[RISCV] Reverse the order of Base and Offset in Core-V RegReg operand. (#133209)

This puts the base before the offset to match the order we use for base
ISA where the offset is an immediate.

I'm investigating using sub-operands for the base ISA loads and stores
too so having a consistent operand order will allow more sharing.

Author: topperc

llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp

@@ -2768,9 +2768,9 @@ ParseStatus RISCVAsmParser::parseRegReg(OperandVector &Operands) {
   if (getLexer().getKind() != AsmToken::Identifier)
     return ParseStatus::NoMatch;
 
-  StringRef RegName = getLexer().getTok().getIdentifier();
-  MCRegister Reg = matchRegisterNameHelper(RegName);
-  if (!Reg)
+  StringRef OffsetRegName = getLexer().getTok().getIdentifier();
+  MCRegister OffsetReg = matchRegisterNameHelper(OffsetRegName);
+  if (!OffsetReg)
     return Error(getLoc(), "invalid register");
   getLexer().Lex();
 
@@ -2780,16 +2780,16 @@ ParseStatus RISCVAsmParser::parseRegReg(OperandVector &Operands) {
   if (getLexer().getKind() != AsmToken::Identifier)
     return Error(getLoc(), "expected register");
 
-  StringRef Reg2Name = getLexer().getTok().getIdentifier();
-  MCRegister Reg2 = matchRegisterNameHelper(Reg2Name);
-  if (!Reg2)
+  StringRef BaseRegName = getLexer().getTok().getIdentifier();
+  MCRegister BaseReg = matchRegisterNameHelper(BaseRegName);
+  if (!BaseReg)
     return Error(getLoc(), "invalid register");
   getLexer().Lex();
 
   if (parseToken(AsmToken::RParen, "expected ')'"))
     return ParseStatus::Failure;
 
-  Operands.push_back(RISCVOperand::createRegReg(Reg, Reg2, getLoc()));
+  Operands.push_back(RISCVOperand::createRegReg(BaseReg, OffsetReg, getLoc()));
 
   return ParseStatus::Success;
 }

llvm/lib/Target/RISCV/MCTargetDesc/RISCVInstPrinter.cpp

@@ -262,15 +262,15 @@ void RISCVInstPrinter::printRlist(const MCInst *MI, unsigned OpNo,
 
 void RISCVInstPrinter::printRegReg(const MCInst *MI, unsigned OpNo,
                                    const MCSubtargetInfo &STI, raw_ostream &O) {
-  const MCOperand &MO = MI->getOperand(OpNo);
+  const MCOperand &OffsetMO = MI->getOperand(OpNo + 1);
 
-  assert(MO.isReg() && "printRegReg can only print register operands");
-  printRegName(O, MO.getReg());
+  assert(OffsetMO.isReg() && "printRegReg can only print register operands");
+  printRegName(O, OffsetMO.getReg());
 
   O << "(";
-  const MCOperand &MO1 = MI->getOperand(OpNo + 1);
-  assert(MO1.isReg() && "printRegReg can only print register operands");
-  printRegName(O, MO1.getReg());
+  const MCOperand &BaseMO = MI->getOperand(OpNo);
+  assert(BaseMO.isReg() && "printRegReg can only print register operands");
+  printRegName(O, BaseMO.getReg());
   O << ")";
 }
 

llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp

@@ -2853,8 +2853,8 @@ bool RISCVDAGToDAGISel::SelectAddrRegReg(SDValue Addr, SDValue &Base,
   if (isa<ConstantSDNode>(Addr.getOperand(1)))
     return false;
 
-  Base = Addr.getOperand(1);
-  Offset = Addr.getOperand(0);
+  Base = Addr.getOperand(0);
+  Offset = Addr.getOperand(1);
   return true;
 }
 

llvm/lib/Target/RISCV/RISCVInstrInfoXCV.td

@@ -25,7 +25,7 @@ def CVrr : Operand<i32>,
            ComplexPattern<i32, 2, "SelectAddrRegReg",[]> {
    let ParserMatchClass = CVrrAsmOperand;
    let PrintMethod = "printRegReg";
-   let MIOperandInfo = (ops GPR:$offset, GPR:$base);
+   let MIOperandInfo = (ops GPR:$base, GPR:$offset);
 }
 
 def cv_tuimm2 : TImmLeaf<XLenVT, [{return isUInt<2>(Imm);}]>;
@@ -287,7 +287,7 @@ class CVLoad_rr_inc<bits<7> funct7, bits<3> funct3, string opcodestr>
 
 class CVLoad_rr<bits<7> funct7, bits<3> funct3, string opcodestr>
     : RVInstR<funct7, funct3, OPC_CUSTOM_1, (outs GPR:$rd),
-              (ins (CVrr $rs2, $rs1):$addr),
+              (ins (CVrr $rs1, $rs2):$addr),
               opcodestr, "$rd, $addr">;
 } // hasSideEffects = 0, mayLoad = 1, mayStore = 0
 
@@ -317,7 +317,7 @@ class CVStore_rr_inc<bits<3> funct3, bits<7> funct7, string opcodestr>
 
 
 class CVStore_rr<bits<3> funct3, bits<7> funct7, string opcodestr>
-    : RVInst<(outs), (ins GPR:$rs2, (CVrr $rs3, $rs1):$addr), opcodestr,
+    : RVInst<(outs), (ins GPR:$rs2, (CVrr $rs1, $rs3):$addr), opcodestr,
              "$rs2, $addr", [], InstFormatOther> {
   bits<5> rs1;
   bits<5> rs2;