[RISCV][NFC] Factor out matchRegisterNameHelper in RISCVAsmParser.cpp

Contains common logic to match a string to a register name.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356330 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp b/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp
index 99ad876..4202d5b 100644 (file)
--- a/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp
+++ b/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp
@@ -908,6 +908,16 @@ bool RISCVAsmParser::MatchAndEmitInstruction(SMLoc IDLoc, unsigned &Opcode,
   llvm_unreachable("Unknown match type detected!");
 }
 
+// Attempts to match Name as a register (either using the default name or
+// alternative ABI names), setting RegNo to the matching register. Upon
+// failure, returns true and sets RegNo to 0.
+static bool matchRegisterNameHelper(unsigned &RegNo, StringRef Name) {
+  RegNo = MatchRegisterName(Name);
+  if (RegNo == 0)
+    RegNo = MatchRegisterAltName(Name);
+  return RegNo == 0;
+}
+
 bool RISCVAsmParser::ParseRegister(unsigned &RegNo, SMLoc &StartLoc,
                                    SMLoc &EndLoc) {
   const AsmToken &Tok = getParser().getTok();
@@ -916,10 +926,7 @@ bool RISCVAsmParser::ParseRegister(unsigned &RegNo, SMLoc &StartLoc,
   RegNo = 0;
   StringRef Name = getLexer().getTok().getIdentifier();
 
-  RegNo = MatchRegisterName(Name);
-  if (RegNo == 0)
-    RegNo = MatchRegisterAltName(Name);
-  if (RegNo == 0)
+  if (matchRegisterNameHelper(RegNo, Name))
     return Error(StartLoc, "invalid register name");
 
   getParser().Lex(); // Eat identifier token.
@@ -946,14 +953,13 @@ OperandMatchResultTy RISCVAsmParser::parseRegister(OperandVector &Operands,
     return MatchOperand_NoMatch;
   case AsmToken::Identifier:
     StringRef Name = getLexer().getTok().getIdentifier();
-    unsigned RegNo = MatchRegisterName(Name);
+    unsigned RegNo;
+    matchRegisterNameHelper(RegNo, Name);
+
     if (RegNo == 0) {
-      RegNo = MatchRegisterAltName(Name);
-      if (RegNo == 0) {
-        if (HadParens)
-          getLexer().UnLex(Buf[0]);
-        return MatchOperand_NoMatch;
-      }
+      if (HadParens)
+        getLexer().UnLex(Buf[0]);
+      return MatchOperand_NoMatch;
     }
     if (HadParens)
       Operands.push_back(RISCVOperand::createToken("(", FirstS, isRV64()));