Index: lib/Analysis/InstructionSimplify.cpp
===================================================================
--- lib/Analysis/InstructionSimplify.cpp
+++ lib/Analysis/InstructionSimplify.cpp
@@ -2129,19 +2129,26 @@
 }
 
 /// Return true if B is known to be implied by A.  A & B must be i1 (boolean)
-/// values. Note that the truth table for implication is the same as <=u on i1
-/// values (but not <=s!).  The truth table for both is:
+/// values or a vector of such values. Note that the truth table for
+/// implication is the same as <=u on i1 values (but not <=s!).  The truth
+/// table for both is: 
 ///    | T | F (B)
 ///  T | T | F
 ///  F | T | T
 /// (A)
 static bool implies(Value *A, Value *B) {
-  // TODO: Consider extending this to vector of i1?
-  assert(A->getType()->isIntegerTy(1) && B->getType()->isIntegerTy(1));
+  assert(A->getType() == B->getType() && "mismatched type");
+  Type *OpTy = A->getType();
+  assert(OpTy->getScalarType()->isIntegerTy(1));
   
   // A ==> A by definition
   if (A == B) return true;
 
+  if (OpTy->isVectorTy())
+    // TODO: extending the code below to handle vectors
+    return false;
+  assert(OpTy->isIntegerTy(1) && "implied by above");
+
   ICmpInst::Predicate APred, BPred;
   Value *I;
   Value *L;
Index: test/Transforms/InstSimplify/implies.ll
===================================================================
--- test/Transforms/InstSimplify/implies.ll
+++ test/Transforms/InstSimplify/implies.ll
@@ -75,3 +75,19 @@
   %res = icmp ule i1 %var30, %var29
   ret i1 %res
 }
+
+; A ==> A for vectors
+define <4 x i1> @test5(<4 x i1> %vec) {
+; CHECK-LABEL: @test5
+; CHECK: ret <4 x i1> <i1 true, i1 true, i1 true, i1 true>
+  %res = icmp ule <4 x i1> %vec, %vec
+  ret <4 x i1> %res
+}
+
+; Don't crash on vector inputs - pr25040
+define <4 x i1> @test6(<4 x i1> %a, <4 x i1> %b) {
+; CHECK-LABEL: @test6
+; CHECK: ret <4 x i1> %res
+  %res = icmp ule <4 x i1> %a, %b
+  ret <4 x i1> %res
+}