // 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).
- std::vector<Value*> idx;
- idx.push_back(strlen_inst);
- GetElementPtrInst* gep =
- new GetElementPtrInst(dest,idx,dest->getName()+".indexed",ci);
+ 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.
- std::vector<Value*> vals;
- vals.push_back(gep); // destination
- vals.push_back(ci->getOperand(2)); // source
- vals.push_back(ConstantInt::get(SLC.getIntPtrType(),len)); // length
- vals.push_back(ConstantInt::get(Type::Int32Ty,1)); // alignment
- new CallInst(SLC.get_memcpy(), vals, "", ci);
-
- // Finally, substitute the first operand of the strcat call for the
- // strcat call itself since strcat returns its first operand; and,
- // kill the strcat CallInst.
- ci->replaceAllUsesWith(dest);
- ci->eraseFromParent();
- return true;
+ Value *Vals[] = {
+ Dst, Src,
+ ConstantInt::get(SLC.getIntPtrType(), SrcStr.size()+1), // copy nul byte.
+ ConstantInt::get(Type::Int32Ty, 1) // alignment
+ };
+ CallInst::Create(SLC.get_memcpy(), Vals, Vals + 4, "", CI);
+
+ return ReplaceCallWith(CI, Dst);
}
} StrCatOptimizer;
/// 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 StrChrOptimization : public LibCallOptimization {
+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){
- if (f->getReturnType() == PointerType::get(Type::Int8Ty) &&
- f->arg_size() == 2)
- return true;
- return false;
+ 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) {
- // If there aren't three operands, bail
- if (ci->getNumOperands() != 3)
- return false;
-
+ virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
// Check that the first argument to strchr is a constant array of sbyte.
- // If it is, get the length and data, otherwise return false.
- uint64_t len = 0;
- ConstantArray* CA = 0;
- if (!getConstantStringLength(ci->getOperand(1), len, &CA))
+ std::string Str;
+ if (!GetConstantStringInfo(CI->getOperand(1), Str))
return false;
- // Check that the second argument to strchr is a constant int. If it isn't
- // a constant signed integer, we can try an alternate optimization
- ConstantInt* CSI = dyn_cast<ConstantInt>(ci->getOperand(2));
+ // If the second operand is not constant, just lower this to memchr since we
+ // know the length of the input string.
+ ConstantInt *CSI = dyn_cast<ConstantInt>(CI->getOperand(2));
if (!CSI) {
- // The second operand is not constant, or not signed. Just lower this to
- // memchr since we know the length of the string since it is constant.
- Constant *f = SLC.get_memchr();
- std::vector<Value*> args;
- args.push_back(ci->getOperand(1));
- args.push_back(ci->getOperand(2));
- args.push_back(ConstantInt::get(SLC.getIntPtrType(), len));
- ci->replaceAllUsesWith(new CallInst(f, args, ci->getName(), ci));
- ci->eraseFromParent();
- return true;
+ Value *Args[3] = {
+ CI->getOperand(1),
+ CI->getOperand(2),
+ ConstantInt::get(SLC.getIntPtrType(), Str.size()+1)
+ };
+ return ReplaceCallWith(CI, CallInst::Create(SLC.get_memchr(), Args, Args + 3,
+ CI->getName(), CI));
}
+ // strchr can find the nul character.
+ Str += '\0';
+
// Get the character we're looking for
- int64_t chr = CSI->getSExtValue();
+ char CharValue = CSI->getSExtValue();
// Compute the offset
- uint64_t offset = 0;
- bool char_found = false;
- for (uint64_t i = 0; i < len; ++i) {
- if (ConstantInt* CI = dyn_cast<ConstantInt>(CA->getOperand(i))) {
- // Check for the null terminator
- if (CI->isNullValue())
- break; // we found end of string
- else if (CI->getSExtValue() == chr) {
- char_found = true;
- offset = i;
- break;
- }
- }
+ 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,c) -> offset_of_in(c,s)
+ // strchr(s+n,c) -> gep(s+n+i,c)
// (if c is a constant integer and s is a constant string)
- if (char_found) {
- std::vector<Value*> indices;
- indices.push_back(ConstantInt::get(Type::Int64Ty,offset));
- GetElementPtrInst* GEP = new GetElementPtrInst(ci->getOperand(1),indices,
- ci->getOperand(1)->getName()+".strchr",ci);
- ci->replaceAllUsesWith(GEP);
- } else {
- ci->replaceAllUsesWith(
- ConstantPointerNull::get(PointerType::get(Type::Int8Ty)));
- }
- ci->eraseFromParent();
- return true;
+ 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;
/// 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 StrCmpOptimization : public LibCallOptimization {
+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){
- return F->getReturnType() == Type::Int32Ty && F->arg_size() == 2;
+ 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) {
+ 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* s1 = ci->getOperand(1);
- Value* s2 = ci->getOperand(2);
- if (s1 == s2) {
- // strcmp(x,x) -> 0
- ci->replaceAllUsesWith(ConstantInt::get(Type::Int32Ty,0));
- ci->eraseFromParent();
- return true;
- }
+ 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));
- bool isstr_1 = false;
- uint64_t len_1 = 0;
- ConstantArray* A1;
- if (getConstantStringLength(s1,len_1,&A1)) {
- isstr_1 = true;
- if (len_1 == 0) {
- // strcmp("",x) -> *x
- LoadInst* load =
- new LoadInst(CastToCStr(s2,*ci), ci->getName()+".load",ci);
- CastInst* cast =
- CastInst::create(Instruction::SExt, load, Type::Int32Ty,
- ci->getName()+".int", ci);
- ci->replaceAllUsesWith(cast);
- ci->eraseFromParent();
- return true;
- }
+ 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);
}
- bool isstr_2 = false;
- uint64_t len_2 = 0;
- ConstantArray* A2;
- if (getConstantStringLength(s2, len_2, &A2)) {
- isstr_2 = true;
- if (len_2 == 0) {
- // strcmp(x,"") -> *x
- LoadInst* load =
- new LoadInst(CastToCStr(s1,*ci),ci->getName()+".val",ci);
- CastInst* cast =
- CastInst::create(Instruction::SExt, load, Type::Int32Ty,
- ci->getName()+".int", ci);
- ci->replaceAllUsesWith(cast);
- ci->eraseFromParent();
- return true;
- }
+ 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);
}
- if (isstr_1 && isstr_2) {
- // strcmp(x,y) -> cnst (if both x and y are constant strings)
- std::string str1 = A1->getAsString();
- std::string str2 = A2->getAsString();
