AMDGPU/GlobalISel: Use ptrtoint to legalize constant 32-bit addrspacecast

This was trying to merge 2 32-bit pointers into a 64-bit pointer. The
artifact combiner was assuming merges to pointers use scalar sources,
and ended up inserting invalid bitcast from a pointer to a scalar. It
should probably be a verifier error to have pointer merge sources with
a pointer result.

Fixes verifier errors with EXPENSIVE_CHECKS.

6 files changed, 109 insertions, 44 deletions

diff --git a/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp b/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
index b84c239..a43be05 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
@@ -2021,13 +2021,9 @@ bool AMDGPULegalizerInfo::legalizeAddrSpaceCast(
       DstTy.getSizeInBits() == 64) {
     const SIMachineFunctionInfo *Info = MF.getInfo<SIMachineFunctionInfo>();
     uint32_t AddrHiVal = Info->get32BitAddressHighBits();
-
-    // FIXME: This is a bit ugly due to creating a merge of 2 pointers to
-    // another. Merge operands are required to be the same type, but creating an
-    // extra ptrtoint would be kind of pointless.
-    auto HighAddr = B.buildConstant(
-        LLT::pointer(AMDGPUAS::CONSTANT_ADDRESS_32BIT, 32), AddrHiVal);
-    B.buildMerge(Dst, {Src, HighAddr});
+    auto PtrLo = B.buildPtrToInt(S32, Src);
+    auto HighAddr = B.buildConstant(S32, AddrHiVal);
+    B.buildMerge(Dst, {PtrLo, HighAddr});
     MI.eraseFromParent();
     return true;
   }
diff --git a/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-addrspacecast.mir b/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-addrspacecast.mir
index c2f33d6..362413e 100644
--- a/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-addrspacecast.mir
+++ b/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-addrspacecast.mir
@@ -424,8 +424,9 @@ body: |
     ; GCN: liveins: $vgpr0
     ; GCN-NEXT: {{  $}}
     ; GCN-NEXT: [[COPY:%[0-9]+]]:_(p6) = COPY $vgpr0
-    ; GCN-NEXT: [[C:%[0-9]+]]:_(p6) = G_CONSTANT i32 0
-    ; GCN-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[COPY]](p6), [[C]](p6)
+    ; GCN-NEXT: [[PTRTOINT:%[0-9]+]]:_(s32) = G_PTRTOINT [[COPY]](p6)
+    ; GCN-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
+    ; GCN-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[PTRTOINT]](s32), [[C]](s32)
     ; GCN-NEXT: $vgpr0_vgpr1 = COPY [[MV]](p4)
     %0:_(p6) = COPY $vgpr0
     %1:_(p4) = G_ADDRSPACE_CAST %0
@@ -444,8 +445,9 @@ body: |
     ; GCN: liveins: $vgpr0
     ; GCN-NEXT: {{  $}}
     ; GCN-NEXT: [[COPY:%[0-9]+]]:_(p6) = COPY $vgpr0
-    ; GCN-NEXT: [[C:%[0-9]+]]:_(p6) = G_CONSTANT i32 -559038737
-    ; GCN-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[COPY]](p6), [[C]](p6)
+    ; GCN-NEXT: [[PTRTOINT:%[0-9]+]]:_(s32) = G_PTRTOINT [[COPY]](p6)
+    ; GCN-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 -559038737
+    ; GCN-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[PTRTOINT]](s32), [[C]](s32)
