1 //===-- MSP430InstPrinter.cpp - Convert MSP430 MCInst to assembly syntax --===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This class prints an MSP430 MCInst to a .s file.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "MSP430InstPrinter.h"
14 #include "MSP430.h"
15 #include "llvm/MC/MCAsmInfo.h"
16 #include "llvm/MC/MCExpr.h"
17 #include "llvm/MC/MCInst.h"
18 #include "llvm/MC/MCInstrInfo.h"
19 #include "llvm/Support/ErrorHandling.h"
20 #include "llvm/Support/FormattedStream.h"
21 using namespace llvm;
22 
23 #define DEBUG_TYPE "asm-printer"
24 
25 // Include the auto-generated portion of the assembly writer.
26 #define PRINT_ALIAS_INSTR
27 #include "MSP430GenAsmWriter.inc"
28 
printRegName(raw_ostream & O,MCRegister Reg) const29 void MSP430InstPrinter::printRegName(raw_ostream &O, MCRegister Reg) const {
30   O << getRegisterName(Reg);
31 }
32 
printInst(const MCInst * MI,uint64_t Address,StringRef Annot,const MCSubtargetInfo & STI,raw_ostream & O)33 void MSP430InstPrinter::printInst(const MCInst *MI, uint64_t Address,
34                                   StringRef Annot, const MCSubtargetInfo &STI,
35                                   raw_ostream &O) {
36   if (!printAliasInstr(MI, Address, O))
37     printInstruction(MI, Address, O);
38   printAnnotation(O, Annot);
39 }
40 
printPCRelImmOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)41 void MSP430InstPrinter::printPCRelImmOperand(const MCInst *MI, unsigned OpNo,
42                                              raw_ostream &O) {
43   const MCOperand &Op = MI->getOperand(OpNo);
44   if (Op.isImm()) {
45     int64_t Imm = Op.getImm() * 2 + 2;
46     O << "$";
47     if (Imm >= 0)
48       O << '+';
49     O << Imm;
50   } else {
51     assert(Op.isExpr() && "unknown pcrel immediate operand");
52     Op.getExpr()->print(O, &MAI);
53   }
54 }
55 
printOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O,const char * Modifier)56 void MSP430InstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
57                                      raw_ostream &O, const char *Modifier) {
58   assert((Modifier == nullptr || Modifier[0] == 0) && "No modifiers supported");
59   const MCOperand &Op = MI->getOperand(OpNo);
60   if (Op.isReg()) {
61     O << getRegisterName(Op.getReg());
62   } else if (Op.isImm()) {
63     O << '#' << Op.getImm();
64   } else {
65     assert(Op.isExpr() && "unknown operand kind in printOperand");
66     O << '#';
67     Op.getExpr()->print(O, &MAI);
68   }
69 }
70 
printSrcMemOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O,const char * Modifier)71 void MSP430InstPrinter::printSrcMemOperand(const MCInst *MI, unsigned OpNo,
72                                            raw_ostream &O,
73                                            const char *Modifier) {
74   const MCOperand &Base = MI->getOperand(OpNo);
75   const MCOperand &Disp = MI->getOperand(OpNo+1);
76 
77   // Print displacement first
78 
79   // If the global address expression is a part of displacement field with a
80   // register base, we should not emit any prefix symbol here, e.g.
81   //   mov.w &foo, r1
82   // vs
83   //   mov.w glb(r1), r2
84   // Otherwise (!) msp430-as will silently miscompile the output :(
85   if (Base.getReg() == MSP430::SR)
86     O << '&';
87 
88   if (Disp.isExpr())
89     Disp.getExpr()->print(O, &MAI);
90   else {
91     assert(Disp.isImm() && "Expected immediate in displacement field");
92     O << Disp.getImm();
93   }
94 
95   // Print register base field
96   if ((Base.getReg() != MSP430::SR) &&
97       (Base.getReg() != MSP430::PC))
98     O << '(' << getRegisterName(Base.getReg()) << ')';
99 }
100 
printIndRegOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)101 void MSP430InstPrinter::printIndRegOperand(const MCInst *MI, unsigned OpNo,
102                                            raw_ostream &O) {
103   const MCOperand &Base = MI->getOperand(OpNo);
104   O << "@" << getRegisterName(Base.getReg());
105 }
106 
printPostIndRegOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)107 void MSP430InstPrinter::printPostIndRegOperand(const MCInst *MI, unsigned OpNo,
108                                                raw_ostream &O) {
109   const MCOperand &Base = MI->getOperand(OpNo);
110   O << "@" << getRegisterName(Base.getReg()) << "+";
111 }
112 
printCCOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O)113 void MSP430InstPrinter::printCCOperand(const MCInst *MI, unsigned OpNo,
114                                        raw_ostream &O) {
115   unsigned CC = MI->getOperand(OpNo).getImm();
116 
117   switch (CC) {
118   default:
119    llvm_unreachable("Unsupported CC code");
120   case MSP430CC::COND_E:
121    O << "eq";
122    break;
123   case MSP430CC::COND_NE:
124    O << "ne";
125    break;
126   case MSP430CC::COND_HS:
127    O << "hs";
128    break;
129   case MSP430CC::COND_LO:
130    O << "lo";
131    break;
132   case MSP430CC::COND_GE:
133    O << "ge";
134    break;
135   case MSP430CC::COND_L:
136    O << 'l';
137    break;
138   case MSP430CC::COND_N:
139    O << 'n';
140    break;
141   }
142 }
143