From 5865a8dfde3be74418b579f1162f111f3e46998d Mon Sep 17 00:00:00 2001
From: Andrew Trick <atrick@apple.com>
Date: Fri, 18 Nov 2011 03:42:41 +0000
Subject: Fix a corner case in updating LoopInfo after fully unrolling an outer
 loop.

The loop tree's inclusive block lists are painful and expensive to
update. (I have no idea why they're inclusive). The design was
supposed to handle this case but the implementation missed it and my
unit tests weren't thorough enough.

Fixes PR11335: loop unroll update.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144970 91177308-0d34-0410-b5e6-96231b3b80d8
---
 test/Transforms/LoopUnroll/unloop.ll | 41 ++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

(limited to 'test/Transforms')

diff --git a/test/Transforms/LoopUnroll/unloop.ll b/test/Transforms/LoopUnroll/unloop.ll
index 217c8ce..5a9cacd 100644
--- a/test/Transforms/LoopUnroll/unloop.ll
+++ b/test/Transforms/LoopUnroll/unloop.ll
@@ -427,3 +427,44 @@ if.end2413:                                       ; preds = %defchar
 return:                                           ; preds = %sw.bb304
   ret void
 }
+
+; PR11335: the most deeply nested block should be removed from the outer loop.
+; CHECK: @removeSubloopBlocks2
+; CHECK: for.cond3:
+; CHECK-NOT: br
+; CHECK: ret void
+define void @removeSubloopBlocks2() nounwind {
+entry:
+  %tobool.i = icmp ne i32 undef, 0
+  br label %lbl_616
+
+lbl_616.loopexit:                                 ; preds = %for.cond
+  br label %lbl_616
+
+lbl_616:                                          ; preds = %lbl_616.loopexit, %entry
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.cond3, %lbl_616
+  br i1 false, label %for.cond1.preheader, label %lbl_616.loopexit
+
+for.cond1.preheader:                              ; preds = %for.cond
+  br label %for.cond1
+
+for.cond1.loopexit:                               ; preds = %for.cond.i
+  br label %for.cond1
+
+for.cond1:                                        ; preds = %for.cond1.loopexit, %for.cond1.preheader
+  br i1 false, label %for.body2, label %for.cond3
+
+for.body2:                                        ; preds = %for.cond1
+  br label %for.cond.i
+
+for.cond.i:                                       ; preds = %for.cond.i, %for.body2
+  br i1 %tobool.i, label %for.cond.i, label %for.cond1.loopexit
+
+for.cond3:                                        ; preds = %for.cond1
+  br i1 false, label %for.cond, label %if.end
+
+if.end:                                           ; preds = %for.cond3
+  ret void
+}
-- 
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