diff --git a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
--- a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
@@ -2824,12 +2824,6 @@
     return false;
 
   Register AndDst = MI.getOperand(0).getReg();
-  LLT DstTy = MRI.getType(AndDst);
-
-  // FIXME: This should be removed once GISelKnownBits supports vectors.
-  if (DstTy.isVector())
-    return false;
-
   Register LHS = MI.getOperand(1).getReg();
   Register RHS = MI.getOperand(2).getReg();
   KnownBits LHSBits = KB->getKnownBits(LHS);
@@ -2870,12 +2864,6 @@
     return false;
 
   Register OrDst = MI.getOperand(0).getReg();
-  LLT DstTy = MRI.getType(OrDst);
-
-  // FIXME: This should be removed once GISelKnownBits supports vectors.
-  if (DstTy.isVector())
-    return false;
-
   Register LHS = MI.getOperand(1).getReg();
   Register RHS = MI.getOperand(2).getReg();
   KnownBits LHSBits = KB->getKnownBits(LHS);
diff --git a/llvm/test/CodeGen/AMDGPU/GlobalISel/combine-or-redundant.mir b/llvm/test/CodeGen/AMDGPU/GlobalISel/combine-or-redundant.mir
--- a/llvm/test/CodeGen/AMDGPU/GlobalISel/combine-or-redundant.mir
+++ b/llvm/test/CodeGen/AMDGPU/GlobalISel/combine-or-redundant.mir
@@ -158,3 +158,63 @@
     $sgpr0 = COPY %8(s32)
     SI_RETURN_TO_EPILOG implicit $sgpr0
 ...
+---
+name:            vector_const_splat_const_splat
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    ; CHECK-LABEL: name: vector_const_splat_const_splat
+    ; CHECK: %mask:_(s16) = G_CONSTANT i16 255
+    ; CHECK-NEXT: %c2:_(<2 x s16>) = G_BUILD_VECTOR %mask(s16), %mask(s16)
+    ; CHECK-NEXT: $vgpr0 = COPY %c2(<2 x s16>)
+    ; CHECK-NEXT: SI_RETURN_TO_EPILOG implicit $vgpr0
+    %mask:_(s16) = G_CONSTANT i16 255
+    %fifteen:_(s16) = G_CONSTANT i16 15
+    %c1:_(<2 x s16>) = G_BUILD_VECTOR %fifteen, %fifteen
+    %c2:_(<2 x s16>) = G_BUILD_VECTOR %mask, %mask
+    %and:_(<2 x s16>) = G_OR %c1(<2 x s16>), %c2(<2 x s16>)
+    $vgpr0 = COPY %and(<2 x s16>)
+    SI_RETURN_TO_EPILOG implicit $vgpr0
+...
+---
+name:            vector_const_valid_not_splat
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    ; CHECK-LABEL: name: vector_const_valid_not_splat
+    ; CHECK: %mask:_(s16) = G_CONSTANT i16 255
+    ; CHECK-NEXT: %c2:_(<2 x s16>) = G_BUILD_VECTOR %mask(s16), %mask(s16)
+    ; CHECK-NEXT: $vgpr0 = COPY %c2(<2 x s16>)
+    ; CHECK-NEXT: SI_RETURN_TO_EPILOG implicit $vgpr0
+    %fifteen:_(s16) = G_CONSTANT i16 15
+    %sixteen:_(s16) = G_CONSTANT i16 16
+    %mask:_(s16) = G_CONSTANT i16 255
+    %c1:_(<2 x s16>) = G_BUILD_VECTOR %fifteen, %sixteen
+    %c2:_(<2 x s16>) = G_BUILD_VECTOR %mask, %mask
+    %and:_(<2 x s16>) = G_OR %c1(<2 x s16>), %c2(<2 x s16>)
+    $vgpr0 = COPY %and(<2 x s16>)
+    SI_RETURN_TO_EPILOG implicit $vgpr0
+...
+---
+name:            vector_dont_combine_const_too_wide
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    ; CHECK-LABEL: name: vector_dont_combine_const_too_wide
+    ; CHECK: %fifteen:_(s16) = G_CONSTANT i16 15
+    ; CHECK-NEXT: %too_wide:_(s16) = G_CONSTANT i16 257
+    ; CHECK-NEXT: %mask:_(s16) = G_CONSTANT i16 255
+    ; CHECK-NEXT: %c1:_(<2 x s16>) = G_BUILD_VECTOR %fifteen(s16), %too_wide(s16)
+    ; CHECK-NEXT: %c2:_(<2 x s16>) = G_BUILD_VECTOR %mask(s16), %mask(s16)
+    ; CHECK-NEXT: %and:_(<2 x s16>) = G_OR %c1, %c2
+    ; CHECK-NEXT: $vgpr0 = COPY %and(<2 x s16>)
+    ; CHECK-NEXT: SI_RETURN_TO_EPILOG implicit $vgpr0
+    %fifteen:_(s16) = G_CONSTANT i16 15
+    %too_wide:_(s16) = G_CONSTANT i16 257
+    %mask:_(s16) = G_CONSTANT i16 255
+    %c1:_(<2 x s16>) = G_BUILD_VECTOR %fifteen, %too_wide
+    %c2:_(<2 x s16>) = G_BUILD_VECTOR %mask, %mask
+    %and:_(<2 x s16>) = G_OR %c1(<2 x s16>), %c2(<2 x s16>)
+    $vgpr0 = COPY %and(<2 x s16>)
+    SI_RETURN_TO_EPILOG implicit $vgpr0
+...
