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1 //===-- X86IntelInstPrinter.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 "X86IntelInstPrinter.h"
17 #include "X86InstComments.h"
18 #include "MCTargetDesc/X86MCTargetDesc.h"
19 #include "llvm/MC/MCInst.h"
20 #include "llvm/MC/MCAsmInfo.h"
21 #include "llvm/MC/MCExpr.h"
22 #include "llvm/Support/ErrorHandling.h"
23 #include "llvm/Support/FormattedStream.h"
24 #include <cctype>
25 using namespace llvm;
26 
27 // Include the auto-generated portion of the assembly writer.
28 #define GET_INSTRUCTION_NAME
29 #include "X86GenAsmWriter1.inc"
30 
printRegName(raw_ostream & OS,unsigned RegNo) const31 void X86IntelInstPrinter::printRegName(raw_ostream &OS, unsigned RegNo) const {
32   OS << getRegisterName(RegNo);
33 }
34 
printInst(const MCInst * MI,raw_ostream & OS,StringRef Annot)35 void X86IntelInstPrinter::printInst(const MCInst *MI, raw_ostream &OS,
36                                     StringRef Annot) {
37   printInstruction(MI, OS);
38 
39   // If verbose assembly is enabled, we can print some informative comments.
40   if (CommentStream) {
41     printAnnotation(OS, Annot);
42     EmitAnyX86InstComments(MI, *CommentStream, getRegisterName);
43   }
44 }
getOpcodeName(unsigned Opcode) const45 StringRef X86IntelInstPrinter::getOpcodeName(unsigned Opcode) const {
46   return getInstructionName(Opcode);
47 }
48 
printSSECC(const MCInst * MI,unsigned Op,raw_ostream & O)49 void X86IntelInstPrinter::printSSECC(const MCInst *MI, unsigned Op,
50                                      raw_ostream &O) {
51   switch (MI->getOperand(Op).getImm()) {
52   default: assert(0 && "Invalid ssecc argument!");
53   case 0: O << "eq"; break;
54   case 1: O << "lt"; break;
55   case 2: O << "le"; break;
56   case 3: O << "unord"; break;
57   case 4: O << "neq"; break;
58   case 5: O << "nlt"; break;
59   case 6: O << "nle"; break;
60   case 7: O << "ord"; break;
61   }
62 }
63 
64 /// print_pcrel_imm - This is used to print an immediate value that ends up
65 /// being encoded as a pc-relative value.
print_pcrel_imm(const MCInst * MI,unsigned OpNo,raw_ostream & O)66 void X86IntelInstPrinter::print_pcrel_imm(const MCInst *MI, unsigned OpNo,
67                                           raw_ostream &O) {
68   const MCOperand &Op = MI->getOperand(OpNo);
69   if (Op.isImm())
70     O << Op.getImm();
71   else {
72     assert(Op.isExpr() && "unknown pcrel immediate operand");
73     O << *Op.getExpr();
74   }
75 }
76 
PrintRegName(raw_ostream & O,StringRef RegName)77 static void PrintRegName(raw_ostream &O, StringRef RegName) {
78   for (unsigned i = 0, e = RegName.size(); i != e; ++i)
79     O << (char)toupper(RegName[i]);
80 }
81 
printOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)82 void X86IntelInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
83                                        raw_ostream &O) {
84   const MCOperand &Op = MI->getOperand(OpNo);
85   if (Op.isReg()) {
86     PrintRegName(O, getRegisterName(Op.getReg()));
87   } else if (Op.isImm()) {
88     O << Op.getImm();
89   } else {
90     assert(Op.isExpr() && "unknown operand kind in printOperand");
91     O << *Op.getExpr();
92   }
93 }
94 
printMemReference(const MCInst * MI,unsigned Op,raw_ostream & O)95 void X86IntelInstPrinter::printMemReference(const MCInst *MI, unsigned Op,
96                                             raw_ostream &O) {
97   const MCOperand &BaseReg  = MI->getOperand(Op);
98   unsigned ScaleVal         = MI->getOperand(Op+1).getImm();
99   const MCOperand &IndexReg = MI->getOperand(Op+2);
100   const MCOperand &DispSpec = MI->getOperand(Op+3);
101   const MCOperand &SegReg   = MI->getOperand(Op+4);
102 
103   // If this has a segment register, print it.
104   if (SegReg.getReg()) {
105     printOperand(MI, Op+4, O);
106     O << ':';
107   }
108 
109   O << '[';
110 
111   bool NeedPlus = false;
112   if (BaseReg.getReg()) {
113     printOperand(MI, Op, O);
114     NeedPlus = true;
115   }
116 
117   if (IndexReg.getReg()) {
118     if (NeedPlus) O << " + ";
119     if (ScaleVal != 1)
120       O << ScaleVal << '*';
121     printOperand(MI, Op+2, O);
122     NeedPlus = true;
123   }
124 
125 
126   if (!DispSpec.isImm()) {
127     if (NeedPlus) O << " + ";
128     assert(DispSpec.isExpr() && "non-immediate displacement for LEA?");
129     O << *DispSpec.getExpr();
130   } else {
131     int64_t DispVal = DispSpec.getImm();
132     if (DispVal || (!IndexReg.getReg() && !BaseReg.getReg())) {
133       if (NeedPlus) {
134         if (DispVal > 0)
135           O << " + ";
136         else {
137           O << " - ";
138           DispVal = -DispVal;
139         }
140       }
141       O << DispVal;
142     }
143   }
144 
145   O << ']';
146 }
147