[llvm] [CodeGen] Use LocationSize for MMO getSize (PR #84751)

[Matt Arsenault via llvm-commits]

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@@ -1046,9 +1055,16 @@ class LLVM_EXTERNAL_VISIBILITY MachineFunction {
   MachineMemOperand *getMachineMemOperand(const MachineMemOperand *MMO,
                                           int64_t Offset, LLT Ty);
   MachineMemOperand *getMachineMemOperand(const MachineMemOperand *MMO,
-                                          int64_t Offset, uint64_t Size) {
+                                          int64_t Offset, LocationSize Size) {
     return getMachineMemOperand(
-        MMO, Offset, Size == ~UINT64_C(0) ? LLT() : LLT::scalar(8 * Size));
+        MMO, Offset,
+        !Size.hasValue() || Size.isScalable()
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arsenm wrote:

Can this just assert Size.hasValue()? I would assume if you have the unknown case you would have been using the LLT constructor in the first place 

https://github.com/llvm/llvm-project/pull/84751