Changes in directory llvm/lib/Transforms/IPO:
SimplifyLibCalls.cpp updated: 1.97 -> 1.98
---
Log message:
fix 3 miscompilations and several compielr crashes in strcmp optimizer.
---
Diffs of the changes: (+35 -44)
SimplifyLibCalls.cpp | 79 ++++++++++++++++++++++-----------------------------
1 files changed, 35 insertions(+), 44 deletions(-)
Index: llvm/lib/Transforms/IPO/SimplifyLibCalls.cpp
diff -u llvm/lib/Transforms/IPO/SimplifyLibCalls.cpp:1.97
llvm/lib/Transforms/IPO/SimplifyLibCalls.cpp:1.98
--- llvm/lib/Transforms/IPO/SimplifyLibCalls.cpp:1.97 Fri Apr 6 18:38:55 2007
+++ llvm/lib/Transforms/IPO/SimplifyLibCalls.cpp Fri Apr 6 19:01:51 2007
@@ -621,66 +621,57 @@
/// @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::get(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) {
+ Value *Str1P = CI->getOperand(1);
+ Value *Str2P = CI->getOperand(2);
+ if (Str1P == Str2P) {
// strcmp(x,x) -> 0
- ci->replaceAllUsesWith(ConstantInt::get(Type::Int32Ty,0));
- ci->eraseFromParent();
+ CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 0));
+ CI->eraseFromParent();
return true;
}
- bool isstr_1 = false;
- uint64_t len_1 = 0, StartIdx;
+ uint64_t Str1Len, Str1StartIdx;
ConstantArray *A1;
- if (GetConstantStringInfo(s1, A1, len_1, StartIdx)) {
- 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;
- }
+ bool Str1IsCst = GetConstantStringInfo(Str1P, A1, Str1Len, Str1StartIdx);
+ if (Str1IsCst && Str1Len == 0) {
+ // strcmp("", x) -> *x
+ Value *V = new LoadInst(Str2P, CI->getName()+".load", CI);
+ V = new ZExtInst(V, CI->getType(), CI->getName()+".int", CI);
+ CI->replaceAllUsesWith(V);
+ CI->eraseFromParent();
+ return true;
}
- bool isstr_2 = false;
- uint64_t len_2;
+ uint64_t Str2Len, Str2StartIdx;
ConstantArray* A2;
- if (GetConstantStringInfo(s2, A2, len_2, StartIdx)) {
- 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;
- }
+ bool Str2IsCst = GetConstantStringInfo(Str2P, A2, Str2Len, Str2StartIdx);
+ if (Str2IsCst && Str2Len == 0) {
+ // strcmp(x,"") -> *x
+ Value *V = new LoadInst(Str1P, CI->getName()+".load", CI);
+ V = new ZExtInst(V, CI->getType(), CI->getName()+".int", CI);
+ CI->replaceAllUsesWith(V);
+ CI->eraseFromParent();
+ return true;
}
- 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();
+ if (Str1IsCst && Str2IsCst && A1->isCString() && A2->isCString()) {
+ // strcmp(x, y) -> cnst (if both x and y are constant strings)
+ std::string S1 = A1->getAsString();
+ std::string S2 = A2->getAsString();
+ int R = strcmp(S1.c_str()+Str1StartIdx, S2.c_str()+Str2StartIdx);
+ CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), R));
+ CI->eraseFromParent();
return true;
}
return false;
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