LoopRotate: When reconstructing loop simplify form don't split edges from indirectbrs.

Yet another chapter in the endless story. While this looks like we leave
the loop in a non-canonical state this replicates the logic in
LoopSimplify so it doesn't diverge from the canonical form in any way.

PR21968

llvm-svn: 230058

1 files changed, 18 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LoopRotate/crash.ll b/llvm/test/Transforms/LoopRotate/crash.ll
index fd922cb5569..e95f9a1f350 100644
--- a/llvm/test/Transforms/LoopRotate/crash.ll
+++ b/llvm/test/Transforms/LoopRotate/crash.ll
@@ -153,3 +153,21 @@ entry:
 "5":                                              ; preds = %"3", %entry
   ret void
 }
+
+; PR21968
+define void @test8(i1 %C, i8* %P) #0 {
+entry:
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.inc, %entry
+  br i1 %C, label %l_bad, label %for.body
+
+for.body:                                         ; preds = %for.cond
+  indirectbr i8* %P, [label %for.inc, label %l_bad]
+
+for.inc:                                          ; preds = %for.body
+  br label %for.cond
+
+l_bad:                                            ; preds = %for.body, %for.cond
+  ret void
+}