From b8cfc0525e082d74870e6e6221f16244322e488a Mon Sep 17 00:00:00 2001
From: Blaise Tine <tinebp@hotmail.com>
Date: Thu, 23 Sep 2021 03:56:36 -0400
Subject: [PATCH] minor update

---
 simX/decode.cpp | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/simX/decode.cpp b/simX/decode.cpp
index ad111846..11b8e92d 100644
--- a/simX/decode.cpp
+++ b/simX/decode.cpp
@@ -294,7 +294,13 @@ std::shared_ptr<Instr> Decoder::decode(Word code) {
   int rs2 = (code >> shift_rs2_) & reg_mask_;
   int rs3 = (code >> shift_rs3_) & reg_mask_;
 
-  auto iType = sc_instTable.at(op).iType;
+  auto op_it = sc_instTable.find(op);
+  if (op_it == sc_instTable.end()) {
+    std::cout << std::hex << "invalid opcode: 0x" << op << ", instruction=0x" << code << std::endl;
+    std::abort();
+  }
+
+  auto iType = op_it->second.iType;
   if (op == Opcode::FL || op == Opcode::FS) { 
     if (func3 != 0x2) {
       iType = InstType::V_TYPE;