|  | ; RUN: opt -S -indvars -loop-vectorize -force-vector-width=2  < %s | FileCheck %s | 
|  |  | 
|  | target 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-n8:16:32-S128" | 
|  |  | 
|  | @a = common global i64 0, align 8 | 
|  | @x = common global i32 0, align 4 | 
|  |  | 
|  | ; We used to assert on this loop because we could not find an induction | 
|  | ; variable but assumed there must be one. Scalar evolution returned a exit | 
|  | ; count for the loop below and from there on we assumed that there must be an | 
|  | ; induction variable. This is not a valid assumption: | 
|  | ;   // getExitCount - Get the expression for the number of loop iterations for | 
|  | ;   // which this loop is *guaranteed not to exit* via ExitingBlock. Otherwise | 
|  | ;   // return SCEVCouldNotCompute. | 
|  | ; For an infinite loop SE can return any number. | 
|  |  | 
|  | ; CHECK-LABEL: @fn1( | 
|  | define void @fn1()  { | 
|  | entry: | 
|  | store i64 0, i64* @a, align 8 | 
|  | br label %for.body | 
|  |  | 
|  | for.body:                                         ; preds = %for.body, %entry | 
|  | %inc1 = phi i64 [ 0, %entry ], [ %inc, %for.body ] | 
|  | store volatile i32 0, i32* @x, align 4 | 
|  | %inc = add nsw i64 %inc1, 1 | 
|  | %cmp = icmp sgt i64 %inc1, -2 | 
|  | br i1 %cmp, label %for.body, label %for.end | 
|  |  | 
|  | for.end:                                          ; preds = %for.body | 
|  | %inc.lcssa = phi i64 [ %inc, %for.body ] | 
|  | store i64 %inc.lcssa, i64* @a, align 8 | 
|  | ret void | 
|  | } |