[llvm] AMDGPU: Replace undef references with poison in some MIR tests (PR #131254)

Fri Mar 14 00:43:05 PDT 2025

https://github.com/arsenm updated https://github.com/llvm/llvm-project/pull/131254

>From d082d36c054190403db92b164c038239d9d2a014 Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault at amd.com>
Date: Thu, 13 Mar 2025 16:20:37 +0700
Subject: [PATCH] AMDGPU: Replace undef references with poison in some MIR
 tests

---
 .../CodeGen/AMDGPU/invert-br-undef-vcc.mir    |   2 +-
 llvm/test/CodeGen/AMDGPU/lds-dma-waitcnt.mir  |  18 +-
 .../memory-legalizer-invalid-addrspace.mir    |   2 +-
 .../CodeGen/AMDGPU/memory-legalizer-local.mir |  40 ++--
 .../AMDGPU/memory-legalizer-region.mir        |  40 ++--
 .../CodeGen/AMDGPU/merge-flat-load-store.mir  | 210 +++++++++---------
 .../merge-flat-with-global-load-store.mir     |  62 +++---
 .../CodeGen/AMDGPU/opt-sgpr-to-vgpr-copy.mir  |   6 +-
 .../AMDGPU/optimize-if-exec-masking.mir       |  22 +-
 .../AMDGPU/scalar-store-cache-flush.mir       |   4 +-
 .../CodeGen/AMDGPU/sched-crash-dbg-value.mir  |  16 +-
 11 files changed, 211 insertions(+), 211 deletions(-)

diff --git a/llvm/test/CodeGen/AMDGPU/invert-br-undef-vcc.mir b/llvm/test/CodeGen/AMDGPU/invert-br-undef-vcc.mir
index c9c99a9953fcd..10c46e39c3664 100644
--- a/llvm/test/CodeGen/AMDGPU/invert-br-undef-vcc.mir
+++ b/llvm/test/CodeGen/AMDGPU/invert-br-undef-vcc.mir
@@ -3,7 +3,7 @@
 
   define amdgpu_kernel void @invert_br_undef_vcc(float %cond, ptr addrspace(1) %out) #0 {
   entry:
-    br i1 undef, label %if, label %else, !structurizecfg.uniform !0, !amdgpu.uniform !0
+    br i1 poison, label %if, label %else, !structurizecfg.uniform !0, !amdgpu.uniform !0
 
   else:                                             ; preds = %entry
     store volatile i32 100, ptr addrspace(1) poison
diff --git a/llvm/test/CodeGen/AMDGPU/lds-dma-waitcnt.mir b/llvm/test/CodeGen/AMDGPU/lds-dma-waitcnt.mir
index 195597c480319..21372c06d3223 100644
--- a/llvm/test/CodeGen/AMDGPU/lds-dma-waitcnt.mir
+++ b/llvm/test/CodeGen/AMDGPU/lds-dma-waitcnt.mir
@@ -10,7 +10,7 @@ name: buffer_load_dword_lds_ds_read
 body:             |
   bb.0:
     $m0 = S_MOV_B32 0
-    BUFFER_LOAD_DWORD_LDS_IDXEN $vgpr0, $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr4, 4, 0, 0, implicit $exec, implicit $m0 :: (load (s32) from `ptr addrspace(1) poison` + 4), (store (s32) into `ptr addrspace(3) undef` + 4)
+    BUFFER_LOAD_DWORD_LDS_IDXEN $vgpr0, $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr4, 4, 0, 0, implicit $exec, implicit $m0 :: (load (s32) from `ptr addrspace(1) poison` + 4), (store (s32) into `ptr addrspace(3) poison` + 4)
     $vgpr0 = DS_READ_B32_gfx9 $vgpr1, 0, 0, implicit $m0, implicit $exec :: (load (s32) from `ptr addrspace(3) poison`)
     S_ENDPGM 0
 
@@ -27,7 +27,7 @@ name: buffer_load_dword_lds_vmcnt_1
 body:             |
   bb.0:
     $m0 = S_MOV_B32 0
-    BUFFER_LOAD_DWORD_LDS_IDXEN $vgpr0, $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr4, 4, 0, 0, implicit $exec, implicit $m0 :: (load (s32) from `ptr addrspace(1) poison`), (store (s32) into `ptr addrspace(3) undef`)
+    BUFFER_LOAD_DWORD_LDS_IDXEN $vgpr0, $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr4, 4, 0, 0, implicit $exec, implicit $m0 :: (load (s32) from `ptr addrspace(1) poison`), (store (s32) into `ptr addrspace(3) poison`)
     $vgpr10 = BUFFER_LOAD_DWORD_IDXEN $vgpr0, $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr4, 4, 0, 0, implicit $exec, implicit $m0 :: (load (s32) from `ptr addrspace(1) poison`)
     $vgpr0 = DS_READ_B32_gfx9 $vgpr1, 0, 0, implicit $m0, implicit $exec :: (load (s32) from `ptr addrspace(3) poison`)
     S_ENDPGM 0
@@ -44,8 +44,8 @@ name: buffer_load_dword_lds_flat_read
 body:             |
   bb.0:
     $m0 = S_MOV_B32 0
-    BUFFER_LOAD_DWORD_LDS_IDXEN $vgpr0, $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr4, 4, 0, 0, implicit $exec, implicit $m0 :: (load (s32) from `ptr addrspace(1) poison`), (store (s32) into `ptr addrspace(3) undef`)
-    $vgpr0 = FLAT_LOAD_DWORD $vgpr0_vgpr1, 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`)
+    BUFFER_LOAD_DWORD_LDS_IDXEN $vgpr0, $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr4, 4, 0, 0, implicit $exec, implicit $m0 :: (load (s32) from `ptr addrspace(1) poison`), (store (s32) into `ptr addrspace(3) poison`)
+    $vgpr0 = FLAT_LOAD_DWORD $vgpr0_vgpr1, 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`)
 
     S_ENDPGM 0
 
@@ -61,7 +61,7 @@ name: global_load_lds_dword_ds_read
 body:             |
   bb.0:
     $m0 = S_MOV_B32 0
-    GLOBAL_LOAD_LDS_DWORD $vgpr0_vgpr1, 4, 0, implicit $exec, implicit $m0 :: (load (s32) from `ptr addrspace(1) poison` + 4), (store (s32) into `ptr addrspace(3) undef` + 4)
+    GLOBAL_LOAD_LDS_DWORD $vgpr0_vgpr1, 4, 0, implicit $exec, implicit $m0 :: (load (s32) from `ptr addrspace(1) poison` + 4), (store (s32) into `ptr addrspace(3) poison` + 4)
     $vgpr0 = DS_READ_B32_gfx9 $vgpr1, 0, 0, implicit $m0, implicit $exec :: (load (s32) from `ptr addrspace(3) poison`)
     S_ENDPGM 0
 
@@ -91,7 +91,7 @@ name: buffer_store_lds_dword_ds_read
 body:             |
   bb.0:
     $m0 = S_MOV_B32 0
-    BUFFER_STORE_LDS_DWORD $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr4, 4, 0, 0, implicit $exec, implicit $m0 :: (load (s32) from `ptr addrspace(3) poison` + 4), (store (s32) into `ptr addrspace(1) undef` + 4)
+    BUFFER_STORE_LDS_DWORD $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr4, 4, 0, 0, implicit $exec, implicit $m0 :: (load (s32) from `ptr addrspace(3) poison` + 4), (store (s32) into `ptr addrspace(1) poison` + 4)
     $vgpr0 = DS_READ_B32_gfx9 $vgpr1, 0, 0, implicit $m0, implicit $exec :: (load (s32) from `ptr addrspace(3) poison`)
     S_ENDPGM 0
 
@@ -110,9 +110,9 @@ name: series_of_buffer_load_dword_lds_ds_read
 body:             |
   bb.0:
     $m0 = S_MOV_B32 0
-    BUFFER_LOAD_DWORD_LDS_IDXEN $vgpr0, $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr4, 0, 0, 0, implicit $exec, implicit $m0 :: (load (s32) from `ptr addrspace(1) poison`), (store (s32) into `ptr addrspace(3) undef`)
-    BUFFER_LOAD_DWORD_LDS_IDXEN $vgpr0, $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr4, 4, 0, 0, implicit $exec, implicit $m0 :: (load (s32) from `ptr addrspace(1) poison` + 4), (store (s32) into `ptr addrspace(3) undef` + 4)
-    BUFFER_LOAD_DWORD_LDS_IDXEN $vgpr0, $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr4, 8, 0, 0, implicit $exec, implicit $m0 :: (load (s32) from `ptr addrspace(1) poison` + 8), (store (s32) into `ptr addrspace(3) undef` + 8)
+    BUFFER_LOAD_DWORD_LDS_IDXEN $vgpr0, $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr4, 0, 0, 0, implicit $exec, implicit $m0 :: (load (s32) from `ptr addrspace(1) poison`), (store (s32) into `ptr addrspace(3) poison`)
+    BUFFER_LOAD_DWORD_LDS_IDXEN $vgpr0, $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr4, 4, 0, 0, implicit $exec, implicit $m0 :: (load (s32) from `ptr addrspace(1) poison` + 4), (store (s32) into `ptr addrspace(3) poison` + 4)
+    BUFFER_LOAD_DWORD_LDS_IDXEN $vgpr0, $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr4, 8, 0, 0, implicit $exec, implicit $m0 :: (load (s32) from `ptr addrspace(1) poison` + 8), (store (s32) into `ptr addrspace(3) poison` + 8)
     $vgpr0 = DS_READ_B32_gfx9 $vgpr1, 0, 0, implicit $m0, implicit $exec :: (load (s32) from `ptr addrspace(3) poison`)
     S_ENDPGM 0
 
