[RISCV] TableGen-erate RISC-V SDNodes (#138381)

This commit moves RISC-V to auto-generate its target-specific SDNode
types. The biggest change is that SDNodes can now be validated against
their expected type profiles, and that we don't need to edit several
different files when declaring a new one.

This takes Sergei's work in #119709 and "finishes" it - by moving the
final five RISCVISD opcodes into tablegen (including defining their
types), and by ensuring the tablegen has expected closing scope
comments.

Co-authored-by: Sergei Barannikov <barannikov88@gmail.com>

Author: lenary

llvm/include/llvm/CodeGen/SDNodeInfo.h

@@ -55,12 +55,14 @@ struct SDTypeConstraint {
   MVT::SimpleValueType VT;
 };
 
+using SDNodeTSFlags = uint32_t;
+
 struct SDNodeDesc {
   uint16_t NumResults;
   int16_t NumOperands;
   uint32_t Properties;
   uint32_t Flags;
-  uint32_t TSFlags;
+  SDNodeTSFlags TSFlags;
   unsigned NameOffset;
   unsigned ConstraintOffset;
   unsigned ConstraintCount;

llvm/lib/Target/RISCV/CMakeLists.txt

@@ -16,6 +16,7 @@ tablegen(LLVM RISCVGenRegisterInfo.inc -gen-register-info)
 tablegen(LLVM RISCVGenSearchableTables.inc -gen-searchable-tables)
 tablegen(LLVM RISCVGenSubtargetInfo.inc -gen-subtarget)
 tablegen(LLVM RISCVGenExegesis.inc -gen-exegesis)
+tablegen(LLVM RISCVGenSDNodeInfo.inc -gen-sd-node-info)
 
 set(LLVM_TARGET_DEFINITIONS RISCVGISel.td)
 tablegen(LLVM RISCVGenGlobalISel.inc -gen-global-isel)

llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp

@@ -16,6 +16,7 @@
 #include "MCTargetDesc/RISCVMatInt.h"
 #include "RISCVISelLowering.h"
 #include "RISCVInstrInfo.h"
+#include "RISCVSelectionDAGInfo.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/IR/IntrinsicsRISCV.h"
 #include "llvm/Support/Alignment.h"
@@ -34,6 +35,9 @@ static cl::opt<bool> UsePseudoMovImm(
              "constant materialization"),
     cl::init(false));
 
+#define GET_DAGISEL_BODY RISCVDAGToDAGISel
+#include "RISCVGenDAGISel.inc"
+
 void RISCVDAGToDAGISel::PreprocessISelDAG() {
   SelectionDAG::allnodes_iterator Position = CurDAG->allnodes_end();
 

llvm/lib/Target/RISCV/RISCVISelDAGToDAG.h

@@ -191,6 +191,7 @@ class RISCVDAGToDAGISel : public SelectionDAGISel {
   }
 
 // Include the pieces autogenerated from the target description.
+#define GET_DAGISEL_DECL
 #include "RISCVGenDAGISel.inc"
 
 private: