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      1 ; PR23524
      2 ; The test is to check redundency produced by loop unroll pass
      3 ; should be cleaned up by later pass.
      4 ; RUN: opt < %s -O2 -S | FileCheck %s
      5 
      6 ; After loop unroll:
      7 ;       %dec18 = add nsw i32 %dec18.in, -1
      8 ;       ...
      9 ;       %dec18.1 = add nsw i32 %dec18, -1
     10 ; should be merged to:
     11 ;       %dec18.1 = add nsw i32 %dec18.in, -2
     12 ;
     13 ; CHECK-LABEL: @_Z3fn1v(
     14 ; CHECK: %dec18.1 = add nsw i32 %dec18.in, -2
     15 
     16 ; ModuleID = '<stdin>'
     17 target triple = "x86_64-unknown-linux-gnu"
     18 
     19 @b = global i32 0, align 4
     20 @c = global i32 0, align 4
     21 
     22 ; Function Attrs: nounwind uwtable
     23 define void @_Z3fn1v() #0 {
     24 entry:
     25   %tmp = load i32, i32* @b, align 4
     26   %tobool20 = icmp eq i32 %tmp, 0
     27   br i1 %tobool20, label %for.end6, label %for.body.lr.ph
     28 
     29 for.body.lr.ph:                                   ; preds = %entry
     30   br label %for.body
     31 
     32 for.cond1.for.cond.loopexit_crit_edge:            ; preds = %for.inc
     33   %add.ptr.lcssa = phi i16* [ %add.ptr, %for.inc ]
     34   %incdec.ptr.lcssa = phi i8* [ %incdec.ptr, %for.inc ]
     35   br label %for.cond.loopexit
     36 
     37 for.cond.loopexit:                                ; preds = %for.body, %for.cond1.for.cond.loopexit_crit_edge
     38   %r.1.lcssa = phi i16* [ %add.ptr.lcssa, %for.cond1.for.cond.loopexit_crit_edge ], [ %r.022, %for.body ]
     39   %a.1.lcssa = phi i8* [ %incdec.ptr.lcssa, %for.cond1.for.cond.loopexit_crit_edge ], [ %a.021, %for.body ]
     40   %tmp1 = load i32, i32* @b, align 4
     41   %tobool = icmp eq i32 %tmp1, 0
     42   br i1 %tobool, label %for.cond.for.end6_crit_edge, label %for.body
     43 
     44 for.body:                                         ; preds = %for.cond.loopexit, %for.body.lr.ph
     45   %r.022 = phi i16* [ undef, %for.body.lr.ph ], [ %r.1.lcssa, %for.cond.loopexit ]
     46   %a.021 = phi i8* [ undef, %for.body.lr.ph ], [ %a.1.lcssa, %for.cond.loopexit ]
     47   %tmp2 = load i32, i32* @c, align 4
     48   %tobool215 = icmp eq i32 %tmp2, 0
     49   br i1 %tobool215, label %for.cond.loopexit, label %for.body3.lr.ph
     50 
     51 for.body3.lr.ph:                                  ; preds = %for.body
     52   br label %for.body3
     53 
     54 for.body3:                                        ; preds = %for.inc, %for.body3.lr.ph
     55   %dec18.in = phi i32 [ %tmp2, %for.body3.lr.ph ], [ %dec18, %for.inc ]
     56   %r.117 = phi i16* [ %r.022, %for.body3.lr.ph ], [ %add.ptr, %for.inc ]
     57   %a.116 = phi i8* [ %a.021, %for.body3.lr.ph ], [ %incdec.ptr, %for.inc ]
     58   %dec18 = add nsw i32 %dec18.in, -1
     59   %tmp3 = load i8, i8* %a.116, align 1
     60   %cmp = icmp eq i8 %tmp3, 0
     61   br i1 %cmp, label %if.then, label %for.inc
     62 
     63 if.then:                                          ; preds = %for.body3
     64   %arrayidx = getelementptr inbounds i16, i16* %r.117, i64 1
     65   store i16 0, i16* %arrayidx, align 2
     66   store i16 0, i16* %r.117, align 2
     67   %arrayidx5 = getelementptr inbounds i16, i16* %r.117, i64 2
     68   store i16 0, i16* %arrayidx5, align 2
     69   br label %for.inc
     70 
     71 for.inc:                                          ; preds = %if.then, %for.body3
     72   %incdec.ptr = getelementptr inbounds i8, i8* %a.116, i64 1
     73   %add.ptr = getelementptr inbounds i16, i16* %r.117, i64 3
     74   %tobool2 = icmp eq i32 %dec18, 0
     75   br i1 %tobool2, label %for.cond1.for.cond.loopexit_crit_edge, label %for.body3, !llvm.loop !0
     76 
     77 for.cond.for.end6_crit_edge:                      ; preds = %for.cond.loopexit
     78   br label %for.end6
     79 
     80 for.end6:                                         ; preds = %for.cond.for.end6_crit_edge, %entry
     81   ret void
     82 }
     83 
     84 !0 = !{!0, !1}
     85 !1 = !{!"llvm.loop.unroll.count", i32 2}
     86