1 //===-- BPFInstPrinter.cpp - Convert BPF 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 BPF MCInst to a .s file.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "BPF.h"
15 #include "BPFInstPrinter.h"
16 #include "llvm/MC/MCAsmInfo.h"
17 #include "llvm/MC/MCExpr.h"
18 #include "llvm/MC/MCInst.h"
19 #include "llvm/MC/MCSymbol.h"
20 #include "llvm/Support/ErrorHandling.h"
21 #include "llvm/Support/FormattedStream.h"
22 using namespace llvm;
23
24 #define DEBUG_TYPE "asm-printer"
25
26 // Include the auto-generated portion of the assembly writer.
27 #include "BPFGenAsmWriter.inc"
28
printInst(const MCInst * MI,raw_ostream & O,StringRef Annot,const MCSubtargetInfo & STI)29 void BPFInstPrinter::printInst(const MCInst *MI, raw_ostream &O,
30 StringRef Annot, const MCSubtargetInfo &STI) {
31 printInstruction(MI, O);
32 printAnnotation(O, Annot);
33 }
34
printExpr(const MCExpr * Expr,raw_ostream & O)35 static void printExpr(const MCExpr *Expr, raw_ostream &O) {
36 #ifndef NDEBUG
37 const MCSymbolRefExpr *SRE;
38
39 if (const MCBinaryExpr *BE = dyn_cast<MCBinaryExpr>(Expr))
40 SRE = dyn_cast<MCSymbolRefExpr>(BE->getLHS());
41 else
42 SRE = dyn_cast<MCSymbolRefExpr>(Expr);
43 assert(SRE && "Unexpected MCExpr type.");
44
45 MCSymbolRefExpr::VariantKind Kind = SRE->getKind();
46
47 assert(Kind == MCSymbolRefExpr::VK_None);
48 #endif
49 O << *Expr;
50 }
51
printOperand(const MCInst * MI,unsigned OpNo,raw_ostream & O,const char * Modifier)52 void BPFInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
53 raw_ostream &O, const char *Modifier) {
54 assert((Modifier == 0 || Modifier[0] == 0) && "No modifiers supported");
55 const MCOperand &Op = MI->getOperand(OpNo);
56 if (Op.isReg()) {
57 O << getRegisterName(Op.getReg());
58 } else if (Op.isImm()) {
59 O << (int32_t)Op.getImm();
60 } else {
61 assert(Op.isExpr() && "Expected an expression");
62 printExpr(Op.getExpr(), O);
63 }
64 }
65
printMemOperand(const MCInst * MI,int OpNo,raw_ostream & O,const char * Modifier)66 void BPFInstPrinter::printMemOperand(const MCInst *MI, int OpNo, raw_ostream &O,
67 const char *Modifier) {
68 const MCOperand &RegOp = MI->getOperand(OpNo);
69 const MCOperand &OffsetOp = MI->getOperand(OpNo + 1);
70 // offset
71 if (OffsetOp.isImm())
72 O << formatDec(OffsetOp.getImm());
73 else
74 assert(0 && "Expected an immediate");
75
76 // register
77 assert(RegOp.isReg() && "Register operand not a register");
78 O << '(' << getRegisterName(RegOp.getReg()) << ')';
79 }
80
printImm64Operand(const MCInst * MI,unsigned OpNo,raw_ostream & O)81 void BPFInstPrinter::printImm64Operand(const MCInst *MI, unsigned OpNo,
82 raw_ostream &O) {
83 const MCOperand &Op = MI->getOperand(OpNo);
84 if (Op.isImm())
85 O << (uint64_t)Op.getImm();
86 else
87 O << Op;
88 }
89