1; RUN: opt < %s -gvn | llvm-dis
2; PR4256
3target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32"
4target triple = "i386-pc-linux-gnu"
5	%llvm.dbg.anchor.type = type { i32, i32 }
6	%struct.cset = type { i8*, i8, i8, i32, i8* }
7	%struct.lmat = type { %struct.re_guts*, i32, %llvm.dbg.anchor.type*, i8*, i8*, i8*, i8*, i8**, i32, i8*, i8*, i8*, i8*, i8* }
8	%struct.re_guts = type { i32*, %struct.cset*, i8*, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i8*, i8*, i32, i32, i32, i32, [1 x i8] }
9
10define i8* @lbackref(%struct.lmat* %m, i8* %start, i8* %stop, i32 %startst, i32 %stopst, i32 %lev, i32 %rec) nounwind {
11entry:
12	br label %bb63
13
14bb:		; preds = %bb63
15	switch i32 0, label %bb62 [
16		i32 268435456, label %bb2
17		i32 805306368, label %bb9
18		i32 -1610612736, label %bb51
19	]
20
21bb2:		; preds = %bb
22	br label %bb62
23
24bb9:		; preds = %bb
25	%0 = load i8, i8* %sp.1, align 1		; <i8> [#uses=0]
26	br label %bb62
27
28bb51:		; preds = %bb
29	%1 = load i8, i8* %sp.1, align 1		; <i8> [#uses=0]
30	ret i8* null
31
32bb62:		; preds = %bb9, %bb2, %bb
33	br label %bb63
34
35bb63:		; preds = %bb84, %bb69, %bb62, %entry
36	%sp.1 = phi i8* [ null, %bb62 ], [ %sp.1.lcssa, %bb84 ], [ %start, %entry ], [ %sp.1.lcssa, %bb69 ]		; <i8*> [#uses=3]
37	br i1 false, label %bb, label %bb65
38
39bb65:		; preds = %bb63
40	%sp.1.lcssa = phi i8* [ %sp.1, %bb63 ]		; <i8*> [#uses=4]
41	br i1 false, label %bb66, label %bb69
42
43bb66:		; preds = %bb65
44	ret i8* null
45
46bb69:		; preds = %bb65
47	switch i32 0, label %bb108.loopexit2.loopexit.loopexit [
48		i32 1342177280, label %bb63
49		i32 1476395008, label %bb84
50		i32 1879048192, label %bb104
51		i32 2013265920, label %bb93
52	]
53
54bb84:		; preds = %bb69
55	%2 = tail call i8* @lbackref(%struct.lmat* %m, i8* %sp.1.lcssa, i8* %stop, i32 0, i32 %stopst, i32 0, i32 0) nounwind		; <i8*> [#uses=0]
56	br label %bb63
57
58bb93:		; preds = %bb69
59	ret i8* null
60
61bb104:		; preds = %bb69
62	%sp.1.lcssa.lcssa33 = phi i8* [ %sp.1.lcssa, %bb69 ]		; <i8*> [#uses=0]
63	unreachable
64
65bb108.loopexit2.loopexit.loopexit:		; preds = %bb69
66	ret i8* null
67}
68