Imported Upstream version 6.0.0.172

Former-commit-id: f3cc9b82f3e5bd8f0fd3ebc098f789556b44e9cd

external/llvm/utils/TableGen/X86DisassemblerShared.h

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+//===- X86DisassemblerShared.h - Emitter shared header ----------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_UTILS_TABLEGEN_X86DISASSEMBLERSHARED_H
+#define LLVM_UTILS_TABLEGEN_X86DISASSEMBLERSHARED_H
+
+#include <cstring>
+#include <string>
+
+#include "../../lib/Target/X86/Disassembler/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];
+};
+
+#endif