[RISCV][AsmParser] Fix parsing of the components of the vtype immediate of vsetvli

[rogfer01]

Summary

This was discovered due to a typo in an assembly file when using an assertion-enabled build.

We are getting the tokens as "identifiers". This triggers an assertion failure when the token is not a proper identifier (e.g an integer literal) and also has the side-effect that we were accepting quoted syntax.

[StephenFan]

Thanks for fixing it! @rogfer01

llvm/test/MC/RISCV/rvv/invalid.s

81

This error message seems a little bad. Would you mind improving the error message? Since improving this error message may cause other cases' error messages badly, doing this may require trade-offs in many cases.
IMO, we can report specific errors and return MatchOperand_ParseFail when the operand must be a VTypeI operand (Maybe if the operand can get 7 tokens or other judge condition, then it must a vtypeI) and we get into trouble in parsing VTypeI's elements.

[rogfer01]

llvm/test/MC/RISCV/rvv/invalid.s

81

Sure. I also noticed the diagnostic always points at the beginning of the whole operand.

I will check that the operand parser routine is not speculatively executed and see if we can be more precise in the diagnostic.

[craig.topper]

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

1724

Should we have been checking that they were identifiers up here?

[craig.topper]

I think this patch is obsolete now.

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

 OperandMatchResultTy RISCVAsmParser::parseVTypeI(OperandVector &Operands) {
   SMLoc S = getLoc();
   if (getLexer().isNot(AsmToken::Identifier))
     return MatchOperand_NoMatch;
 
   SmallVector<AsmToken, 7> VTypeIElements;
   // Put all the tokens for vtypei operand into VTypeIElements vector.
   while (getLexer().isNot(AsmToken::EndOfStatement)) {
     VTypeIElements.push_back(getLexer().getTok());
     getLexer().Lex();
     if (getLexer().is(AsmToken::EndOfStatement))
       break;
     if (getLexer().isNot(AsmToken::Comma))
       goto MatchFail;
     AsmToken Comma = getLexer().getTok();
     VTypeIElements.push_back(Comma);
     getLexer().Lex();
   }
 
   if (VTypeIElements.size() == 7) {
     // The VTypeIElements layout is:
     // SEW comma LMUL comma TA comma MA
     //  0    1    2     3    4   5    6
-    StringRef Name = VTypeIElements[0].getIdentifier();
+    StringRef Name = VTypeIElements[0].getString();
     if (!Name.consume_front("e"))
       goto MatchFail;
     unsigned Sew;
     if (Name.getAsInteger(10, Sew))
       goto MatchFail;
     if (!RISCVVType::isValidSEW(Sew))
       goto MatchFail;
 
-    Name = VTypeIElements[2].getIdentifier();
+    Name = VTypeIElements[2].getString();
     if (!Name.consume_front("m"))
       goto MatchFail;
     // "m" or "mf"
     bool Fractional = Name.consume_front("f");
     unsigned Lmul;
     if (Name.getAsInteger(10, Lmul))
       goto MatchFail;
     if (!RISCVVType::isValidLMUL(Lmul, Fractional))
       goto MatchFail;
 
     // ta or tu
-    Name = VTypeIElements[4].getIdentifier();
+    Name = VTypeIElements[4].getString();
     bool TailAgnostic;
     if (Name == "ta")
       TailAgnostic = true;
     else if (Name == "tu")
       TailAgnostic = false;
     else
       goto MatchFail;
 
     // ma or mu
-    Name = VTypeIElements[6].getIdentifier();
+    Name = VTypeIElements[6].getString();
     bool MaskAgnostic;
     if (Name == "ma")
       MaskAgnostic = true;
     else if (Name == "mu")
       MaskAgnostic = false;
     else
       goto MatchFail;
 

llvm/test/MC/RISCV/rvv/invalid.s

 # CHECK-ERROR: operand must be e[8|16|32|64|128|256|512|1024],m[1|2|4|8|f2|f4|f8],[ta|tu],[ma|mu]
 
 vsetvli a2, a0, e8,m1
 # CHECK-ERROR: operand must be e[8|16|32|64|128|256|512|1024],m[1|2|4|8|f2|f4|f8],[ta|tu],[ma|mu]
 
 vsetvli a2, a0, e8,m1,ta
 # CHECK-ERROR: operand must be e[8|16|32|64|128|256|512|1024],m[1|2|4|8|f2|f4|f8],[ta|tu],[ma|mu]
 
+vsetvli zero, zero, 1, m1, ta, mu
+# CHECK-ERROR: error: invalid operand for instruction
+
+vsetvli zero, zero, e32, 2, ta, mu
+# CHECK-ERROR: operand must be e[8|16|32|64|128|256|512|1024],m[1|2|4|8|f2|f4|f8],[ta|tu],[ma|mu]
+
+vsetvli zero, zero, e32, m1, 3, mu
+# CHECK-ERROR: operand must be e[8|16|32|64|128|256|512|1024],m[1|2|4|8|f2|f4|f8],[ta|tu],[ma|mu]
+
+vsetvli zero, zero, e32, m1, ta, 4
+# CHECK-ERROR: operand must be e[8|16|32|64|128|256|512|1024],m[1|2|4|8|f2|f4|f8],[ta|tu],[ma|mu]
+
+vsetvli zero, zero, "e32", m1, ta, mu
+# CHECK-ERROR: operand must be e[8|16|32|64|128|256|512|1024],m[1|2|4|8|f2|f4|f8],[ta|tu],[ma|mu]
+
+vsetvli zero, zero, e32, "m1", ta, mu
+# CHECK-ERROR: operand must be e[8|16|32|64|128|256|512|1024],m[1|2|4|8|f2|f4|f8],[ta|tu],[ma|mu]
+
 vadd.vv v1, v3, v2, v4.t
 # CHECK-ERROR: operand must be v0.t
 
 vadd.vv v1, v3, v2, v0
 # CHECK-ERROR: expected '.t' suffix
 
 vadd.vv v1, v3, a0
 # CHECK-ERROR: invalid operand for instruction