     ; GCN-NEXT: $vgpr0_vgpr1 = COPY [[MV]](p4)
     %0:_(p6) = COPY $vgpr0
     %1:_(p4) = G_ADDRSPACE_CAST %0
@@ -479,8 +481,9 @@ body: |
     ; GCN: liveins: $vgpr0
     ; GCN-NEXT: {{  $}}
     ; GCN-NEXT: [[COPY:%[0-9]+]]:_(p6) = COPY $vgpr0
-    ; GCN-NEXT: [[C:%[0-9]+]]:_(p6) = G_CONSTANT i32 0
-    ; GCN-NEXT: [[MV:%[0-9]+]]:_(p0) = G_MERGE_VALUES [[COPY]](p6), [[C]](p6)
+    ; GCN-NEXT: [[PTRTOINT:%[0-9]+]]:_(s32) = G_PTRTOINT [[COPY]](p6)
+    ; GCN-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
+    ; GCN-NEXT: [[MV:%[0-9]+]]:_(p0) = G_MERGE_VALUES [[PTRTOINT]](s32), [[C]](s32)
     ; GCN-NEXT: $vgpr0_vgpr1 = COPY [[MV]](p0)
     %0:_(p6) = COPY $vgpr0
     %1:_(p0) = G_ADDRSPACE_CAST %0
diff --git a/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-load-constant-32bit.mir b/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-load-constant-32bit.mir
index 904aac0..cd23abe 100644
--- a/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-load-constant-32bit.mir
+++ b/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-load-constant-32bit.mir
@@ -11,8 +11,9 @@ body: |
     ; CI: liveins: $vgpr0
     ; CI-NEXT: {{  $}}
     ; CI-NEXT: [[COPY:%[0-9]+]]:_(p6) = COPY $vgpr0
-    ; CI-NEXT: [[C:%[0-9]+]]:_(p6) = G_CONSTANT i32 0
-    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[COPY]](p6), [[C]](p6)
+    ; CI-NEXT: [[PTRTOINT:%[0-9]+]]:_(s32) = G_PTRTOINT [[COPY]](p6)
+    ; CI-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
+    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[PTRTOINT]](s32), [[C]](s32)
     ; CI-NEXT: [[ZEXTLOAD:%[0-9]+]]:_(s32) = G_ZEXTLOAD [[MV]](p4) :: (load (s8), addrspace 6)
     ; CI-NEXT: [[C1:%[0-9]+]]:_(s64) = G_CONSTANT i64 1
     ; CI-NEXT: [[PTR_ADD:%[0-9]+]]:_(p4) = G_PTR_ADD [[MV]], [[C1]](s64)
@@ -46,8 +47,9 @@ body: |
     ; CI: liveins: $vgpr0
     ; CI-NEXT: {{  $}}
     ; CI-NEXT: [[COPY:%[0-9]+]]:_(p6) = COPY $vgpr0
-    ; CI-NEXT: [[C:%[0-9]+]]:_(p6) = G_CONSTANT i32 0
-    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[COPY]](p6), [[C]](p6)
+    ; CI-NEXT: [[PTRTOINT:%[0-9]+]]:_(s32) = G_PTRTOINT [[COPY]](p6)
+    ; CI-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
+    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[PTRTOINT]](s32), [[C]](s32)
     ; CI-NEXT: [[LOAD:%[0-9]+]]:_(s32) = G_LOAD [[MV]](p4) :: (load (s32), addrspace 6)
     ; CI-NEXT: $vgpr0 = COPY [[LOAD]](s32)
     %0:_(p6) = COPY $vgpr0
diff --git a/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-sextload-constant-32bit.mir b/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-sextload-constant-32bit.mir
index ea8d909..d87212d 100644
--- a/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-sextload-constant-32bit.mir
+++ b/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-sextload-constant-32bit.mir
@@ -12,8 +12,9 @@ body: |
     ; CI: liveins: $sgpr0
     ; CI-NEXT: {{  $}}
     ; CI-NEXT: [[COPY:%[0-9]+]]:_(p6) = COPY $sgpr0
