Update various Loop optimization passes to cope with the possibility that
LoopSimplify form may not be available.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86175 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/IPO/LoopExtractor.cpp b/lib/Transforms/IPO/LoopExtractor.cpp
index fd69aeb..cb81330 100644
--- a/lib/Transforms/IPO/LoopExtractor.cpp
+++ b/lib/Transforms/IPO/LoopExtractor.cpp
@@ -75,6 +75,10 @@
if (L->getParentLoop())
return false;
+ // If LoopSimplify form is not available, stay out of trouble.
+ if (!L->isLoopSimplifyForm())
+ return false;
+
DominatorTree &DT = getAnalysis<DominatorTree>();
bool Changed = false;
diff --git a/lib/Transforms/Scalar/IndVarSimplify.cpp b/lib/Transforms/Scalar/IndVarSimplify.cpp
index b0bc70c..2912421 100644
--- a/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -536,8 +536,10 @@
BasicBlock *ExitBlock = L->getExitBlock();
if (!ExitBlock) return;
- Instruction *InsertPt = ExitBlock->getFirstNonPHI();
BasicBlock *Preheader = L->getLoopPreheader();
+ if (!Preheader) return;
+
+ Instruction *InsertPt = ExitBlock->getFirstNonPHI();
BasicBlock::iterator I = Preheader->getTerminator();
while (I != Preheader->begin()) {
--I;
diff --git a/lib/Transforms/Scalar/LICM.cpp b/lib/Transforms/Scalar/LICM.cpp
index 756fbf3..104c873 100644
--- a/lib/Transforms/Scalar/LICM.cpp
+++ b/lib/Transforms/Scalar/LICM.cpp
@@ -263,7 +263,6 @@
// Get the preheader block to move instructions into...
Preheader = L->getLoopPreheader();
- assert(Preheader&&"Preheader insertion pass guarantees we have a preheader!");
// Loop over the body of this loop, looking for calls, invokes, and stores.
// Because subloops have already been incorporated into AST, we skip blocks in
@@ -286,12 +285,14 @@
// us to sink instructions in one pass, without iteration. After sinking
// instructions, we perform another pass to hoist them out of the loop.
//
- SinkRegion(DT->getNode(L->getHeader()));
- HoistRegion(DT->getNode(L->getHeader()));
+ if (L->hasDedicatedExits())
+ SinkRegion(DT->getNode(L->getHeader()));
+ if (Preheader)
+ HoistRegion(DT->getNode(L->getHeader()));
// Now that all loop invariants have been removed from the loop, promote any
// memory references to scalars that we can...
- if (!DisablePromotion)
+ if (!DisablePromotion && Preheader && L->hasDedicatedExits())
PromoteValuesInLoop();
// Clear out loops state information for the next iteration
diff --git a/lib/Transforms/Scalar/LoopIndexSplit.cpp b/lib/Transforms/Scalar/LoopIndexSplit.cpp
index 920d85c..8b6a233 100644
--- a/lib/Transforms/Scalar/LoopIndexSplit.cpp
+++ b/lib/Transforms/Scalar/LoopIndexSplit.cpp
@@ -209,6 +209,10 @@
L = IncomingLoop;
LPM = &LPM_Ref;
+ // If LoopSimplify form is not available, stay out of trouble.
+ if (!L->isLoopSimplifyForm())
+ return false;
+
// FIXME - Nested loops make dominator info updates tricky.
if (!L->getSubLoops().empty())
return false;
diff --git a/lib/Transforms/Scalar/LoopRotation.cpp b/lib/Transforms/Scalar/LoopRotation.cpp
index a18d9d4..5004483 100644
--- a/lib/Transforms/Scalar/LoopRotation.cpp
+++ b/lib/Transforms/Scalar/LoopRotation.cpp
@@ -104,17 +104,18 @@
bool LoopRotate::rotateLoop(Loop *Lp, LPPassManager &LPM) {
L = Lp;
- OrigHeader = L->getHeader();
OrigPreHeader = L->getLoopPreheader();
+ if (!OrigPreHeader) return false;
+
OrigLatch = L->getLoopLatch();
+ if (!OrigLatch) return false;
+
+ OrigHeader = L->getHeader();
// If the loop has only one block then there is not much to rotate.
if (L->getBlocks().size() == 1)
return false;
- assert(OrigHeader && OrigLatch && OrigPreHeader &&
- "Loop is not in canonical form");
-
// If the loop header is not one of the loop exiting blocks then
// either this loop is already rotated or it is not
// suitable for loop rotation transformations.
diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index e20fb16..288dd47 100644
--- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -2528,6 +2528,10 @@
SE = &getAnalysis<ScalarEvolution>();
Changed = false;
+ // If LoopSimplify form is not available, stay out of trouble.
+ if (!L->getLoopPreheader() || !L->getLoopLatch())
+ return false;
+
if (!IU->IVUsesByStride.empty()) {
DEBUG(errs() << "\nLSR on \"" << L->getHeader()->getParent()->getName()
<< "\" ";
diff --git a/lib/Transforms/Scalar/LoopUnswitch.cpp b/lib/Transforms/Scalar/LoopUnswitch.cpp
index c7b00da..be8366d 100644
--- a/lib/Transforms/Scalar/LoopUnswitch.cpp
+++ b/lib/Transforms/Scalar/LoopUnswitch.cpp
@@ -407,6 +407,10 @@
initLoopData();
Function *F = loopHeader->getParent();
+ // If LoopSimplify was unable to form a preheader, don't do any unswitching.
+ if (!loopPreheader)
+ return false;
+
// If the condition is trivial, always unswitch. There is no code growth for
// this case.
if (!IsTrivialUnswitchCondition(LoopCond)) {