Index: llvm/lib/Transforms/Utils/LoopUnrollPeel.cpp
===================================================================
--- llvm/lib/Transforms/Utils/LoopUnrollPeel.cpp
+++ llvm/lib/Transforms/Utils/LoopUnrollPeel.cpp
@@ -262,10 +262,9 @@
     // iteration. See if that makes !Pred become unknown again.
     if (ICmpInst::isEquality(Pred) &&
         !SE.isKnownPredicate(ICmpInst::getInversePredicate(Pred), NextIterVal,
-                             RightSCEV)) {
-      assert(!SE.isKnownPredicate(Pred, IterVal, RightSCEV) &&
-             SE.isKnownPredicate(Pred, NextIterVal, RightSCEV) &&
-             "Expected Pred to go from known to unknown.");
+                             RightSCEV) &&
+        !SE.isKnownPredicate(Pred, IterVal, RightSCEV)  &&
+        SE.isKnownPredicate(Pred, NextIterVal, RightSCEV)) {
       if (!CanPeelOneMoreIteration())
         continue; // Need to peel one more iteration, but can't. Give up.
       PeelOneMoreIteration(); // Great!
Index: llvm/test/Transforms/LoopUnroll/wrong_assert_in_peeling.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/LoopUnroll/wrong_assert_in_peeling.ll
@@ -0,0 +1,110 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S < %s -loop-unroll | FileCheck %s
+; RUN: opt -S < %s -passes=unroll | FileCheck %s
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128-ni:1-p2:32:8:8:32-ni:2"
+target triple = "x86_64-unknown-linux-gnu"
+
+define i32 @test() {
+; CHECK-LABEL: @test(
+; CHECK-NEXT:  bb:
+; CHECK-NEXT:    br label [[BB1:%.*]]
+; CHECK:       bb1:
+; CHECK-NEXT:    [[TMP:%.*]] = phi i32 [ -147, [[BB:%.*]] ], [ [[TMP14:%.*]], [[BB13:%.*]] ]
+; CHECK-NEXT:    br label [[BB2_PEEL_BEGIN:%.*]]
+; CHECK:       bb2.peel.begin:
+; CHECK-NEXT:    br label [[BB2_PEEL:%.*]]
+; CHECK:       bb2.peel:
+; CHECK-NEXT:    [[TMP4_PEEL:%.*]] = add nsw i32 undef, [[TMP]]
+; CHECK-NEXT:    br label [[BB5_PEEL:%.*]]
+; CHECK:       bb5.peel:
+; CHECK-NEXT:    [[TMP6_PEEL:%.*]] = icmp eq i32 undef, 33
+; CHECK-NEXT:    br i1 [[TMP6_PEEL]], label [[BB7_PEEL:%.*]], label [[BB15_LOOPEXIT2:%.*]]
+; CHECK:       bb7.peel:
+; CHECK-NEXT:    [[TMP8_PEEL:%.*]] = sub nsw i32 undef, undef
+; CHECK-NEXT:    [[TMP9_PEEL:%.*]] = icmp eq i32 [[TMP8_PEEL]], 0
+; CHECK-NEXT:    br i1 [[TMP9_PEEL]], label [[BB10_PEEL:%.*]], label [[BB10_PEEL]]
+; CHECK:       bb10.peel:
+; CHECK-NEXT:    [[TMP11_PEEL:%.*]] = icmp eq i8 undef, 0
+; CHECK-NEXT:    br i1 [[TMP11_PEEL]], label [[BB12_PEEL:%.*]], label [[BB17_LOOPEXIT3:%.*]]
+; CHECK:       bb12.peel:
+; CHECK-NEXT:    br i1 false, label [[BB13]], label [[BB2_PEEL_NEXT:%.*]]
+; CHECK:       bb2.peel.next:
+; CHECK-NEXT:    br label [[BB2_PEEL_NEXT1:%.*]]
+; CHECK:       bb2.peel.next1:
+; CHECK-NEXT:    br label [[BB1_PEEL_NEWPH:%.*]]
+; CHECK:       bb1.peel.newph:
+; CHECK-NEXT:    br label [[BB2:%.*]]