- int result = strcmp(str1.c_str(), str2.c_str());
- ci->replaceAllUsesWith(ConstantInt::get(Type::Int32Ty,result));
- ci->eraseFromParent();
- return true;
- }
- return false;
+ // 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;
/// 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 StrNCmpOptimization : public LibCallOptimization {
+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){
- if (f->getReturnType() == Type::Int32Ty && f->arg_size() == 3)
- return true;
+ 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 strncpy optimization
- virtual bool OptimizeCall(CallInst *ci, SimplifyLibCalls &SLC) {
+ /// @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* s1 = ci->getOperand(1);
- Value* s2 = ci->getOperand(2);
- if (s1 == s2) {
- // strncmp(x,x,l) -> 0
- ci->replaceAllUsesWith(ConstantInt::get(Type::Int32Ty,0));
- ci->eraseFromParent();
- return true;
- }
-
+ 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 len_arg = 0;
- bool len_arg_is_const = false;
- if (ConstantInt* len_CI = dyn_cast<ConstantInt>(ci->getOperand(3))) {
- len_arg_is_const = true;
- len_arg = len_CI->getZExtValue();
- if (len_arg == 0) {
- // strncmp(x,y,0) -> 0
- ci->replaceAllUsesWith(ConstantInt::get(Type::Int32Ty,0));
- ci->eraseFromParent();
- return true;
- }
- }
-
- bool isstr_1 = false;
- uint64_t len_1 = 0;
- ConstantArray* A1;
- if (getConstantStringLength(s1, len_1, &A1)) {
- isstr_1 = true;
- if (len_1 == 0) {
- // strncmp("",x) -> *x
- LoadInst* load = new LoadInst(s1,ci->getName()+".load",ci);
- CastInst* cast =
- CastInst::create(Instruction::SExt, load, Type::Int32Ty,
- ci->getName()+".int", ci);
- ci->replaceAllUsesWith(cast);
- ci->eraseFromParent();
- return true;
- }
- }
-
- bool isstr_2 = false;
- uint64_t len_2 = 0;
- ConstantArray* A2;
- if (getConstantStringLength(s2,len_2,&A2)) {
- isstr_2 = true;
- if (len_2 == 0) {
- // strncmp(x,"") -> *x
- LoadInst* load = new LoadInst(s2,ci->getName()+".val",ci);
- CastInst* cast =
- CastInst::create(Instruction::SExt, load, Type::Int32Ty,
- ci->getName()+".int", ci);
- ci->replaceAllUsesWith(cast);
- ci->eraseFromParent();
- return true;
- }
+ 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);
}
-
- if (isstr_1 && isstr_2 && len_arg_is_const) {
- // strncmp(x,y,const) -> constant
- std::string str1 = A1->getAsString();
- std::string str2 = A2->getAsString();
- int result = strncmp(str1.c_str(), str2.c_str(), len_arg);
- ci->replaceAllUsesWith(ConstantInt::get(Type::Int32Ty,result));
- ci->eraseFromParent();
- return true;
+
+ 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);
}
- return false;
+
+ // 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;
/// (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 StrCpyOptimization : public LibCallOptimization {
+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){
- if (f->getReturnType() == PointerType::get(Type::Int8Ty))
- if (f->arg_size() == 2) {
- Function::const_arg_iterator AI = f->arg_begin();
- if (AI++->getType() == PointerType::get(Type::Int8Ty))
- if (AI->getType() == PointerType::get(Type::Int8Ty)) {
- // Indicate this is a suitable call type.
- return true;
- }
- }
- return false;
+ 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) {
+ 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* dest = ci->getOperand(1);
- Value* src = ci->getOperand(2);
- if (dest == src) {
- ci->replaceAllUsesWith(dest);
- ci->eraseFromParent();
- return true;
+ Value *Dst = CI->getOperand(1);
+ Value *Src = CI->getOperand(2);
+ if (Dst == Src) {
+ // strcpy(x, x) -> x
+ return ReplaceCallWith(CI, Dst);
}
-
- // Get the length of the constant string referenced by the second operand,
- // the "src" parameter. Fail the optimization if we can't get the length
- // (note that getConstantStringLength does lots of checks to make sure this
- // is valid).
- uint64_t len = 0;
- if (!getConstantStringLength(ci->getOperand(2),len))
+
+ // Get the length of the constant string referenced by the Src operand.
+ std::string SrcStr;
+ if (!GetConstantStringInfo(Src, SrcStr))
return false;
-
+
// 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),ci->getOperand(1),ci);
- ci->replaceAllUsesWith(dest);
- ci->eraseFromParent();
- return true;
+ if (SrcStr.empty()) {
+ new StoreInst(ConstantInt::get(Type::Int8Ty, 0), Dst, CI);
+ return ReplaceCallWith(CI, Dst);
}
- // Increment the length because we actually want to memcpy the null
- // terminator as well.
- len++;
-
// We have enough information to now generate the memcpy call to
// do the concatenation for us.
- std::vector<Value*> vals;
- vals.push_back(dest); // destination
- vals.push_back(src); // source
- vals.push_back(ConstantInt::get(SLC.getIntPtrType(),len)); // length
- vals.push_back(ConstantInt::get(Type::Int32Ty,1)); // alignment
- new CallInst(SLC.get_memcpy(), vals, "", ci);
-
- // Finally, substitute the first operand of the strcat call for the
- // strcat call itself since strcat returns its first operand; and,
- // kill the strcat CallInst.
- ci->replaceAllUsesWith(dest);
- ci->eraseFromParent();
- return true;
+ Value *MemcpyOps[] = {
+ Dst, Src, // Pass length including nul byte.
+ ConstantInt::get(SLC.getIntPtrType(), SrcStr.size()+1),
+ ConstantInt::get(Type::Int32Ty, 1) // alignment
+ };
+ CallInst::Create(SLC.get_memcpy(), MemcpyOps, MemcpyOps + 4, "", CI);
+
+ return ReplaceCallWith(CI, Dst);
}
} StrCpyOptimizer;
/// 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 StrLenOptimization : public LibCallOptimization {
+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)
- {
- if (f->getReturnType() == SLC.getTargetData()->getIntPtrType())
- if (f->arg_size() == 1)
- if (Function::const_arg_iterator AI = f->arg_begin())
- if (AI->getType() == PointerType::get(Type::Int8Ty))
- return true;
- return false;
+ 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)
- {
+ virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
// Make sure we're dealing with an sbyte* here.