diff --git a/llvm/test/CodeGen/AMDGPU/memory-legalizer-invalid-addrspace.mir b/llvm/test/CodeGen/AMDGPU/memory-legalizer-invalid-addrspace.mir
index c24a4ee20664d..7a914c2322229 100644
--- a/llvm/test/CodeGen/AMDGPU/memory-legalizer-invalid-addrspace.mir
+++ b/llvm/test/CodeGen/AMDGPU/memory-legalizer-invalid-addrspace.mir
@@ -14,7 +14,7 @@ body:             |
     renamable $vgpr2 = FLAT_LOAD_DWORD killed renamable $vgpr0_vgpr1, 0, 0, implicit $exec, implicit $flat_scr :: (volatile load syncscope("one-as") seq_cst (s32) from `ptr addrspace(42) undef`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
diff --git a/llvm/test/CodeGen/AMDGPU/memory-legalizer-local.mir b/llvm/test/CodeGen/AMDGPU/memory-legalizer-local.mir
index 0e22ea40354bb..adaee7ebaddd3 100644
--- a/llvm/test/CodeGen/AMDGPU/memory-legalizer-local.mir
+++ b/llvm/test/CodeGen/AMDGPU/memory-legalizer-local.mir
@@ -20,7 +20,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 0, implicit $m0, implicit $exec :: (volatile load syncscope("singlethread-one-as") unordered (s32) from `ptr addrspace(3) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -44,7 +44,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 0, implicit $m0, implicit $exec :: (volatile load syncscope("singlethread-one-as") monotonic (s32) from `ptr addrspace(3) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -68,7 +68,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 0, implicit $m0, implicit $exec :: (volatile load syncscope("singlethread-one-as") acquire (s32) from `ptr addrspace(3) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -92,7 +92,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 0, implicit $m0, implicit $exec :: (volatile load syncscope("singlethread-one-as") seq_cst (s32) from `ptr addrspace(3) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -116,7 +116,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 0, implicit $m0, implicit $exec :: (volatile load syncscope("wavefront-one-as") unordered (s32) from `ptr addrspace(3) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -140,7 +140,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 0, implicit $m0, implicit $exec :: (volatile load syncscope("wavefront-one-as") monotonic (s32) from `ptr addrspace(3) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -164,7 +164,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 0, implicit $m0, implicit $exec :: (volatile load syncscope("wavefront-one-as") acquire (s32) from `ptr addrspace(3) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -188,7 +188,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 0, implicit $m0, implicit $exec :: (volatile load syncscope("wavefront-one-as") seq_cst (s32) from `ptr addrspace(3) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -212,7 +212,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 0, implicit $m0, implicit $exec :: (volatile load syncscope("workgroup-one-as") unordered (s32) from `ptr addrspace(3) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -236,7 +236,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 0, implicit $m0, implicit $exec :: (volatile load syncscope("workgroup-one-as") monotonic (s32) from `ptr addrspace(3) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -260,7 +260,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 0, implicit $m0, implicit $exec :: (volatile load syncscope("workgroup-one-as") acquire (s32) from `ptr addrspace(3) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -284,7 +284,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 0, implicit $m0, implicit $exec :: (volatile load syncscope("workgroup-one-as") seq_cst (s32) from `ptr addrspace(3) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -308,7 +308,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 0, implicit $m0, implicit $exec :: (volatile load syncscope("agent-one-as") unordered (s32) from `ptr addrspace(3) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -332,7 +332,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 0, implicit $m0, implicit $exec :: (volatile load syncscope("agent-one-as") monotonic (s32) from `ptr addrspace(3) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -356,7 +356,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 0, implicit $m0, implicit $exec :: (volatile load syncscope("agent-one-as") acquire (s32) from `ptr addrspace(3) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -380,7 +380,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 0, implicit $m0, implicit $exec :: (volatile load syncscope("agent-one-as") seq_cst (s32) from `ptr addrspace(3) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -404,7 +404,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 0, implicit $m0, implicit $exec :: (volatile load syncscope("one-as") unordered (s32) from `ptr addrspace(3) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -428,7 +428,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 0, implicit $m0, implicit $exec :: (volatile load syncscope("one-as") monotonic (s32) from `ptr addrspace(3) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -452,7 +452,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 0, implicit $m0, implicit $exec :: (volatile load syncscope("one-as") acquire (s32) from `ptr addrspace(3) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -476,7 +476,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 0, implicit $m0, implicit $exec :: (volatile load syncscope("one-as") seq_cst (s32) from `ptr addrspace(3) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
diff --git a/llvm/test/CodeGen/AMDGPU/memory-legalizer-region.mir b/llvm/test/CodeGen/AMDGPU/memory-legalizer-region.mir
index 0d9d8fb32c6a1..9405c8a946627 100644
--- a/llvm/test/CodeGen/AMDGPU/memory-legalizer-region.mir
+++ b/llvm/test/CodeGen/AMDGPU/memory-legalizer-region.mir
@@ -20,7 +20,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 1, 0, implicit $m0, implicit $exec :: (volatile load syncscope("singlethread-one-as") unordered (s32) from `ptr addrspace(2) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -44,7 +44,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 1, implicit $m0, implicit $exec :: (volatile load syncscope("singlethread-one-as") monotonic (s32) from `ptr addrspace(2) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -68,7 +68,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 1, implicit $m0, implicit $exec :: (volatile load syncscope("singlethread-one-as") acquire (s32) from `ptr addrspace(2) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -92,7 +92,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 1, implicit $m0, implicit $exec :: (volatile load syncscope("singlethread-one-as") seq_cst (s32) from `ptr addrspace(2) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -116,7 +116,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 1, implicit $m0, implicit $exec :: (volatile load syncscope("wavefront-one-as") unordered (s32) from `ptr addrspace(2) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -140,7 +140,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 1, implicit $m0, implicit $exec :: (volatile load syncscope("wavefront-one-as") monotonic (s32) from `ptr addrspace(2) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -164,7 +164,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 1, implicit $m0, implicit $exec :: (volatile load syncscope("wavefront-one-as") acquire (s32) from `ptr addrspace(2) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -188,7 +188,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 1, implicit $m0, implicit $exec :: (volatile load syncscope("wavefront-one-as") seq_cst (s32) from `ptr addrspace(2) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -212,7 +212,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 1, implicit $m0, implicit $exec :: (volatile load syncscope("workgroup-one-as") unordered (s32) from `ptr addrspace(2) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -236,7 +236,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 1, implicit $m0, implicit $exec :: (volatile load syncscope("workgroup-one-as") monotonic (s32) from `ptr addrspace(2) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -260,7 +260,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 1, implicit $m0, implicit $exec :: (volatile load syncscope("workgroup-one-as") acquire (s32) from `ptr addrspace(2) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -284,7 +284,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 1, implicit $m0, implicit $exec :: (volatile load syncscope("workgroup-one-as") seq_cst (s32) from `ptr addrspace(2) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -308,7 +308,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 1, implicit $m0, implicit $exec :: (volatile load syncscope("agent-one-as") unordered (s32) from `ptr addrspace(2) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -332,7 +332,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 1, implicit $m0, implicit $exec :: (volatile load syncscope("agent-one-as") monotonic (s32) from `ptr addrspace(2) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -356,7 +356,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 1, implicit $m0, implicit $exec :: (volatile load syncscope("agent-one-as") acquire (s32) from `ptr addrspace(2) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -380,7 +380,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 1, implicit $m0, implicit $exec :: (volatile load syncscope("agent-one-as") seq_cst (s32) from `ptr addrspace(2) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -404,7 +404,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 1, implicit $m0, implicit $exec :: (volatile load syncscope("one-as") unordered (s32) from `ptr addrspace(2) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -428,7 +428,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 1, implicit $m0, implicit $exec :: (volatile load syncscope("one-as") monotonic (s32) from `ptr addrspace(2) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -452,7 +452,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 1, implicit $m0, implicit $exec :: (volatile load syncscope("one-as") acquire (s32) from `ptr addrspace(2) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
@@ -476,7 +476,7 @@ body:             |
     renamable $vgpr2 = DS_READ_B32 killed renamable $vgpr0, 0, 1, implicit $m0, implicit $exec :: (volatile load syncscope("one-as") seq_cst (s32) from `ptr addrspace(2) poison`)
     $vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
     $vgpr1 = V_MOV_B32_e32 killed $sgpr1, implicit $exec, implicit $sgpr0_sgpr1, implicit $exec
-    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD killed renamable $vgpr0_vgpr1, killed renamable $vgpr2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     S_ENDPGM 0
 
 ...
diff --git a/llvm/test/CodeGen/AMDGPU/merge-flat-load-store.mir b/llvm/test/CodeGen/AMDGPU/merge-flat-load-store.mir
index 71846f74bbf03..31ff5bd841f86 100644
--- a/llvm/test/CodeGen/AMDGPU/merge-flat-load-store.mir
+++ b/llvm/test/CodeGen/AMDGPU/merge-flat-load-store.mir
@@ -8,13 +8,13 @@ body:             |
 
     ; GCN-LABEL: name: merge_flat_load_dword_2
     ; GCN: [[DEF:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
-    ; GCN-NEXT: [[FLAT_LOAD_DWORDX2_:%[0-9]+]]:vreg_64_align2 = FLAT_LOAD_DWORDX2 [[DEF]], 0, 0, implicit $exec, implicit $flat_scr :: (load (s64) from `ptr undef`, align 4)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORDX2_:%[0-9]+]]:vreg_64_align2 = FLAT_LOAD_DWORDX2 [[DEF]], 0, 0, implicit $exec, implicit $flat_scr :: (load (s64) from `ptr poison`, align 4)
     ; GCN-NEXT: [[COPY:%[0-9]+]]:vgpr_32 = COPY [[FLAT_LOAD_DWORDX2_]].sub0
     ; GCN-NEXT: [[COPY1:%[0-9]+]]:vgpr_32 = COPY killed [[FLAT_LOAD_DWORDX2_]].sub1
     ; GCN-NEXT: S_NOP 0, implicit [[COPY]], implicit [[COPY1]]
     %0:vreg_64_align2 = IMPLICIT_DEF
-    %1:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
-    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 4, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
+    %1:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
+    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 4, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
     S_NOP 0, implicit %1, implicit %2
 ...
 
@@ -25,16 +25,16 @@ body:             |
 
     ; GCN-LABEL: name: merge_flat_load_dword_3
     ; GCN: [[DEF:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
-    ; GCN-NEXT: [[FLAT_LOAD_DWORDX3_:%[0-9]+]]:vreg_96_align2 = FLAT_LOAD_DWORDX3 [[DEF]], 0, 1, implicit $exec, implicit $flat_scr :: (load (s96) from `ptr undef`, align 4)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORDX3_:%[0-9]+]]:vreg_96_align2 = FLAT_LOAD_DWORDX3 [[DEF]], 0, 1, implicit $exec, implicit $flat_scr :: (load (s96) from `ptr poison`, align 4)
     ; GCN-NEXT: [[COPY:%[0-9]+]]:vreg_64_align2 = COPY [[FLAT_LOAD_DWORDX3_]].sub0_sub1
     ; GCN-NEXT: [[COPY1:%[0-9]+]]:vgpr_32 = COPY killed [[FLAT_LOAD_DWORDX3_]].sub2
     ; GCN-NEXT: [[COPY2:%[0-9]+]]:vgpr_32 = COPY [[COPY]].sub0
     ; GCN-NEXT: [[COPY3:%[0-9]+]]:vgpr_32 = COPY killed [[COPY]].sub1
     ; GCN-NEXT: S_NOP 0, implicit [[COPY2]], implicit [[COPY3]], implicit [[COPY1]]
     %0:vreg_64_align2 = IMPLICIT_DEF
-    %1:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 1, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
-    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 4, 1, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
-    %3:vgpr_32 = FLAT_LOAD_DWORD %0, 8, 1, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
+    %1:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 1, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
+    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 4, 1, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
+    %3:vgpr_32 = FLAT_LOAD_DWORD %0, 8, 1, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
     S_NOP 0, implicit %1, implicit %2, implicit %3
 ...
 
@@ -45,7 +45,7 @@ body:             |
 
     ; GCN-LABEL: name: merge_flat_load_dword_4
     ; GCN: [[DEF:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
-    ; GCN-NEXT: [[FLAT_LOAD_DWORDX4_:%[0-9]+]]:vreg_128_align2 = FLAT_LOAD_DWORDX4 [[DEF]], 0, 2, implicit $exec, implicit $flat_scr :: (load (s128) from `ptr undef`, align 4)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORDX4_:%[0-9]+]]:vreg_128_align2 = FLAT_LOAD_DWORDX4 [[DEF]], 0, 2, implicit $exec, implicit $flat_scr :: (load (s128) from `ptr poison`, align 4)
     ; GCN-NEXT: [[COPY:%[0-9]+]]:vreg_96_align2 = COPY [[FLAT_LOAD_DWORDX4_]].sub0_sub1_sub2
     ; GCN-NEXT: [[COPY1:%[0-9]+]]:vgpr_32 = COPY killed [[FLAT_LOAD_DWORDX4_]].sub3
     ; GCN-NEXT: [[COPY2:%[0-9]+]]:vreg_64_align2 = COPY [[COPY]].sub0_sub1
@@ -54,10 +54,10 @@ body:             |
     ; GCN-NEXT: [[COPY5:%[0-9]+]]:vgpr_32 = COPY killed [[COPY2]].sub1
     ; GCN-NEXT: S_NOP 0, implicit [[COPY4]], implicit [[COPY5]], implicit [[COPY3]], implicit [[COPY1]]
     %0:vreg_64_align2 = IMPLICIT_DEF
-    %1:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 2, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
-    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 4, 2, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
-    %3:vgpr_32 = FLAT_LOAD_DWORD %0, 8, 2, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
-    %4:vgpr_32 = FLAT_LOAD_DWORD %0, 12, 2, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
+    %1:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 2, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
+    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 4, 2, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
+    %3:vgpr_32 = FLAT_LOAD_DWORD %0, 8, 2, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
+    %4:vgpr_32 = FLAT_LOAD_DWORD %0, 12, 2, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
     S_NOP 0, implicit %1, implicit %2, implicit %3, implicit %4
 ...
 
