Move trip count discovery outside of the generic LoopUnroll helper. This
removes its dependence on canonical induction variables.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135829 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/LoopUnrollPass.cpp b/lib/Transforms/Scalar/LoopUnrollPass.cpp
index 38259f0..6d7901f 100644
--- a/lib/Transforms/Scalar/LoopUnrollPass.cpp
+++ b/lib/Transforms/Scalar/LoopUnrollPass.cpp
@@ -137,9 +137,14 @@
// Find trip count
unsigned TripCount = L->getSmallConstantTripCount();
- unsigned Count = CurrentCount;
+
+ // Find trip multiple if count is not available
+ unsigned TripMultiple = 1;
+ if (TripCount == 0)
+ TripMultiple = L->getSmallConstantTripMultiple();
// Automatically select an unroll count.
+ unsigned Count = CurrentCount;
if (Count == 0) {
// Conservative heuristic: if we know the trip count, see if we can
// completely unroll (subject to the threshold, checked below); otherwise
@@ -183,7 +188,7 @@
// Unroll the loop.
Function *F = L->getHeader()->getParent();
- if (!UnrollLoop(L, Count, LI, &LPM))
+ if (!UnrollLoop(L, Count, TripCount, TripMultiple, LI, &LPM))
return false;
// FIXME: Reconstruct dom info, because it is not preserved properly.
diff --git a/lib/Transforms/Utils/LoopUnroll.cpp b/lib/Transforms/Utils/LoopUnroll.cpp
index ce04da7..27382c2 100644
--- a/lib/Transforms/Utils/LoopUnroll.cpp
+++ b/lib/Transforms/Utils/LoopUnroll.cpp
@@ -11,9 +11,6 @@
// actual pass or policy, but provides a single function to perform loop
// unrolling.
//
-// It works best when loops have been canonicalized by the -indvars pass,
-// allowing it to determine the trip counts of loops easily.
-//
// The process of unrolling can produce extraneous basic blocks linked with
// unconditional branches. This will be corrected in the future.
//
@@ -113,8 +110,8 @@
///
/// If a LoopPassManager is passed in, and the loop is fully removed, it will be
/// removed from the LoopPassManager as well. LPM can also be NULL.
-bool llvm::UnrollLoop(Loop *L, unsigned Count,
- LoopInfo *LI, LPPassManager *LPM) {
+bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount,
+ unsigned TripMultiple, LoopInfo *LI, LPPassManager *LPM) {
BasicBlock *Preheader = L->getLoopPreheader();
if (!Preheader) {
DEBUG(dbgs() << " Can't unroll; loop preheader-insertion failed.\n");
@@ -149,13 +146,6 @@
if (ScalarEvolution *SE = LPM->getAnalysisIfAvailable<ScalarEvolution>())
SE->forgetLoop(L);
- // Find trip count
- unsigned TripCount = L->getSmallConstantTripCount();
- // Find trip multiple if count is not available
- unsigned TripMultiple = 1;
- if (TripCount == 0)
- TripMultiple = L->getSmallConstantTripMultiple();
-
if (TripCount != 0)
DEBUG(dbgs() << " Trip Count = " << TripCount << "\n");
if (TripMultiple != 1)