- Value* str = ci->getOperand(1);
- if (str->getType() != PointerType::get(Type::Int8Ty))
- return false;
+ Value *Src = CI->getOperand(1);
// Does the call to strlen have exactly one use?
- if (ci->hasOneUse())
+ if (CI->hasOneUse()) {
// Is that single use a icmp operator?
- if (ICmpInst* bop = dyn_cast<ICmpInst>(ci->use_back()))
+ if (ICmpInst *Cmp = dyn_cast<ICmpInst>(CI->use_back()))
// Is it compared against a constant integer?
- if (ConstantInt* CI = dyn_cast<ConstantInt>(bop->getOperand(1)))
- {
- // Get the value the strlen result is compared to
- uint64_t val = CI->getZExtValue();
-
+ if (ConstantInt *Cst = dyn_cast<ConstantInt>(Cmp->getOperand(1))) {
// If its compared against length 0 with == or !=
- if (val == 0 &&
- (bop->getPredicate() == ICmpInst::ICMP_EQ ||
- bop->getPredicate() == ICmpInst::ICMP_NE))
- {
+ if (Cst->getZExtValue() == 0 && Cmp->isEquality()) {
// strlen(x) != 0 -> *x != 0
// strlen(x) == 0 -> *x == 0
- LoadInst* load = new LoadInst(str,str->getName()+".first",ci);
- ICmpInst* rbop = new ICmpInst(bop->getPredicate(), load,
- ConstantInt::get(Type::Int8Ty,0),
- bop->getName()+".strlen", ci);
- bop->replaceAllUsesWith(rbop);
- bop->eraseFromParent();
- ci->eraseFromParent();
- return true;
+ 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
- uint64_t len = 0;
- if (!getConstantStringLength(ci->getOperand(1),len))
+ std::string Str;
+ if (!GetConstantStringInfo(Src, Str))
return false;
-
+
// strlen("xyz") -> 3 (for example)
- const Type *Ty = SLC.getTargetData()->getIntPtrType();
- ci->replaceAllUsesWith(ConstantInt::get(Ty, len));
-
- ci->eraseFromParent();
- return true;
+ return ReplaceCallWith(CI, ConstantInt::get(CI->getType(), Str.size()));
}
} StrLenOptimizer;
static bool IsOnlyUsedInEqualsZeroComparison(Instruction *I) {
for (Value::use_iterator UI = I->use_begin(), E = I->use_end();
UI != E; ++UI) {
- Instruction *User = cast<Instruction>(*UI);
- if (ICmpInst *IC = dyn_cast<ICmpInst>(User)) {
- if ((IC->getPredicate() == ICmpInst::ICMP_NE ||
- IC->getPredicate() == ICmpInst::ICMP_EQ) &&
- isa<Constant>(IC->getOperand(1)) &&
- cast<Constant>(IC->getOperand(1))->isNullValue())
- continue;
- } else if (CastInst *CI = dyn_cast<CastInst>(User))
- if (CI->getType() == Type::Int1Ty)
- continue;
+ 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;
}
/// This memcmpOptimization will simplify a call to the memcmp library
/// function.
-struct memcmpOptimization : public LibCallOptimization {
+struct VISIBILITY_HIDDEN memcmpOptimization : public LibCallOptimization {
/// @brief Default Constructor
memcmpOptimization()
: LibCallOptimization("memcmp", "Number of 'memcmp' calls simplified") {}
// If the two operands are the same, return zero.
if (LHS == RHS) {
// memcmp(s,s,x) -> 0
- CI->replaceAllUsesWith(Constant::getNullValue(CI->getType()));
- CI->eraseFromParent();
- return true;
+ return ReplaceCallWith(CI, Constant::getNullValue(CI->getType()));
}
// Make sure we have a constant length.
switch (Len) {
case 0:
// memcmp(s1,s2,0) -> 0
- CI->replaceAllUsesWith(Constant::getNullValue(CI->getType()));
- CI->eraseFromParent();
- return true;
+ return ReplaceCallWith(CI, Constant::getNullValue(CI->getType()));
case 1: {
// memcmp(S1,S2,1) -> *(ubyte*)S1 - *(ubyte*)S2
- const Type *UCharPtr = PointerType::get(Type::Int8Ty);
+ const Type *UCharPtr = PointerType::getUnqual(Type::Int8Ty);
CastInst *Op1Cast = CastInst::create(
Instruction::BitCast, LHS, UCharPtr, LHS->getName(), CI);
CastInst *Op2Cast = CastInst::create(
if (RV->getType() != CI->getType())
RV = CastInst::createIntegerCast(RV, CI->getType(), false,
RV->getName(), CI);
- CI->replaceAllUsesWith(RV);
- CI->eraseFromParent();
- return true;
+ 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::get(Type::Int8Ty);
+ const Type *UCharPtr = PointerType::getUnqual(Type::Int8Ty);
CastInst *Op1Cast = CastInst::create(
Instruction::BitCast, LHS, UCharPtr, LHS->getName(), CI);
CastInst *Op2Cast = CastInst::create(
Value *D1 = BinaryOperator::createSub(S1V1, S2V1,
CI->getName()+".d1", CI);
Constant *One = ConstantInt::get(Type::Int32Ty, 1);
- Value *G1 = new GetElementPtrInst(Op1Cast, One, "next1v", CI);
- Value *G2 = new GetElementPtrInst(Op2Cast, One, "next2v", CI);
+ 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,
if (Or->getType() != CI->getType())
Or = CastInst::createIntegerCast(Or, CI->getType(), false /*ZExt*/,
Or->getName(), CI);
- CI->replaceAllUsesWith(Or);
- CI->eraseFromParent();
- return true;
+ return ReplaceCallWith(CI, Or);
}
break;
default:
}
} 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 LLVMMemCpyMoveOptzn : public LibCallOptimization {
+struct VISIBILITY_HIDDEN LLVMMemCpyMoveOptzn : public LibCallOptimization {
LLVMMemCpyMoveOptzn(const char* fname, const char* desc)
: LibCallOptimization(fname, desc) {}
