lib/Target/X86/AsmPrinter/X86ATTInstPrinter.cpp

   1 //===-- X86ATTInstPrinter.cpp - AT&T assembly instruction printing --------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file includes code for rendering MCInst instances as AT&T-style
  11 // assembly.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #define DEBUG_TYPE "asm-printer"
  16 #include "X86ATTInstPrinter.h"
  17 #include "llvm/MC/MCInst.h"
  18 #include "llvm/MC/MCAsmInfo.h"
  19 #include "llvm/MC/MCExpr.h"
  20 #include "llvm/Support/ErrorHandling.h"
  21 #include "llvm/Support/FormattedStream.h"
  22 using namespace llvm;
  23
  24 // Include the auto-generated portion of the assembly writer.
  25 #define MachineInstr MCInst
  26 #define NO_ASM_WRITER_BOILERPLATE
  27 #include "X86GenAsmWriter.inc"
  28 #undef MachineInstr
  29
  30 void X86ATTInstPrinter::printInst(const MCInst *MI) { printInstruction(MI); }
  31
  32 void X86ATTInstPrinter::printSSECC(const MCInst *MI, unsigned Op) {
  33   switch (MI->getOperand(Op).getImm()) {
  34   default: llvm_unreachable("Invalid ssecc argument!");
  35   case 0: O << "eq"; break;
  36   case 1: O << "lt"; break;
  37   case 2: O << "le"; break;
  38   case 3: O << "unord"; break;
  39   case 4: O << "neq"; break;
  40   case 5: O << "nlt"; break;
  41   case 6: O << "nle"; break;
  42   case 7: O << "ord"; break;
  43   }
  44 }
  45
  46 void X86ATTInstPrinter::printPICLabel(const MCInst *MI, unsigned Op) {
  47   llvm_unreachable("This is only used for MOVPC32r,"
  48                    "should lower before instruction printing!");
  49 }
  50
  51 /// print_pcrel_imm - This is used to print an immediate value that ends up
  52 /// being encoded as a pc-relative value.  These print slightly differently, for
  53 /// example, a $ is not emitted.
  54 void X86ATTInstPrinter::print_pcrel_imm(const MCInst *MI, unsigned OpNo) {
  55   const MCOperand &Op = MI->getOperand(OpNo);
  56   if (Op.isImm())
  57     O << Op.getImm();
  58   else {
  59     assert(Op.isExpr() && "unknown pcrel immediate operand");
  60     Op.getExpr()->print(O, &MAI);
  61   }
  62 }
  63
  64 void X86ATTInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
  65                                      const char *Modifier) {
  66   assert(Modifier == 0 && "Modifiers should not be used");
  67
  68   const MCOperand &Op = MI->getOperand(OpNo);
  69   if (Op.isReg()) {
  70     O << '%' << getRegisterName(Op.getReg());
  71   } else if (Op.isImm()) {
  72     O << '$' << Op.getImm();
  73   } else {
  74     assert(Op.isExpr() && "unknown operand kind in printOperand");
  75     O << '$';
  76     Op.getExpr()->print(O, &MAI);
  77   }
  78 }
  79
  80 void X86ATTInstPrinter::printLeaMemReference(const MCInst *MI, unsigned Op) {
  81   const MCOperand &BaseReg  = MI->getOperand(Op);
  82   const MCOperand &IndexReg = MI->getOperand(Op+2);
  83   const MCOperand &DispSpec = MI->getOperand(Op+3);
  84
  85   if (DispSpec.isImm()) {
  86     int64_t DispVal = DispSpec.getImm();
  87     if (DispVal || (!IndexReg.getReg() && !BaseReg.getReg()))
  88       O << DispVal;
  89   } else {
  90     assert(DispSpec.isExpr() && "non-immediate displacement for LEA?");
  91     DispSpec.getExpr()->print(O, &MAI);
  92   }
  93
  94   if (IndexReg.getReg() || BaseReg.getReg()) {
  95     O << '(';
  96     if (BaseReg.getReg())
  97       printOperand(MI, Op);
  98
  99     if (IndexReg.getReg()) {
 100       O << ',';
 101       printOperand(MI, Op+2);
 102       unsigned ScaleVal = MI->getOperand(Op+1).getImm();
 103       if (ScaleVal != 1)
 104         O << ',' << ScaleVal;
 105     }
 106     O << ')';
 107   }
 108 }
 109
 110 void X86ATTInstPrinter::printMemReference(const MCInst *MI, unsigned Op) {
 111   // If this has a segment register, print it.
 112   if (MI->getOperand(Op+4).getReg()) {
 113     printOperand(MI, Op+4);
 114     O << ':';
 115   }
 116   printLeaMemReference(MI, Op);
 117 }