final step needed to resolve PR6627, which allows us to flatten the code down to
a nice and tidy:
%x1 = load i32* %0, align 4
%1 = icmp eq i32 %x1, 1179403647
br i1 %1, label %if.then, label %if.end
instead of doing lots of loads and branches. May the FreeBSD bootloader
long fit in its allocated space.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130416 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp
index 7480ed8..abd7689 100644
--- a/lib/Transforms/Scalar/GVN.cpp
+++ b/lib/Transforms/Scalar/GVN.cpp
@@ -432,14 +432,14 @@
/// addToLeaderTable - Push a new Value to the LeaderTable onto the list for
/// its value number.
void addToLeaderTable(uint32_t N, Value *V, BasicBlock *BB) {
- LeaderTableEntry& Curr = LeaderTable[N];
+ LeaderTableEntry &Curr = LeaderTable[N];
if (!Curr.Val) {
Curr.Val = V;
Curr.BB = BB;
return;
}
- LeaderTableEntry* Node = TableAllocator.Allocate<LeaderTableEntry>();
+ LeaderTableEntry *Node = TableAllocator.Allocate<LeaderTableEntry>();
Node->Val = V;
Node->BB = BB;
Node->Next = Curr.Next;
@@ -944,7 +944,10 @@
Value *PtrVal = SrcVal->getPointerOperand();
- IRBuilder<> Builder(SrcVal->getParent(), SrcVal);
+ // Insert the new load after the old load. This ensures that subsequent
+ // memdep queries will find the new load. We can't easily remove the old
+ // load completely because it is already in the value numbering table.
+ IRBuilder<> Builder(SrcVal->getParent(), ++BasicBlock::iterator(SrcVal));
const Type *DestPTy =
IntegerType::get(LoadTy->getContext(), NewLoadSize*8);
DestPTy = PointerType::get(DestPTy,
@@ -967,6 +970,7 @@
RV = Builder.CreateTrunc(RV, SrcVal->getType());
SrcVal->replaceAllUsesWith(RV);
gvn.getMemDep().removeInstruction(SrcVal);
+ //gvn.markInstructionForDeletion(SrcVal);
SrcVal = NewLoad;
}