Factorize code: remove variants of "strip off
pointer bitcasts and GEP's", and centralize the
logic in Value::getUnderlyingObject. The
difference with stripPointerCasts is that
stripPointerCasts only strips GEPs if all
indices are zero, while getUnderlyingObject
strips GEPs no matter what the indices are.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56922 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index aa47fb3..22b73b2 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -76,30 +76,6 @@
return false;
}
-/// getUnderlyingObject - This traverses the use chain to figure out what object
-/// the specified value points to. If the value points to, or is derived from,
-/// a unique object or an argument, return it. This returns:
-/// Arguments, GlobalVariables, Functions, Allocas, Mallocs.
-static const Value *getUnderlyingObject(const Value *V) {
- if (!isa<PointerType>(V->getType())) return V;
-
- // If we are at some type of object, return it. GlobalValues and Allocations
- // have unique addresses.
- if (isa<GlobalValue>(V) || isa<AllocationInst>(V) || isa<Argument>(V))
- return V;
-
- // Traverse through different addressing mechanisms...
- if (const Instruction *I = dyn_cast<Instruction>(V)) {
- if (isa<BitCastInst>(I) || isa<GetElementPtrInst>(I))
- return getUnderlyingObject(I->getOperand(0));
- } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
- if (CE->getOpcode() == Instruction::BitCast ||
- CE->getOpcode() == Instruction::GetElementPtr)
- return getUnderlyingObject(CE->getOperand(0));
- }
- return V;
-}
-
static const User *isGEP(const Value *V) {
if (isa<GetElementPtrInst>(V) ||
(isa<ConstantExpr>(V) &&
@@ -314,7 +290,7 @@
/// global) or not.
bool BasicAliasAnalysis::pointsToConstantMemory(const Value *P) {
if (const GlobalVariable *GV =
- dyn_cast<GlobalVariable>(getUnderlyingObject(P)))
+ dyn_cast<GlobalVariable>(P->getUnderlyingObject()))
return GV->isConstant();
return false;
}
@@ -327,7 +303,7 @@
AliasAnalysis::ModRefResult
BasicAliasAnalysis::getModRefInfo(CallSite CS, Value *P, unsigned Size) {
if (!isa<Constant>(P)) {
- const Value *Object = getUnderlyingObject(P);
+ const Value *Object = P->getUnderlyingObject();
// If this is a tail call and P points to a stack location, we know that
// the tail call cannot access or modify the local stack.
@@ -390,8 +366,8 @@
return alias(V1, V1Size, I->getOperand(0), V2Size);
// Figure out what objects these things are pointing to if we can...
- const Value *O1 = getUnderlyingObject(V1);
- const Value *O2 = getUnderlyingObject(V2);
+ const Value *O1 = V1->getUnderlyingObject();
+ const Value *O2 = V2->getUnderlyingObject();
if (O1 != O2) {
// If V1/V2 point to two different objects we know that we have no alias.
diff --git a/lib/Analysis/IPA/GlobalsModRef.cpp b/lib/Analysis/IPA/GlobalsModRef.cpp
index 74327d5..99e9d21 100644
--- a/lib/Analysis/IPA/GlobalsModRef.cpp
+++ b/lib/Analysis/IPA/GlobalsModRef.cpp
@@ -157,29 +157,6 @@
Pass *llvm::createGlobalsModRefPass() { return new GlobalsModRef(); }
-/// getUnderlyingObject - This traverses the use chain to figure out what object
-/// the specified value points to. If the value points to, or is derived from,
-/// a global object, return it.
-static Value *getUnderlyingObject(Value *V) {
- if (!isa<PointerType>(V->getType())) return V;
-
- // If we are at some type of object... return it.
- if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) return GV;
-
- // Traverse through different addressing mechanisms.
- if (Instruction *I = dyn_cast<Instruction>(V)) {
- if (isa<BitCastInst>(I) || isa<GetElementPtrInst>(I))
- return getUnderlyingObject(I->getOperand(0));
- } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
- if (CE->getOpcode() == Instruction::BitCast ||
- CE->getOpcode() == Instruction::GetElementPtr)
- return getUnderlyingObject(CE->getOperand(0));
- }
-
- // Otherwise, we don't know what this is, return it as the base pointer.
- return V;
-}
-
/// AnalyzeGlobals - Scan through the users of all of the internal
/// GlobalValue's in the program. If none of them have their "address taken"
/// (really, their address passed to something nontrivial), record this fact,
@@ -304,7 +281,7 @@
continue;
// Check the value being stored.
- Value *Ptr = getUnderlyingObject(SI->getOperand(0));
+ Value *Ptr = SI->getOperand(0)->getUnderlyingObject();
if (isa<MallocInst>(Ptr)) {
// Okay, easy case.
@@ -468,8 +445,8 @@
GlobalsModRef::alias(const Value *V1, unsigned V1Size,
const Value *V2, unsigned V2Size) {
// Get the base object these pointers point to.
- Value *UV1 = getUnderlyingObject(const_cast<Value*>(V1));
- Value *UV2 = getUnderlyingObject(const_cast<Value*>(V2));
+ Value *UV1 = const_cast<Value*>(V1->getUnderlyingObject());
+ Value *UV2 = const_cast<Value*>(V2->getUnderlyingObject());
// If either of the underlying values is a global, they may be non-addr-taken
// globals, which we can answer queries about.
@@ -526,7 +503,7 @@
// If we are asking for mod/ref info of a direct call with a pointer to a
// global we are tracking, return information if we have it.
- if (GlobalValue *GV = dyn_cast<GlobalValue>(getUnderlyingObject(P)))
+ if (GlobalValue *GV = dyn_cast<GlobalValue>(P->getUnderlyingObject()))
if (GV->hasInternalLinkage())
if (Function *F = CS.getCalledFunction())
if (NonAddressTakenGlobals.count(GV))