diff --git a/llvm/test/CodeGen/AMDGPU/GlobalISel/combine-redundant-and.mir b/llvm/test/CodeGen/AMDGPU/GlobalISel/combine-redundant-and.mir
--- a/llvm/test/CodeGen/AMDGPU/GlobalISel/combine-redundant-and.mir
+++ b/llvm/test/CodeGen/AMDGPU/GlobalISel/combine-redundant-and.mir
@@ -167,3 +167,64 @@
     $sgpr0 = COPY %and(s32)
     SI_RETURN_TO_EPILOG implicit $sgpr0
 ...
+---
+name:            vector_const_splat_const_splat
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    ; CHECK-LABEL: name: vector_const_splat_const_splat
+    ; CHECK: %fifteen:_(s16) = G_CONSTANT i16 15
+    ; CHECK-NEXT: %c1:_(<2 x s16>) = G_BUILD_VECTOR %fifteen(s16), %fifteen(s16)
+    ; CHECK-NEXT: $vgpr0 = COPY %c1(<2 x s16>)
+    ; CHECK-NEXT: SI_RETURN_TO_EPILOG implicit $vgpr0
+    %fifteen:_(s16) = G_CONSTANT i16 15
+    %mask:_(s16) = G_CONSTANT i16 255
+    %c1:_(<2 x s16>) = G_BUILD_VECTOR %fifteen, %fifteen
+    %c2:_(<2 x s16>) = G_BUILD_VECTOR %mask, %mask
+    %and:_(<2 x s16>) = G_AND %c1(<2 x s16>), %c2(<2 x s16>)
+    $vgpr0 = COPY %and(<2 x s16>)
+    SI_RETURN_TO_EPILOG implicit $vgpr0
+...
+---
+name:            vector_const_valid_not_splat
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    ; CHECK-LABEL: name: vector_const_valid_not_splat
+    ; CHECK: %fifteen:_(s16) = G_CONSTANT i16 15
+    ; CHECK-NEXT: %sixteen:_(s16) = G_CONSTANT i16 16
+    ; CHECK-NEXT: %c1:_(<2 x s16>) = G_BUILD_VECTOR %fifteen(s16), %sixteen(s16)
+    ; CHECK-NEXT: $vgpr0 = COPY %c1(<2 x s16>)
+    ; CHECK-NEXT: SI_RETURN_TO_EPILOG implicit $vgpr0
+    %fifteen:_(s16) = G_CONSTANT i16 15
+    %sixteen:_(s16) = G_CONSTANT i16 16
+    %mask:_(s16) = G_CONSTANT i16 255
+    %c1:_(<2 x s16>) = G_BUILD_VECTOR %fifteen, %sixteen
+    %c2:_(<2 x s16>) = G_BUILD_VECTOR %mask, %mask
+    %and:_(<2 x s16>) = G_AND %c1(<2 x s16>), %c2(<2 x s16>)
+    $vgpr0 = COPY %and(<2 x s16>)
+    SI_RETURN_TO_EPILOG implicit $vgpr0
+...
+---
+name:            vector_dont_combine_const_too_wide
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    ; CHECK-LABEL: name: vector_dont_combine_const_too_wide
+    ; CHECK: %fifteen:_(s16) = G_CONSTANT i16 15
+    ; CHECK-NEXT: %too_wide:_(s16) = G_CONSTANT i16 257
+    ; CHECK-NEXT: %mask:_(s16) = G_CONSTANT i16 255
+    ; CHECK-NEXT: %c1:_(<2 x s16>) = G_BUILD_VECTOR %fifteen(s16), %too_wide(s16)
+    ; CHECK-NEXT: %c2:_(<2 x s16>) = G_BUILD_VECTOR %mask(s16), %mask(s16)
+    ; CHECK-NEXT: %and:_(<2 x s16>) = G_AND %c1, %c2
+    ; CHECK-NEXT: $vgpr0 = COPY %and(<2 x s16>)
+    ; CHECK-NEXT: SI_RETURN_TO_EPILOG implicit $vgpr0
+    %fifteen:_(s16) = G_CONSTANT i16 15
+    %too_wide:_(s16) = G_CONSTANT i16 257
+    %mask:_(s16) = G_CONSTANT i16 255
+    %c1:_(<2 x s16>) = G_BUILD_VECTOR %fifteen, %too_wide
+    %c2:_(<2 x s16>) = G_BUILD_VECTOR %mask, %mask
+    %and:_(<2 x s16>) = G_AND %c1(<2 x s16>), %c2(<2 x s16>)
+    $vgpr0 = COPY %and(<2 x s16>)
+    SI_RETURN_TO_EPILOG implicit $vgpr0
+...