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authorStephen Hines <srhines@google.com>2013-03-05 23:27:24 -0800
committerStephen Hines <srhines@google.com>2013-03-05 23:27:24 -0800
commit5adb136be579e8fff3734461580cb34d1d2983b8 (patch)
treebff1a422e9c9789df563aaf9a7e91e63e8ec0384 /lib/Analysis/ValueTracking.cpp
parent227a4a4ade38716ba9eb3205f48b52910f3b955e (diff)
parentb3201c5cf1e183d840f7c99ff779d57f1549d8e5 (diff)
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Merge commit 'b3201c5cf1e183d840f7c99ff779d57f1549d8e5' into merge_20130226
Conflicts: include/llvm/Support/ELF.h lib/Support/DeltaAlgorithm.cpp Change-Id: I24a4fbce62eb39d924efee3c687b55e1e17b30cd
Diffstat (limited to 'lib/Analysis/ValueTracking.cpp')
-rw-r--r--lib/Analysis/ValueTracking.cpp26
1 files changed, 22 insertions, 4 deletions
diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp
index efb9b08..8e3994e 100644
--- a/lib/Analysis/ValueTracking.cpp
+++ b/lib/Analysis/ValueTracking.cpp
@@ -1510,7 +1510,7 @@ static Value *BuildSubAggregate(Value *From, Value* To, Type *IndexedType,
SmallVector<unsigned, 10> &Idxs,
unsigned IdxSkip,
Instruction *InsertBefore) {
- llvm::StructType *STy = llvm::dyn_cast<llvm::StructType>(IndexedType);
+ llvm::StructType *STy = dyn_cast<llvm::StructType>(IndexedType);
if (STy) {
// Save the original To argument so we can modify it
Value *OrigTo = To;
@@ -1671,8 +1671,10 @@ Value *llvm::FindInsertedValue(Value *V, ArrayRef<unsigned> idx_range,
/// it can be expressed as a base pointer plus a constant offset. Return the
/// base and offset to the caller.
Value *llvm::GetPointerBaseWithConstantOffset(Value *Ptr, int64_t &Offset,
- const DataLayout &TD) {
- unsigned BitWidth = TD.getPointerSizeInBits();
+ const DataLayout *TD) {
+ // Without DataLayout, conservatively assume 64-bit offsets, which is
+ // the widest we support.
+ unsigned BitWidth = TD ? TD->getPointerSizeInBits() : 64;
APInt ByteOffset(BitWidth, 0);
while (1) {
if (Ptr->getType()->isVectorTy())
@@ -1680,7 +1682,7 @@ Value *llvm::GetPointerBaseWithConstantOffset(Value *Ptr, int64_t &Offset,
if (GEPOperator *GEP = dyn_cast<GEPOperator>(Ptr)) {
APInt GEPOffset(BitWidth, 0);
- if (!GEP->accumulateConstantOffset(TD, GEPOffset))
+ if (TD && !GEP->accumulateConstantOffset(*TD, GEPOffset))
break;
ByteOffset += GEPOffset;
Ptr = GEP->getPointerOperand();
@@ -2012,3 +2014,19 @@ bool llvm::isSafeToSpeculativelyExecute(const Value *V,
return false; // Misc instructions which have effects
}
}
+
+/// isKnownNonNull - Return true if we know that the specified value is never
+/// null.
+bool llvm::isKnownNonNull(const Value *V) {
+ // Alloca never returns null, malloc might.
+ if (isa<AllocaInst>(V)) return true;
+
+ // A byval argument is never null.
+ if (const Argument *A = dyn_cast<Argument>(V))
+ return A->hasByValAttr();
+
+ // Global values are not null unless extern weak.
+ if (const GlobalValue *GV = dyn_cast<GlobalValue>(V))
+ return !GV->hasExternalWeakLinkage();
+ return false;
+}