| ; 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 | |
| } |