[IRCE] Be resilient in the face of non-simplified loops
Loops containing `indirectbr` may not be in simplified form, even after
running LoopSimplify. Reject then gracefully, instead of tripping an
assert.
llvm-svn: 278611
diff --git a/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp b/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
index b3bd1f0..3f9432e 100644
--- a/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
@@ -622,9 +622,12 @@
Optional<LoopStructure>
LoopStructure::parseLoopStructure(ScalarEvolution &SE, BranchProbabilityInfo &BPI,
Loop &L, const char *&FailureReason) {
- assert(L.isLoopSimplifyForm() && "should follow from addRequired<>");
+ if (!L.isLoopSimplifyForm())
+ return None;
BasicBlock *Latch = L.getLoopLatch();
+ assert(Latch && "Simplified loops only have one latch!");
+
if (!L.isLoopExiting(Latch)) {
FailureReason = "no loop latch";
return None;