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	Made LEA memory operands emit only 4 MCInst operands. Made the scale operand equal 1 for instructions that have no SIB byte. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91919 91177308-0d34-0410-b5e6-96231b3b80d8
		
			
				
	
	
		
			477 lines
		
	
	
		
			15 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			477 lines
		
	
	
		
			15 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| //===- X86Disassembler.cpp - Disassembler for x86 and x86_64 ----*- C++ -*-===//
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| //
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| //                     The LLVM Compiler Infrastructure
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| //
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| // This file is distributed under the University of Illinois Open Source
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| // License. See LICENSE.TXT for details.
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| //
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| //===----------------------------------------------------------------------===//
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| //
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| // This file is part of the X86 Disassembler.
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| // It contains code to translate the data produced by the decoder into
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| //  MCInsts.
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| // Documentation for the disassembler can be found in X86Disassembler.h.
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| //
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| //===----------------------------------------------------------------------===//
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| 
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| #include "X86Disassembler.h"
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| #include "X86DisassemblerDecoder.h"
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| 
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| #include "llvm/MC/MCDisassembler.h"
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| #include "llvm/MC/MCDisassembler.h"
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| #include "llvm/MC/MCInst.h"
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| #include "llvm/Target/TargetRegistry.h"
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| #include "llvm/Support/MemoryObject.h"
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| #include "llvm/Support/ErrorHandling.h"
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| #include "llvm/Support/raw_ostream.h"
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| 
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| #include "X86GenRegisterNames.inc"
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| 
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| using namespace llvm;
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| using namespace llvm::X86Disassembler;
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| 
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| namespace llvm {  
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|   
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| // Fill-ins to make the compiler happy.  These constants are never actually
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| //   assigned; they are just filler to make an automatically-generated switch
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| //   statement work.
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| namespace X86 {
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|   enum {
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|     BX_SI = 500,
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|     BX_DI = 501,
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|     BP_SI = 502,
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|     BP_DI = 503,
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|     sib   = 504,
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|     sib64 = 505
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|   };
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| }
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| 
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| extern Target TheX86_32Target, TheX86_64Target;
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| 
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| }
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| 
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| static void translateInstruction(MCInst &target,
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|                                  InternalInstruction &source);
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| 
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| X86GenericDisassembler::X86GenericDisassembler(DisassemblerMode mode) :
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|     MCDisassembler(),
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|     fMode(mode) {
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| }
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| 
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| X86GenericDisassembler::~X86GenericDisassembler() {
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| }
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| 
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| /// regionReader - a callback function that wraps the readByte method from
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| ///   MemoryObject.
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| ///
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| /// @param arg      - The generic callback parameter.  In this case, this should
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| ///                   be a pointer to a MemoryObject.
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| /// @param byte     - A pointer to the byte to be read.
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| /// @param address  - The address to be read.
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| static int regionReader(void* arg, uint8_t* byte, uint64_t address) {
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|   MemoryObject* region = static_cast<MemoryObject*>(arg);
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|   return region->readByte(address, byte);
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| }
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| 
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| /// logger - a callback function that wraps the operator<< method from
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| ///   raw_ostream.
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| ///
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| /// @param arg      - The generic callback parameter.  This should be a pointe
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| ///                   to a raw_ostream.
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| /// @param log      - A string to be logged.  logger() adds a newline.
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| static void logger(void* arg, const char* log) {
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|   if (!arg)
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|     return;
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|   
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|   raw_ostream &vStream = *(static_cast<raw_ostream*>(arg));
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|   vStream << log << "\n";
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| }  
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|   
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| //
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| // Public interface for the disassembler
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| //
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| 
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| bool X86GenericDisassembler::getInstruction(MCInst &instr,
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|                                             uint64_t &size,
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|                                             const MemoryObject ®ion,
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|                                             uint64_t address,
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|                                             raw_ostream &vStream) const {
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|   InternalInstruction internalInstr;
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|   
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|   int ret = decodeInstruction(&internalInstr,
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|                               regionReader,
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|                               (void*)®ion,
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|                               logger,
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|                               (void*)&vStream,
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|                               address,
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|                               fMode);
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| 
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|   if(ret) {
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|     size = internalInstr.readerCursor - address;
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|     return false;
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|   }
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|   else {
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|     size = internalInstr.length;
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|     translateInstruction(instr, internalInstr);
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|     return true;
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|   }
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| }