@@ -68,21 +68,21 @@ body:             |
 
     ; GCN-LABEL: name: merge_flat_load_dword_5
     ; GCN: [[DEF:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
-    ; GCN-NEXT: [[FLAT_LOAD_DWORDX4_:%[0-9]+]]:vreg_128_align2 = FLAT_LOAD_DWORDX4 [[DEF]], 0, 3, implicit $exec, implicit $flat_scr :: (load (s128) from `ptr undef`, align 4)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORDX4_:%[0-9]+]]:vreg_128_align2 = FLAT_LOAD_DWORDX4 [[DEF]], 0, 3, implicit $exec, implicit $flat_scr :: (load (s128) from `ptr poison`, align 4)
     ; GCN-NEXT: [[COPY:%[0-9]+]]:vreg_96_align2 = COPY [[FLAT_LOAD_DWORDX4_]].sub0_sub1_sub2
     ; GCN-NEXT: [[COPY1:%[0-9]+]]:vgpr_32 = COPY killed [[FLAT_LOAD_DWORDX4_]].sub3
     ; GCN-NEXT: [[COPY2:%[0-9]+]]:vreg_64_align2 = COPY [[COPY]].sub0_sub1
     ; GCN-NEXT: [[COPY3:%[0-9]+]]:vgpr_32 = COPY killed [[COPY]].sub2
     ; GCN-NEXT: [[COPY4:%[0-9]+]]:vgpr_32 = COPY [[COPY2]].sub0
     ; GCN-NEXT: [[COPY5:%[0-9]+]]:vgpr_32 = COPY killed [[COPY2]].sub1
-    ; GCN-NEXT: [[FLAT_LOAD_DWORD:%[0-9]+]]:vgpr_32 = FLAT_LOAD_DWORD [[DEF]], 16, 3, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORD:%[0-9]+]]:vgpr_32 = FLAT_LOAD_DWORD [[DEF]], 16, 3, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`)
     ; GCN-NEXT: S_NOP 0, implicit [[COPY4]], implicit [[COPY5]], implicit [[COPY3]], implicit [[COPY1]], implicit [[FLAT_LOAD_DWORD]]
     %0:vreg_64_align2 = IMPLICIT_DEF
-    %1:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 3, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
-    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 4, 3, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
-    %3:vgpr_32 = FLAT_LOAD_DWORD %0, 8, 3, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
-    %4:vgpr_32 = FLAT_LOAD_DWORD %0, 12, 3, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
-    %5:vgpr_32 = FLAT_LOAD_DWORD %0, 16, 3, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
+    %1:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 3, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
+    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 4, 3, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
+    %3:vgpr_32 = FLAT_LOAD_DWORD %0, 8, 3, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
+    %4:vgpr_32 = FLAT_LOAD_DWORD %0, 12, 3, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
+    %5:vgpr_32 = FLAT_LOAD_DWORD %0, 16, 3, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
     S_NOP 0, implicit %1, implicit %2, implicit %3, implicit %4, implicit %5
 ...
 
@@ -93,24 +93,24 @@ body:             |
 
     ; GCN-LABEL: name: merge_flat_load_dword_6
     ; GCN: [[DEF:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
-    ; GCN-NEXT: [[FLAT_LOAD_DWORDX4_:%[0-9]+]]:vreg_128_align2 = FLAT_LOAD_DWORDX4 [[DEF]], 0, 0, implicit $exec, implicit $flat_scr :: (load (s128) from `ptr undef`, align 4)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORDX4_:%[0-9]+]]:vreg_128_align2 = FLAT_LOAD_DWORDX4 [[DEF]], 0, 0, implicit $exec, implicit $flat_scr :: (load (s128) from `ptr poison`, align 4)
     ; GCN-NEXT: [[COPY:%[0-9]+]]:vreg_96_align2 = COPY [[FLAT_LOAD_DWORDX4_]].sub0_sub1_sub2
     ; GCN-NEXT: [[COPY1:%[0-9]+]]:vgpr_32 = COPY killed [[FLAT_LOAD_DWORDX4_]].sub3
     ; GCN-NEXT: [[COPY2:%[0-9]+]]:vreg_64_align2 = COPY [[COPY]].sub0_sub1
     ; GCN-NEXT: [[COPY3:%[0-9]+]]:vgpr_32 = COPY killed [[COPY]].sub2
     ; GCN-NEXT: [[COPY4:%[0-9]+]]:vgpr_32 = COPY [[COPY2]].sub0
     ; GCN-NEXT: [[COPY5:%[0-9]+]]:vgpr_32 = COPY killed [[COPY2]].sub1
-    ; GCN-NEXT: [[FLAT_LOAD_DWORDX2_:%[0-9]+]]:vreg_64_align2 = FLAT_LOAD_DWORDX2 [[DEF]], 16, 0, implicit $exec, implicit $flat_scr :: (load (s64) from `ptr undef`, align 4)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORDX2_:%[0-9]+]]:vreg_64_align2 = FLAT_LOAD_DWORDX2 [[DEF]], 16, 0, implicit $exec, implicit $flat_scr :: (load (s64) from `ptr poison`, align 4)
     ; GCN-NEXT: [[COPY6:%[0-9]+]]:vgpr_32 = COPY [[FLAT_LOAD_DWORDX2_]].sub0
     ; GCN-NEXT: [[COPY7:%[0-9]+]]:vgpr_32 = COPY killed [[FLAT_LOAD_DWORDX2_]].sub1
     ; GCN-NEXT: S_NOP 0, implicit [[COPY4]], implicit [[COPY5]], implicit [[COPY3]], implicit [[COPY1]], implicit [[COPY6]], implicit [[COPY7]]
     %0:vreg_64_align2 = IMPLICIT_DEF
-    %1:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
-    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 4, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
-    %3:vgpr_32 = FLAT_LOAD_DWORD %0, 8, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
-    %4:vgpr_32 = FLAT_LOAD_DWORD %0, 12, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
-    %5:vgpr_32 = FLAT_LOAD_DWORD %0, 16, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
-    %6:vgpr_32 = FLAT_LOAD_DWORD %0, 20, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
+    %1:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
+    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 4, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
+    %3:vgpr_32 = FLAT_LOAD_DWORD %0, 8, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
+    %4:vgpr_32 = FLAT_LOAD_DWORD %0, 12, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
+    %5:vgpr_32 = FLAT_LOAD_DWORD %0, 16, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
+    %6:vgpr_32 = FLAT_LOAD_DWORD %0, 20, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
     S_NOP 0, implicit %1, implicit %2, implicit %3, implicit %4, implicit %5, implicit %6
 ...
 
@@ -121,13 +121,13 @@ body:             |
 
     ; GCN-LABEL: name: merge_flat_load_dwordx2
     ; GCN: [[DEF:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
-    ; GCN-NEXT: [[FLAT_LOAD_DWORDX4_:%[0-9]+]]:vreg_128_align2 = FLAT_LOAD_DWORDX4 [[DEF]], 0, 0, implicit $exec, implicit $flat_scr :: (load (s128) from `ptr undef`, align 4)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORDX4_:%[0-9]+]]:vreg_128_align2 = FLAT_LOAD_DWORDX4 [[DEF]], 0, 0, implicit $exec, implicit $flat_scr :: (load (s128) from `ptr poison`, align 4)
     ; GCN-NEXT: [[COPY:%[0-9]+]]:vreg_64_align2 = COPY [[FLAT_LOAD_DWORDX4_]].sub0_sub1
     ; GCN-NEXT: [[COPY1:%[0-9]+]]:vreg_64_align2 = COPY killed [[FLAT_LOAD_DWORDX4_]].sub2_sub3
     ; GCN-NEXT: S_NOP 0, implicit [[COPY]], implicit [[COPY1]]
     %0:vreg_64_align2 = IMPLICIT_DEF
-    %1:vreg_64_align2 = FLAT_LOAD_DWORDX2 %0, 0, 0, implicit $exec, implicit $flat_scr :: (load (s64) from `ptr undef`, align 4)
-    %2:vreg_64_align2 = FLAT_LOAD_DWORDX2 %0, 8, 0, implicit $exec, implicit $flat_scr :: (load (s64) from `ptr undef`, align 4)
+    %1:vreg_64_align2 = FLAT_LOAD_DWORDX2 %0, 0, 0, implicit $exec, implicit $flat_scr :: (load (s64) from `ptr poison`, align 4)
+    %2:vreg_64_align2 = FLAT_LOAD_DWORDX2 %0, 8, 0, implicit $exec, implicit $flat_scr :: (load (s64) from `ptr poison`, align 4)
     S_NOP 0, implicit %1, implicit %2
 ...
 
@@ -138,13 +138,13 @@ body:             |
 
     ; GCN-LABEL: name: merge_flat_load_dwordx3_with_dwordx1
     ; GCN: [[DEF:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
-    ; GCN-NEXT: [[FLAT_LOAD_DWORDX4_:%[0-9]+]]:vreg_128_align2 = FLAT_LOAD_DWORDX4 [[DEF]], 12, 0, implicit $exec, implicit $flat_scr :: (load (s128) from `ptr undef`, align 8)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORDX4_:%[0-9]+]]:vreg_128_align2 = FLAT_LOAD_DWORDX4 [[DEF]], 12, 0, implicit $exec, implicit $flat_scr :: (load (s128) from `ptr poison`, align 8)
     ; GCN-NEXT: [[COPY:%[0-9]+]]:vreg_96_align2 = COPY [[FLAT_LOAD_DWORDX4_]].sub0_sub1_sub2
     ; GCN-NEXT: [[COPY1:%[0-9]+]]:vgpr_32 = COPY killed [[FLAT_LOAD_DWORDX4_]].sub3
     ; GCN-NEXT: S_NOP 0, implicit [[COPY]], implicit [[COPY1]]
     %0:vreg_64_align2 = IMPLICIT_DEF
-    %1:vreg_96_align2 = FLAT_LOAD_DWORDX3 %0, 12, 0, implicit $exec, implicit $flat_scr :: (load (s96) from `ptr undef`, align 8)
-    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 24, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
+    %1:vreg_96_align2 = FLAT_LOAD_DWORDX3 %0, 12, 0, implicit $exec, implicit $flat_scr :: (load (s96) from `ptr poison`, align 8)
+    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 24, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
     S_NOP 0, implicit %1, implicit %2
 ...
 
