[RISCV][NFC] Move Zawrs/Zacas implementation to RISCVInstrInfoZa.td (#76940)

To keep the structure of TableGen files clear.

The definitions are simplified by the way.

Author: wangpc-pp

llvm/lib/Target/RISCV/RISCVInstrInfo.td

@@ -729,22 +729,6 @@ def UNIMP : RVInstI<0b001, OPC_SYSTEM, (outs), (ins), "unimp", "">,
   let imm12 = 0b110000000000;
 }
 
-let Predicates = [HasStdExtZawrs] in {
-def WRS_NTO : RVInstI<0b000, OPC_SYSTEM, (outs), (ins), "wrs.nto", "">,
-              Sched<[]> {
-  let rs1 = 0;
-  let rd = 0;
-  let imm12 = 0b000000001101;
-}
-
-def WRS_STO : RVInstI<0b000, OPC_SYSTEM, (outs), (ins), "wrs.sto", "">,
-              Sched<[]> {
-  let rs1 = 0;
-  let rd = 0;
-  let imm12 = 0b000000011101;
-}
-} // Predicates = [HasStdExtZawrs]
-
 } // hasSideEffects = 1, mayLoad = 0, mayStore = 0
 
 def CSRRW : CSR_ir<0b001, "csrrw">;
@@ -2095,6 +2079,7 @@ include "RISCVInstrInfoM.td"
 
 // Atomic
 include "RISCVInstrInfoA.td"
+include "RISCVInstrInfoZa.td"
 
 // Scalar FP
 include "RISCVInstrInfoF.td"

llvm/lib/Target/RISCV/RISCVInstrInfoA.td

@@ -7,8 +7,7 @@
 //===----------------------------------------------------------------------===//
 //
 // This file describes the RISC-V instructions from the standard 'A', Atomic
-// Instructions extension as well as the experimental 'Zacas' (Atomic
-// Compare-and-Swap) extension.
+// Instructions extension.
 //
 //===----------------------------------------------------------------------===//
 
@@ -96,15 +95,6 @@ defm AMOMAXU_D  : AMO_rr_aq_rl<0b11100, 0b011, "amomaxu.d">,
                   Sched<[WriteAtomicD, ReadAtomicDA, ReadAtomicDD]>;
 } // Predicates = [HasStdExtA, IsRV64]
 
-let Predicates = [HasStdExtZacas] in {
-defm AMOCAS_W : AMO_rr_aq_rl<0b00101, 0b010, "amocas.w">;
-defm AMOCAS_D : AMO_rr_aq_rl<0b00101, 0b011, "amocas.d">;
-} // Predicates = [HasStdExtZacas]
-
-let Predicates = [HasStdExtZacas, IsRV64] in {
-defm AMOCAS_Q : AMO_rr_aq_rl<0b00101, 0b100, "amocas.q">;
-} // Predicates = [HasStdExtZacas, IsRV64]
-
 //===----------------------------------------------------------------------===//
 // Pseudo-instructions and codegen patterns
 //===----------------------------------------------------------------------===//

llvm/lib/Target/RISCV/RISCVInstrInfoZa.td

@@ -0,0 +1,44 @@
+//===-- RISCVInstrInfoZa.td - RISC-V Atomic instructions ---*- tablegen -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file describes the RISC-V instructions from the standard atomic 'Za*'
+// extensions:
+//   - Zawrs (v1.0) : Wait-on-Reservation-Set.
+//   - Zacas (v1.0-rc1) : Atomic Compare-and-Swap.
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+// Zacas (Atomic Compare-and-Swap)
+//===----------------------------------------------------------------------===//
+
+let Predicates = [HasStdExtZacas] in {
+defm AMOCAS_W : AMO_rr_aq_rl<0b00101, 0b010, "amocas.w">;
+defm AMOCAS_D : AMO_rr_aq_rl<0b00101, 0b011, "amocas.d">;
+} // Predicates = [HasStdExtZacas]
+
+let Predicates = [HasStdExtZacas, IsRV64] in {
+defm AMOCAS_Q : AMO_rr_aq_rl<0b00101, 0b100, "amocas.q">;
+} // Predicates = [HasStdExtZacas, IsRV64]
+
+//===----------------------------------------------------------------------===//
+// Zawrs (Wait-on-Reservation-Set)
+//===----------------------------------------------------------------------===//
+
+let hasSideEffects = 1, mayLoad = 0, mayStore = 0 in
+class WRSInst<bits<12> funct12, string opcodestr>
+    : RVInstI<0b000, OPC_SYSTEM, (outs), (ins), opcodestr, ""> {
+  let rs1 = 0;
+  let rd = 0;
+  let imm12 = funct12;
+}
+
+let Predicates = [HasStdExtZawrs] in {
+def WRS_NTO : WRSInst<0b000000001101, "wrs.nto">, Sched<[]>;
+def WRS_STO : WRSInst<0b000000011101, "wrs.sto">, Sched<[]>;
+} // Predicates = [HasStdExtZawrs]