Value* dest = ci->getOperand(1);
Value* src = ci->getOperand(2);
const Type* castType = 0;
- switch (len)
- {
+ switch (len) {
case 0:
- // memcpy(d,s,0,a) -> noop
- ci->eraseFromParent();
- return true;
+ // 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;
// Cast source and dest to the right sized primitive and then load/store
CastInst* SrcCast = CastInst::create(Instruction::BitCast,
- src, PointerType::get(castType), src->getName()+".cast", ci);
+ src, PointerType::getUnqual(castType), src->getName()+".cast", ci);
CastInst* DestCast = CastInst::create(Instruction::BitCast,
- dest, PointerType::get(castType),dest->getName()+".cast", ci);
+ dest, PointerType::getUnqual(castType),dest->getName()+".cast", ci);
LoadInst* LI = new LoadInst(SrcCast,SrcCast->getName()+".val",ci);
new StoreInst(LI, DestCast, ci);
- ci->eraseFromParent();
- return true;
+ return ReplaceCallWith(ci, 0);
}
};
/// 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 LLVMMemSetOptimization : public LibCallOptimization {
+struct VISIBILITY_HIDDEN LLVMMemSetOptimization : public LibCallOptimization {
/// @brief Default Constructor
LLVMMemSetOptimization(const char *Name) : LibCallOptimization(Name,
"Number of 'llvm.memset' calls simplified") {}
// If the length is zero, this is a no-op
if (len == 0) {
// memset(d,c,0,a) -> noop
- ci->eraseFromParent();
- return true;
+ return ReplaceCallWith(ci, 0);
}
// If the length is larger than the alignment, we can't optimize
}
// Cast dest to the right sized primitive and then load/store
- CastInst* DestCast = new BitCastInst(dest, PointerType::get(castType),
+ CastInst* DestCast = new BitCastInst(dest, PointerType::getUnqual(castType),
dest->getName()+".cast", ci);
new StoreInst(ConstantInt::get(castType,fill_value),DestCast, ci);
- ci->eraseFromParent();
- return true;
+ return ReplaceCallWith(ci, 0);
}
};
/// 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 PowOptimization : public LibCallOptimization {
+struct VISIBILITY_HIDDEN PowOptimization : public LibCallOptimization {
public:
/// @brief Default Constructor
PowOptimization() : LibCallOptimization("pow",
/// @brief Perform the pow optimization.
virtual bool OptimizeCall(CallInst *ci, SimplifyLibCalls &SLC) {
const Type *Ty = cast<Function>(ci->getOperand(0))->getReturnType();
+ if (Ty!=Type::FloatTy && Ty!=Type::DoubleTy)
+ return false; // FIXME long double not yet supported
Value* base = ci->getOperand(1);
Value* expn = ci->getOperand(2);
if (ConstantFP *Op1 = dyn_cast<ConstantFP>(base)) {
- double Op1V = Op1->getValue();
- if (Op1V == 1.0) {
- // pow(1.0,x) -> 1.0
- ci->replaceAllUsesWith(ConstantFP::get(Ty,1.0));
- ci->eraseFromParent();
- return true;
- }
+ if (Op1->isExactlyValue(1.0)) // pow(1.0,x) -> 1.0
+ return ReplaceCallWith(ci, ConstantFP::get(Ty,
+ Ty==Type::FloatTy ? APFloat(1.0f) : APFloat(1.0)));
} else if (ConstantFP* Op2 = dyn_cast<ConstantFP>(expn)) {
- double Op2V = Op2->getValue();
- if (Op2V == 0.0) {
+ if (Op2->getValueAPF().isZero()) {
// pow(x,0.0) -> 1.0
- ci->replaceAllUsesWith(ConstantFP::get(Ty,1.0));
- ci->eraseFromParent();
- return true;
- } else if (Op2V == 0.5) {
+ return ReplaceCallWith(ci, ConstantFP::get(Ty,
+ Ty==Type::FloatTy ? APFloat(1.0f) : APFloat(1.0)));
+ } else if (Op2->isExactlyValue(0.5)) {
// pow(x,0.5) -> sqrt(x)
- CallInst* sqrt_inst = new CallInst(SLC.get_sqrt(), base,
- ci->getName()+".pow",ci);
- ci->replaceAllUsesWith(sqrt_inst);
- ci->eraseFromParent();
- return true;
- } else if (Op2V == 1.0) {
+ CallInst* sqrt_inst = CallInst::Create(SLC.get_sqrt(), base,
+ ci->getName()+".pow",ci);
+ return ReplaceCallWith(ci, sqrt_inst);
+ } else if (Op2->isExactlyValue(1.0)) {
// pow(x,1.0) -> x
- ci->replaceAllUsesWith(base);
- ci->eraseFromParent();
- return true;
- } else if (Op2V == -1.0) {
+ return ReplaceCallWith(ci, base);
+ } else if (Op2->isExactlyValue(-1.0)) {
// pow(x,-1.0) -> 1.0/x
- BinaryOperator* div_inst= BinaryOperator::createFDiv(
- ConstantFP::get(Ty,1.0), base, ci->getName()+".pow", ci);
- ci->replaceAllUsesWith(div_inst);
- ci->eraseFromParent();
- return true;
+ Value *div_inst =
+ BinaryOperator::createFDiv(ConstantFP::get(Ty,
+ Ty==Type::FloatTy ? APFloat(1.0f) : APFloat(1.0)),
+ base, ci->getName()+".pow", ci);
+ return ReplaceCallWith(ci, div_inst);
}
}
return false; // opt failed
/// 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 PrintfOptimization : public LibCallOptimization {
+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 arguments
- return (f->arg_size() >= 1);
+ 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) {
- // If the call has more than 2 operands, we can't optimize it
- if (ci->getNumOperands() > 3 || ci->getNumOperands() <= 2)
- return false;
-
- // If the result of the printf call is used, none of these optimizations
- // can be made.
