Index: lib/Transforms/Vectorize/SLPVectorizer.cpp
===================================================================
--- lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -6399,7 +6399,8 @@
         for (int J = I + 1; J < E && Candidates.size() > 1; ++J) {
           auto *GEPJ = cast<GetElementPtrInst>(GEPList[J]);
           auto *SCEVJ = SE->getSCEV(GEPList[J]);
-          if (isa<SCEVConstant>(SE->getMinusSCEV(SCEVI, SCEVJ))) {
+          if (SCEVJ->getType() == SCEVI->getType() &&
+              isa<SCEVConstant>(SE->getMinusSCEV(SCEVI, SCEVJ))) {
             Candidates.remove(GEPList[I]);
             Candidates.remove(GEPList[J]);
           } else if (GEPI->idx_begin()->get() == GEPJ->idx_begin()->get()) {
Index: test/Transforms/SLPVectorizer/AMDGPU/address-space-ptr-sze-gep-index-assert.ll
===================================================================
--- /dev/null
+++ test/Transforms/SLPVectorizer/AMDGPU/address-space-ptr-sze-gep-index-assert.ll
@@ -0,0 +1,74 @@
+; RUN: opt -S -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -slp-vectorizer -slp-threshold=-18 < %s | FileCheck %s
+
+; Make sure there's no SCEV assert when the indexes are for different
+; sized address spaces
+
+target datalayout = "e-p:64:64-p1:64:64-p2:32:32-p3:32:32-p4:64:64-p5:32:32-p6:32:32-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024-v2048:2048-n32:64-S32-A5"
+
+
+; CHECK-LABEL: @slp_scev_assert(
+; CHECK: %tmp = addrspacecast i8 addrspace(5)* undef to i8*
+; CHECK-NEXT: %tmp2 = getelementptr inbounds i8, i8 addrspace(5)* undef, i32 %idx
+; CHECK-NEXT: %tmp4 = getelementptr inbounds i8, i8* %tmp, i64 %tmp3
+; CHECK-NEXT: store i8 0, i8 addrspace(5)* %tmp2
+; CHECK-NEXT: store i8 0, i8* %tmp4
+define void @slp_scev_assert(i32 %idx, i64 %tmp3) #0 {
+bb:
+  %tmp = addrspacecast i8 addrspace(5)* undef to i8*
+  %tmp2 = getelementptr inbounds i8, i8 addrspace(5)* undef, i32 %idx
+  %tmp4 = getelementptr inbounds i8, i8* %tmp, i64 %tmp3
+  store i8 0, i8 addrspace(5)* %tmp2
+  store i8 0, i8* %tmp4
+  ret void
+}
+
+; CHECK-LABEL: @getelementptr_4x32_same_size_as(
+; CHECK: add nsw <2 x i32>
+; CHECK: getelementptr inbounds i32, i32* %g, i32
+; CHECK: getelementptr inbounds i32, i32* %g, i32
+
+; CHECK: add nsw <2 x i32>
+; CHECK: getelementptr inbounds i32, i32 addrspace(1)* %g1, i32
+; CHECK: getelementptr inbounds i32, i32 addrspace(1)* %g1, i32
+define i32 @getelementptr_4x32_same_size_as(i32* nocapture readonly %g, i32 addrspace(1)* nocapture readonly %g1, i32 %n, i32 %x, i32 %y, i32 %z) {
+entry:
+  %cmp31 = icmp sgt i32 %n, 0
+  br i1 %cmp31, label %for.body.preheader, label %for.cond.cleanup
+
+for.body.preheader:
+  br label %for.body
+
+for.cond.cleanup.loopexit:
+  br label %for.cond.cleanup
+
+for.cond.cleanup:
+  %sum.0.lcssa = phi i32 [ 0, %entry ], [ %add16, %for.cond.cleanup.loopexit ]
+  ret i32 %sum.0.lcssa
+
+for.body:
+  %indvars.iv = phi i32 [ 0, %for.body.preheader ], [ %indvars.iv.next, %for.body ]
+  %sum.032 = phi i32 [ 0, %for.body.preheader ], [ %add16, %for.body ]
+  %t4 = shl nsw i32 %indvars.iv, 1
+  %t5 = add nsw i32 %t4, 0
+  %arrayidx = getelementptr inbounds i32, i32* %g, i32 %t5
+  %t6 = load i32, i32* %arrayidx, align 4
+  %add1 = add nsw i32 %t6, %sum.032
+  %t7 = add nsw i32 %t4, %x
+  %arrayidx5 = getelementptr inbounds i32, i32* %g, i32 %t7
+  %t8 = load i32, i32* %arrayidx5, align 4
+  %add6 = add nsw i32 %add1, %t8
+  %t9 = add nsw i32 %t4, %y
+  %arrayidx10 = getelementptr inbounds i32, i32 addrspace(1)* %g1, i32 %t9
+  %t10 = load i32, i32 addrspace(1)* %arrayidx10, align 4
+  %add11 = add nsw i32 %add6, %t10
+  %t11 = add nsw i32 %t4, %z
+  %arrayidx15 = getelementptr inbounds i32, i32 addrspace(1)* %g1, i32 %t11
+  %t12 = load i32, i32 addrspace(1)* %arrayidx15, align 4
+  %add16 = add nsw i32 %add11, %t12
+  %indvars.iv.next = add nuw nsw i32 %indvars.iv, 1
+  %exitcond = icmp eq i32 %indvars.iv.next , %n
+  br i1 %exitcond, label %for.cond.cleanup.loopexit, label %for.body
+}
+
+attributes #0 = { nounwind }
+