Index: llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
===================================================================
--- llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -283,10 +283,9 @@
     // The select condition may be a vector. We may only change the operand
     // type if the vector width remains the same (and matches the condition).
     if (auto *CondVTy = dyn_cast<VectorType>(CondTy)) {
-      if (!FIOpndTy->isVectorTy())
-        return nullptr;
-      if (cast<FixedVectorType>(CondVTy)->getNumElements() !=
-          cast<FixedVectorType>(FIOpndTy)->getNumElements())
+      if (!FIOpndTy->isVectorTy() ||
+          CondVTy->getElementCount() !=
+              cast<VectorType>(FIOpndTy)->getElementCount())
         return nullptr;
 
       // TODO: If the backend knew how to deal with casts better, we could
Index: llvm/test/Transforms/InstCombine/select.ll
===================================================================
--- llvm/test/Transforms/InstCombine/select.ll
+++ llvm/test/Transforms/InstCombine/select.ll
@@ -68,6 +68,15 @@
   ret <2 x i1> %R
 }
 
+define <vscale x 2 x i1> @test8vvec(<vscale x 2 x i1> %C, <vscale x 2 x i1> %X) {
+; CHECK-LABEL: @test8vvec(
+; CHECK-NEXT:    [[R:%.*]] = and <vscale x 2 x i1> [[C:%.*]],  [[X:%.*]]
+; CHECK-NEXT:    ret <vscale x 2 x i1> [[R]]
+;
+  %R = select <vscale x 2 x i1> %C, <vscale x 2 x i1> %X, <vscale x 2 x i1> zeroinitializer
+  ret <vscale x 2 x i1> %R
+}
+
 define i1 @test9(i1 %C, i1 %X) {
 ; CHECK-LABEL: @test9(
 ; CHECK-NEXT:    [[NOT_C:%.*]] = xor i1 [[C:%.*]], true
@@ -88,6 +97,16 @@
   ret <2 x i1> %R
 }
 
+define <vscale x 2 x i1> @test9vvec(<vscale x 2 x i1> %C, <vscale x 2 x i1> %X) {
+; CHECK-LABEL: @test9vvec(
+; CHECK-NEXT:    [[NOT_C:%.*]] = xor <vscale x 2 x i1> [[C:%.*]], shufflevector (<vscale x 2 x i1> insertelement (<vscale x 2 x i1> undef, i1 true, i32 0), <vscale x 2 x i1> undef, <vscale x 2 x i32> zeroinitializer)
+; CHECK-NEXT:    [[R:%.*]] = and <vscale x 2 x i1> [[NOT_C]], [[X:%.*]]
+; CHECK-NEXT:    ret <vscale x 2 x i1> [[R]]
+;
+  %R = select <vscale x 2 x i1> %C, <vscale x 2 x i1> zeroinitializer, <vscale x 2 x i1> %X
+  ret <vscale x 2 x i1> %R
+}
+
 define i1 @test10(i1 %C, i1 %X) {
 ; CHECK-LABEL: @test10(
 ; CHECK-NEXT:    [[NOT_C:%.*]] = xor i1 [[C:%.*]], true