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Simplify this code a bit by relying on recursive simplification. Support 

sprintf("%s", P)'s that have uses.

s/hasNUses(0)/use_empty()/

llvm-svn: 23425
This commit is contained in:
Chris Lattner 2005-09-24 22:17:06 +00:00
parent 906d705644
commit 175463a165
1 changed files with 43 additions and 51 deletions
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94
llvm/lib/Transforms/IPO/SimplifyLibCalls.cpp
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@ -1282,7 +1282,7 @@ public:
// If the result of the fprintf call is used, none of these optimizations
// can be made.
if (!ci->hasNUses(0))
if (!ci->use_empty())
return false;
// All the optimizations depend on the length of the second argument and the
@ -1477,57 +1477,49 @@ public:
// Get the second character and switch on its value
ConstantInt* CI = dyn_cast<ConstantInt>(CA->getOperand(1));
switch (CI->getRawValue())
{
case 's':
{
uint64_t len = 0;
if (ci->hasNUses(0))
{
// sprintf(dest,"%s",str) -> strcpy(dest,str)
Function* strcpy_func = SLC.get_strcpy();
if (!strcpy_func)
return false;
std::vector<Value*> args;
args.push_back(CastToCStr(ci->getOperand(1), *ci));
args.push_back(CastToCStr(ci->getOperand(3), *ci));
new CallInst(strcpy_func,args,"",ci);
}
else if (getConstantStringLength(ci->getOperand(3),len))
{
// sprintf(dest,"%s",cstr) -> llvm.memcpy(dest,str,strlen(str),1)
len++; // get the null-terminator
Function* memcpy_func = SLC.get_memcpy();
if (!memcpy_func)
return false;
std::vector<Value*> args;
args.push_back(CastToCStr(ci->getOperand(1), *ci));
args.push_back(CastToCStr(ci->getOperand(3), *ci));
args.push_back(ConstantUInt::get(Type::UIntTy,len));
args.push_back(ConstantUInt::get(Type::UIntTy,1));
new CallInst(memcpy_func,args,"",ci);
ci->replaceAllUsesWith(ConstantSInt::get(Type::IntTy,len));
}
break;
}
case 'c':
{
// sprintf(dest,"%c",chr) -> store chr, dest
CastInst* cast =
new CastInst(ci->getOperand(3),Type::SByteTy,"char",ci);
new StoreInst(cast, ci->getOperand(1), ci);
GetElementPtrInst* gep = new GetElementPtrInst(ci->getOperand(1),
ConstantUInt::get(Type::UIntTy,1),ci->getOperand(1)->getName()+".end",
ci);
new StoreInst(ConstantInt::get(Type::SByteTy,0),gep,ci);
ci->replaceAllUsesWith(ConstantSInt::get(Type::IntTy,1));
break;
}
default:
switch (CI->getRawValue()) {
case 's': {
// sprintf(dest,"%s",str) -> llvm.memcpy(dest, str, strlen(str)+1, 1)
Function* strlen_func = SLC.get_strlen();
Function* memcpy_func = SLC.get_memcpy();
if (!strlen_func || !memcpy_func)
return false;
Value *Len = new CallInst(strlen_func, 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() != Type::UIntTy)
Len1 = new CastInst(Len1, Type::UIntTy, 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(ConstantUInt::get(Type::UIntTy,1));
new CallInst(memcpy_func, args, "", ci);
// The strlen result is the unincremented number of bytes in the string.
if (!ci->use_empty() && Len->getType() != ci->getType())
Len = new CastInst(Len, ci->getType(), Len->getName(), ci);
ci->replaceAllUsesWith(Len);
ci->eraseFromParent();
return true;
}
ci->eraseFromParent();
return true;
case 'c': {
// sprintf(dest,"%c",chr) -> store chr, dest
CastInst* cast = new CastInst(ci->getOperand(3),Type::SByteTy,"char",ci);
new StoreInst(cast, ci->getOperand(1), ci);
GetElementPtrInst* gep = new GetElementPtrInst(ci->getOperand(1),
ConstantUInt::get(Type::UIntTy,1),ci->getOperand(1)->getName()+".end",
ci);
new StoreInst(ConstantInt::get(Type::SByteTy,0),gep,ci);
ci->replaceAllUsesWith(ConstantSInt::get(Type::IntTy,1));
ci->eraseFromParent();
return true;
}
}
return false;
}
} SPrintFOptimizer;
@ -1556,7 +1548,7 @@ public:
virtual bool OptimizeCall(CallInst* ci, SimplifyLibCalls& SLC)
{
// If the result is used, none of these optimizations work
if (!ci->hasNUses(0))
if (!ci->use_empty())
return false;
// All the optimizations depend on the length of the first argument and the