[llvm] [CodeGen] Add MachineRegisterClassInfo analysis pass (PR #120690)

[Jay Foad via llvm-commits]

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@@ -42,7 +43,7 @@ class SIPreAllocateWWMRegs {
   LiveIntervals *LIS;
   LiveRegMatrix *Matrix;
   VirtRegMap *VRM;
-  RegisterClassInfo RegClassInfo;
+  RegisterClassInfo *RegClassInfo;
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jayfoad wrote:

It's not strictly necessary but it's nicer because `RegClassInfo` is always available when this class is constructed, so it can never be nullptr. It also avoids touching some lines just to replace`.` with `->`.

https://github.com/llvm/llvm-project/pull/120690