[llvm] [AMDGPU] Emit b32 movs if (a)v_mov_b64_pseudo dest vgprs are misaligned (PR #160547)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,33 @@
+# RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx942 -start-after=si-load-store-opt %s -o - | FileCheck %s
+
+# CHECK: misaligned_regsequence:
+# CHECK: ; %bb.0:
+# CHECK:         s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+# CHECK:         s_load_dwordx2 s[0:1], s[4:5], 0x0
+# CHECK:         v_mov_b32_e32 v5, 0
+# CHECK:         v_mov_b32_e32 v4, 0
+# CHECK:         v_mov_b32_e32 v6, 0
+# CHECK:         s_waitcnt lgkmcnt(0)
+# CHECK:         v_mov_b64_e32 v[2:3], s[0:1]
+# CHECK:         flat_store_dwordx3 v[2:3], v[4:6]
+# CHECK:         s_endpgm
+
+--- |
+  define void @misaligned_regsequence() { ret void }
+...
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arsenm wrote:

```suggestion
```

https://github.com/llvm/llvm-project/pull/160547