--- /dev/null
+; RUN: opt -indvars -S < %s | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+; indvars will try to replace %b.0.lcssa with %t.1. If it does this,
+; it will break LCSSA.
+
+@c = external global i32, align 4
+
+; CHECK-LABEL: @fn1
+define void @fn1() {
+entry:
+ br label %for.body
+
+for.cond1.preheader: ; preds = %for.body
+ %0 = load i32, i32* @c, align 4
+ br i1 undef, label %for.cond1.us.preheader, label %for.cond1
+
+for.cond1.us.preheader: ; preds = %for.cond1.preheader
+ br label %for.cond1.us
+
+for.cond1.us: ; preds = %for.cond1.us, %for.cond1.us.preheader
+ br label %for.cond1.us
+
+for.body: ; preds = %for.body, %entry
+ br i1 undef, label %for.body, label %for.cond1.preheader
+
+for.cond1: ; preds = %for.cond1.preheader
+ br i1 true, label %for.body9.lr.ph, label %for.cond13.preheader
+
+for.body9.lr.ph: ; preds = %for.cond1
+ br i1 undef, label %for.body9.us.preheader, label %for.body9
+
+for.body9.us.preheader: ; preds = %for.body9.lr.ph
+ br label %for.body9.us
+
+for.body9.us: ; preds = %for.body9.us, %for.body9.us.preheader
+ br label %for.body9.us
+
+for.cond13.preheader: ; preds = %for.body9, %for.cond1
+ %b.0.lcssa = phi i32 [ %0, %for.body9 ], [ 0, %for.cond1 ]
+ br label %for.cond13
+
+for.body9: ; preds = %for.body9.lr.ph
+ br label %for.cond13.preheader
+
+for.cond13: ; preds = %for.cond13, %for.cond13.preheader
+ %d.1 = phi i32 [ %t.1, %for.cond13 ], [ %0, %for.cond13.preheader ]
+ %t.1 = phi i32 [ %b.0.lcssa, %for.cond13 ], [ %0, %for.cond13.preheader ]
+ br i1 undef, label %for.cond18.preheader, label %for.cond13
+
+for.cond18.preheader: ; preds = %for.cond13
+ br label %for.cond18
+
+for.cond18: ; preds = %for.cond18, %for.cond18.preheader
+ %b.1 = phi i32 [ %xor, %for.cond18 ], [ %b.0.lcssa, %for.cond18.preheader ]
+ %add = add nsw i32 %b.1, %d.1
+ %xor = xor i32 %add, %b.1
+ br label %for.cond18
+}