BPFInstPrinter.cpp revision 0c7f116bb6950ef819323d855415b2f2b0aad987 
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"
22using 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
29void BPFInstPrinter::printInst(const MCInst *MI, raw_ostream &O,
30                               StringRef Annot, const MCSubtargetInfo &STI) {
31  printInstruction(MI, O);
32  printAnnotation(O, Annot);
33}
34
35static void printExpr(const MCExpr *Expr, raw_ostream &O) {
36  const MCSymbolRefExpr *SRE;
37
38  if (const MCBinaryExpr *BE = dyn_cast<MCBinaryExpr>(Expr))
39    SRE = dyn_cast<MCSymbolRefExpr>(BE->getLHS());
40  else
41    SRE = dyn_cast<MCSymbolRefExpr>(Expr);
42  assert(SRE && "Unexpected MCExpr type.");
43
44  MCSymbolRefExpr::VariantKind Kind = SRE->getKind();
45
46  assert(Kind == MCSymbolRefExpr::VK_None);
47  O << *Expr;
48}
49
50void BPFInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
51                                  raw_ostream &O, const char *Modifier) {
52  assert((Modifier == 0 || Modifier[0] == 0) && "No modifiers supported");
53  const MCOperand &Op = MI->getOperand(OpNo);
54  if (Op.isReg()) {
55    O << getRegisterName(Op.getReg());
56  } else if (Op.isImm()) {
57    O << (int32_t)Op.getImm();
58  } else {
59    assert(Op.isExpr() && "Expected an expression");
60    printExpr(Op.getExpr(), O);
61  }
62}
63
64void BPFInstPrinter::printMemOperand(const MCInst *MI, int OpNo, raw_ostream &O,
65                                     const char *Modifier) {
66  const MCOperand &RegOp = MI->getOperand(OpNo);
67  const MCOperand &OffsetOp = MI->getOperand(OpNo + 1);
68  // offset
69  if (OffsetOp.isImm())
70    O << formatDec(OffsetOp.getImm());
71  else
72    assert(0 && "Expected an immediate");
73
74  // register
75  assert(RegOp.isReg() && "Register operand not a register");
76  O << '(' << getRegisterName(RegOp.getReg()) << ')';
77}
78
79void BPFInstPrinter::printImm64Operand(const MCInst *MI, unsigned OpNo,
80                                       raw_ostream &O) {
81  const MCOperand &Op = MI->getOperand(OpNo);
82  if (Op.isImm())
83    O << (uint64_t)Op.getImm();
84  else
85    O << Op;
86}
87