[llvm] [AMDGPU] Support merging 16-bit TBUFFER load/store instruction (PR #145078)

[Harrison Hao via llvm-commits]

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@@ -1040,32 +1040,58 @@ bool SILoadStoreOptimizer::offsetsCanBeCombined(CombineInfo &CI,
   if (CI.Offset == Paired.Offset)
     return false;
 
+  // Use 2-byte element size if both tbuffer formats are 16-bit.
+  unsigned EltSize = CI.EltSize;
+  auto Has16BitComponents = [&](unsigned Format) -> bool {
+    const auto *Info = AMDGPU::getGcnBufferFormatInfo(Format, STI);
+    return Info && Info->BitsPerComp == 16;
+  };
+
+  if ((CI.InstClass == TBUFFER_LOAD || CI.InstClass == TBUFFER_STORE)) {
+    // TODO: Support merging 8-bit tbuffer load/store instructions
+    if (Has16BitComponents(CI.Format) && Has16BitComponents(Paired.Format))
+      EltSize = 2;
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harrisonGPU wrote:

Thanks , I have already set `EltSize` in setMI.

https://github.com/llvm/llvm-project/pull/145078