Generalize LoadAndStorePromoter a bit and switch LICM
to use it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123501 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Utils/SSAUpdater.cpp b/lib/Transforms/Utils/SSAUpdater.cpp
index 2ecae35..0474a78 100644
--- a/lib/Transforms/Utils/SSAUpdater.cpp
+++ b/lib/Transforms/Utils/SSAUpdater.cpp
@@ -348,23 +348,25 @@
// LoadAndStorePromoter Implementation
//===----------------------------------------------------------------------===//
-void LoadAndStorePromoter::run(StringRef BaseName,
- const SmallVectorImpl<Instruction*> &Insts,
- SSAUpdater *SSA) {
+LoadAndStorePromoter::
+LoadAndStorePromoter(const SmallVectorImpl<Instruction*> &Insts,
+ SSAUpdater &S, StringRef BaseName) : SSA(S) {
if (Insts.empty()) return;
- // If no SSAUpdater was provided, use a default one. This allows the client
- // to capture inserted PHI nodes etc if they want.
- SSAUpdater DefaultSSA;
- if (SSA == 0) SSA = &DefaultSSA;
-
- const Type *ValTy;
+ Value *SomeVal;
if (LoadInst *LI = dyn_cast<LoadInst>(Insts[0]))
- ValTy = LI->getType();
+ SomeVal = LI;
else
- ValTy = cast<StoreInst>(Insts[0])->getOperand(0)->getType();
-
- SSA->Initialize(ValTy, BaseName);
+ SomeVal = cast<StoreInst>(Insts[0])->getOperand(0);
+
+ if (BaseName.empty())
+ BaseName = SomeVal->getName();
+ SSA.Initialize(SomeVal->getType(), BaseName);
+}
+
+
+void LoadAndStorePromoter::
+run(const SmallVectorImpl<Instruction*> &Insts) const {
// First step: bucket up uses of the alloca by the block they occur in.
// This is important because we have to handle multiple defs/uses in a block
@@ -396,7 +398,7 @@
if (BlockUses.size() == 1) {
// If it is a store, it is a trivial def of the value in the block.
if (StoreInst *SI = dyn_cast<StoreInst>(User))
- SSA->AddAvailableValue(BB, SI->getOperand(0));
+ SSA.AddAvailableValue(BB, SI->getOperand(0));
else
// Otherwise it is a load, queue it to rewrite as a live-in load.
LiveInLoads.push_back(cast<LoadInst>(User));
@@ -437,6 +439,7 @@
// If we haven't seen a store yet, this is a live in use, otherwise
// use the stored value.
if (StoredValue) {
+ replaceLoadWithValue(L, StoredValue);
L->replaceAllUsesWith(StoredValue);
ReplacedLoads[L] = StoredValue;
} else {
@@ -456,7 +459,7 @@
// The last stored value that happened is the live-out for the block.
assert(StoredValue && "Already checked that there is a store in block");
- SSA->AddAvailableValue(BB, StoredValue);
+ SSA.AddAvailableValue(BB, StoredValue);
BlockUses.clear();
}
@@ -464,11 +467,15 @@
// inserting PHI nodes as necessary.
for (unsigned i = 0, e = LiveInLoads.size(); i != e; ++i) {
LoadInst *ALoad = LiveInLoads[i];
- Value *NewVal = SSA->GetValueInMiddleOfBlock(ALoad->getParent());
+ Value *NewVal = SSA.GetValueInMiddleOfBlock(ALoad->getParent());
+ replaceLoadWithValue(ALoad, NewVal);
ALoad->replaceAllUsesWith(NewVal);
ReplacedLoads[ALoad] = NewVal;
}
+ // Allow the client to do stuff before we start nuking things.
+ doExtraRewritesBeforeFinalDeletion();
+
// Now that everything is rewritten, delete the old instructions from the
// function. They should all be dead now.
for (unsigned i = 0, e = Insts.size(); i != e; ++i) {
@@ -491,9 +498,11 @@
RLI = ReplacedLoads.find(NewVal);
}
+ replaceLoadWithValue(cast<LoadInst>(User), NewVal);
User->replaceAllUsesWith(NewVal);
}
+ instructionDeleted(User);
User->eraseFromParent();
}
}