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Change CastToCStr to take a pointer instead of a reference.

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Fix some miscompilations in fprintf optimizer.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35753 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2007-04-07 21:04:50 +00:00
parent 31102896e5
commit 3492cda48f
1 changed files with 76 additions and 82 deletions
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158
lib/Transforms/IPO/SimplifyLibCalls.cpp
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@ -393,7 +393,7 @@ namespace {
// Forward declare utility functions.
static bool GetConstantStringInfo(Value *V, ConstantArray *&Array,
uint64_t &Length, uint64_t &StartIdx);
static Value *CastToCStr(Value *V, Instruction &IP);
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
@ -1228,7 +1228,7 @@ public:
return false;
// printf("%s\n",str) -> puts(str)
new CallInst(SLC.get_puts(), CastToCStr(CI->getOperand(2), *CI),
new CallInst(SLC.get_puts(), CastToCStr(CI->getOperand(2), CI),
CI->getName(), CI);
return ReplaceCallWith(CI, 0);
}
@ -1262,104 +1262,98 @@ public:
"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::get(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)
return false;
// If the result of the fprintf call is used, none of these optimizations
// can be made.
if (!ci->use_empty())
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, StartIdx;
ConstantArray* CA = 0;
if (!GetConstantStringInfo(ci->getOperand(2), CA, len, StartIdx))
uint64_t FormatLen, FormatStartIdx;
ConstantArray *CA = 0;
if (!GetConstantStringInfo(CI->getOperand(2), CA, FormatLen,FormatStartIdx))
return false;
if (ci->getNumOperands() == 3) {
// IF fthis is just a format string, turn it into fwrite.
if (CI->getNumOperands() == 3) {
if (!CA->isCString()) return false;
// 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;
}
}
std::string S = CA->getAsString();
for (unsigned i = FormatStartIdx, e = S.size(); i != e; ++i)
if (S[i] == '%')
return false; // we found a format specifier
// fprintf(file,fmt) -> fwrite(fmt,strlen(fmt),file)
const Type* FILEptr_type = ci->getOperand(1)->getType();
const Type *FILEty = 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;
Value* args[4] = {
ci->getOperand(2),
ConstantInt::get(SLC.getIntPtrType(),len),
ConstantInt::get(SLC.getIntPtrType(),1),
ci->getOperand(1)
Value *FWriteArgs[] = {
CI->getOperand(2),
ConstantInt::get(SLC.getIntPtrType(), FormatLen),
ConstantInt::get(SLC.getIntPtrType(), 1),
CI->getOperand(1)
};
new CallInst(SLC.get_fwrite(FILEptr_type), args, 4, ci->getName(), ci);
return ReplaceCallWith(ci, ConstantInt::get(Type::Int32Ty,len));
new CallInst(SLC.get_fwrite(FILEty), FWriteArgs, 4, CI->getName(), CI);
return ReplaceCallWith(CI, ConstantInt::get(CI->getType(), FormatLen));
}
// 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 (FormatLen != 2)
return false;
// The first character has to be a %
if (ConstantInt* CI = dyn_cast<ConstantInt>(CA->getOperand(0)))
if (CI->getZExtValue() != '%')
return false;
// The first character has to be a % for us to handle it.
if (cast<ConstantInt>(CA->getOperand(FormatStartIdx))->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, StartIdx;
ConstantArray* CA = 0;
if (GetConstantStringInfo(ci->getOperand(3), CA, len, StartIdx)) {
// fprintf(file,"%s",str) -> fwrite(str,strlen(str),1,file)
const Type* FILEptr_type = ci->getOperand(1)->getType();
Value* args[4] = {
CastToCStr(ci->getOperand(3), *ci),
ConstantInt::get(SLC.getIntPtrType(), len),
ConstantInt::get(SLC.getIntPtrType(), 1),
ci->getOperand(1)
};
new CallInst(SLC.get_fwrite(FILEptr_type), args, 4,ci->getName(), ci);
return ReplaceCallWith(ci, ConstantInt::get(Type::Int32Ty, len));
}
// 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);
return ReplaceCallWith(ci, ConstantInt::get(Type::Int32Ty,len));
switch(cast<ConstantInt>(CA->getOperand(FormatStartIdx+1))->getZExtValue()){
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);
new CallInst(SLC.get_fputc(FILETy), C, CI->getOperand(1), "", CI);
return ReplaceCallWith(CI, ConstantInt::get(CI->getType(), 1));
}
case 's': {
const Type *FILETy = CI->getOperand(1)->getType();
uint64_t LitStrLen, LitStartIdx;
ConstantArray *CA = 0;
if (GetConstantStringInfo(CI->getOperand(3), CA, LitStrLen, LitStartIdx)){
// fprintf(file,"%s",str) -> fwrite(str,strlen(str),1,file)
Value *FWriteArgs[] = {
CastToCStr(CI->getOperand(3), CI),
ConstantInt::get(SLC.getIntPtrType(), LitStrLen),
ConstantInt::get(SLC.getIntPtrType(), 1),
CI->getOperand(1)
};
new CallInst(SLC.get_fwrite(FILETy), FWriteArgs, 4, CI->getName(), CI);
return ReplaceCallWith(CI, ConstantInt::get(Type::Int32Ty, LitStrLen));
}
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);
return ReplaceCallWith(ci, ConstantInt::get(Type::Int32Ty,1));
}
default:
// If the result of the fprintf call is used, we can't do this.
// TODO: we could insert a strlen call.
if (!CI->use_empty())
return false;
// fprintf(file,"%s",str) -> fputs(str,file)
new CallInst(SLC.get_fputs(FILETy), CastToCStr(CI->getOperand(3), CI),
CI->getOperand(1), CI->getName(), CI);
return ReplaceCallWith(CI, 0);
}
default:
return false;
}
}
} FPrintFOptimizer;
@ -1441,7 +1435,7 @@ public:
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),
CastToCStr(ci->getOperand(3), ci),
ci->getOperand(3)->getName()+".len", ci);
Value *Len1 = BinaryOperator::createAdd(Len,
ConstantInt::get(Len->getType(), 1),
@ -1450,8 +1444,8 @@ public:
Len1 = CastInst::createIntegerCast(Len1, SLC.getIntPtrType(), false,
Len1->getName(), ci);
Value *args[4] = {
CastToCStr(ci->getOperand(1), *ci),
CastToCStr(ci->getOperand(3), *ci),
CastToCStr(ci->getOperand(1), ci),
CastToCStr(ci->getOperand(3), ci),
Len1,
ConstantInt::get(Type::Int32Ty,1)
};
@ -1946,12 +1940,12 @@ static bool GetConstantStringInfo(Value *V, ConstantArray *&Array,
/// CastToCStr - Return V if it is an sbyte*, otherwise cast it to sbyte*,
/// inserting the cast before IP, and return the cast.
/// @brief Cast a value to a "C" string.
static Value *CastToCStr(Value *V, Instruction &IP) {
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);
if (V->getType() != SBPTy)
return new BitCastInst(V, SBPTy, V->getName(), &IP);
return new BitCastInst(V, SBPTy, V->getName(), IP);
return V;
}