[llvm] [AMDGPU] Sink uniform buffer address offsets into soffset (PR #169230)

[Matt Arsenault via llvm-commits]

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@@ -2046,6 +2056,75 @@ bool AMDGPUCodeGenPrepareImpl::visitSqrt(IntrinsicInst &Sqrt) {
   return true;
 }
 
+/// Sink uniform addends in buffer address calculations into soffset.
+///
+/// Transforms buffer loads/stores with voffset = add(uniform, divergent)
+/// into voffset = divergent, soffset = uniform for better address coalescing
+/// Only applies to raw buffer operations with soffset initially zero.
+bool AMDGPUCodeGenPrepareImpl::visitBufferIntrinsic(IntrinsicInst &I) {
+  Intrinsic::ID IID = I.getIntrinsicID();
+  bool IsLoad = (IID == Intrinsic::amdgcn_raw_buffer_load ||
+                 IID == Intrinsic::amdgcn_raw_buffer_load_format ||
+                 IID == Intrinsic::amdgcn_raw_ptr_buffer_load ||
+                 IID == Intrinsic::amdgcn_raw_ptr_buffer_load_format);
+  bool IsStore = (IID == Intrinsic::amdgcn_raw_buffer_store ||
+                  IID == Intrinsic::amdgcn_raw_buffer_store_format ||
+                  IID == Intrinsic::amdgcn_raw_ptr_buffer_store ||
+                  IID == Intrinsic::amdgcn_raw_ptr_buffer_store_format);
+
+  if (!IsLoad && !IsStore)
+    return false;
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arsenm wrote:

```suggestion
```

This is unreachable

https://github.com/llvm/llvm-project/pull/169230