@@ -155,13 +155,13 @@ body:             |
 
     ; GCN-LABEL: name: merge_flat_load_dwordx1_with_dwordx2
     ; GCN: [[DEF:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
-    ; GCN-NEXT: [[FLAT_LOAD_DWORDX3_:%[0-9]+]]:vreg_96_align2 = FLAT_LOAD_DWORDX3 [[DEF]], 12, 0, implicit $exec, implicit $flat_scr :: (load (s96) from `ptr undef`, align 4)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORDX3_:%[0-9]+]]:vreg_96_align2 = FLAT_LOAD_DWORDX3 [[DEF]], 12, 0, implicit $exec, implicit $flat_scr :: (load (s96) from `ptr poison`, align 4)
     ; GCN-NEXT: [[COPY:%[0-9]+]]:vgpr_32 = COPY [[FLAT_LOAD_DWORDX3_]].sub0
     ; GCN-NEXT: [[COPY1:%[0-9]+]]:vreg_64_align2 = COPY killed [[FLAT_LOAD_DWORDX3_]].sub1_sub2
     ; GCN-NEXT: S_NOP 0, implicit [[COPY1]], implicit [[COPY]]
     %0:vreg_64_align2 = IMPLICIT_DEF
-    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 12, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
-    %1:vreg_64_align2 = FLAT_LOAD_DWORDX2 %0, 16, 0, implicit $exec, implicit $flat_scr :: (load (s64) from `ptr undef`, align 8)
+    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 12, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
+    %1:vreg_64_align2 = FLAT_LOAD_DWORDX2 %0, 16, 0, implicit $exec, implicit $flat_scr :: (load (s64) from `ptr poison`, align 8)
     S_NOP 0, implicit %1, implicit %2
 ...
 
@@ -172,12 +172,12 @@ body:             |
 
     ; GCN-LABEL: name: no_merge_flat_load_dword_agpr_with_vgpr
     ; GCN: [[DEF:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
-    ; GCN-NEXT: [[FLAT_LOAD_DWORD:%[0-9]+]]:vgpr_32 = FLAT_LOAD_DWORD [[DEF]], 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`)
-    ; GCN-NEXT: [[FLAT_LOAD_DWORD1:%[0-9]+]]:agpr_32 = FLAT_LOAD_DWORD [[DEF]], 4, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORD:%[0-9]+]]:vgpr_32 = FLAT_LOAD_DWORD [[DEF]], 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORD1:%[0-9]+]]:agpr_32 = FLAT_LOAD_DWORD [[DEF]], 4, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`)
     ; GCN-NEXT: S_NOP 0, implicit [[FLAT_LOAD_DWORD]], implicit [[FLAT_LOAD_DWORD1]]
     %0:vreg_64_align2 = IMPLICIT_DEF
-    %1:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
-    %2:agpr_32 = FLAT_LOAD_DWORD %0, 4, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
+    %1:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
+    %2:agpr_32 = FLAT_LOAD_DWORD %0, 4, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
     S_NOP 0, implicit %1, implicit %2
 ...
 
@@ -188,12 +188,12 @@ body:             |
 
     ; GCN-LABEL: name: no_merge_flat_load_dword_disjoint
     ; GCN: [[DEF:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
-    ; GCN-NEXT: [[FLAT_LOAD_DWORD:%[0-9]+]]:vgpr_32 = FLAT_LOAD_DWORD [[DEF]], 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`)
-    ; GCN-NEXT: [[FLAT_LOAD_DWORD1:%[0-9]+]]:vgpr_32 = FLAT_LOAD_DWORD [[DEF]], 8, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORD:%[0-9]+]]:vgpr_32 = FLAT_LOAD_DWORD [[DEF]], 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORD1:%[0-9]+]]:vgpr_32 = FLAT_LOAD_DWORD [[DEF]], 8, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`)
     ; GCN-NEXT: S_NOP 0, implicit [[FLAT_LOAD_DWORD]], implicit [[FLAT_LOAD_DWORD1]]
     %0:vreg_64_align2 = IMPLICIT_DEF
-    %1:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
-    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 8, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
+    %1:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
+    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 8, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
     S_NOP 0, implicit %1, implicit %2
 ...
 
@@ -204,12 +204,12 @@ body:             |
 
     ; GCN-LABEL: name: no_merge_flat_load_dword_overlap
     ; GCN: [[DEF:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
-    ; GCN-NEXT: [[FLAT_LOAD_DWORD:%[0-9]+]]:vgpr_32 = FLAT_LOAD_DWORD [[DEF]], 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`)
-    ; GCN-NEXT: [[FLAT_LOAD_DWORD1:%[0-9]+]]:vgpr_32 = FLAT_LOAD_DWORD [[DEF]], 3, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORD:%[0-9]+]]:vgpr_32 = FLAT_LOAD_DWORD [[DEF]], 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORD1:%[0-9]+]]:vgpr_32 = FLAT_LOAD_DWORD [[DEF]], 3, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`)
     ; GCN-NEXT: S_NOP 0, implicit [[FLAT_LOAD_DWORD]], implicit [[FLAT_LOAD_DWORD1]]
     %0:vreg_64_align2 = IMPLICIT_DEF
-    %1:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
-    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 3, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`)
+    %1:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
+    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 3, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`)
     S_NOP 0, implicit %1, implicit %2
 ...
 
@@ -220,12 +220,12 @@ body:             |
 
     ; GCN-LABEL: name: no_merge_flat_load_dword_different_cpol
     ; GCN: [[DEF:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
-    ; GCN-NEXT: [[FLAT_LOAD_DWORD:%[0-9]+]]:vgpr_32 = FLAT_LOAD_DWORD [[DEF]], 0, 1, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`)
-    ; GCN-NEXT: [[FLAT_LOAD_DWORD1:%[0-9]+]]:vgpr_32 = FLAT_LOAD_DWORD [[DEF]], 4, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORD:%[0-9]+]]:vgpr_32 = FLAT_LOAD_DWORD [[DEF]], 0, 1, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORD1:%[0-9]+]]:vgpr_32 = FLAT_LOAD_DWORD [[DEF]], 4, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`)
     ; GCN-NEXT: S_NOP 0, implicit [[FLAT_LOAD_DWORD]], implicit [[FLAT_LOAD_DWORD1]]
     %0:vreg_64_align2 = IMPLICIT_DEF
-    %1:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 1, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
-    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 4, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, align 4)
+    %1:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 1, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
+    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 4, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, align 4)
     S_NOP 0, implicit %1, implicit %2
 ...
 
@@ -239,12 +239,12 @@ body:             |
     ; GCN-NEXT: [[DEF1:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF2:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
     ; GCN-NEXT: [[REG_SEQUENCE:%[0-9]+]]:vreg_64_align2 = REG_SEQUENCE killed [[DEF1]], %subreg.sub0, killed [[DEF2]], %subreg.sub1
-    ; GCN-NEXT: FLAT_STORE_DWORDX2 [[DEF]], killed [[REG_SEQUENCE]], 0, 0, implicit $exec, implicit $flat_scr :: (store (s64) into `ptr undef`, align 4)
+    ; GCN-NEXT: FLAT_STORE_DWORDX2 [[DEF]], killed [[REG_SEQUENCE]], 0, 0, implicit $exec, implicit $flat_scr :: (store (s64) into `ptr poison`, align 4)
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:vgpr_32 = IMPLICIT_DEF
     %2:vgpr_32 = IMPLICIT_DEF
-    FLAT_STORE_DWORD %0, killed %1, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
-    FLAT_STORE_DWORD killed %0, killed %2, 4, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
+    FLAT_STORE_DWORD %0, killed %1, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
+    FLAT_STORE_DWORD killed %0, killed %2, 4, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
 ...
 
 ---
@@ -259,14 +259,14 @@ body:             |
     ; GCN-NEXT: [[DEF3:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
     ; GCN-NEXT: [[REG_SEQUENCE:%[0-9]+]]:vreg_64_align2 = REG_SEQUENCE killed [[DEF1]], %subreg.sub0, killed [[DEF2]], %subreg.sub1
     ; GCN-NEXT: [[REG_SEQUENCE1:%[0-9]+]]:vreg_96_align2 = REG_SEQUENCE killed [[REG_SEQUENCE]], %subreg.sub0_sub1, killed [[DEF3]], %subreg.sub2
-    ; GCN-NEXT: FLAT_STORE_DWORDX3 [[DEF]], killed [[REG_SEQUENCE1]], 4, 1, implicit $exec, implicit $flat_scr :: (store (s96) into `ptr undef`, align 4)
+    ; GCN-NEXT: FLAT_STORE_DWORDX3 [[DEF]], killed [[REG_SEQUENCE1]], 4, 1, implicit $exec, implicit $flat_scr :: (store (s96) into `ptr poison`, align 4)
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:vgpr_32 = IMPLICIT_DEF
     %2:vgpr_32 = IMPLICIT_DEF
     %3:vgpr_32 = IMPLICIT_DEF
-    FLAT_STORE_DWORD %0, killed %1, 4, 1, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
-    FLAT_STORE_DWORD %0, killed %2, 8, 1, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
-    FLAT_STORE_DWORD killed %0, killed %3, 12, 1, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
+    FLAT_STORE_DWORD %0, killed %1, 4, 1, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
+    FLAT_STORE_DWORD %0, killed %2, 8, 1, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
+    FLAT_STORE_DWORD killed %0, killed %3, 12, 1, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
 ...
 
 ---
@@ -280,13 +280,13 @@ body:             |
     ; GCN-NEXT: [[REG_SEQUENCE:%[0-9]+]]:vreg_64_align2 = REG_SEQUENCE [[DEF1]].sub1, %subreg.sub1, [[DEF1]].sub0, %subreg.sub0
     ; GCN-NEXT: [[REG_SEQUENCE1:%[0-9]+]]:vreg_96_align2 = REG_SEQUENCE [[DEF1]].sub2, %subreg.sub2, killed [[REG_SEQUENCE]], %subreg.sub0_sub1
     ; GCN-NEXT: [[REG_SEQUENCE2:%[0-9]+]]:vreg_128_align2 = REG_SEQUENCE [[DEF1]].sub3, %subreg.sub3, killed [[REG_SEQUENCE1]], %subreg.sub0_sub1_sub2
-    ; GCN-NEXT: FLAT_STORE_DWORDX4 [[DEF]], killed [[REG_SEQUENCE2]], 4, 2, implicit $exec, implicit $flat_scr :: (store (s128) into `ptr undef`, align 4)
+    ; GCN-NEXT: FLAT_STORE_DWORDX4 [[DEF]], killed [[REG_SEQUENCE2]], 4, 2, implicit $exec, implicit $flat_scr :: (store (s128) into `ptr poison`, align 4)
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:vreg_128 = IMPLICIT_DEF
-    FLAT_STORE_DWORD %0, %1.sub1, 8, 2, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
-    FLAT_STORE_DWORD %0, %1.sub2, 12, 2, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
-    FLAT_STORE_DWORD %0, %1.sub3, 16, 2, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
-    FLAT_STORE_DWORD killed %0, %1.sub0, 4, 2, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
+    FLAT_STORE_DWORD %0, %1.sub1, 8, 2, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
+    FLAT_STORE_DWORD %0, %1.sub2, 12, 2, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
+    FLAT_STORE_DWORD %0, %1.sub3, 16, 2, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
+    FLAT_STORE_DWORD killed %0, %1.sub0, 4, 2, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
 ...
 
