[llvm] [AIX][TLS] Optimize the small local-exec access sequence for non-zero offsets (PR #71485)

[via llvm-commits]

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@@ -7734,7 +7828,19 @@ void PPCDAGToDAGISel::PeepholePPC64() {
         ImmOpnd = CurDAG->getTargetConstant(Offset, SDLoc(ImmOpnd),
                                             ImmOpnd.getValueType());
       } else if (Offset != 0) {
-        continue;
+        // This optimization is performed for non-TOC-based local-exec accesses.
+        if (HasAIXSmallLocalExecTLS &&
+            isEligibleToFoldADDIForLocalExecAccesses(CurDAG, Base)) {
+          // Add the non-zero offset information into the load or store
+          // instruction to be used for non-TOC-based local-exec accesses.
+          GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(ImmOpnd);
+          if (!GA)
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diggerlin wrote:

nit: change to assert here ?  since you have 
```
if (!GA)
  return false;
```
  
  in `isEligibleToFoldADDIForLocalExecAccesses`

https://github.com/llvm/llvm-project/pull/71485