MCAtom.cpp revision 124e1821033a4b3220f552229652d9460ed90673 
1//===- lib/MC/MCAtom.cpp - MCAtom implementation --------------------------===//
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#include "llvm/MC/MCAtom.h"
11#include "llvm/MC/MCModule.h"
12#include "llvm/Support/ErrorHandling.h"
13
14using namespace llvm;
15
16MCAtom *MCAtom::split(uint64_t SplitPt) {
17  assert((SplitPt > Begin && SplitPt <= End) &&
18         "Splitting at point not contained in atom!");
19
20  // Compute the new begin/end points.
21  uint64_t LeftBegin = Begin;
22  uint64_t LeftEnd = SplitPt - 1;
23  uint64_t RightBegin = SplitPt;
24  uint64_t RightEnd = End;
25
26  // Remap this atom to become the lower of the two new ones.
27  Parent->remap(this, LeftBegin, LeftEnd);
28
29  // Create a new atom for the higher atom.
30  MCAtom *RightAtom = Parent->createAtom(Type, RightBegin, RightEnd);
31
32  // Split the contents of the original atom between it and the new one.  The
33  // precise method depends on whether this is a data or a text atom.
34  if (isDataAtom()) {
35    std::vector<MCData>::iterator I = Data.begin() + (RightBegin - LeftBegin);
36
37    assert(I != Data.end() && "Split point not found in range!");
38
39    std::copy(I, Data.end(), RightAtom->Data.end());
40    Data.erase(I, Data.end());
41  } else if (isTextAtom()) {
42    std::vector<std::pair<uint64_t, MCInst> >::iterator I = Text.begin();
43
44    while (I != Text.end() && I->first < SplitPt) ++I;
45
46    assert(I != Text.end() && "Split point not found in disassembly!");
47    assert(I->first == SplitPt &&
48           "Split point does not fall on instruction boundary!");
49
50    std::copy(I, Text.end(), RightAtom->Text.end());
51    Text.erase(I, Text.end());
52  } else
53    llvm_unreachable("Unknown atom type!");
54
55  return RightAtom;
56}
57
58void MCAtom::truncate(uint64_t TruncPt) {
59  assert((TruncPt >= Begin && TruncPt < End) &&
60         "Truncation point not contained in atom!");
61
62  Parent->remap(this, Begin, TruncPt);
63
64  if (isDataAtom()) {
65    Data.resize(TruncPt - Begin + 1);
66  } else if (isTextAtom()) {
67    std::vector<std::pair<uint64_t, MCInst> >::iterator I = Text.begin();
68
69    while (I != Text.end() && I->first <= TruncPt) ++I;
70
71    assert(I != Text.end() && "Truncation point not found in disassembly!");
72    assert(I->first == TruncPt+1 &&
73           "Truncation point does not fall on instruction boundary");
74
75    Text.erase(I, Text.end());
76  } else
77    llvm_unreachable("Unknown atom type!");
78}
79
80