-    ; CI-NEXT: [[C:%[0-9]+]]:_(p6) = G_CONSTANT i32 0
-    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[COPY]](p6), [[C]](p6)
+    ; CI-NEXT: [[PTRTOINT:%[0-9]+]]:_(s32) = G_PTRTOINT [[COPY]](p6)
+    ; CI-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
+    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[PTRTOINT]](s32), [[C]](s32)
     ; CI-NEXT: [[LOAD:%[0-9]+]]:_(s32) = G_LOAD [[MV]](p4) :: (load (s32), addrspace 6)
     ; CI-NEXT: [[SEXT:%[0-9]+]]:_(s64) = G_SEXT [[LOAD]](s32)
     ; CI-NEXT: $vgpr0_vgpr1 = COPY [[SEXT]](s64)
@@ -32,8 +33,9 @@ body: |
     ; CI: liveins: $sgpr0
     ; CI-NEXT: {{  $}}
     ; CI-NEXT: [[COPY:%[0-9]+]]:_(p6) = COPY $sgpr0
-    ; CI-NEXT: [[C:%[0-9]+]]:_(p6) = G_CONSTANT i32 0
-    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[COPY]](p6), [[C]](p6)
+    ; CI-NEXT: [[PTRTOINT:%[0-9]+]]:_(s32) = G_PTRTOINT [[COPY]](p6)
+    ; CI-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
+    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[PTRTOINT]](s32), [[C]](s32)
     ; CI-NEXT: [[LOAD:%[0-9]+]]:_(s32) = G_LOAD [[MV]](p4) :: (load (s32), align 2, addrspace 6)
     ; CI-NEXT: [[SEXT:%[0-9]+]]:_(s64) = G_SEXT [[LOAD]](s32)
     ; CI-NEXT: $vgpr0_vgpr1 = COPY [[SEXT]](s64)
@@ -52,8 +54,9 @@ body: |
     ; CI: liveins: $sgpr0
     ; CI-NEXT: {{  $}}
     ; CI-NEXT: [[COPY:%[0-9]+]]:_(p6) = COPY $sgpr0
-    ; CI-NEXT: [[C:%[0-9]+]]:_(p6) = G_CONSTANT i32 0
-    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[COPY]](p6), [[C]](p6)
+    ; CI-NEXT: [[PTRTOINT:%[0-9]+]]:_(s32) = G_PTRTOINT [[COPY]](p6)
+    ; CI-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
+    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[PTRTOINT]](s32), [[C]](s32)
     ; CI-NEXT: [[LOAD:%[0-9]+]]:_(s32) = G_LOAD [[MV]](p4) :: (load (s32), align 1, addrspace 6)
     ; CI-NEXT: [[SEXT:%[0-9]+]]:_(s64) = G_SEXT [[LOAD]](s32)
     ; CI-NEXT: $vgpr0_vgpr1 = COPY [[SEXT]](s64)
@@ -72,8 +75,9 @@ body: |
     ; CI: liveins: $sgpr0
     ; CI-NEXT: {{  $}}
     ; CI-NEXT: [[COPY:%[0-9]+]]:_(p6) = COPY $sgpr0
-    ; CI-NEXT: [[C:%[0-9]+]]:_(p6) = G_CONSTANT i32 0
-    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[COPY]](p6), [[C]](p6)
+    ; CI-NEXT: [[PTRTOINT:%[0-9]+]]:_(s32) = G_PTRTOINT [[COPY]](p6)
+    ; CI-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
+    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[PTRTOINT]](s32), [[C]](s32)
     ; CI-NEXT: [[SEXTLOAD:%[0-9]+]]:_(s32) = G_SEXTLOAD [[MV]](p4) :: (load (s8), addrspace 6)
     ; CI-NEXT: $vgpr0 = COPY [[SEXTLOAD]](s32)
     %0:_(p6) = COPY $sgpr0
@@ -91,8 +95,9 @@ body: |
     ; CI: liveins: $sgpr0
     ; CI-NEXT: {{  $}}
     ; CI-NEXT: [[COPY:%[0-9]+]]:_(p6) = COPY $sgpr0
-    ; CI-NEXT: [[C:%[0-9]+]]:_(p6) = G_CONSTANT i32 0
-    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[COPY]](p6), [[C]](p6)
+    ; CI-NEXT: [[PTRTOINT:%[0-9]+]]:_(s32) = G_PTRTOINT [[COPY]](p6)
+    ; CI-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