- if (!ci->use_empty())
- return false;
-
+ 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
- uint64_t len = 0;
- ConstantArray* CA = 0;
- if (!getConstantStringLength(ci->getOperand(1), len, &CA))
+ 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));
+ }
- if (len != 2 && len != 3)
+ // 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;
- // The first character has to be a %
- if (ConstantInt* CI = dyn_cast<ConstantInt>(CA->getOperand(0)))
- if (CI->getZExtValue() != '%')
+ // 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;
- // Get the second character and switch on its value
- ConstantInt* CI = dyn_cast<ConstantInt>(CA->getOperand(1));
- switch (CI->getZExtValue()) {
- case 's':
- {
- if (len != 3 ||
- dyn_cast<ConstantInt>(CA->getOperand(2))->getZExtValue() != '\n')
- return false;
-
- // printf("%s\n",str) -> puts(str)
- std::vector<Value*> args;
- new CallInst(SLC.get_puts(), CastToCStr(ci->getOperand(2), *ci),
- ci->getName(), ci);
- ci->replaceAllUsesWith(ConstantInt::get(Type::Int32Ty, len));
- break;
- }
- case 'c':
- {
- // printf("%c",c) -> putchar(c)
- if (len != 2)
- return false;
-
- CastInst *Char = CastInst::createSExtOrBitCast(
- ci->getOperand(2), Type::Int32Ty, CI->getName()+".int", ci);
- new CallInst(SLC.get_putchar(), Char, "", ci);
- ci->replaceAllUsesWith(ConstantInt::get(Type::Int32Ty, 1));
- break;
- }
- default:
+ // 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));
+ }
}
- ci->eraseFromParent();
- return true;
}
} PrintfOptimizer;
/// 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 FPrintFOptimization : public LibCallOptimization {
+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){
- // Just make sure this has at least 2 arguments
- return (f->arg_size() >= 2);
+ 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) {
+ virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
// If the call has more than 3 operands, we can't optimize it
- if (ci->getNumOperands() > 4 || ci->getNumOperands() <= 2)
+ if (CI->getNumOperands() != 3 && CI->getNumOperands() != 4)
return false;
- // If the result of the fprintf call is used, none of these optimizations
- // can be made.
- if (!ci->use_empty())
+ // All the optimizations depend on the format string.
+ std::string FormatStr;
+ if (!GetConstantStringInfo(CI->getOperand(2), FormatStr))
return false;
- // All the optimizations depend on the length of the second argument and the
- // fact that it is a constant string array. Check that now
- uint64_t len = 0;
- ConstantArray* CA = 0;
- if (!getConstantStringLength(ci->getOperand(2), len, &CA))
- return false;
-
- if (ci->getNumOperands() == 3) {
- // Make sure there's no % in the constant array
- for (unsigned i = 0; i < len; ++i) {
- if (ConstantInt* CI = dyn_cast<ConstantInt>(CA->getOperand(i))) {
- // Check for the null terminator
- if (CI->getZExtValue() == '%')
- return false; // we found end of string
- } else {
- 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* FILEptr_type = ci->getOperand(1)->getType();
-
- // Make sure that the fprintf() and fwrite() functions both take the
- // same type of char pointer.
- if (ci->getOperand(2)->getType() != PointerType::get(Type::Int8Ty))
- return false;
-
- std::vector<Value*> args;
- args.push_back(ci->getOperand(2));
- args.push_back(ConstantInt::get(SLC.getIntPtrType(),len));
- args.push_back(ConstantInt::get(SLC.getIntPtrType(),1));
- args.push_back(ci->getOperand(1));
- new CallInst(SLC.get_fwrite(FILEptr_type), args, ci->getName(), ci);
- ci->replaceAllUsesWith(ConstantInt::get(Type::Int32Ty,len));
- ci->eraseFromParent();
- return true;
+ 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
+
+ // The remaining optimizations require the format string to be length 2:
// "%s" or "%c".
- if (len != 2)
+ if (FormatStr.size() != 2 || FormatStr[0] != '%')
return false;
- // The first character has to be a %
- if (ConstantInt* CI = dyn_cast<ConstantInt>(CA->getOperand(0)))
- if (CI->getZExtValue() != '%')
- return false;
-
// Get the second character and switch on its value
- ConstantInt* CI = dyn_cast<ConstantInt>(CA->getOperand(1));
- switch (CI->getZExtValue()) {
- case 's':
- {
- uint64_t len = 0;
- ConstantArray* CA = 0;
- if (getConstantStringLength(ci->getOperand(3), len, &CA)) {
- // fprintf(file,"%s",str) -> fwrite(str,strlen(str),1,file)
- const Type* FILEptr_type = ci->getOperand(1)->getType();
- std::vector<Value*> args;
- args.push_back(CastToCStr(ci->getOperand(3), *ci));
- args.push_back(ConstantInt::get(SLC.getIntPtrType(), len));
- args.push_back(ConstantInt::get(SLC.getIntPtrType(), 1));
- args.push_back(ci->getOperand(1));
- new CallInst(SLC.get_fwrite(FILEptr_type), args, ci->getName(), ci);
- ci->replaceAllUsesWith(ConstantInt::get(Type::Int32Ty, len));
- } else {
- // fprintf(file,"%s",str) -> fputs(str,file)
- const Type* FILEptr_type = ci->getOperand(1)->getType();
- new CallInst(SLC.get_fputs(FILEptr_type),
- CastToCStr(ci->getOperand(3), *ci),
- ci->getOperand(1), ci->getName(),ci);
- ci->replaceAllUsesWith(ConstantInt::get(Type::Int32Ty,len));
- }
- break;
- }
- case 'c':
- {
- // fprintf(file,"%c",c) -> fputc(c,file)
- const Type* FILEptr_type = ci->getOperand(1)->getType();
- CastInst* cast = CastInst::createSExtOrBitCast(