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| 
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| //
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| // Private code that translates from struct InternalInstructions to MCInsts.
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| //
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| 
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| /// translateRegister - Translates an internal register to the appropriate LLVM
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| ///   register, and appends it as an operand to an MCInst.
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| ///
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| /// @param mcInst     - The MCInst to append to.
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| /// @param reg        - The Reg to append.
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| static void translateRegister(MCInst &mcInst, Reg reg) {
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| #define ENTRY(x) X86::x,
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|   uint8_t llvmRegnums[] = {
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|     ALL_REGS
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|     0
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|   };
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| #undef ENTRY
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| 
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|   uint8_t llvmRegnum = llvmRegnums[reg];
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|   mcInst.addOperand(MCOperand::CreateReg(llvmRegnum));
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| }
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| 
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| /// translateImmediate  - Appends an immediate operand to an MCInst.
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| ///
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| /// @param mcInst       - The MCInst to append to.
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| /// @param immediate    - The immediate value to append.
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| static void translateImmediate(MCInst &mcInst, uint64_t immediate) {
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|   mcInst.addOperand(MCOperand::CreateImm(immediate));
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| }
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| 
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| /// translateRMRegister - Translates a register stored in the R/M field of the
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| ///   ModR/M byte to its LLVM equivalent and appends it to an MCInst.
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| /// @param mcInst       - The MCInst to append to.
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| /// @param insn         - The internal instruction to extract the R/M field
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| ///                       from.
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| static void translateRMRegister(MCInst &mcInst,
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|                                 InternalInstruction &insn) {
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|   assert(insn.eaBase != EA_BASE_sib && insn.eaBase != EA_BASE_sib64 && 
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|          "A R/M register operand may not have a SIB byte");
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|   
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|   switch (insn.eaBase) {
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|   case EA_BASE_NONE:
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|     llvm_unreachable("EA_BASE_NONE for ModR/M base");
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|     break;
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| #define ENTRY(x) case EA_BASE_##x:
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|   ALL_EA_BASES
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| #undef ENTRY
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|     llvm_unreachable("A R/M register operand may not have a base; "
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|                      "the operand must be a register.");
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|     break;
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| #define ENTRY(x)                                                        \
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|   case EA_REG_##x:                                                    \
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|     mcInst.addOperand(MCOperand::CreateReg(X86::x)); break;
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|   ALL_REGS
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| #undef ENTRY
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|   default:
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|     llvm_unreachable("Unexpected EA base register");
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|   }
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| }
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| 
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| /// translateRMMemory - Translates a memory operand stored in the Mod and R/M
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| ///   fields of an internal instruction (and possibly its SIB byte) to a memory
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| ///   operand in LLVM's format, and appends it to an MCInst.
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| ///
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| /// @param mcInst       - The MCInst to append to.
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| /// @param insn         - The instruction to extract Mod, R/M, and SIB fields
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| ///                       from.
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| /// @param sr           - Whether or not to emit the segment register.  The
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| ///                       LEA instruction does not expect a segment-register
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| ///                       operand.
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| static void translateRMMemory(MCInst &mcInst,
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|                               InternalInstruction &insn,
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|                               bool sr) {
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|   // Addresses in an MCInst are represented as five operands:
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|   //   1. basereg       (register)  The R/M base, or (if there is a SIB) the 
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|   //                                SIB base
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|   //   2. scaleamount   (immediate) 1, or (if there is a SIB) the specified 
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|   //                                scale amount
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|   //   3. indexreg      (register)  x86_registerNONE, or (if there is a SIB)
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|   //                                the index (which is multiplied by the 
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|   //                                scale amount)
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|   //   4. displacement  (immediate) 0, or the displacement if there is one
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|   //   5. segmentreg    (register)  x86_registerNONE for now, but could be set
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|   //                                if we have segment overrides
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|   
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|   MCOperand baseReg;
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|   MCOperand scaleAmount;
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|   MCOperand indexReg;
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|   MCOperand displacement;
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|   MCOperand segmentReg;
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|   
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|   if (insn.eaBase == EA_BASE_sib || insn.eaBase == EA_BASE_sib64) {
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|     if (insn.sibBase != SIB_BASE_NONE) {
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|       switch (insn.sibBase) {
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|       default:
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|         llvm_unreachable("Unexpected sibBase");
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| #define ENTRY(x)                                          \
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|       case SIB_BASE_##x:                                  \
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|         baseReg = MCOperand::CreateReg(X86::x); break;
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|       ALL_SIB_BASES
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| #undef ENTRY
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|       }
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|     } else {
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|       baseReg = MCOperand::CreateReg(0);
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|     }
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|     
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|     if (insn.sibIndex != SIB_INDEX_NONE) {
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|       switch (insn.sibIndex) {
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|       default:
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|         llvm_unreachable("Unexpected sibIndex");
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| #define ENTRY(x)                                          \
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|       case SIB_INDEX_##x:                                 \