+    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[PTRTOINT]](s32), [[C]](s32)
     ; CI-NEXT: [[SEXTLOAD:%[0-9]+]]:_(s32) = G_SEXTLOAD [[MV]](p4) :: (load (s16), addrspace 6)
     ; CI-NEXT: $vgpr0 = COPY [[SEXTLOAD]](s32)
     %0:_(p6) = COPY $sgpr0
@@ -110,8 +115,9 @@ body: |
     ; CI: liveins: $sgpr0
     ; CI-NEXT: {{  $}}
     ; CI-NEXT: [[COPY:%[0-9]+]]:_(p6) = COPY $sgpr0
-    ; CI-NEXT: [[C:%[0-9]+]]:_(p6) = G_CONSTANT i32 0
-    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[COPY]](p6), [[C]](p6)
+    ; CI-NEXT: [[PTRTOINT:%[0-9]+]]:_(s32) = G_PTRTOINT [[COPY]](p6)
+    ; CI-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
+    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[PTRTOINT]](s32), [[C]](s32)
     ; CI-NEXT: [[SEXTLOAD:%[0-9]+]]:_(s32) = G_SEXTLOAD [[MV]](p4) :: (load (s16), align 1, addrspace 6)
     ; CI-NEXT: $vgpr0 = COPY [[SEXTLOAD]](s32)
     %0:_(p6) = COPY $sgpr0
diff --git a/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-zextload-constant-32bit.mir b/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-zextload-constant-32bit.mir
index 4374d45..a4971e94 100644
--- a/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-zextload-constant-32bit.mir
+++ b/llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-zextload-constant-32bit.mir
@@ -13,8 +13,9 @@ body: |
     ; CI: liveins: $sgpr0
     ; CI-NEXT: {{  $}}
     ; CI-NEXT: [[COPY:%[0-9]+]]:_(p6) = COPY $sgpr0
-    ; CI-NEXT: [[C:%[0-9]+]]:_(p6) = G_CONSTANT i32 0
-    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[COPY]](p6), [[C]](p6)
+    ; CI-NEXT: [[PTRTOINT:%[0-9]+]]:_(s32) = G_PTRTOINT [[COPY]](p6)
+    ; CI-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
+    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[PTRTOINT]](s32), [[C]](s32)
     ; CI-NEXT: [[LOAD:%[0-9]+]]:_(s32) = G_LOAD [[MV]](p4) :: (load (s32), addrspace 6)
     ; CI-NEXT: [[ZEXT:%[0-9]+]]:_(s64) = G_ZEXT [[LOAD]](s32)
     ; CI-NEXT: $vgpr0_vgpr1 = COPY [[ZEXT]](s64)
@@ -33,8 +34,9 @@ body: |
     ; CI: liveins: $sgpr0
     ; CI-NEXT: {{  $}}
     ; CI-NEXT: [[COPY:%[0-9]+]]:_(p6) = COPY $sgpr0
-    ; CI-NEXT: [[C:%[0-9]+]]:_(p6) = G_CONSTANT i32 0
-    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[COPY]](p6), [[C]](p6)
+    ; CI-NEXT: [[PTRTOINT:%[0-9]+]]:_(s32) = G_PTRTOINT [[COPY]](p6)
+    ; CI-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
+    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[PTRTOINT]](s32), [[C]](s32)
     ; CI-NEXT: [[LOAD:%[0-9]+]]:_(s32) = G_LOAD [[MV]](p4) :: (load (s32), align 2, addrspace 6)
     ; CI-NEXT: [[ZEXT:%[0-9]+]]:_(s64) = G_ZEXT [[LOAD]](s32)
     ; CI-NEXT: $vgpr0_vgpr1 = COPY [[ZEXT]](s64)
@@ -53,8 +55,9 @@ body: |
     ; CI: liveins: $sgpr0
     ; CI-NEXT: {{  $}}
     ; CI-NEXT: [[COPY:%[0-9]+]]:_(p6) = COPY $sgpr0
-    ; CI-NEXT: [[C:%[0-9]+]]:_(p6) = G_CONSTANT i32 0
-    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[COPY]](p6), [[C]](p6)