- ci->getOperand(3), Type::Int32Ty, CI->getName()+".int", ci);
- new CallInst(SLC.get_fputc(FILEptr_type), cast,ci->getOperand(1),"",ci);
- ci->replaceAllUsesWith(ConstantInt::get(Type::Int32Ty,1));
- break;
- }
- default:
+ 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())
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;
}
- ci->eraseFromParent();
- return true;
}
} FPrintFOptimizer;
/// 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 SPrintFOptimization : public LibCallOptimization {
+struct VISIBILITY_HIDDEN SPrintFOptimization : public LibCallOptimization {
public:
/// @brief Default Constructor
SPrintFOptimization() : LibCallOptimization("sprintf",
"Number of 'sprintf' calls simplified") {}
- /// @brief Make sure that the "fprintf" function has the right prototype
- virtual bool ValidateCalledFunction(const Function *f, SimplifyLibCalls &SLC){
- // Just make sure this has at least 2 arguments
- return (f->getReturnType() == Type::Int32Ty && f->arg_size() >= 2);
+ /// @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) {
+ virtual bool OptimizeCall(CallInst *CI, SimplifyLibCalls &SLC) {
// If the call has more than 3 operands, we can't optimize it
- if (ci->getNumOperands() > 4 || ci->getNumOperands() < 3)
+ if (CI->getNumOperands() != 3 && CI->getNumOperands() != 4)
return false;
- // All the optimizations depend on the length of the second argument and the
- // fact that it is a constant string array. Check that now
- uint64_t len = 0;
- ConstantArray* CA = 0;
- if (!getConstantStringLength(ci->getOperand(2), len, &CA))
+ std::string FormatStr;
+ if (!GetConstantStringInfo(CI->getOperand(2), FormatStr))
return false;
-
- if (ci->getNumOperands() == 3) {
- if (len == 0) {
- // If the length is 0, we just need to store a null byte
- new StoreInst(ConstantInt::get(Type::Int8Ty,0),ci->getOperand(1),ci);
- ci->replaceAllUsesWith(ConstantInt::get(Type::Int32Ty,0));
- ci->eraseFromParent();
- return true;
- }
-
+
+ if (CI->getNumOperands() == 3) {
// Make sure there's no % in the constant array
- for (unsigned i = 0; i < len; ++i) {
- if (ConstantInt* CI = dyn_cast<ConstantInt>(CA->getOperand(i))) {
- // Check for the null terminator
- if (CI->getZExtValue() == '%')
- return false; // we found a %, can't optimize
- } else {
- return false; // initializer is not constant int, can't optimize
- }
- }
-
- // Increment length because we want to copy the null byte too
- len++;
-
+ 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)
- std::vector<Value*> args;
- args.push_back(ci->getOperand(1));
- args.push_back(ci->getOperand(2));
- args.push_back(ConstantInt::get(SLC.getIntPtrType(),len));
- args.push_back(ConstantInt::get(Type::Int32Ty,1));
- new CallInst(SLC.get_memcpy(), args, "", ci);
- ci->replaceAllUsesWith(ConstantInt::get(Type::Int32Ty,len));
- ci->eraseFromParent();
- return true;
+ 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 length 2
- // "%s" or "%c".
- if (len != 2)
+ // The remaining optimizations require the format string to be "%s" or "%c".
+ if (FormatStr.size() != 2 || FormatStr[0] != '%')
return false;
- // The first character has to be a %
- if (ConstantInt* CI = dyn_cast<ConstantInt>(CA->getOperand(0)))
- if (CI->getZExtValue() != '%')
- return false;
-
// Get the second character and switch on its value
- ConstantInt* CI = dyn_cast<ConstantInt>(CA->getOperand(1));
- switch (CI->getZExtValue()) {
+ 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 = new CallInst(SLC.get_strlen(),
- CastToCStr(ci->getOperand(3), *ci),
- ci->getOperand(3)->getName()+".len", ci);
- Value *Len1 = BinaryOperator::createAdd(Len,
- ConstantInt::get(Len->getType(), 1),
- Len->getName()+"1", ci);
- if (Len1->getType() != SLC.getIntPtrType())
- Len1 = CastInst::createIntegerCast(Len1, SLC.getIntPtrType(), false,
- Len1->getName(), ci);
- std::vector<Value*> args;
- args.push_back(CastToCStr(ci->getOperand(1), *ci));
- args.push_back(CastToCStr(ci->getOperand(3), *ci));
- args.push_back(Len1);
- args.push_back(ConstantInt::get(Type::Int32Ty,1));
- new CallInst(SLC.get_memcpy(), args, "", ci);
+ 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 (Len->getType() != ci->getType())
- Len = CastInst::createIntegerCast(Len, ci->getType(), false,
- Len->getName(), ci);
- ci->replaceAllUsesWith(Len);
+ if (!CI->use_empty()) {
+ if (UnincLen->getType() != CI->getType())
+ UnincLen = CastInst::createIntegerCast(UnincLen, CI->getType(), false,
+ Len->getName(), CI);
+ CI->replaceAllUsesWith(UnincLen);
}
- ci->eraseFromParent();
- return true;
- }
- case 'c': {
- // sprintf(dest,"%c",chr) -> store chr, dest
- CastInst* cast = CastInst::createTruncOrBitCast(
- ci->getOperand(3), Type::Int8Ty, "char", ci);
- new StoreInst(cast, ci->getOperand(1), ci);
- GetElementPtrInst* gep = new GetElementPtrInst(ci->getOperand(1),
- ConstantInt::get(Type::Int32Ty,1),ci->getOperand(1)->getName()+".end",
- ci);
- new StoreInst(ConstantInt::get(Type::Int8Ty,0),gep,ci);
- ci->replaceAllUsesWith(ConstantInt::get(Type::Int32Ty,1));
- ci->eraseFromParent();
- return true;
+ return ReplaceCallWith(CI, 0);
}
}
return false;
/// 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 puts library function.
-struct PutsOptimization : public LibCallOptimization {
+/// @brief Simplify the fputs library function.
