[llvm] [CGP][AArch64] Rebase the common base offset for better ISel (PR #74046)

[David Green via llvm-commits]

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@@ -2721,6 +2721,12 @@ class TargetLoweringBase {
                                      Type *Ty, unsigned AddrSpace,
                                      Instruction *I = nullptr) const;
 
+  /// Return the perfered common base offset.
+  virtual int64_t getPreferBaseOffset(int64_t MinOffset,
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davemgreen wrote:

Maybe call this something like getPreferredLargeGEPBaseOffset?

https://github.com/llvm/llvm-project/pull/74046