|  | ; RUN: opt < %s -loop-unswitch -disable-output | 
|  | ; PR12887 | 
|  | target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" | 
|  | target triple = "x86_64-unknown-linux-gnu" | 
|  |  | 
|  | @a = common global i32 0, align 4 | 
|  | @c = common global i32 0, align 4 | 
|  | @b = common global i32 0, align 4 | 
|  |  | 
|  | define void @func() noreturn nounwind uwtable { | 
|  | entry: | 
|  | %0 = load i32, i32* @a, align 4 | 
|  | %tobool = icmp eq i32 %0, 0 | 
|  | %1 = load i32, i32* @b, align 4 | 
|  | br label %while.body | 
|  |  | 
|  | while.body:                                       ; preds = %while.body, %entry | 
|  | %d.0 = phi i8 [ undef, %entry ], [ %conv2, %while.body ] | 
|  | %conv = sext i8 %d.0 to i32 | 
|  | %cond = select i1 %tobool, i32 0, i32 %conv | 
|  | %conv11 = zext i8 %d.0 to i32 | 
|  | %add = add i32 %1, %conv11 | 
|  | %conv2 = trunc i32 %add to i8 | 
|  | br label %while.body | 
|  | } |