[clang] [llvm] [RISCV] Add MC layer support for XSfmm*. (PR #133031)

[Craig Topper via cfe-commits]

================
@@ -2331,6 +2337,65 @@ bool RISCVAsmParser::generateVTypeError(SMLoc ErrorLoc) {
       "e[8|16|32|64],m[1|2|4|8|f2|f4|f8],[ta|tu],[ma|mu]");
 }
 
+ParseStatus RISCVAsmParser::parseXSfmmVType(OperandVector &Operands) {
+  SMLoc S = getLoc();
+
+  unsigned Widen = 0;
+  unsigned SEW = 0;
+  bool AltFmt = false;
+  StringRef Identifier;
+
+  if (getTok().isNot(AsmToken::Identifier))
+    goto Fail;
+
+  Identifier = getTok().getIdentifier();
+
+  if (!Identifier.consume_front("e"))
+    goto Fail;
+
+  if (Identifier.getAsInteger(10, SEW)) {
+    if (Identifier != "16alt")
+      goto Fail;
+
+    AltFmt = true;
+    SEW = 16;
+  }
+  if (!RISCVVType::isValidSEW(SEW))
+    goto Fail;
+
+  Lex();
+
+  if (!parseOptionalToken(AsmToken::Comma))
+    goto Fail;
+
+  if (getTok().isNot(AsmToken::Identifier))
+    goto Fail;
+
+  Identifier = getTok().getIdentifier();
+
+  if (!Identifier.consume_front("w"))
+    goto Fail;
+  if (Identifier.getAsInteger(10, Widen))
+    goto Fail;
+  if (Widen != 1 && Widen != 2 && Widen != 4)
+    goto Fail;
+
+  Lex();
+
+  if (getLexer().is(AsmToken::EndOfStatement)) {
----------------
topperc wrote:

I believe this check was trying to make sure there aren't additional operands left for this instruction. We're parsing multiple comma separated identifiers here as a single custom operand. Looks like we are missing a test for that.

https://github.com/llvm/llvm-project/pull/133031