fix overflow check.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56011 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Transforms/LoopStrengthReduce/2008-09-09-Overflow.ll b/test/Transforms/LoopStrengthReduce/2008-09-09-Overflow.ll
new file mode 100644
index 0000000..703aebe
--- /dev/null
+++ b/test/Transforms/LoopStrengthReduce/2008-09-09-Overflow.ll
@@ -0,0 +1,48 @@
+; RUN: llvm-as < %s | opt -loop-reduce | llvm-dis | grep phi | count 2
+; PR 2779
+@g_19 = common global i32 0 ; <i32*> [#uses=3]
+@"\01LC" = internal constant [4 x i8] c"%d\0A\00" ; <[4 x i8]*> [#uses=1]
+
+define i32 @func_8(i8 zeroext %p_9) nounwind {
+entry:
+ ret i32 1
+}
+
+define i32 @func_3(i8 signext %p_5) nounwind {
+entry:
+ ret i32 1
+}
+
+define void @func_1() nounwind {
+entry:
+ br label %bb
+
+bb: ; preds = %bb, %entry
+ %indvar = phi i16 [ 0, %entry ], [ %indvar.next, %bb ] ; <i16> [#uses=2]
+ %tmp = sub i16 0, %indvar ; <i16> [#uses=1]
+ %tmp27 = trunc i16 %tmp to i8 ; <i8> [#uses=1]
+ load i32* @g_19, align 4 ; <i32>:0 [#uses=2]
+ add i32 %0, 1 ; <i32>:1 [#uses=1]
+ store i32 %1, i32* @g_19, align 4
+ trunc i32 %0 to i8 ; <i8>:2 [#uses=1]
+ tail call i32 @func_8( i8 zeroext %2 ) nounwind ; <i32>:3 [#uses=0]
+ shl i8 %tmp27, 2 ; <i8>:4 [#uses=1]
+ add i8 %4, -112 ; <i8>:5 [#uses=1]
+ tail call i32 @func_3( i8 signext %5 ) nounwind ; <i32>:6 [#uses=0]
+ %indvar.next = add i16 %indvar, 1 ; <i16> [#uses=2]
+ %exitcond = icmp eq i16 %indvar.next, -28 ; <i1> [#uses=1]
+ br i1 %exitcond, label %return, label %bb
+
+return: ; preds = %bb
+ ret void
+}
+
+define i32 @main() nounwind {
+entry:
+ tail call void @func_1( ) nounwind
+ load i32* @g_19, align 4 ; <i32>:0 [#uses=1]
+ tail call i32 (i8*, ...)* @printf( i8* getelementptr ([4 x i8]* @"\01LC", i32 0, i32 0), i32 %0 ) nounwind ; <i32>:1 [#uses=0]
+ ret i32 0
+}
+
+declare i32 @printf(i8*, ...) nounwind