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-rw-r--r--contrib/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp118
1 files changed, 0 insertions, 118 deletions
diff --git a/contrib/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp b/contrib/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
index 2f1ae00..ec625b4 100644
--- a/contrib/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
+++ b/contrib/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
@@ -558,121 +558,3 @@ void llvm::FindFunctionBackedges(const Function &F,
}
-
-
-
-/// AreEquivalentAddressValues - Test if A and B will obviously have the same
-/// value. This includes recognizing that %t0 and %t1 will have the same
-/// value in code like this:
-/// %t0 = getelementptr \@a, 0, 3
-/// store i32 0, i32* %t0
-/// %t1 = getelementptr \@a, 0, 3
-/// %t2 = load i32* %t1
-///
-static bool AreEquivalentAddressValues(const Value *A, const Value *B) {
- // Test if the values are trivially equivalent.
- if (A == B) return true;
-
- // Test if the values come from identical arithmetic instructions.
- // Use isIdenticalToWhenDefined instead of isIdenticalTo because
- // this function is only used when one address use dominates the
- // other, which means that they'll always either have the same
- // value or one of them will have an undefined value.
- if (isa<BinaryOperator>(A) || isa<CastInst>(A) ||
- isa<PHINode>(A) || isa<GetElementPtrInst>(A))
- if (const Instruction *BI = dyn_cast<Instruction>(B))
- if (cast<Instruction>(A)->isIdenticalToWhenDefined(BI))
- return true;
-
- // Otherwise they may not be equivalent.
- return false;
-}
-
-/// FindAvailableLoadedValue - Scan the ScanBB block backwards (starting at the
-/// instruction before ScanFrom) checking to see if we have the value at the
-/// memory address *Ptr locally available within a small number of instructions.
-/// If the value is available, return it.
-///
-/// If not, return the iterator for the last validated instruction that the
-/// value would be live through. If we scanned the entire block and didn't find
-/// something that invalidates *Ptr or provides it, ScanFrom would be left at
-/// begin() and this returns null. ScanFrom could also be left
-///
-/// MaxInstsToScan specifies the maximum instructions to scan in the block. If
-/// it is set to 0, it will scan the whole block. You can also optionally
-/// specify an alias analysis implementation, which makes this more precise.
-Value *llvm::FindAvailableLoadedValue(Value *Ptr, BasicBlock *ScanBB,
- BasicBlock::iterator &ScanFrom,
- unsigned MaxInstsToScan,
- AliasAnalysis *AA) {
- if (MaxInstsToScan == 0) MaxInstsToScan = ~0U;
-
- // If we're using alias analysis to disambiguate get the size of *Ptr.
- unsigned AccessSize = 0;
- if (AA) {
- const Type *AccessTy = cast<PointerType>(Ptr->getType())->getElementType();
- AccessSize = AA->getTypeStoreSize(AccessTy);
- }
-
- while (ScanFrom != ScanBB->begin()) {
- // We must ignore debug info directives when counting (otherwise they
- // would affect codegen).
- Instruction *Inst = --ScanFrom;
- if (isa<DbgInfoIntrinsic>(Inst))
- continue;
-
- // Restore ScanFrom to expected value in case next test succeeds
- ScanFrom++;
-
- // Don't scan huge blocks.
- if (MaxInstsToScan-- == 0) return 0;
-
- --ScanFrom;
- // If this is a load of Ptr, the loaded value is available.
- if (LoadInst *LI = dyn_cast<LoadInst>(Inst))
- if (AreEquivalentAddressValues(LI->getOperand(0), Ptr))
- return LI;
-
- if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) {
- // If this is a store through Ptr, the value is available!
- if (AreEquivalentAddressValues(SI->getOperand(1), Ptr))
- return SI->getOperand(0);
-
- // If Ptr is an alloca and this is a store to a different alloca, ignore
- // the store. This is a trivial form of alias analysis that is important
- // for reg2mem'd code.
- if ((isa<AllocaInst>(Ptr) || isa<GlobalVariable>(Ptr)) &&
- (isa<AllocaInst>(SI->getOperand(1)) ||
- isa<GlobalVariable>(SI->getOperand(1))))
- continue;
-
- // If we have alias analysis and it says the store won't modify the loaded
- // value, ignore the store.
- if (AA &&
- (AA->getModRefInfo(SI, Ptr, AccessSize) & AliasAnalysis::Mod) == 0)
- continue;
-
- // Otherwise the store that may or may not alias the pointer, bail out.
- ++ScanFrom;
- return 0;
- }
-
- // If this is some other instruction that may clobber Ptr, bail out.
- if (Inst->mayWriteToMemory()) {
- // If alias analysis claims that it really won't modify the load,
- // ignore it.
- if (AA &&
- (AA->getModRefInfo(Inst, Ptr, AccessSize) & AliasAnalysis::Mod) == 0)
- continue;
-
- // May modify the pointer, bail out.
- ++ScanFrom;
- return 0;
- }
- }
-
- // Got to the start of the block, we didn't find it, but are done for this
- // block.
- return 0;
-}
-
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