 ---
@@ -304,19 +304,19 @@ body:             |
     ; GCN-NEXT: [[REG_SEQUENCE:%[0-9]+]]:areg_64_align2 = REG_SEQUENCE [[DEF1]], %subreg.sub0, [[DEF2]], %subreg.sub1
     ; GCN-NEXT: [[REG_SEQUENCE1:%[0-9]+]]:areg_96_align2 = REG_SEQUENCE killed [[REG_SEQUENCE]], %subreg.sub0_sub1, [[DEF3]], %subreg.sub2
     ; GCN-NEXT: [[REG_SEQUENCE2:%[0-9]+]]:areg_128_align2 = REG_SEQUENCE killed [[REG_SEQUENCE1]], %subreg.sub0_sub1_sub2, [[DEF4]], %subreg.sub3
-    ; GCN-NEXT: FLAT_STORE_DWORDX4 [[DEF]], killed [[REG_SEQUENCE2]], 4, 3, implicit $exec, implicit $flat_scr :: (store (s128) into `ptr undef`, align 4)
-    ; GCN-NEXT: FLAT_STORE_DWORD [[DEF]], [[DEF5]], 20, 3, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    ; GCN-NEXT: FLAT_STORE_DWORDX4 [[DEF]], killed [[REG_SEQUENCE2]], 4, 3, implicit $exec, implicit $flat_scr :: (store (s128) into `ptr poison`, align 4)
+    ; GCN-NEXT: FLAT_STORE_DWORD [[DEF]], [[DEF5]], 20, 3, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:agpr_32 = IMPLICIT_DEF
     %2:agpr_32 = IMPLICIT_DEF
     %3:agpr_32 = IMPLICIT_DEF
     %4:agpr_32 = IMPLICIT_DEF
     %5:agpr_32 = IMPLICIT_DEF
-    FLAT_STORE_DWORD %0, %1, 4, 3, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
-    FLAT_STORE_DWORD %0, %2, 8, 3, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 8)
-    FLAT_STORE_DWORD %0, %3, 12, 3, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
-    FLAT_STORE_DWORD %0, %4, 16, 3, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
-    FLAT_STORE_DWORD %0, %5, 20, 3, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
+    FLAT_STORE_DWORD %0, %1, 4, 3, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
+    FLAT_STORE_DWORD %0, %2, 8, 3, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 8)
+    FLAT_STORE_DWORD %0, %3, 12, 3, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
+    FLAT_STORE_DWORD %0, %4, 16, 3, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
+    FLAT_STORE_DWORD %0, %5, 20, 3, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
 ...
 
 ---
@@ -335,9 +335,9 @@ body:             |
     ; GCN-NEXT: [[REG_SEQUENCE:%[0-9]+]]:vreg_64_align2 = REG_SEQUENCE [[DEF1]], %subreg.sub0, [[DEF2]], %subreg.sub1
     ; GCN-NEXT: [[REG_SEQUENCE1:%[0-9]+]]:vreg_96_align2 = REG_SEQUENCE killed [[REG_SEQUENCE]], %subreg.sub0_sub1, [[DEF3]], %subreg.sub2
     ; GCN-NEXT: [[REG_SEQUENCE2:%[0-9]+]]:vreg_128_align2 = REG_SEQUENCE killed [[REG_SEQUENCE1]], %subreg.sub0_sub1_sub2, [[DEF4]], %subreg.sub3
-    ; GCN-NEXT: FLAT_STORE_DWORDX4 [[DEF]], killed [[REG_SEQUENCE2]], 4, 0, implicit $exec, implicit $flat_scr :: (store (s128) into `ptr undef`, align 8)
+    ; GCN-NEXT: FLAT_STORE_DWORDX4 [[DEF]], killed [[REG_SEQUENCE2]], 4, 0, implicit $exec, implicit $flat_scr :: (store (s128) into `ptr poison`, align 8)
     ; GCN-NEXT: [[REG_SEQUENCE3:%[0-9]+]]:vreg_64_align2 = REG_SEQUENCE [[DEF5]], %subreg.sub0, [[DEF6]], %subreg.sub1
-    ; GCN-NEXT: FLAT_STORE_DWORDX2 [[DEF]], killed [[REG_SEQUENCE3]], 20, 0, implicit $exec, implicit $flat_scr :: (store (s64) into `ptr undef`, align 4)
+    ; GCN-NEXT: FLAT_STORE_DWORDX2 [[DEF]], killed [[REG_SEQUENCE3]], 20, 0, implicit $exec, implicit $flat_scr :: (store (s64) into `ptr poison`, align 4)
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:vgpr_32 = IMPLICIT_DEF
     %2:vgpr_32 = IMPLICIT_DEF
@@ -345,12 +345,12 @@ body:             |
     %4:vgpr_32 = IMPLICIT_DEF
     %5:vgpr_32 = IMPLICIT_DEF
     %6:vgpr_32 = IMPLICIT_DEF
-    FLAT_STORE_DWORD %0, %1, 4, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 8)
-    FLAT_STORE_DWORD %0, %2, 8, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
-    FLAT_STORE_DWORD %0, %3, 12, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
-    FLAT_STORE_DWORD %0, %4, 16, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
-    FLAT_STORE_DWORD %0, %5, 20, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
-    FLAT_STORE_DWORD %0, %6, 24, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
+    FLAT_STORE_DWORD %0, %1, 4, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 8)
+    FLAT_STORE_DWORD %0, %2, 8, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
+    FLAT_STORE_DWORD %0, %3, 12, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
+    FLAT_STORE_DWORD %0, %4, 16, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
+    FLAT_STORE_DWORD %0, %5, 20, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
+    FLAT_STORE_DWORD %0, %6, 24, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
 ...
 
 ---
@@ -363,12 +363,12 @@ body:             |
     ; GCN-NEXT: [[DEF1:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF2:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
     ; GCN-NEXT: [[REG_SEQUENCE:%[0-9]+]]:vreg_128_align2 = REG_SEQUENCE killed [[DEF1]], %subreg.sub0_sub1, killed [[DEF2]], %subreg.sub2_sub3
-    ; GCN-NEXT: FLAT_STORE_DWORDX4 [[DEF]], killed [[REG_SEQUENCE]], 4, 0, implicit $exec, implicit $flat_scr :: (store (s128) into `ptr undef`, align 4)
+    ; GCN-NEXT: FLAT_STORE_DWORDX4 [[DEF]], killed [[REG_SEQUENCE]], 4, 0, implicit $exec, implicit $flat_scr :: (store (s128) into `ptr poison`, align 4)
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:vreg_64_align2 = IMPLICIT_DEF
     %2:vreg_64_align2 = IMPLICIT_DEF
-    FLAT_STORE_DWORDX2 %0, killed %1, 4, 0, implicit $exec, implicit $flat_scr :: (store (s64) into `ptr undef`, align 4)
-    FLAT_STORE_DWORDX2 %0, killed %2, 12, 0, implicit $exec, implicit $flat_scr :: (store (s64) into `ptr undef`, align 4)
+    FLAT_STORE_DWORDX2 %0, killed %1, 4, 0, implicit $exec, implicit $flat_scr :: (store (s64) into `ptr poison`, align 4)
+    FLAT_STORE_DWORDX2 %0, killed %2, 12, 0, implicit $exec, implicit $flat_scr :: (store (s64) into `ptr poison`, align 4)
 ...
 
 ---
@@ -381,12 +381,12 @@ body:             |
     ; GCN-NEXT: [[DEF1:%[0-9]+]]:vreg_96_align2 = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF2:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
     ; GCN-NEXT: [[REG_SEQUENCE:%[0-9]+]]:vreg_128_align2 = REG_SEQUENCE killed [[DEF1]], %subreg.sub0_sub1_sub2, killed [[DEF2]], %subreg.sub3
-    ; GCN-NEXT: FLAT_STORE_DWORDX4 [[DEF]], killed [[REG_SEQUENCE]], 4, 0, implicit $exec, implicit $flat_scr :: (store (s128) into `ptr undef`)
+    ; GCN-NEXT: FLAT_STORE_DWORDX4 [[DEF]], killed [[REG_SEQUENCE]], 4, 0, implicit $exec, implicit $flat_scr :: (store (s128) into `ptr poison`)
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:vreg_96_align2 = IMPLICIT_DEF
     %2:vgpr_32 = IMPLICIT_DEF
-    FLAT_STORE_DWORDX3 %0, killed %1, 4, 0, implicit $exec, implicit $flat_scr :: (store (s96) into `ptr undef`, align 16)
-    FLAT_STORE_DWORD %0, killed %2, 16, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
+    FLAT_STORE_DWORDX3 %0, killed %1, 4, 0, implicit $exec, implicit $flat_scr :: (store (s96) into `ptr poison`, align 16)
+    FLAT_STORE_DWORD %0, killed %2, 16, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
 ...
 
 ---
@@ -398,13 +398,13 @@ body:             |
     ; GCN: [[DEF:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF1:%[0-9]+]]:agpr_32 = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF2:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
-    ; GCN-NEXT: FLAT_STORE_DWORD [[DEF]], killed [[DEF1]], 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
-    ; GCN-NEXT: FLAT_STORE_DWORD killed [[DEF]], killed [[DEF2]], 4, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    ; GCN-NEXT: FLAT_STORE_DWORD [[DEF]], killed [[DEF1]], 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
+    ; GCN-NEXT: FLAT_STORE_DWORD killed [[DEF]], killed [[DEF2]], 4, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:agpr_32 = IMPLICIT_DEF
     %2:vgpr_32 = IMPLICIT_DEF
-    FLAT_STORE_DWORD %0, killed %1, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
-    FLAT_STORE_DWORD killed %0, killed %2, 4, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
+    FLAT_STORE_DWORD %0, killed %1, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
+    FLAT_STORE_DWORD killed %0, killed %2, 4, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
 ...
 
 ---
@@ -416,13 +416,13 @@ body:             |
     ; GCN: [[DEF:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF1:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF2:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
-    ; GCN-NEXT: FLAT_STORE_DWORD [[DEF]], killed [[DEF1]], 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
-    ; GCN-NEXT: FLAT_STORE_DWORD killed [[DEF]], killed [[DEF2]], 6, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    ; GCN-NEXT: FLAT_STORE_DWORD [[DEF]], killed [[DEF1]], 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
+    ; GCN-NEXT: FLAT_STORE_DWORD killed [[DEF]], killed [[DEF2]], 6, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:vgpr_32 = IMPLICIT_DEF
     %2:vgpr_32 = IMPLICIT_DEF
-    FLAT_STORE_DWORD %0, killed %1, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
-    FLAT_STORE_DWORD killed %0, killed %2, 6, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
+    FLAT_STORE_DWORD %0, killed %1, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
+    FLAT_STORE_DWORD killed %0, killed %2, 6, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
 ...
 
 ---
@@ -434,13 +434,13 @@ body:             |
     ; GCN: [[DEF:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF1:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF2:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
-    ; GCN-NEXT: FLAT_STORE_DWORD [[DEF]], killed [[DEF1]], 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
-    ; GCN-NEXT: FLAT_STORE_DWORD killed [[DEF]], killed [[DEF2]], 2, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 2)
+    ; GCN-NEXT: FLAT_STORE_DWORD [[DEF]], killed [[DEF1]], 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
+    ; GCN-NEXT: FLAT_STORE_DWORD killed [[DEF]], killed [[DEF2]], 2, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 2)
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:vgpr_32 = IMPLICIT_DEF
     %2:vgpr_32 = IMPLICIT_DEF
-    FLAT_STORE_DWORD %0, killed %1, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
-    FLAT_STORE_DWORD killed %0, killed %2, 2, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 2)
+    FLAT_STORE_DWORD %0, killed %1, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
+    FLAT_STORE_DWORD killed %0, killed %2, 2, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 2)
 ...
 
 ---
@@ -452,13 +452,13 @@ body:             |
     ; GCN: [[DEF:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF1:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF2:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
-    ; GCN-NEXT: FLAT_STORE_DWORD [[DEF]], killed [[DEF1]], 0, 1, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
-    ; GCN-NEXT: FLAT_STORE_DWORD killed [[DEF]], killed [[DEF2]], 4, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    ; GCN-NEXT: FLAT_STORE_DWORD [[DEF]], killed [[DEF1]], 0, 1, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
+    ; GCN-NEXT: FLAT_STORE_DWORD killed [[DEF]], killed [[DEF2]], 4, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:vgpr_32 = IMPLICIT_DEF
     %2:vgpr_32 = IMPLICIT_DEF
-    FLAT_STORE_DWORD %0, killed %1, 0, 1, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
-    FLAT_STORE_DWORD killed %0, killed %2, 4, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
+    FLAT_STORE_DWORD %0, killed %1, 0, 1, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
+    FLAT_STORE_DWORD killed %0, killed %2, 4, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
 ...
 