+struct VISIBILITY_HIDDEN FPutsOptimization : public LibCallOptimization {
public:
/// @brief Default Constructor
- PutsOptimization() : LibCallOptimization("fputs",
+ FPutsOptimization() : LibCallOptimization("fputs",
"Number of 'fputs' calls simplified") {}
/// @brief Make sure that the "fputs" function has the right prototype
}
/// @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())
+ 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 and the
// fact that it is a constant string array. Check that now
- uint64_t len = 0;
- if (!getConstantStringLength(ci->getOperand(1), len))
+ std::string Str;
+ if (!GetConstantStringInfo(CI->getOperand(1), Str))
return false;
- switch (len) {
- case 0:
- // fputs("",F) -> noop
- break;
- case 1:
- {
- // fputs(s,F) -> fputc(s[0],F) (if s is constant and strlen(s) == 1)
- const Type* FILEptr_type = ci->getOperand(2)->getType();
- LoadInst* loadi = new LoadInst(ci->getOperand(1),
- ci->getOperand(1)->getName()+".byte",ci);
- CastInst* casti = new SExtInst(loadi, Type::Int32Ty,
- loadi->getName()+".int", ci);
- new CallInst(SLC.get_fputc(FILEptr_type), casti,
- ci->getOperand(2), "", ci);
- break;
- }
- default:
- {
- // fputs(s,F) -> fwrite(s,1,len,F) (if s is constant and strlen(s) > 1)
- const Type* FILEptr_type = ci->getOperand(2)->getType();
- std::vector<Value*> parms;
- parms.push_back(ci->getOperand(1));
- parms.push_back(ConstantInt::get(SLC.getIntPtrType(),len));
- parms.push_back(ConstantInt::get(SLC.getIntPtrType(),1));
- parms.push_back(ci->getOperand(2));
- new CallInst(SLC.get_fwrite(FILEptr_type), parms, "", ci);
- break;
- }
+ const Type *FILETy = CI->getOperand(2)->getType();
+ // fputs(s,F) -> fwrite(s,1,len,F) (if s is constant and strlen(s) > 1)
+ Value *FWriteParms[4] = {
+ CI->getOperand(1),
+ ConstantInt::get(SLC.getIntPtrType(), Str.size()),
+ ConstantInt::get(SLC.getIntPtrType(), 1),
+ CI->getOperand(2)
+ };
+ CallInst::Create(SLC.get_fwrite(FILETy), FWriteParms, FWriteParms + 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));
}
- ci->eraseFromParent();
- return true; // success
+ return false;
}
-} PutsOptimizer;
+} 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 isdigitOptimization : public LibCallOptimization {
+struct VISIBILITY_HIDDEN isdigitOptimization : public LibCallOptimization {
public:
isdigitOptimization() : LibCallOptimization("isdigit",
"Number of 'isdigit' calls simplified") {}
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')
- ci->replaceAllUsesWith(ConstantInt::get(Type::Int32Ty,1));
+ if (val >= '0' && val <= '9')
+ return ReplaceCallWith(ci, ConstantInt::get(Type::Int32Ty, 1));
else
- ci->replaceAllUsesWith(ConstantInt::get(Type::Int32Ty,0));
- ci->eraseFromParent();
- return true;
+ return ReplaceCallWith(ci, ConstantInt::get(Type::Int32Ty, 0));
}
// isdigit(c) -> (unsigned)c - '0' <= 9
ci->getOperand(1)->getName()+".cmp",ci);
CastInst* c2 = new ZExtInst(setcond_inst, Type::Int32Ty,
ci->getOperand(1)->getName()+".isdigit", ci);
- ci->replaceAllUsesWith(c2);
- ci->eraseFromParent();
- return true;
+ return ReplaceCallWith(ci, c2);
}
} isdigitOptimizer;
-struct isasciiOptimization : public LibCallOptimization {
+struct VISIBILITY_HIDDEN isasciiOptimization : public LibCallOptimization {
public:
isasciiOptimization()
: LibCallOptimization("isascii", "Number of 'isascii' calls simplified") {}
ConstantInt::get(V->getType(), 128),
V->getName()+".isascii", CI);
if (Cmp->getType() != CI->getType())
- Cmp = new BitCastInst(Cmp, CI->getType(), Cmp->getName(), CI);
- CI->replaceAllUsesWith(Cmp);
- CI->eraseFromParent();
- return true;
+ Cmp = new ZExtInst(Cmp, CI->getType(), Cmp->getName(), CI);
+ return ReplaceCallWith(CI, Cmp);
}
} isasciiOptimizer;
/// 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 ToAsciiOptimization : public LibCallOptimization {
+struct VISIBILITY_HIDDEN ToAsciiOptimization : public LibCallOptimization {
public:
/// @brief Default Constructor
ToAsciiOptimization() : LibCallOptimization("toascii",
/// @brief Perform the toascii optimization.
virtual bool OptimizeCall(CallInst *ci, SimplifyLibCalls &SLC) {
// toascii(c) -> (c & 0x7f)
- Value* chr = ci->getOperand(1);
- BinaryOperator* and_inst = BinaryOperator::createAnd(chr,
+ Value *chr = ci->getOperand(1);
+ Value *and_inst = BinaryOperator::createAnd(chr,
ConstantInt::get(chr->getType(),0x7F),ci->getName()+".toascii",ci);
- ci->replaceAllUsesWith(and_inst);
- ci->eraseFromParent();
- return true;
+ return ReplaceCallWith(ci, and_inst);
}
} ToAsciiOptimizer;
/// optimization is to compute the result at compile time if the argument is
/// a constant.
/// @brief Simplify the ffs library function.
-struct FFSOptimization : public LibCallOptimization {
+struct VISIBILITY_HIDDEN FFSOptimization : public LibCallOptimization {
protected:
/// @brief Subclass Constructor
FFSOptimization(const char* funcName, const char* description)
val >>= 1;
}
}
- TheCall->replaceAllUsesWith(ConstantInt::get(Type::Int32Ty, result));
- TheCall->eraseFromParent();
- return true;
+ return ReplaceCallWith(TheCall, ConstantInt::get(Type::Int32Ty, result));
}
// ffs(x) -> x == 0 ? 0 : llvm.cttz(x)+1
ArgType, NULL);
Value *V = CastInst::createIntegerCast(TheCall->getOperand(1), ArgType,
false/*ZExt*/, "tmp", TheCall);
- Value *V2 = new CallInst(F, V, "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),
Value *Cond = new ICmpInst(ICmpInst::ICMP_EQ, V,
Constant::getNullValue(V->getType()), "tmp",
TheCall);
- V2 = new SelectInst(Cond, ConstantInt::get(Type::Int32Ty, 0), V2,
- TheCall->getName(), TheCall);
- TheCall->replaceAllUsesWith(V2);
- TheCall->eraseFromParent();
- return true;
+ V2 = SelectInst::Create(Cond, ConstantInt::get(Type::Int32Ty, 0), V2,
+ TheCall->getName(), TheCall);
+ return ReplaceCallWith(TheCall, V2);
}
} FFSOptimizer;
/// calls. It simply uses FFSOptimization for which the transformation is
/// identical.
/// @brief Simplify the ffsl library function.
-struct FFSLOptimization : public FFSOptimization {
+struct VISIBILITY_HIDDEN FFSLOptimization : public FFSOptimization {
public:
/// @brief Default Constructor
FFSLOptimization() : FFSOptimization("ffsl",
/// calls. It simply uses FFSOptimization for which the transformation is
/// identical.
/// @brief Simplify the ffsl library function.
