File: BPFInstPrinter.cpp

package info (click to toggle)
llvm-toolchain-9 1%3A9.0.1-16.1
  • links: PTS, VCS
  • area: main
  • in suites: bullseye
  • size: 882,388 kB
  • sloc: cpp: 4,167,636; ansic: 714,256; asm: 457,610; python: 155,927; objc: 65,094; sh: 42,856; lisp: 26,908; perl: 7,786; pascal: 7,722; makefile: 6,881; ml: 5,581; awk: 3,648; cs: 2,027; xml: 888; javascript: 381; ruby: 156
file content (107 lines) | stat: -rw-r--r-- 3,301 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
//===-- BPFInstPrinter.cpp - Convert BPF MCInst to asm syntax -------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This class prints an BPF MCInst to a .s file.
//
//===----------------------------------------------------------------------===//

#include "MCTargetDesc/BPFInstPrinter.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/FormattedStream.h"
using namespace llvm;

#define DEBUG_TYPE "asm-printer"

// Include the auto-generated portion of the assembly writer.
#include "BPFGenAsmWriter.inc"

void BPFInstPrinter::printInst(const MCInst *MI, raw_ostream &O,
                               StringRef Annot, const MCSubtargetInfo &STI) {
  printInstruction(MI, O);
  printAnnotation(O, Annot);
}

static void printExpr(const MCExpr *Expr, raw_ostream &O) {
#ifndef NDEBUG
  const MCSymbolRefExpr *SRE;

  if (const MCBinaryExpr *BE = dyn_cast<MCBinaryExpr>(Expr))
    SRE = dyn_cast<MCSymbolRefExpr>(BE->getLHS());
  else
    SRE = dyn_cast<MCSymbolRefExpr>(Expr);
  assert(SRE && "Unexpected MCExpr type.");

  MCSymbolRefExpr::VariantKind Kind = SRE->getKind();

  assert(Kind == MCSymbolRefExpr::VK_None);
#endif
  O << *Expr;
}

void BPFInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
                                  raw_ostream &O, const char *Modifier) {
  assert((Modifier == 0 || Modifier[0] == 0) && "No modifiers supported");
  const MCOperand &Op = MI->getOperand(OpNo);
  if (Op.isReg()) {
    O << getRegisterName(Op.getReg());
  } else if (Op.isImm()) {
    O << formatImm((int32_t)Op.getImm());
  } else {
    assert(Op.isExpr() && "Expected an expression");
    printExpr(Op.getExpr(), O);
  }
}

void BPFInstPrinter::printMemOperand(const MCInst *MI, int OpNo, raw_ostream &O,
                                     const char *Modifier) {
  const MCOperand &RegOp = MI->getOperand(OpNo);
  const MCOperand &OffsetOp = MI->getOperand(OpNo + 1);

  // register
  assert(RegOp.isReg() && "Register operand not a register");
  O << getRegisterName(RegOp.getReg());

  // offset
  if (OffsetOp.isImm()) {
    auto Imm = OffsetOp.getImm();
    if (Imm >= 0)
      O << " + " << formatImm(Imm);
    else
      O << " - " << formatImm(-Imm);
  } else {
    assert(0 && "Expected an immediate");
  }
}

void BPFInstPrinter::printImm64Operand(const MCInst *MI, unsigned OpNo,
                                       raw_ostream &O) {
  const MCOperand &Op = MI->getOperand(OpNo);
  if (Op.isImm())
    O << formatImm(Op.getImm());
  else if (Op.isExpr())
    printExpr(Op.getExpr(), O);
  else
    O << Op;
}

void BPFInstPrinter::printBrTargetOperand(const MCInst *MI, unsigned OpNo,
                                       raw_ostream &O) {
  const MCOperand &Op = MI->getOperand(OpNo);
  if (Op.isImm()) {
    int16_t Imm = Op.getImm();
    O << ((Imm >= 0) ? "+" : "") << formatImm(Imm);
  } else if (Op.isExpr()) {
    printExpr(Op.getExpr(), O);
  } else {
    O << Op;
  }
}