 ---
@@ -470,11 +470,11 @@ body:             |
     ; GCN: [[DEF:%[0-9]+]]:vreg_128_align2 = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF1:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF2:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
-    ; GCN-NEXT: FLAT_STORE_DWORD [[DEF]].sub0_sub1, killed [[DEF1]], 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
-    ; GCN-NEXT: FLAT_STORE_DWORD [[DEF]].sub2_sub3, killed [[DEF2]], 4, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    ; GCN-NEXT: FLAT_STORE_DWORD [[DEF]].sub0_sub1, killed [[DEF1]], 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
+    ; GCN-NEXT: FLAT_STORE_DWORD [[DEF]].sub2_sub3, killed [[DEF2]], 4, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     %0:vreg_128_align2 = IMPLICIT_DEF
     %1:vgpr_32 = IMPLICIT_DEF
     %2:vgpr_32 = IMPLICIT_DEF
-    FLAT_STORE_DWORD %0.sub0_sub1, killed %1, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
-    FLAT_STORE_DWORD %0.sub2_sub3, killed %2, 4, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`, align 4)
+    FLAT_STORE_DWORD %0.sub0_sub1, killed %1, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
+    FLAT_STORE_DWORD %0.sub2_sub3, killed %2, 4, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`, align 4)
 ...
diff --git a/llvm/test/CodeGen/AMDGPU/merge-flat-with-global-load-store.mir b/llvm/test/CodeGen/AMDGPU/merge-flat-with-global-load-store.mir
index 7e9bc0935e0a9..a67cf22bdd1ce 100644
--- a/llvm/test/CodeGen/AMDGPU/merge-flat-with-global-load-store.mir
+++ b/llvm/test/CodeGen/AMDGPU/merge-flat-with-global-load-store.mir
@@ -8,12 +8,12 @@ body:             |
 
     ; GCN-LABEL: name: merge_flat_global_load_dword_2
     ; GCN: [[DEF:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
-    ; GCN-NEXT: [[FLAT_LOAD_DWORDX2_:%[0-9]+]]:vreg_64_align2 = FLAT_LOAD_DWORDX2 [[DEF]], 0, 0, implicit $exec, implicit $flat_scr :: (load (s64) from `ptr undef` + 4, align 4)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORDX2_:%[0-9]+]]:vreg_64_align2 = FLAT_LOAD_DWORDX2 [[DEF]], 0, 0, implicit $exec, implicit $flat_scr :: (load (s64) from `ptr poison` + 4, align 4)
     ; GCN-NEXT: [[COPY:%[0-9]+]]:vgpr_32 = COPY [[FLAT_LOAD_DWORDX2_]].sub0
     ; GCN-NEXT: [[COPY1:%[0-9]+]]:vgpr_32 = COPY killed [[FLAT_LOAD_DWORDX2_]].sub1
     ; GCN-NEXT: S_NOP 0, implicit [[COPY]], implicit [[COPY1]]
     %0:vreg_64_align2 = IMPLICIT_DEF
-    %1:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef` + 4, basealign 4)
+    %1:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison` + 4, basealign 4)
     %2:vgpr_32 = GLOBAL_LOAD_DWORD %0, 4, 0, implicit $exec :: (load (s32) from `ptr addrspace(1) poison` + 8, basealign 4, addrspace 1)
     S_NOP 0, implicit %1, implicit %2
 ...
@@ -31,7 +31,7 @@ body:             |
     ; GCN-NEXT: S_NOP 0, implicit [[COPY]], implicit [[COPY1]]
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:vgpr_32 = GLOBAL_LOAD_DWORD %0, 0, 0, implicit $exec :: (load (s32) from `ptr addrspace(1) poison`, basealign 8, addrspace 1)
-    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 4, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef` + 4, basealign 8)
+    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 4, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison` + 4, basealign 8)
     S_NOP 0, implicit %1, implicit %2
 ...
 
@@ -42,7 +42,7 @@ body:             |
 
     ; GCN-LABEL: name: merge_global_flat_load_dword_3
     ; GCN: [[DEF:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
-    ; GCN-NEXT: [[FLAT_LOAD_DWORDX3_:%[0-9]+]]:vreg_96_align2 = FLAT_LOAD_DWORDX3 [[DEF]], 0, 0, implicit $exec, implicit $flat_scr :: (load (s96) from `ptr undef`, align 16)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORDX3_:%[0-9]+]]:vreg_96_align2 = FLAT_LOAD_DWORDX3 [[DEF]], 0, 0, implicit $exec, implicit $flat_scr :: (load (s96) from `ptr poison`, align 16)
     ; GCN-NEXT: [[COPY:%[0-9]+]]:vreg_64_align2 = COPY [[FLAT_LOAD_DWORDX3_]].sub0_sub1
     ; GCN-NEXT: [[COPY1:%[0-9]+]]:vgpr_32 = COPY killed [[FLAT_LOAD_DWORDX3_]].sub2
     ; GCN-NEXT: [[COPY2:%[0-9]+]]:vgpr_32 = COPY [[COPY]].sub1
@@ -50,7 +50,7 @@ body:             |
     ; GCN-NEXT: S_NOP 0, implicit [[COPY2]], implicit [[COPY3]]
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:vgpr_32 = GLOBAL_LOAD_DWORD %0, 4, 0, implicit $exec :: (load (s32) from `ptr addrspace(1) poison` + 4, basealign 8, addrspace 1)
-    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, basealign 16)
+    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, basealign 16)
     %3:vgpr_32 = GLOBAL_LOAD_DWORD %0, 8, 0, implicit $exec :: (load (s32) from `ptr addrspace(1) poison` + 8, basealign 8, addrspace 1)
     S_NOP 0, implicit %1, implicit %2
 ...
@@ -74,7 +74,7 @@ body:             |
     %1:vgpr_32 = GLOBAL_LOAD_DWORD %0, 4, 0, implicit $exec :: (load (s32) from `ptr addrspace(1) poison` + 4, basealign 8, addrspace 1)
     %2:vgpr_32 = GLOBAL_LOAD_DWORD %0, 8, 0, implicit $exec :: (load (s32) from `ptr addrspace(1) poison` + 8, basealign 8, addrspace 1)
     %3:vgpr_32 = GLOBAL_LOAD_DWORD %0, 12, 0, implicit $exec :: (load (s32) from `ptr addrspace(1) poison` + 12, basealign 8, addrspace 1)
-    %4:vgpr_32 = FLAT_LOAD_DWORD %0, 16, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef` + 16)
+    %4:vgpr_32 = FLAT_LOAD_DWORD %0, 16, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison` + 16)
     S_NOP 0, implicit %1, implicit %2, implicit %3, implicit %4
 ...
 
@@ -85,12 +85,12 @@ body:             |
 
     ; GCN-LABEL: name: merge_flat_global_load_dwordx2
     ; GCN: [[DEF:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
-    ; GCN-NEXT: [[FLAT_LOAD_DWORDX4_:%[0-9]+]]:vreg_128_align2 = FLAT_LOAD_DWORDX4 [[DEF]], 0, 0, implicit $exec, implicit $flat_scr :: (load (s128) from `ptr undef`, align 8)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORDX4_:%[0-9]+]]:vreg_128_align2 = FLAT_LOAD_DWORDX4 [[DEF]], 0, 0, implicit $exec, implicit $flat_scr :: (load (s128) from `ptr poison`, align 8)
     ; GCN-NEXT: [[COPY:%[0-9]+]]:vreg_64_align2 = COPY [[FLAT_LOAD_DWORDX4_]].sub0_sub1
     ; GCN-NEXT: [[COPY1:%[0-9]+]]:vreg_64_align2 = COPY killed [[FLAT_LOAD_DWORDX4_]].sub2_sub3
     ; GCN-NEXT: S_NOP 0, implicit [[COPY]], implicit [[COPY1]]
     %0:vreg_64_align2 = IMPLICIT_DEF
-    %1:vreg_64_align2 = FLAT_LOAD_DWORDX2 %0, 0, 0, implicit $exec, implicit $flat_scr :: (load (s64) from `ptr undef`)
+    %1:vreg_64_align2 = FLAT_LOAD_DWORDX2 %0, 0, 0, implicit $exec, implicit $flat_scr :: (load (s64) from `ptr poison`)
     %2:vreg_64_align2 = GLOBAL_LOAD_DWORDX2 %0, 8, 0, implicit $exec :: (load (s64) from `ptr addrspace(1) poison`, addrspace 1)
     S_NOP 0, implicit %1, implicit %2
 ...
@@ -102,12 +102,12 @@ body:             |
 
     ; GCN-LABEL: name: merge_flat_global_load_dwordx3
     ; GCN: [[DEF:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
-    ; GCN-NEXT: [[FLAT_LOAD_DWORDX4_:%[0-9]+]]:vreg_128_align2 = FLAT_LOAD_DWORDX4 [[DEF]], 0, 0, implicit $exec, implicit $flat_scr :: (load (s128) from `ptr undef`, align 4)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORDX4_:%[0-9]+]]:vreg_128_align2 = FLAT_LOAD_DWORDX4 [[DEF]], 0, 0, implicit $exec, implicit $flat_scr :: (load (s128) from `ptr poison`, align 4)
     ; GCN-NEXT: [[COPY:%[0-9]+]]:vgpr_32 = COPY [[FLAT_LOAD_DWORDX4_]].sub0
     ; GCN-NEXT: [[COPY1:%[0-9]+]]:vreg_96_align2 = COPY killed [[FLAT_LOAD_DWORDX4_]].sub1_sub2_sub3
     ; GCN-NEXT: S_NOP 0, implicit [[COPY]], implicit [[COPY1]]
     %0:vreg_64_align2 = IMPLICIT_DEF
-    %1:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`)
+    %1:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`)
     %2:vreg_96_align2 = GLOBAL_LOAD_DWORDX3 %0, 4, 0, implicit $exec :: (load (s96) from `ptr addrspace(1) poison`, addrspace 1)
     S_NOP 0, implicit %1, implicit %2
 ...
@@ -125,7 +125,7 @@ body:             |
     ; GCN-NEXT: S_NOP 0, implicit [[COPY]], implicit [[COPY1]]
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:vgpr_32 = GLOBAL_LOAD_DWORD %0, 0, 0, implicit $exec :: (load (s32) from `ptr addrspace(1) poison`, addrspace 1)
-    %2:vreg_96_align2 = FLAT_LOAD_DWORDX3 %0, 4, 0, implicit $exec, implicit $flat_scr :: (load (s96) from `ptr undef`)
+    %2:vreg_96_align2 = FLAT_LOAD_DWORDX3 %0, 4, 0, implicit $exec, implicit $flat_scr :: (load (s96) from `ptr poison`)
     S_NOP 0, implicit %1, implicit %2
 ...
 
