1 //===-- RISCVInstPrinter.cpp - Convert RISCV MCInst to asm syntax ---------===//
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 class prints an RISCV MCInst to a .s file.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "RISCVInstPrinter.h"
15 #include "MCTargetDesc/RISCVMCExpr.h"
16 #include "Utils/RISCVBaseInfo.h"
17 #include "llvm/MC/MCAsmInfo.h"
18 #include "llvm/MC/MCExpr.h"
19 #include "llvm/MC/MCInst.h"
20 #include "llvm/MC/MCRegisterInfo.h"
21 #include "llvm/MC/MCSubtargetInfo.h"
22 #include "llvm/MC/MCSymbol.h"
23 #include "llvm/Support/CommandLine.h"
24 #include "llvm/Support/ErrorHandling.h"
25 #include "llvm/Support/FormattedStream.h"
26 using namespace llvm;
27 
28 #define DEBUG_TYPE "asm-printer"
29 
30 // Include the auto-generated portion of the assembly writer.
31 #define PRINT_ALIAS_INSTR
32 #include "RISCVGenAsmWriter.inc"
33 
34 // Include the auto-generated portion of the compress emitter.
35 #define GEN_UNCOMPRESS_INSTR
36 #include "RISCVGenCompressInstEmitter.inc"
37 
38 static cl::opt<bool>
39     NoAliases("riscv-no-aliases",
40               cl::desc("Disable the emission of assembler pseudo instructions"),
41               cl::init(false), cl::Hidden);
42 
printInst(const MCInst * MI,raw_ostream & O,StringRef Annot,const MCSubtargetInfo & STI)43 void RISCVInstPrinter::printInst(const MCInst *MI, raw_ostream &O,
44                                  StringRef Annot, const MCSubtargetInfo &STI) {
45   bool Res = false;
46   const MCInst *NewMI = MI;
47   MCInst UncompressedMI;
48   if (!NoAliases)
49     Res = uncompressInst(UncompressedMI, *MI, MRI, STI);
50   if (Res)
51     NewMI = const_cast<MCInst *>(&UncompressedMI);
52   if (NoAliases || !printAliasInstr(NewMI, STI, O))
53     printInstruction(NewMI, STI, O);
54   printAnnotation(O, Annot);
55 }
56 
printRegName(raw_ostream & O,unsigned RegNo) const57 void RISCVInstPrinter::printRegName(raw_ostream &O, unsigned RegNo) const {
58   O << getRegisterName(RegNo);
59 }
60 
printOperand(const MCInst * MI,unsigned OpNo,const MCSubtargetInfo & STI,raw_ostream & O,const char * Modifier)61 void RISCVInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
62                                     const MCSubtargetInfo &STI, raw_ostream &O,
63                                     const char *Modifier) {
64   assert((Modifier == 0 || Modifier[0] == 0) && "No modifiers supported");
65   const MCOperand &MO = MI->getOperand(OpNo);
66 
67   if (MO.isReg()) {
68     printRegName(O, MO.getReg());
69     return;
70   }
71 
72   if (MO.isImm()) {
73     O << MO.getImm();
74     return;
75   }
76 
77   assert(MO.isExpr() && "Unknown operand kind in printOperand");
78   MO.getExpr()->print(O, &MAI);
79 }
80 
printCSRSystemRegister(const MCInst * MI,unsigned OpNo,const MCSubtargetInfo & STI,raw_ostream & O)81 void RISCVInstPrinter::printCSRSystemRegister(const MCInst *MI, unsigned OpNo,
82                                               const MCSubtargetInfo &STI,
83                                               raw_ostream &O) {
84   unsigned Imm = MI->getOperand(OpNo).getImm();
85   auto SysReg = RISCVSysReg::lookupSysRegByEncoding(Imm);
86   if (SysReg && SysReg->haveRequiredFeatures(STI.getFeatureBits()))
87     O << SysReg->Name;
88   else
89     O << Imm;
90 }
91 
printFenceArg(const MCInst * MI,unsigned OpNo,const MCSubtargetInfo & STI,raw_ostream & O)92 void RISCVInstPrinter::printFenceArg(const MCInst *MI, unsigned OpNo,
93                                      const MCSubtargetInfo &STI,
94                                      raw_ostream &O) {
95   unsigned FenceArg = MI->getOperand(OpNo).getImm();
96   assert (((FenceArg >> 4) == 0) && "Invalid immediate in printFenceArg");
97 
98   if ((FenceArg & RISCVFenceField::I) != 0)
99     O << 'i';
100   if ((FenceArg & RISCVFenceField::O) != 0)
101     O << 'o';
102   if ((FenceArg & RISCVFenceField::R) != 0)
103     O << 'r';
104   if ((FenceArg & RISCVFenceField::W) != 0)
105     O << 'w';
106   if (FenceArg == 0)
107     O << "unknown";
108 }
109 
printFRMArg(const MCInst * MI,unsigned OpNo,const MCSubtargetInfo & STI,raw_ostream & O)110 void RISCVInstPrinter::printFRMArg(const MCInst *MI, unsigned OpNo,
111                                    const MCSubtargetInfo &STI, raw_ostream &O) {
112   auto FRMArg =
113       static_cast<RISCVFPRndMode::RoundingMode>(MI->getOperand(OpNo).getImm());
114   O << RISCVFPRndMode::roundingModeToString(FRMArg);
115 }
116