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fix a miscompilation in printf optimizer. 

llvm-svn: 35713
This commit is contained in:
Chris Lattner 2007-04-07 01:18:36 +00:00
parent 6a36d636e9
commit 0f1509511e
1 changed files with 37 additions and 39 deletions
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76
llvm/lib/Transforms/IPO/SimplifyLibCalls.cpp
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@ -1189,67 +1189,65 @@ public:
"Number of 'printf' calls simplified") {}
/// @brief Make sure that the "printf" function has the right prototype
virtual bool ValidateCalledFunction(const Function* f, SimplifyLibCalls& SLC){
virtual bool ValidateCalledFunction(const Function *F, SimplifyLibCalls &SLC){
// Just make sure this has at least 1 arguments
return (f->arg_size() >= 1);
return F->arg_size() >= 1;
}
/// @brief Perform the printf optimization.
virtual bool OptimizeCall(CallInst* ci, SimplifyLibCalls& SLC) {
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)
if (CI->getNumOperands() != 3)
return false;
// If the result of the printf call is used, none of these optimizations
// can be made.
if (!ci->use_empty())
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, StartIdx;
ConstantArray* CA = 0;
if (!GetConstantStringInfo(ci->getOperand(1), CA, len, StartIdx))
uint64_t FormatLen, FormatIdx;
ConstantArray *CA = 0;
if (!GetConstantStringInfo(CI->getOperand(1), CA, FormatLen, FormatIdx))
return false;
if (len != 2 && len != 3)
if (FormatLen != 2 && FormatLen != 3)
return false;
// The first character has to be a %
if (ConstantInt* CI = dyn_cast<ConstantInt>(CA->getOperand(0)))
if (CI->getZExtValue() != '%')
return false;
if (cast<ConstantInt>(CA->getOperand(FormatIdx))->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':
{
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);
return ReplaceCallWith(ci, ConstantInt::get(Type::Int32Ty, len));
}
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);
return ReplaceCallWith(ci, ConstantInt::get(Type::Int32Ty, 1));
}
default:
switch (cast<ConstantInt>(CA->getOperand(FormatIdx+1))->getZExtValue()) {
default: return false;
case 's': {
if (FormatLen != 3 ||
cast<ConstantInt>(CA->getOperand(FormatIdx+2))->getZExtValue() !='\n')
return false;
// printf("%s\n",str) -> puts(str)
new CallInst(SLC.get_puts(), CastToCStr(CI->getOperand(2), *CI),
CI->getName(), CI);
return ReplaceCallWith(CI, 0);
}
case 'c': {
// printf("%c",c) -> putchar(c)
if (FormatLen != 2)
return false;
Value *V = CI->getOperand(2);
if (!isa<IntegerType>(V->getType()) ||
cast<IntegerType>(V->getType())->getBitWidth() < 32)
return false;
V = CastInst::createSExtOrBitCast(V, Type::Int32Ty, CI->getName()+".int",
CI);
new CallInst(SLC.get_putchar(), V, "", CI);
return ReplaceCallWith(CI, 0);
}
}
return false;
}
} PrintfOptimizer;