[llvm] [SelectionDAG] Virtualize isTargetStrictFPOpcode / isTargetMemoryOpcode (PR #119969)

[Matt Arsenault via llvm-commits]

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@@ -688,22 +687,6 @@ END_TWO_BYTE_PACK()
   /// \<target\>ISD namespace).
   bool isTargetOpcode() const { return NodeType >= ISD::BUILTIN_OP_END; }
 
-  /// Test if this node has a target-specific opcode that may raise
-  /// FP exceptions (in the \<target\>ISD namespace and greater than
-  /// FIRST_TARGET_STRICTFP_OPCODE).  Note that all target memory
-  /// opcode are currently automatically considered to possibly raise
-  /// FP exceptions as well.
-  bool isTargetStrictFPOpcode() const {
-    return NodeType >= ISD::FIRST_TARGET_STRICTFP_OPCODE;
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arsenm wrote:

> Not all memory opcodes will be generated, because some targets do not provide a tablegen description for all memory nodes. 

This sounds more like a bug. Your RFC sold not requiring targets to use this as a feature, but I'd consider it a defect. It would be better if targets were required to generate this kind of information from tablegen 

https://github.com/llvm/llvm-project/pull/119969