Index: lib/Transforms/Utils/LoopUtils.cpp
===================================================================
--- lib/Transforms/Utils/LoopUtils.cpp
+++ lib/Transforms/Utils/LoopUtils.cpp
@@ -869,8 +869,12 @@
     return false;
   }
 
-  assert(TheLoop->getHeader() == Phi->getParent() &&
-         "PHI is an AddRec for a different loop?!");
+  if (AR->getLoop() != TheLoop) {
+    // FIXME: We should probably just treat this as a uniform.
+    DEBUG(dbgs() << "LV: PHI is a recurrence with respect to an outer loop.\n");
+    return false;    
+  }
+
   Value *StartValue =
     Phi->getIncomingValueForBlock(AR->getLoop()->getLoopPreheader());
   const SCEV *Step = AR->getStepRecurrence(*SE);
Index: test/Transforms/LoopVectorize/pr31190.ll
===================================================================
--- test/Transforms/LoopVectorize/pr31190.ll
+++ test/Transforms/LoopVectorize/pr31190.ll
@@ -0,0 +1,34 @@
+; RUN: opt -licm -loop-vectorize < %s 2>&1 | FileCheck %s
+; REQUIRES: asserts
+
+@c = external global i32, align 4
+@a = external global i32, align 4
+@b = external global [1 x i32], align 4
+
+; CHECK: LV: PHI is a recurrence with respect to an outer loop.
+; CHECK: LV: Not vectorizing: Cannot prove legality.
+; CHECK-LABEL: @test
+define void @test() {
+entry:
+  br label %for.cond1.preheader
+
+for.cond1.preheader:
+  br label %for.body3
+
+for.body3:
+  %0 = phi i32 [ undef, %for.cond1.preheader ], [ %2, %for.body3 ]
+  %idxprom = sext i32 %0 to i64
+  %arrayidx = getelementptr inbounds [1 x i32], [1 x i32]* @b, i64 0, i64 %idxprom
+  store i32 4, i32* %arrayidx, align 4
+  %1 = load i32, i32* @a, align 4
+  %inc = add nsw i32 %1, 1
+  store i32 %inc, i32* @a, align 4
+  %tobool2 = icmp eq i32 %inc, 0
+  %2 = load i32, i32* @c, align 4
+  br i1 %tobool2, label %for.cond1.for.inc4_crit_edge, label %for.body3
+
+for.cond1.for.inc4_crit_edge:
+  %inc5 = add nsw i32 %2, 1
+  store i32 %inc5, i32* @c, align 4
+  br label %for.cond1.preheader
+}