[LoopInfo][Refactor] Make SetLoopAlreadyUnrolled a member function of the Loop Pass, NFC.
This avoid code duplication and allow us to add the disable unroll metadata elsewhere.
Differential Revision: https://reviews.llvm.org/D38928
llvm-svn: 315850
diff --git a/llvm/lib/Analysis/LoopInfo.cpp b/llvm/lib/Analysis/LoopInfo.cpp
index 30d497b..8f5a043 100644
--- a/llvm/lib/Analysis/LoopInfo.cpp
+++ b/llvm/lib/Analysis/LoopInfo.cpp
@@ -268,6 +268,39 @@
}
}
+void Loop::setLoopAlreadyUnrolled() {
+ MDNode *LoopID = getLoopID();
+ // First remove any existing loop unrolling metadata.
+ SmallVector<Metadata *, 4> MDs;
+ // Reserve first location for self reference to the LoopID metadata node.
+ MDs.push_back(nullptr);
+
+ if (LoopID) {
+ for (unsigned i = 1, ie = LoopID->getNumOperands(); i < ie; ++i) {
+ bool IsUnrollMetadata = false;
+ MDNode *MD = dyn_cast<MDNode>(LoopID->getOperand(i));
+ if (MD) {
+ const MDString *S = dyn_cast<MDString>(MD->getOperand(0));
+ IsUnrollMetadata = S && S->getString().startswith("llvm.loop.unroll.");
+ }
+ if (!IsUnrollMetadata)
+ MDs.push_back(LoopID->getOperand(i));
+ }
+ }
+
+ // Add unroll(disable) metadata to disable future unrolling.
+ LLVMContext &Context = getHeader()->getContext();
+ SmallVector<Metadata *, 1> DisableOperands;
+ DisableOperands.push_back(MDString::get(Context, "llvm.loop.unroll.disable"));
+ MDNode *DisableNode = MDNode::get(Context, DisableOperands);
+ MDs.push_back(DisableNode);
+
+ MDNode *NewLoopID = MDNode::get(Context, MDs);
+ // Set operand 0 to refer to the loop id itself.
+ NewLoopID->replaceOperandWith(0, NewLoopID);
+ setLoopID(NewLoopID);
+}
+
bool Loop::isAnnotatedParallel() const {
MDNode *DesiredLoopIdMetadata = getLoopID();