The patch set unroll disable pragma when unroll
with user specified count has been applied.
Summary:
Previously SetLoopAlreadyUnrolled() set the disable pragma only if
there was some loop metadata.
Now it set the pragma in all cases. This helps to prevent multiple
unroll when -unroll-count=N is given.
Reviewers: mzolotukhin
Differential Revision: http://reviews.llvm.org/D20765
From: Evgeny Stupachenko <evstupac@gmail.com>
llvm-svn: 272195
diff --git a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
index ddc1c60..65eab47 100644
--- a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
@@ -604,22 +604,22 @@
// unrolling pass is run more than once (which it generally is).
static void SetLoopAlreadyUnrolled(Loop *L) {
MDNode *LoopID = L->getLoopID();
- if (!LoopID)
- return;
-
// 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);
- 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 (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));
}
- if (!IsUnrollMetadata)
- MDs.push_back(LoopID->getOperand(i));
}
// Add unroll(disable) metadata to disable future unrolling.