@@ -137,14 +137,14 @@ body:             |
     ; GCN-LABEL: name: no_merge_flat_global_load_dword_saddr
     ; GCN: [[DEF:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF1:%[0-9]+]]:sreg_64_xexec_xnull = IMPLICIT_DEF
-    ; GCN-NEXT: [[FLAT_LOAD_DWORD:%[0-9]+]]:vgpr_32 = FLAT_LOAD_DWORD [[DEF]], 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORD:%[0-9]+]]:vgpr_32 = FLAT_LOAD_DWORD [[DEF]], 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`)
     ; GCN-NEXT: [[GLOBAL_LOAD_DWORDX2_SADDR:%[0-9]+]]:vreg_64_align2 = GLOBAL_LOAD_DWORDX2_SADDR [[DEF1]], [[DEF]].sub0, 4, 0, implicit $exec :: (load (s64) from `ptr addrspace(1) poison` + 4, align 4, addrspace 1)
     ; GCN-NEXT: [[COPY:%[0-9]+]]:vgpr_32 = COPY [[GLOBAL_LOAD_DWORDX2_SADDR]].sub0
     ; GCN-NEXT: [[COPY1:%[0-9]+]]:vgpr_32 = COPY killed [[GLOBAL_LOAD_DWORDX2_SADDR]].sub1
     ; GCN-NEXT: S_NOP 0, implicit [[FLAT_LOAD_DWORD]], implicit [[COPY]], implicit [[COPY1]]
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:sreg_64_xexec_xnull = IMPLICIT_DEF
-    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef`, basealign 4)
+    %2:vgpr_32 = FLAT_LOAD_DWORD %0, 0, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison`, basealign 4)
     %3:vgpr_32 = GLOBAL_LOAD_DWORD_SADDR %1, %0.sub0, 4, 0, implicit $exec :: (load (s32) from `ptr addrspace(1) poison` + 4, basealign 4, addrspace 1)
     %4:vgpr_32 = GLOBAL_LOAD_DWORD_SADDR %1, %0.sub0, 8, 0, implicit $exec :: (load (s32) from `ptr addrspace(1) poison` + 8, basealign 4, addrspace 1)
     S_NOP 0, implicit %2, implicit %3, implicit %4
@@ -159,15 +159,15 @@ body:             |
     ; GCN: [[DEF:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF1:%[0-9]+]]:sreg_64_xexec_xnull = IMPLICIT_DEF
     ; GCN-NEXT: [[GLOBAL_LOAD_DWORD_SADDR:%[0-9]+]]:vgpr_32 = GLOBAL_LOAD_DWORD_SADDR [[DEF1]], [[DEF]].sub0, 0, 0, implicit $exec :: (load (s32) from `ptr addrspace(1) poison`, addrspace 1)
-    ; GCN-NEXT: [[FLAT_LOAD_DWORDX2_:%[0-9]+]]:vreg_64_align2 = FLAT_LOAD_DWORDX2 [[DEF]], 4, 0, implicit $exec, implicit $flat_scr :: (load (s64) from `ptr undef` + 4, align 4)
+    ; GCN-NEXT: [[FLAT_LOAD_DWORDX2_:%[0-9]+]]:vreg_64_align2 = FLAT_LOAD_DWORDX2 [[DEF]], 4, 0, implicit $exec, implicit $flat_scr :: (load (s64) from `ptr poison` + 4, align 4)
     ; GCN-NEXT: [[COPY:%[0-9]+]]:vgpr_32 = COPY [[FLAT_LOAD_DWORDX2_]].sub0
     ; GCN-NEXT: [[COPY1:%[0-9]+]]:vgpr_32 = COPY killed [[FLAT_LOAD_DWORDX2_]].sub1
     ; GCN-NEXT: S_NOP 0, implicit [[GLOBAL_LOAD_DWORD_SADDR]], implicit [[COPY]], implicit [[COPY1]]
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:sreg_64_xexec_xnull = IMPLICIT_DEF
     %2:vgpr_32 = GLOBAL_LOAD_DWORD_SADDR %1, %0.sub0, 0, 0, implicit $exec :: (load (s32) from `ptr addrspace(1) poison`, addrspace 1)
-    %3:vgpr_32 = FLAT_LOAD_DWORD %0, 4, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef` + 4)
-    %4:vgpr_32 = FLAT_LOAD_DWORD %0, 8, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr undef` + 8)
+    %3:vgpr_32 = FLAT_LOAD_DWORD %0, 4, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison` + 4)
+    %4:vgpr_32 = FLAT_LOAD_DWORD %0, 8, 0, implicit $exec, implicit $flat_scr :: (load (s32) from `ptr poison` + 8)
     S_NOP 0, implicit %2, implicit %3, implicit %4
 ...
 
@@ -180,11 +180,11 @@ body:             |
     ; GCN-NEXT: [[DEF1:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF2:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
     ; GCN-NEXT: [[REG_SEQUENCE:%[0-9]+]]:vreg_64_align2 = REG_SEQUENCE killed [[DEF1]], %subreg.sub0, killed [[DEF2]], %subreg.sub1
-    ; GCN-NEXT: FLAT_STORE_DWORDX2 [[DEF]], killed [[REG_SEQUENCE]], 0, 0, implicit $exec, implicit $flat_scr :: (store (s64) into `ptr undef`, align 4)
+    ; GCN-NEXT: FLAT_STORE_DWORDX2 [[DEF]], killed [[REG_SEQUENCE]], 0, 0, implicit $exec, implicit $flat_scr :: (store (s64) into `ptr poison`, align 4)
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:vgpr_32 = IMPLICIT_DEF
     %2:vgpr_32 = IMPLICIT_DEF
-    FLAT_STORE_DWORD %0, killed %1, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD %0, killed %1, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     GLOBAL_STORE_DWORD killed %0, killed %2, 4, 0, implicit $exec :: (store (s32) into `ptr addrspace(1) poison`, addrspace 1)
 ...
 
@@ -202,7 +202,7 @@ body:             |
     %1:vgpr_32 = IMPLICIT_DEF
     %2:vgpr_32 = IMPLICIT_DEF
     GLOBAL_STORE_DWORD %0, killed %1, 0, 0, implicit $exec :: (store (s32) into `ptr addrspace(1) poison`, addrspace 1)
-    FLAT_STORE_DWORD %0, killed %2, 4, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD %0, killed %2, 4, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
 ...
 
 ---
@@ -214,11 +214,11 @@ body:             |
     ; GCN-NEXT: [[DEF1:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF2:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
     ; GCN-NEXT: [[REG_SEQUENCE:%[0-9]+]]:vreg_96_align2 = REG_SEQUENCE [[DEF1]], %subreg.sub0, [[DEF2]], %subreg.sub1_sub2
-    ; GCN-NEXT: FLAT_STORE_DWORDX3 [[DEF]], killed [[REG_SEQUENCE]], 0, 0, implicit $exec, implicit $flat_scr :: (store (s96) into `ptr undef`, align 4)
+    ; GCN-NEXT: FLAT_STORE_DWORDX3 [[DEF]], killed [[REG_SEQUENCE]], 0, 0, implicit $exec, implicit $flat_scr :: (store (s96) into `ptr poison`, align 4)
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:vgpr_32 = IMPLICIT_DEF
     %2:vreg_64_align2 = IMPLICIT_DEF
-    FLAT_STORE_DWORD %0, %1, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD %0, %1, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     GLOBAL_STORE_DWORDX2 %0, %2, 4, 0, implicit $exec :: (store (s64) into `ptr addrspace(1) poison`, addrspace 1)
 ...
 
@@ -231,11 +231,11 @@ body:             |
     ; GCN-NEXT: [[DEF1:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF2:%[0-9]+]]:vreg_96_align2 = IMPLICIT_DEF
     ; GCN-NEXT: [[REG_SEQUENCE:%[0-9]+]]:vreg_128_align2 = REG_SEQUENCE [[DEF1]], %subreg.sub0, [[DEF2]], %subreg.sub1_sub2_sub3
-    ; GCN-NEXT: FLAT_STORE_DWORDX4 [[DEF]], killed [[REG_SEQUENCE]], 0, 0, implicit $exec, implicit $flat_scr :: (store (s128) into `ptr undef`, align 4)
+    ; GCN-NEXT: FLAT_STORE_DWORDX4 [[DEF]], killed [[REG_SEQUENCE]], 0, 0, implicit $exec, implicit $flat_scr :: (store (s128) into `ptr poison`, align 4)
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:vgpr_32 = IMPLICIT_DEF
     %2:vreg_96_align2 = IMPLICIT_DEF
-    FLAT_STORE_DWORD %0, %1, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD %0, %1, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     GLOBAL_STORE_DWORDX3 %0, %2, 4, 0, implicit $exec :: (store (s96) into `ptr addrspace(1) poison`, addrspace 1)
 ...
 
@@ -248,12 +248,12 @@ body:             |
     ; GCN-NEXT: [[DEF1:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF2:%[0-9]+]]:vreg_64_align2 = IMPLICIT_DEF
     ; GCN-NEXT: [[REG_SEQUENCE:%[0-9]+]]:vreg_96_align2 = REG_SEQUENCE [[DEF1]], %subreg.sub2, [[DEF2]], %subreg.sub0_sub1
-    ; GCN-NEXT: FLAT_STORE_DWORDX3 [[DEF]], killed [[REG_SEQUENCE]], 0, 0, implicit $exec, implicit $flat_scr :: (store (s96) into `ptr undef`, align 8)
+    ; GCN-NEXT: FLAT_STORE_DWORDX3 [[DEF]], killed [[REG_SEQUENCE]], 0, 0, implicit $exec, implicit $flat_scr :: (store (s96) into `ptr poison`, align 8)
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:vgpr_32 = IMPLICIT_DEF
     %2:vreg_64_align2 = IMPLICIT_DEF
     GLOBAL_STORE_DWORD %0, %1, 8, 0, implicit $exec :: (store (s32) into `ptr addrspace(1) poison`, addrspace 1)
-    FLAT_STORE_DWORDX2 %0, %2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s64) into `ptr undef`)
+    FLAT_STORE_DWORDX2 %0, %2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s64) into `ptr poison`)
 ...
 
 ---
@@ -265,12 +265,12 @@ body:             |
     ; GCN-NEXT: [[DEF1:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF2:%[0-9]+]]:vreg_96_align2 = IMPLICIT_DEF
     ; GCN-NEXT: [[REG_SEQUENCE:%[0-9]+]]:vreg_128_align2 = REG_SEQUENCE [[DEF1]], %subreg.sub3, [[DEF2]], %subreg.sub0_sub1_sub2
-    ; GCN-NEXT: FLAT_STORE_DWORDX4 [[DEF]], killed [[REG_SEQUENCE]], 0, 0, implicit $exec, implicit $flat_scr :: (store (s128) into `ptr undef`)
+    ; GCN-NEXT: FLAT_STORE_DWORDX4 [[DEF]], killed [[REG_SEQUENCE]], 0, 0, implicit $exec, implicit $flat_scr :: (store (s128) into `ptr poison`)
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:vgpr_32 = IMPLICIT_DEF
     %2:vreg_96_align2 = IMPLICIT_DEF
     GLOBAL_STORE_DWORD %0, %1, 12, 0, implicit $exec :: (store (s32) into `ptr addrspace(1) poison`, addrspace 1)
-    FLAT_STORE_DWORDX3 %0, %2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s96) into `ptr undef`)
+    FLAT_STORE_DWORDX3 %0, %2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s96) into `ptr poison`)
 ...
 
 ---
@@ -282,13 +282,13 @@ body:             |
     ; GCN-NEXT: [[DEF1:%[0-9]+]]:sreg_64_xexec_xnull = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF2:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF3:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
-    ; GCN-NEXT: FLAT_STORE_DWORD [[DEF]], [[DEF2]], 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    ; GCN-NEXT: FLAT_STORE_DWORD [[DEF]], [[DEF2]], 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     ; GCN-NEXT: GLOBAL_STORE_DWORD_SADDR [[DEF]].sub0, [[DEF3]], [[DEF1]], 4, 0, implicit $exec :: (store (s32) into `ptr addrspace(1) poison`, addrspace 1)
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:sreg_64_xexec_xnull = IMPLICIT_DEF
     %2:vgpr_32 = IMPLICIT_DEF
     %3:vgpr_32 = IMPLICIT_DEF
-    FLAT_STORE_DWORD %0, %2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD %0, %2, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     GLOBAL_STORE_DWORD_SADDR %0.sub0, %3, %1, 4, 0, implicit $exec :: (store (s32) into `ptr addrspace(1) poison`, addrspace 1)
 ...
 