+; CHECK:       bb2:
+; CHECK-NEXT:    [[TMP3:%.*]] = phi i32 [ [[TMP4_PEEL]], [[BB1_PEEL_NEWPH]] ], [ [[TMP4:%.*]], [[BB12:%.*]] ]
+; CHECK-NEXT:    [[TMP4]] = add nsw i32 [[TMP3]], [[TMP]]
+; CHECK-NEXT:    br label [[BB5:%.*]]
+; CHECK:       bb5:
+; CHECK-NEXT:    br i1 false, label [[BB7:%.*]], label [[BB15_LOOPEXIT:%.*]]
+; CHECK:       bb7:
+; CHECK-NEXT:    br i1 undef, label [[BB10:%.*]], label [[BB10]]
+; CHECK:       bb10:
+; CHECK-NEXT:    br i1 false, label [[BB12]], label [[BB17_LOOPEXIT:%.*]]
+; CHECK:       bb12:
+; CHECK-NEXT:    br i1 false, label [[BB13_LOOPEXIT:%.*]], label [[BB2]], !llvm.loop !0
+; CHECK:       bb13.loopexit:
+; CHECK-NEXT:    br label [[BB13]]
+; CHECK:       bb13:
+; CHECK-NEXT:    [[TMP14]] = add nsw i32 [[TMP]], -1
+; CHECK-NEXT:    br label [[BB1]]
+; CHECK:       bb15.loopexit:
+; CHECK-NEXT:    br label [[BB15:%.*]]
+; CHECK:       bb15.loopexit2:
+; CHECK-NEXT:    br label [[BB15]]
+; CHECK:       bb15:
+; CHECK-NEXT:    [[TMP16:%.*]] = call i32 (...) @llvm.experimental.deoptimize.i32(i32 17) [ "deopt"() ]
+; CHECK-NEXT:    ret i32 [[TMP16]]
+; CHECK:       bb17.loopexit:
+; CHECK-NEXT:    br label [[BB17:%.*]]
+; CHECK:       bb17.loopexit3:
+; CHECK-NEXT:    br label [[BB17]]
+; CHECK:       bb17:
+; CHECK-NEXT:    [[TMP18:%.*]] = call i32 (...) @llvm.experimental.deoptimize.i32(i32 6) [ "deopt"() ]
+; CHECK-NEXT:    ret i32 [[TMP18]]
+;
+bb:
+  br label %bb1
+
+bb1:                                              ; preds = %bb13, %bb
+  %tmp = phi i32 [ -147, %bb ], [ %tmp14, %bb13 ]
+  br label %bb2
+
+bb2:                                              ; preds = %bb12, %bb1
+  %tmp3 = phi i32 [ undef, %bb1 ], [ %tmp4, %bb12 ]
+  %tmp4 = add nsw i32 %tmp3, %tmp
+  br label %bb5
+
+bb5:                                              ; preds = %bb2
+  %tmp6 = icmp eq i32 undef, 33
+  br i1 %tmp6, label %bb7, label %bb15
+
+bb7:                                              ; preds = %bb5
+  %tmp8 = sub nsw i32 %tmp3, undef
+  %tmp9 = icmp eq i32 %tmp8, 0
+  br i1 %tmp9, label %bb10, label %bb10
+
+bb10:                                             ; preds = %bb7, %bb7
+  %tmp11 = icmp eq i8 undef, 0
+  br i1 %tmp11, label %bb12, label %bb17
+
+bb12:                                             ; preds = %bb10
+  br i1 false, label %bb13, label %bb2
+
+bb13:                                             ; preds = %bb12
+  %tmp14 = add nsw i32 %tmp, -1
+  br label %bb1
+
+bb15:                                             ; preds = %bb5
+  %tmp16 = call i32 (...) @llvm.experimental.deoptimize.i32(i32 17) [ "deopt"() ]
+  ret i32 %tmp16
+
+bb17:                                             ; preds = %bb10
+  %tmp18 = call i32 (...) @llvm.experimental.deoptimize.i32(i32 6) [ "deopt"() ]
+  ret i32 %tmp18
+}
+
+declare i32 @llvm.experimental.deoptimize.i32(...)