+    ; CI-NEXT: [[PTRTOINT:%[0-9]+]]:_(s32) = G_PTRTOINT [[COPY]](p6)
+    ; CI-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
+    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[PTRTOINT]](s32), [[C]](s32)
     ; CI-NEXT: [[LOAD:%[0-9]+]]:_(s32) = G_LOAD [[MV]](p4) :: (load (s32), align 1, addrspace 6)
     ; CI-NEXT: [[ZEXT:%[0-9]+]]:_(s64) = G_ZEXT [[LOAD]](s32)
     ; CI-NEXT: $vgpr0_vgpr1 = COPY [[ZEXT]](s64)
@@ -73,8 +76,9 @@ body: |
     ; CI: liveins: $sgpr0
     ; CI-NEXT: {{  $}}
     ; CI-NEXT: [[COPY:%[0-9]+]]:_(p6) = COPY $sgpr0
-    ; CI-NEXT: [[C:%[0-9]+]]:_(p6) = G_CONSTANT i32 0
-    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[COPY]](p6), [[C]](p6)
+    ; CI-NEXT: [[PTRTOINT:%[0-9]+]]:_(s32) = G_PTRTOINT [[COPY]](p6)
+    ; CI-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
+    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[PTRTOINT]](s32), [[C]](s32)
     ; CI-NEXT: [[ZEXTLOAD:%[0-9]+]]:_(s32) = G_ZEXTLOAD [[MV]](p4) :: (load (s8), addrspace 6)
     ; CI-NEXT: $vgpr0 = COPY [[ZEXTLOAD]](s32)
     %0:_(p6) = COPY $sgpr0
@@ -92,8 +96,9 @@ body: |
     ; CI: liveins: $sgpr0
     ; CI-NEXT: {{  $}}
     ; CI-NEXT: [[COPY:%[0-9]+]]:_(p6) = COPY $sgpr0
-    ; CI-NEXT: [[C:%[0-9]+]]:_(p6) = G_CONSTANT i32 0
-    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[COPY]](p6), [[C]](p6)
+    ; CI-NEXT: [[PTRTOINT:%[0-9]+]]:_(s32) = G_PTRTOINT [[COPY]](p6)
+    ; CI-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
+    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[PTRTOINT]](s32), [[C]](s32)
     ; CI-NEXT: [[ZEXTLOAD:%[0-9]+]]:_(s32) = G_ZEXTLOAD [[MV]](p4) :: (load (s16), addrspace 6)
     ; CI-NEXT: $vgpr0 = COPY [[ZEXTLOAD]](s32)
     %0:_(p6) = COPY $sgpr0
@@ -111,8 +116,9 @@ body: |
     ; CI: liveins: $sgpr0
     ; CI-NEXT: {{  $}}
     ; CI-NEXT: [[COPY:%[0-9]+]]:_(p6) = COPY $sgpr0
-    ; CI-NEXT: [[C:%[0-9]+]]:_(p6) = G_CONSTANT i32 0
-    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[COPY]](p6), [[C]](p6)
+    ; CI-NEXT: [[PTRTOINT:%[0-9]+]]:_(s32) = G_PTRTOINT [[COPY]](p6)
+    ; CI-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
+    ; CI-NEXT: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[PTRTOINT]](s32), [[C]](s32)
     ; CI-NEXT: [[ZEXTLOAD:%[0-9]+]]:_(s32) = G_ZEXTLOAD [[MV]](p4) :: (load (s16), align 1, addrspace 6)
     ; CI-NEXT: $vgpr0 = COPY [[ZEXTLOAD]](s32)
     %0:_(p6) = COPY $sgpr0
diff --git a/llvm/test/CodeGen/AMDGPU/addrspacecast.gfx6.ll b/llvm/test/CodeGen/AMDGPU/addrspacecast.gfx6.ll
index 10dec31..2d60faa 100644
--- a/llvm/test/CodeGen/AMDGPU/addrspacecast.gfx6.ll
+++ b/llvm/test/CodeGen/AMDGPU/addrspacecast.gfx6.ll
@@ -1,6 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc -global-isel=0 -mtriple=amdgcn-amd-amdpal -mcpu=tahiti < %s | FileCheck %s
-; RUN: llc -global-isel=1 -mtriple=amdgcn-amd-amdpal -mcpu=tahiti < %s | FileCheck %s