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|         indexReg = MCOperand::CreateReg(X86::x); break;
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|       EA_BASES_32BIT
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|       EA_BASES_64BIT
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| #undef ENTRY
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|       }
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|     } else {
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|       indexReg = MCOperand::CreateReg(0);
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|     }
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|     
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|     scaleAmount = MCOperand::CreateImm(insn.sibScale);
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|   } else {
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|     switch (insn.eaBase) {
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|     case EA_BASE_NONE:
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|       assert(insn.eaDisplacement != EA_DISP_NONE && 
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|              "EA_BASE_NONE and EA_DISP_NONE for ModR/M base");
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|       
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|       if (insn.mode == MODE_64BIT)
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|         baseReg = MCOperand::CreateReg(X86::RIP); // Section 2.2.1.6
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|       else
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|         baseReg = MCOperand::CreateReg(0);
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|       
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|       indexReg = MCOperand::CreateReg(0);
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|       break;
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|     case EA_BASE_BX_SI:
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|       baseReg = MCOperand::CreateReg(X86::BX);
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|       indexReg = MCOperand::CreateReg(X86::SI);
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|       break;
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|     case EA_BASE_BX_DI:
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|       baseReg = MCOperand::CreateReg(X86::BX);
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|       indexReg = MCOperand::CreateReg(X86::DI);
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|       break;
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|     case EA_BASE_BP_SI:
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|       baseReg = MCOperand::CreateReg(X86::BP);
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|       indexReg = MCOperand::CreateReg(X86::SI);
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|       break;
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|     case EA_BASE_BP_DI:
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|       baseReg = MCOperand::CreateReg(X86::BP);
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|       indexReg = MCOperand::CreateReg(X86::DI);
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|       break;
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|     default:
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|       indexReg = MCOperand::CreateReg(0);
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|       switch (insn.eaBase) {
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|       default:
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|         llvm_unreachable("Unexpected eaBase");
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|         break;
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|         // Here, we will use the fill-ins defined above.  However,
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|         //   BX_SI, BX_DI, BP_SI, and BP_DI are all handled above and
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|         //   sib and sib64 were handled in the top-level if, so they're only
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|         //   placeholders to keep the compiler happy.
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| #define ENTRY(x)                                        \
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|       case EA_BASE_##x:                                 \
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|         baseReg = MCOperand::CreateReg(X86::x); break; 
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|       ALL_EA_BASES
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| #undef ENTRY
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| #define ENTRY(x) case EA_REG_##x:
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|       ALL_REGS
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| #undef ENTRY
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|         llvm_unreachable("A R/M memory operand may not be a register; "
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|                          "the base field must be a base.");
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|             break;
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|       }
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|     }
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|     
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|     scaleAmount = MCOperand::CreateImm(1);
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|   }
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|   
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|   displacement = MCOperand::CreateImm(insn.displacement);
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|   
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|   static const uint8_t segmentRegnums[SEG_OVERRIDE_max] = {
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|     0,        // SEG_OVERRIDE_NONE
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|     X86::CS,
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|     X86::SS,
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|     X86::DS,
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|     X86::ES,
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|     X86::FS,
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|     X86::GS
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|   };
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|   
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|   segmentReg = MCOperand::CreateReg(segmentRegnums[insn.segmentOverride]);
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|   
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|   mcInst.addOperand(baseReg);
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|   mcInst.addOperand(scaleAmount);
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|   mcInst.addOperand(indexReg);
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|   mcInst.addOperand(displacement);
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|   
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|   if (sr)
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|     mcInst.addOperand(segmentReg);
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| }
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| 
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| /// translateRM - Translates an operand stored in the R/M (and possibly SIB)
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| ///   byte of an instruction to LLVM form, and appends it to an MCInst.
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| ///
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| /// @param mcInst       - The MCInst to append to.
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| /// @param operand      - The operand, as stored in the descriptor table.
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| /// @param insn         - The instruction to extract Mod, R/M, and SIB fields
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| ///                       from.
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| static void translateRM(MCInst &mcInst,
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|                         OperandSpecifier &operand,
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|                         InternalInstruction &insn) {
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|   switch (operand.type) {
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|   default:
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|     llvm_unreachable("Unexpected type for a R/M operand");
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|   case TYPE_R8:
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|   case TYPE_R16:
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|   case TYPE_R32:
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|   case TYPE_R64:
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|   case TYPE_Rv:
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|   case TYPE_MM:
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|   case TYPE_MM32:
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|   case TYPE_MM64:
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|   case TYPE_XMM:
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|   case TYPE_XMM32:
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|   case TYPE_XMM64:
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|   case TYPE_XMM128:
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|   case TYPE_DEBUGREG:
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|   case TYPE_CR32:
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|   case TYPE_CR64:
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|     translateRMRegister(mcInst, insn);
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|     break;
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|   case TYPE_M:
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|   case TYPE_M8:
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|   case TYPE_M16:
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|   case TYPE_M32:
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|   case TYPE_M64:
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|   case TYPE_M128:
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|   case TYPE_M512:
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|   case TYPE_Mv:
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|   case TYPE_M32FP:
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|   case TYPE_M64FP:
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|   case TYPE_M80FP:
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|   case TYPE_M16INT:
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|   case TYPE_M32INT:
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|   case TYPE_M64INT:
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|   case TYPE_M1616:
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|   case TYPE_M1632:
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|   case TYPE_M1664:
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|     translateRMMemory(mcInst, insn, true);
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|     break;
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|   case TYPE_LEA:
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|     translateRMMemory(mcInst, insn, false);
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|     break;
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|   }
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| }
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|   
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| /// translateFPRegister - Translates a stack position on the FPU stack to its
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| ///   LLVM form, and appends it to an MCInst.
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| ///
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| /// @param mcInst       - The MCInst to append to.
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| /// @param stackPos     - The stack position to translate.
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| static void translateFPRegister(MCInst &mcInst,
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|                                 uint8_t stackPos) {
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|   assert(stackPos < 8 && "Invalid FP stack position");
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|   
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|   mcInst.addOperand(MCOperand::CreateReg(X86::ST0 + stackPos));
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| }
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| 
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| /// translateOperand - Translates an operand stored in an internal instruction 
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| ///   to LLVM's format and appends it to an MCInst.
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| ///
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| /// @param mcInst       - The MCInst to append to.
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| /// @param operand      - The operand, as stored in the descriptor table.
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| /// @param insn         - The internal instruction.
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| static void translateOperand(MCInst &mcInst,
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|                              OperandSpecifier &operand,
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|                              InternalInstruction &insn) {
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|   switch (operand.encoding) {
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|   default:
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|     llvm_unreachable("Unhandled operand encoding during translation");
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|   case ENCODING_REG:
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|     translateRegister(mcInst, insn.reg);
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|     break;
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|   case ENCODING_RM:
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|     translateRM(mcInst, operand, insn);
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|     break;
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|   case ENCODING_CB:
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|   case ENCODING_CW:
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|   case ENCODING_CD:
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|   case ENCODING_CP:
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|   case ENCODING_CO:
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|   case ENCODING_CT:
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|     llvm_unreachable("Translation of code offsets isn't supported.");
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|   case ENCODING_IB:
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|   case ENCODING_IW:
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|   case ENCODING_ID:
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|   case ENCODING_IO:
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|   case ENCODING_Iv:
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|   case ENCODING_Ia:
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|     translateImmediate(mcInst, 
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|                        insn.immediates[insn.numImmediatesTranslated++]);
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|     break;
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|   case ENCODING_RB:
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|   case ENCODING_RW:
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|   case ENCODING_RD:
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|   case ENCODING_RO:
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|     translateRegister(mcInst, insn.opcodeRegister);
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|     break;
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|   case ENCODING_I:
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|     translateFPRegister(mcInst, insn.opcodeModifier);
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|     break;
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|   case ENCODING_Rv:
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|     translateRegister(mcInst, insn.opcodeRegister);
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|     break;
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|   case ENCODING_DUP:
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|     translateOperand(mcInst,
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|                      insn.spec->operands[operand.type - TYPE_DUP0],
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|                      insn);
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|     break;
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|   }
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| }
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|   
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| /// translateInstruction - Translates an internal instruction and all its
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| ///   operands to an MCInst.
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| ///
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| /// @param mcInst       - The MCInst to populate with the instruction's data.
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| /// @param insn         - The internal instruction.
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| static void translateInstruction(MCInst &mcInst,
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|                                  InternalInstruction &insn) {  
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|   assert(insn.spec);
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|   
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|   mcInst.setOpcode(insn.instructionID);
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|   
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|   int index;
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|   
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|   insn.numImmediatesTranslated = 0;
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|   
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|   for (index = 0; index < X86_MAX_OPERANDS; ++index) {
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|     if (insn.spec->operands[index].encoding != ENCODING_NONE)                
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|       translateOperand(mcInst, insn.spec->operands[index], insn);
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|   }
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| }
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| 
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| static const MCDisassembler *createX86_32Disassembler(const Target &T) {
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|   return new X86Disassembler::X86_32Disassembler;
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| }
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| 
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| static const MCDisassembler *createX86_64Disassembler(const Target &T) {
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|   return new X86Disassembler::X86_64Disassembler;
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| }
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| 
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| extern "C" void LLVMInitializeX86Disassembler() { 
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|   // Register the disassembler.
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|   TargetRegistry::RegisterMCDisassembler(TheX86_32Target, 
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|                                          createX86_32Disassembler);
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|   TargetRegistry::RegisterMCDisassembler(TheX86_64Target,
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|                                          createX86_64Disassembler);
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| }
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