@@ -302,11 +302,11 @@ body:             |
     ; GCN-NEXT: [[DEF2:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
     ; GCN-NEXT: [[DEF3:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
     ; GCN-NEXT: GLOBAL_STORE_DWORD_SADDR [[DEF]].sub0, [[DEF2]], [[DEF1]], 0, 0, implicit $exec :: (store (s32) into `ptr addrspace(1) poison`, addrspace 1)
-    ; GCN-NEXT: FLAT_STORE_DWORD [[DEF]], [[DEF3]], 4, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    ; GCN-NEXT: FLAT_STORE_DWORD [[DEF]], [[DEF3]], 4, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
     %0:vreg_64_align2 = IMPLICIT_DEF
     %1:sreg_64_xexec_xnull = IMPLICIT_DEF
     %2:vgpr_32 = IMPLICIT_DEF
     %3:vgpr_32 = IMPLICIT_DEF
     GLOBAL_STORE_DWORD_SADDR %0.sub0, %2, %1, 0, 0, implicit $exec :: (store (s32) into `ptr addrspace(1) poison`, addrspace 1)
-    FLAT_STORE_DWORD %0, %3, 4, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr undef`)
+    FLAT_STORE_DWORD %0, %3, 4, 0, implicit $exec, implicit $flat_scr :: (store (s32) into `ptr poison`)
 ...
diff --git a/llvm/test/CodeGen/AMDGPU/opt-sgpr-to-vgpr-copy.mir b/llvm/test/CodeGen/AMDGPU/opt-sgpr-to-vgpr-copy.mir
index 748775dc2cf1d..48ac1c60550d7 100644
--- a/llvm/test/CodeGen/AMDGPU/opt-sgpr-to-vgpr-copy.mir
+++ b/llvm/test/CodeGen/AMDGPU/opt-sgpr-to-vgpr-copy.mir
@@ -6,7 +6,7 @@
 --- |
   define amdgpu_kernel void @const_to_sgpr(ptr addrspace(1) nocapture %arg, i64 %id) {
   bb:
-    br i1 undef, label %bb1, label %bb2
+    br i1 poison, label %bb1, label %bb2
 
   bb1:                                              ; preds = %bb
     br label %bb2
@@ -17,7 +17,7 @@
 
   define amdgpu_kernel void @const_to_sgpr_multiple_use(ptr addrspace(1) nocapture %arg, i64 %id1, i64 %id2) {
   bb:
-    br i1 undef, label %bb1, label %bb2
+    br i1 poison, label %bb1, label %bb2
 
   bb1:                                              ; preds = %bb
     br label %bb2
@@ -28,7 +28,7 @@
 
   define amdgpu_kernel void @const_to_sgpr_subreg(ptr addrspace(1) nocapture %arg, i64 %id) {
   bb:
-    br i1 undef, label %bb1, label %bb2
+    br i1 poison, label %bb1, label %bb2
 
   bb1:                                              ; preds = %bb
     br label %bb2
diff --git a/llvm/test/CodeGen/AMDGPU/optimize-if-exec-masking.mir b/llvm/test/CodeGen/AMDGPU/optimize-if-exec-masking.mir
index 0ca277b9b2d7e..0d8334cf09606 100644
--- a/llvm/test/CodeGen/AMDGPU/optimize-if-exec-masking.mir
+++ b/llvm/test/CodeGen/AMDGPU/optimize-if-exec-masking.mir
@@ -3,7 +3,7 @@
 --- |
   define amdgpu_kernel void @optimize_if_and_saveexec_xor(i32 %z, i32 %v) {
   main_body:
-    br i1 undef, label %if, label %end
+    br i1 poison, label %if, label %end
 
   if:                                               ; preds = %main_body
     %v.if = load volatile i32, ptr addrspace(1) poison
@@ -15,7 +15,7 @@
 
   define amdgpu_kernel void @optimize_if_and_saveexec(i32 %z, i32 %v) {
   main_body:
-    br i1 undef, label %if, label %end
+    br i1 poison, label %if, label %end
 
   if:
     br label %end
@@ -26,7 +26,7 @@
 
   define amdgpu_kernel void @optimize_if_or_saveexec(i32 %z, i32 %v) {
   main_body:
-    br i1 undef, label %if, label %end
+    br i1 poison, label %if, label %end
 
   if:
     br label %end
@@ -37,7 +37,7 @@
 
   define amdgpu_kernel void @optimize_if_and_saveexec_xor_valu_middle(i32 %z, i32 %v) {
   main_body:
-    br i1 undef, label %if, label %end
+    br i1 poison, label %if, label %end
 
   if:                                               ; preds = %main_body
     br label %end
@@ -48,7 +48,7 @@
 
   define amdgpu_kernel void @optimize_if_and_saveexec_xor_wrong_reg(i32 %z, i32 %v) {
   main_body:
-    br i1 undef, label %if, label %end
+    br i1 poison, label %if, label %end
 
   if:
     br label %end
@@ -59,7 +59,7 @@
 
   define amdgpu_kernel void @optimize_if_and_saveexec_xor_modify_copy_to_exec(i32 %z, i32 %v) {
   main_body:
-    br i1 undef, label %if, label %end
+    br i1 poison, label %if, label %end
 
   if:
     br label %end
@@ -70,7 +70,7 @@
 
   define amdgpu_kernel void @optimize_if_and_saveexec_xor_live_out_setexec(i32 %z, i32 %v) {
   main_body:
-    br i1 undef, label %if, label %end
+    br i1 poison, label %if, label %end
 
   if:
     br label %end
@@ -81,7 +81,7 @@
 
   define amdgpu_kernel void @optimize_if_unknown_saveexec(i32 %z, i32 %v) {
   main_body:
-    br i1 undef, label %if, label %end
+    br i1 poison, label %if, label %end
 
   if:
     br label %end
@@ -92,7 +92,7 @@
 
   define amdgpu_kernel void @optimize_if_andn2_saveexec(i32 %z, i32 %v) {
   main_body:
-    br i1 undef, label %if, label %end
+    br i1 poison, label %if, label %end
 
   if:
     br label %end
@@ -103,7 +103,7 @@
 
   define amdgpu_kernel void @optimize_if_andn2_saveexec_no_commute(i32 %z, i32 %v) {
   main_body:
-    br i1 undef, label %if, label %end
+    br i1 poison, label %if, label %end
 
   if:
     br label %end
@@ -114,7 +114,7 @@
 
   define amdgpu_kernel void @if_and_xor_read_exec_copy_subreg() {
   main_body:
-    br i1 undef, label %if, label %end
+    br i1 poison, label %if, label %end
 
   if:                                               ; preds = %main_body
     br label %end
diff --git a/llvm/test/CodeGen/AMDGPU/scalar-store-cache-flush.mir b/llvm/test/CodeGen/AMDGPU/scalar-store-cache-flush.mir
index b0cbeeb5707b0..3d6571e397426 100644
--- a/llvm/test/CodeGen/AMDGPU/scalar-store-cache-flush.mir
+++ b/llvm/test/CodeGen/AMDGPU/scalar-store-cache-flush.mir
@@ -19,7 +19,7 @@
 
   define amdgpu_kernel void @multi_block_store() {
   bb0:
-    br i1 undef, label %bb1, label %bb2
+    br i1 poison, label %bb1, label %bb2
 
    bb1:
      ret void
@@ -30,7 +30,7 @@
 
   define amdgpu_kernel void @one_block_store() {
   bb0:
-    br i1 undef, label %bb1, label %bb2
+    br i1 poison, label %bb1, label %bb2
 
    bb1:
      ret void
diff --git a/llvm/test/CodeGen/AMDGPU/sched-crash-dbg-value.mir b/llvm/test/CodeGen/AMDGPU/sched-crash-dbg-value.mir
index 6ae277f2bc693..eabbfca91ca55 100644
--- a/llvm/test/CodeGen/AMDGPU/sched-crash-dbg-value.mir
+++ b/llvm/test/CodeGen/AMDGPU/sched-crash-dbg-value.mir
@@ -10,7 +10,7 @@
   %struct.wombat = type { <4 x float>, <4 x float>, <4 x float>, <4 x float>, <4 x float>, <4 x float>, <4 x float>, [2 x i16], [2 x i16] }
   %struct.wombat.1 = type { [4 x i32], [4 x i32], [4 x i32], [4 x i32], i32, i32, i32, i32 }
 
-  @sched_dbg_value_crash.tmp6 = internal unnamed_addr addrspace(3) global [256 x [16 x i8]] undef, align 16
+  @sched_dbg_value_crash.tmp6 = internal unnamed_addr addrspace(3) global [256 x [16 x i8]] poison, align 16
 
   define amdgpu_kernel void @sched_dbg_value_crash(ptr addrspace(1) nocapture readonly %arg, ptr addrspace(1) nocapture readonly %arg1, ptr addrspace(1) nocapture readonly %arg2, ptr addrspace(1) nocapture readonly %arg3, ptr addrspace(1) nocapture %arg4) local_unnamed_addr #2 {
   bb:
@@ -98,9 +98,9 @@
     %tmp67 = extractelement <4 x float> %tmp16, i64 0
     %tmp69 = fsub fast float -0.000000e+00, %tmp67
     %tmp70 = fmul float %tmp67, 0.000000e+00
-    %tmp = fmul fast float %tmp67, undef
+    %tmp = fmul fast float %tmp67, poison
     %tmp71 = fsub fast float %tmp, %tmp70
-    %tmp73 = fadd fast float %tmp, undef
+    %tmp73 = fadd fast float %tmp, poison
     %tmp74 = insertelement <4 x float> <float poison, float poison, float poison, float 0.000000e+00>, float %tmp69, i32 0
     %tmp75 = insertelement <4 x float> %tmp74, float %tmp71, i32 1
     %tmp76 = insertelement <4 x float> %tmp75, float %tmp73, i32 2
@@ -110,10 +110,10 @@
     %tmp79 = extractelement <4 x float> %tmp66, i32 2
     %tmp80 = extractelement <4 x float> %tmp59, i32 2
     %tmp81 = fsub float %tmp79, %tmp80
-    %tmp82 = fmul fast float %tmp81, undef
-    %tmp83 = fmul fast float %tmp78, undef
+    %tmp82 = fmul fast float %tmp81, poison
+    %tmp83 = fmul fast float %tmp78, poison
     %tmp84 = fadd fast float %tmp83, %tmp77
-    %tmp85 = fadd fast float %tmp84, undef
+    %tmp85 = fadd fast float %tmp84, poison
     %tmp86 = fmul float %tmp82, %tmp82
     %tmp87 = fdiv float 1.000000e+00, %tmp86
     tail call void @llvm.dbg.value(metadata float %tmp87, metadata !5, metadata !DIExpression(DW_OP_constu, 1, DW_OP_swap, DW_OP_xderef)) #3, !dbg !8
@@ -125,8 +125,8 @@
     %tmp93 = fmul float %tmp42, %tmp87
     %tmp94 = call float @llvm.fmuladd.f32(float %tmp92, float %tmp36, float %tmp93)
     %tmp95 = call float @llvm.fmuladd.f32(float %tmp48, float poison, float %tmp94)
-    %fmul = fmul <2 x float> undef, undef
-    %fadd = fadd <2 x float> %fmul, undef
+    %fmul = fmul <2 x float> poison, poison
+    %fadd = fadd <2 x float> %fmul, poison
     %extractelement = extractelement <2 x float> %fadd, i64 1
     %tmp96 = fsub float %extractelement, %tmp95
     %tmp97 = getelementptr inbounds %struct.wombat, ptr addrspace(5) %tmp5, i32 0, i32 8, i32 1

