[RISCV] Only disassemble fcvtmod.w.d if the rounding mode is rtz. (#1…

…11308) If we disassemble other rounding modes, we'll print something that can't be parsed.
llvm · Oct 7, 2024 · 35f1966 · 35f1966
1 parent 8c15470
commit 35f1966
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Showing 2 changed files with 11 additions and 1 deletion.
diff --git a/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp b/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp
@@ -375,6 +375,16 @@ static DecodeStatus decodeFRMArg(MCInst &Inst, uint32_t Imm, int64_t Address,
   return MCDisassembler::Success;
 }
 
+static DecodeStatus decodeRTZArg(MCInst &Inst, uint32_t Imm, int64_t Address,
+                                 const MCDisassembler *Decoder) {
+  assert(isUInt<3>(Imm) && "Invalid immediate");
+  if (Imm != RISCVFPRndMode::RTZ)
+    return MCDisassembler::Fail;
+
+  Inst.addOperand(MCOperand::createImm(Imm));
+  return MCDisassembler::Success;
+}
+
 static DecodeStatus decodeRVCInstrRdRs1ImmZero(MCInst &Inst, uint32_t Insn,
                                                uint64_t Address,
                                                const MCDisassembler *Decoder);

diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfoZfa.td b/llvm/lib/Target/RISCV/RISCVInstrInfoZfa.td
@@ -47,7 +47,7 @@ def RTZArg : AsmOperandClass {
 def rtzarg : Operand<XLenVT> {
   let ParserMatchClass = RTZArg;
   let PrintMethod = "printFRMArg";
-  let DecoderMethod = "decodeFRMArg";
+  let DecoderMethod = "decodeRTZArg";
 }
 
 //===----------------------------------------------------------------------===//