+; RUN: llc -global-isel=0 -mtriple=amdgcn-amd-amdpal -mcpu=tahiti < %s | FileCheck -check-prefixes=CHECK,SDAG %s
+; RUN: llc -global-isel=1 -mtriple=amdgcn-amd-amdpal -mcpu=tahiti < %s | FileCheck -check-prefixes=CHECK,GISEL %s
 
 define ptr @global_to_flat_addrspacecast(ptr addrspace(1) %ptr) {
 ; CHECK-LABEL: global_to_flat_addrspacecast:
@@ -83,7 +83,7 @@ define ptr addrspace(6) @constant_to_constant32_addrspacecast(ptr addrspace(4) %
   ret ptr addrspace(6) %gep
 }
 
-define ptr addrspace(6)  @global_to_constant32_addrspacecast(ptr addrspace(1) %ptr, i32 %offset) {
+define ptr addrspace(6) @global_to_constant32_addrspacecast(ptr addrspace(1) %ptr, i32 %offset) {
 ; CHECK-LABEL: global_to_constant32_addrspacecast:
 ; CHECK:       ; %bb.0:
 ; CHECK-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
@@ -114,6 +114,58 @@ define ptr @constant32bit_to_flat_addrspacecast_1(ptr addrspace(6) %ptr) #0 {
   ret ptr %stof
 }
 
+define ptr @constant32bit_to_flat_addrspacecast_null() {
+; CHECK-LABEL: constant32bit_to_flat_addrspacecast_null:
+; CHECK:       ; %bb.0:
+; CHECK-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; CHECK-NEXT:    v_mov_b32_e32 v0, 0
+; CHECK-NEXT:    v_mov_b32_e32 v1, 0
+; CHECK-NEXT:    s_setpc_b64 s[30:31]
+  %stof = addrspacecast ptr addrspace(6) null to ptr
+  ret ptr %stof
+}
+
+define ptr @constant32bit_to_flat_addrspacecast_undef() #0 {
+; SDAG-LABEL: constant32bit_to_flat_addrspacecast_undef:
+; SDAG:       ; %bb.0:
+; SDAG-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; SDAG-NEXT:    v_mov_b32_e32 v1, 0
+; SDAG-NEXT:    s_setpc_b64 s[30:31]
+;
+; GISEL-LABEL: constant32bit_to_flat_addrspacecast_undef:
+; GISEL:       ; %bb.0:
+; GISEL-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GISEL-NEXT:    s_setpc_b64 s[30:31]
+  %stof = addrspacecast ptr addrspace(6) undef to ptr
+  ret ptr %stof
+}
+
+define ptr @constant32bit_to_flat_addrspacecast_poison() #0 {
+; SDAG-LABEL: constant32bit_to_flat_addrspacecast_poison:
+; SDAG:       ; %bb.0:
+; SDAG-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; SDAG-NEXT:    v_mov_b32_e32 v1, 0
+; SDAG-NEXT:    s_setpc_b64 s[30:31]
+;
+; GISEL-LABEL: constant32bit_to_flat_addrspacecast_poison:
+; GISEL:       ; %bb.0:
+; GISEL-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GISEL-NEXT:    s_setpc_b64 s[30:31]
+  %stof = addrspacecast ptr addrspace(6) poison to ptr
+  ret ptr %stof
+}
+
+define ptr @constant32bit_to_flat_addrspacecast_constant() #0 {
+; CHECK-LABEL: constant32bit_to_flat_addrspacecast_constant:
+; CHECK:       ; %bb.0:
+; CHECK-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; CHECK-NEXT:    v_mov_b32_e32 v0, 0x3039
+; CHECK-NEXT:    v_mov_b32_e32 v1, 0xffff8000
+; CHECK-NEXT:    s_setpc_b64 s[30:31]
+  %stof = addrspacecast ptr addrspace(6) inttoptr (i32 12345 to ptr addrspace(6)) to ptr
+  ret ptr %stof
+}
+
 define ptr addrspace(1) @addrspacecast_flat_null_to_global() {
 ; CHECK-LABEL: addrspacecast_flat_null_to_global:
 ; CHECK:       ; %bb.0: