1 files changed, 57 insertions, 0 deletions
diff --git a/llvm/utils/TableGen/X86DisassemblerShared.h b/llvm/utils/TableGen/X86DisassemblerShared.h
new file mode 100644
index 000000000000..093f220fda5e
--- /dev/null
+++ b/llvm/utils/TableGen/X86DisassemblerShared.h
@@ -0,0 +1,57 @@
+//===- X86DisassemblerShared.h - Emitter shared header ----------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_UTILS_TABLEGEN_X86DISASSEMBLERSHARED_H
+#define LLVM_UTILS_TABLEGEN_X86DISASSEMBLERSHARED_H
+
+#include <cstring>
+#include <string>
+
+#include "llvm/Support/X86DisassemblerDecoderCommon.h"
+
+struct InstructionSpecifier {
+  llvm::X86Disassembler::OperandSpecifier
+      operands[llvm::X86Disassembler::X86_MAX_OPERANDS];
+  llvm::X86Disassembler::InstructionContext insnContext;
+  std::string name;
+
+  InstructionSpecifier() {
+    insnContext = llvm::X86Disassembler::IC;
+    name = "";
+    memset(operands, 0, sizeof(operands));
+  }
+};
+
+/// Specifies whether a ModR/M byte is needed and (if so) which
+/// instruction each possible value of the ModR/M byte corresponds to. Once
+/// this information is known, we have narrowed down to a single instruction.
+struct ModRMDecision {
+  uint8_t modrm_type;
+  llvm::X86Disassembler::InstrUID instructionIDs[256];
+};
+
+/// Specifies which set of ModR/M->instruction tables to look at
+/// given a particular opcode.
+struct OpcodeDecision {
+  ModRMDecision modRMDecisions[256];
+};
+
+/// Specifies which opcode->instruction tables to look at given
+/// a particular context (set of attributes).  Since there are many possible
+/// contexts, the decoder first uses CONTEXTS_SYM to determine which context
+/// applies given a specific set of attributes.  Hence there are only IC_max
+/// entries in this table, rather than 2^(ATTR_max).
+struct ContextDecision {
+  OpcodeDecision opcodeDecisions[llvm::X86Disassembler::IC_max];
+
+  ContextDecision() {
+    memset(opcodeDecisions, 0, sizeof(opcodeDecisions));
+  }
+};
+
+#endif