-struct FFSLLOptimization : public FFSOptimization {
+struct VISIBILITY_HIDDEN FFSLLOptimization : public FFSOptimization {
public:
/// @brief Default Constructor
FFSLLOptimization() : FFSOptimization("ffsll",
/// no precision loss.
static bool ShrinkFunctionToFloatVersion(CallInst *CI, SimplifyLibCalls &SLC,
Constant *(SimplifyLibCalls::*FP)()){
- if (CastInst *Cast = dyn_cast<CastInst>(CI->getOperand(1)))
+ if (FPExtInst *Cast = dyn_cast<FPExtInst>(CI->getOperand(1)))
if (Cast->getOperand(0)->getType() == Type::FloatTy) {
- Value *New = new CallInst((SLC.*FP)(), Cast->getOperand(0),
- CI->getName(), CI);
+ 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();
};
-struct FloorOptimization : public UnaryDoubleFPOptimizer {
+struct VISIBILITY_HIDDEN FloorOptimization : public UnaryDoubleFPOptimizer {
FloorOptimization()
: UnaryDoubleFPOptimizer("floor", "Number of 'floor' calls simplified") {}
}
} FloorOptimizer;
-struct CeilOptimization : public UnaryDoubleFPOptimizer {
+struct VISIBILITY_HIDDEN CeilOptimization : public UnaryDoubleFPOptimizer {
CeilOptimization()
: UnaryDoubleFPOptimizer("ceil", "Number of 'ceil' calls simplified") {}
}
} CeilOptimizer;
-struct RoundOptimization : public UnaryDoubleFPOptimizer {
+struct VISIBILITY_HIDDEN RoundOptimization : public UnaryDoubleFPOptimizer {
RoundOptimization()
: UnaryDoubleFPOptimizer("round", "Number of 'round' calls simplified") {}
}
} RoundOptimizer;
-struct RintOptimization : public UnaryDoubleFPOptimizer {
+struct VISIBILITY_HIDDEN RintOptimization : public UnaryDoubleFPOptimizer {
RintOptimization()
: UnaryDoubleFPOptimizer("rint", "Number of 'rint' calls simplified") {}
}
} RintOptimizer;
-struct NearByIntOptimization : public UnaryDoubleFPOptimizer {
+struct VISIBILITY_HIDDEN NearByIntOptimization : public UnaryDoubleFPOptimizer {
NearByIntOptimization()
: UnaryDoubleFPOptimizer("nearbyint",
"Number of 'nearbyint' calls simplified") {}
}
} NearByIntOptimizer;
-/// A function to compute 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.
+/// 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. In that case, the \p len parameter is set to the length
-/// of the null-terminated string. If false is returned, the conditions were
-/// not met and len is set to 0.
-/// @brief Get the length of a constant string (null-terminated array).
-bool getConstantStringLength(Value *V, uint64_t &len, ConstantArray **CA) {
- assert(V != 0 && "Invalid args to getConstantStringLength");
- len = 0; // make sure we initialize this
- User* GEP = 0;
+/// 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
- if (GetElementPtrInst* GEPI = dyn_cast<GetElementPtrInst>(V))
+ 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)
- GEP = CE;
- else
+ } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
+ if (CE->getOpcode() != Instruction::GetElementPtr)
return false;
- else
+ GEP = CE;
+ } else {
return false;
+ }
// Make sure the GEP has exactly three arguments.
if (GEP->getNumOperands() != 3)
// 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* op1 = dyn_cast<ConstantInt>(GEP->getOperand(1))) {
- if (!op1->isNullValue())
+ if (ConstantInt *Idx = dyn_cast<ConstantInt>(GEP->getOperand(1))) {
+ if (!Idx->isZero())
return false;
} else
return false;
- // Ensure that the second operand is a ConstantInt. If it isn't then this
- // GEP is wonky and we're not really sure what were referencing into and
- // better of not optimizing it. While we're at it, get the second index
- // value. We'll need this later for indexing the ConstantArray.
- uint64_t start_idx = 0;
- if (ConstantInt* CI = dyn_cast<ConstantInt>(GEP->getOperand(2)))
- start_idx = CI->getZExtValue();
+ // 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;
GlobalVariable* GV = dyn_cast<GlobalVariable>(GEP->getOperand(0));
if (!GV || !GV->isConstant() || !GV->hasInitializer())
return false;
-
- // Get the initializer.
- Constant* INTLZR = GV->getInitializer();
+ Constant *GlobalInit = GV->getInitializer();
// Handle the ConstantAggregateZero case
- if (isa<ConstantAggregateZero>(INTLZR)) {
+ if (isa<ConstantAggregateZero>(GlobalInit)) {
// This is a degenerate case. The initializer is constant zero so the
// length of the string must be zero.
- len = 0;
+ Str.clear();
return true;
}
// Must be a Constant Array
- ConstantArray* A = dyn_cast<ConstantArray>(INTLZR);
- if (!A)
- return false;
+ ConstantArray *Array = dyn_cast<ConstantArray>(GlobalInit);
+ if (!Array) return false;
// Get the number of elements in the array
- uint64_t max_elems = A->getType()->getNumElements();
+ uint64_t NumElts = Array->getType()->getNumElements();
- // Traverse the constant array from start_idx (derived above) which is
+ // Traverse the constant array from StartIdx (derived above) which is
// the place the GEP refers to in the array.
- for (len = start_idx; len < max_elems; len++) {
- if (ConstantInt *CI = dyn_cast<ConstantInt>(A->getOperand(len))) {
- // Check for the null terminator
- if (CI->isNullValue())
- break; // we found end of string
- } else
- return false; // This array isn't suitable, non-int initializer
+ 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();
}
- if (len >= max_elems)
- return false; // This array isn't null terminated
-
- // Subtract out the initial value from the length
- len -= start_idx;
- if (CA)
- *CA = A;
- return true; // success!
+ return false; // The array isn't null terminated.
}
/// 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.
-Value *CastToCStr(Value *V, Instruction &IP) {
+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::get(Type::Int8Ty);
+ const Type *SBPTy = PointerType::getUnqual(Type::Int8Ty);
if (V->getType() != SBPTy)
- return new BitCastInst(V, SBPTy, V->getName(), &IP);
+ return new BitCastInst(V, SBPTy, V->getName(), IP);
return V;
}
// * pow(pow(x,y),z)-> pow(x,y*z)
//
// puts:
-// * puts("") -> fputc("\n",stdout) (how do we get "stdout"?)
+// * puts("") -> putchar("\n")
//
// round, roundf, roundl:
// * round(cnst) -> cnst'
projects / oota-llvm.git / blobdiff