--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/Transforms/BBVectorize/cycle.ll	Thu Dec 12 13:56:28 2013 +0900
@@ -0,0 +1,112 @@
+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"
+; RUN: opt < %s -bb-vectorize -bb-vectorize-req-chain-depth=3 -bb-vectorize-ignore-target-info -instcombine -gvn -S | FileCheck %s
+
+; This test checks the non-trivial pairing-induced cycle avoidance. Without this cycle avoidance, the algorithm would otherwise
+; want to select the pairs:
+; %div77 = fdiv double %sub74, %mul76.v.r1 <->   %div125 = fdiv double %mul121, %mul76.v.r2 (div125 depends on mul117)
+; %add84 = fadd double %sub83, 2.000000e+00 <->   %add127 = fadd double %mul126, 1.000000e+00 (add127 depends on div77)
+; %mul95 = fmul double %sub45.v.r1, %sub36.v.r1 <->   %mul88 = fmul double %sub36.v.r1, %sub87 (mul88 depends on add84)
+; %mul117 = fmul double %sub39.v.r1, %sub116 <->   %mul97 = fmul double %mul96, %sub39.v.r1 (mul97 depends on mul95)
+; and so a dependency cycle would be created.
+
+declare double @fabs(double) nounwind readnone
+define void @test1(double %a, double %b, double %c, double %add80, double %mul1, double %mul2.v.r1, double %mul73, double %sub, double %sub65, double %F.0, i32 %n.0, double %Bnm3.0, double %Bnm2.0, double %Bnm1.0, double %Anm3.0, double %Anm2.0, double %Anm1.0) {
+entry:
+  br label %go
+go:
+  %conv = sitofp i32 %n.0 to double
+  %add35 = fadd double %conv, %a
+  %sub36 = fadd double %add35, -1.000000e+00
+  %add38 = fadd double %conv, %b
+  %sub39 = fadd double %add38, -1.000000e+00
+  %add41 = fadd double %conv, %c
+  %sub42 = fadd double %add41, -1.000000e+00
+  %sub45 = fadd double %add35, -2.000000e+00
+  %sub48 = fadd double %add38, -2.000000e+00
+  %sub51 = fadd double %add41, -2.000000e+00
+  %mul52 = shl nsw i32 %n.0, 1
+  %sub53 = add nsw i32 %mul52, -1
+  %conv54 = sitofp i32 %sub53 to double
+  %sub56 = add nsw i32 %mul52, -3
+  %conv57 = sitofp i32 %sub56 to double
+  %sub59 = add nsw i32 %mul52, -5
+  %conv60 = sitofp i32 %sub59 to double
+  %mul61 = mul nsw i32 %n.0, %n.0
+  %conv62 = sitofp i32 %mul61 to double
+  %mul63 = fmul double %conv62, 3.000000e+00
+  %mul67 = fmul double %sub65, %conv
+  %add68 = fadd double %mul63, %mul67
+  %add69 = fadd double %add68, 2.000000e+00
+  %sub71 = fsub double %add69, %mul2.v.r1
+  %sub74 = fsub double %sub71, %mul73
+  %mul75 = fmul double %conv57, 2.000000e+00
+  %mul76 = fmul double %mul75, %sub42
+  %div77 = fdiv double %sub74, %mul76
+  %mul82 = fmul double %add80, %conv
+  %sub83 = fsub double %mul63, %mul82
+  %add84 = fadd double %sub83, 2.000000e+00
+  %sub86 = fsub double %add84, %mul2.v.r1
+  %sub87 = fsub double -0.000000e+00, %sub86
+  %mul88 = fmul double %sub36, %sub87
+  %mul89 = fmul double %mul88, %sub39
+  %mul90 = fmul double %conv54, 4.000000e+00
+  %mul91 = fmul double %mul90, %conv57
+  %mul92 = fmul double %mul91, %sub51
+  %mul93 = fmul double %mul92, %sub42
+  %div94 = fdiv double %mul89, %mul93
+  %mul95 = fmul double %sub45, %sub36
+  %mul96 = fmul double %mul95, %sub48
+  %mul97 = fmul double %mul96, %sub39
+  %sub99 = fsub double %conv, %a
+  %sub100 = fadd double %sub99, -2.000000e+00
+  %mul101 = fmul double %mul97, %sub100
+  %sub103 = fsub double %conv, %b
+  %sub104 = fadd double %sub103, -2.000000e+00
+  %mul105 = fmul double %mul101, %sub104
+  %mul106 = fmul double %conv57, 8.000000e+00
+  %mul107 = fmul double %mul106, %conv57
+  %mul108 = fmul double %mul107, %conv60
+  %sub111 = fadd double %add41, -3.000000e+00
+  %mul112 = fmul double %mul108, %sub111
+  %mul113 = fmul double %mul112, %sub51
+  %mul114 = fmul double %mul113, %sub42
+  %div115 = fdiv double %mul105, %mul114
+  %sub116 = fsub double -0.000000e+00, %sub36
+  %mul117 = fmul double %sub39, %sub116
+  %sub119 = fsub double %conv, %c
+  %sub120 = fadd double %sub119, -1.000000e+00
+  %mul121 = fmul double %mul117, %sub120
+  %mul123 = fmul double %mul75, %sub51
+  %mul124 = fmul double %mul123, %sub42
+  %div125 = fdiv double %mul121, %mul124
+  %mul126 = fmul double %div77, %sub
+  %add127 = fadd double %mul126, 1.000000e+00
+  %mul128 = fmul double %add127, %Anm1.0
+  %mul129 = fmul double %div94, %sub
+  %add130 = fadd double %div125, %mul129
+  %mul131 = fmul double %add130, %sub
+  %mul132 = fmul double %mul131, %Anm2.0
+  %add133 = fadd double %mul128, %mul132
+  %mul134 = fmul double %div115, %mul1
+  %mul135 = fmul double %mul134, %Anm3.0
+  %add136 = fadd double %add133, %mul135
+  %mul139 = fmul double %add127, %Bnm1.0
+  %mul143 = fmul double %mul131, %Bnm2.0
+  %add144 = fadd double %mul139, %mul143
+  %mul146 = fmul double %mul134, %Bnm3.0
+  %add147 = fadd double %add144, %mul146
+  %div148 = fdiv double %add136, %add147
+  %sub149 = fsub double %F.0, %div148
+  %div150 = fdiv double %sub149, %F.0
+  %call = tail call double @fabs(double %div150) nounwind readnone
+  %cmp = fcmp olt double %call, 0x3CB0000000000000
+  %cmp152 = icmp sgt i32 %n.0, 20000
+  %or.cond = or i1 %cmp, %cmp152
+  br i1 %or.cond, label %done, label %go
+done:
+  ret void
+; CHECK-LABEL: @test1(
+; CHECK: go:
+; CHECK: %conv.v.i0.1 = insertelement <2 x i32> undef, i32 %n.0, i32 0
+; FIXME: When tree pruning is deterministic, include the entire output.
+}