1 files changed, 47 insertions, 0 deletions
diff --git a/llvm/test/Transforms/LoopStrengthReduce/scev-insertpt-bug.ll b/llvm/test/Transforms/LoopStrengthReduce/scev-insertpt-bug.ll
new file mode 100644
index 00000000000..81a6b07fe95
--- /dev/null
+++ b/llvm/test/Transforms/LoopStrengthReduce/scev-insertpt-bug.ll
@@ -0,0 +1,47 @@
+; RUN: opt < %s -loop-reduce -S
+
+; Test that SCEV insertpoint's don't get corrupted and cause an
+; invalid instruction to be inserted in a block other than its parent.
+; See http://reviews.llvm.org/D20703 for context.
+define void @test() {
+entry:
+  %bf.load = load i32, i32* null, align 4
+  %bf.clear = lshr i32 %bf.load, 1
+  %div = and i32 %bf.clear, 134217727
+  %sub = add nsw i32 %div, -1
+  %0 = zext i32 %sub to i64
+  br label %while.cond
+
+while.cond:                                       ; preds = %cond.end, %entry
+  %indvars.iv = phi i64 [ %indvars.iv.next, %cond.end ], [ 0, %entry ]
+  %cmp = icmp eq i64 %indvars.iv, %0
+  br i1 %cmp, label %cleanup16, label %while.body
+
+while.body:                                       ; preds = %while.cond
+  %1 = trunc i64 %indvars.iv to i32
+  %mul = shl i32 %1, 1
+  %add = add nuw i32 %mul, 2
+  %cmp3 = icmp ult i32 %add, 0
+  br i1 %cmp3, label %if.end, label %if.then
+
+if.then:                                          ; preds = %while.body
+  unreachable
+
+if.end:                                           ; preds = %while.body
+  br i1 false, label %cond.end, label %cond.true
+
+cond.true:                                        ; preds = %if.end
+  br label %cond.end
+
+cond.end:                                         ; preds = %cond.true, %if.end
+  %add7 = add i32 %1, 1
+  %cmp12 = icmp ugt i32 %add7, %sub
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  br i1 %cmp12, label %if.then13, label %while.cond
+
+if.then13:                                        ; preds = %cond.end
+  unreachable
+
+cleanup16:                                        ; preds = %while.cond
+  ret void
+}