summaryrefslogtreecommitdiff
path: root/lib/Transforms/Utils/ValueMapper.cpp
blob: 2fba938324a61c65c8add23be3df074a2caac39c (plain)
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
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
//===- ValueMapper.cpp - Interface shared by lib/Transforms/Utils ---------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the MapValue function, which is shared by various parts of
// the lib/Transforms/Utils library.
//
//===----------------------------------------------------------------------===//

#include "llvm/Transforms/Utils/ValueMapper.h"
#include "llvm/DerivedTypes.h"  // For getNullValue(Type::Int32Ty)
#include "llvm/Constants.h"
#include "llvm/Function.h"
#include "llvm/IntrinsicInst.h"
#include "llvm/Metadata.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/ErrorHandling.h"
using namespace llvm;

Value *llvm::MapValue(const Value *V, ValueMapTy &VM) {
  Value *&VMSlot = VM[V];
  if (VMSlot) return VMSlot;      // Does it exist in the map yet?
  
  // NOTE: VMSlot can be invalidated by any reference to VM, which can grow the
  // DenseMap.  This includes any recursive calls to MapValue.

  // Global values and non-function-local metadata do not need to be seeded into
  // the ValueMap if they are using the identity mapping.
  if (isa<GlobalValue>(V) || isa<InlineAsm>(V) || isa<MDString>(V) ||
      (isa<MDNode>(V) && !dyn_cast<MDNode>(V)->isFunctionLocal()))
    return VMSlot = const_cast<Value*>(V);

  if (isa<MDNode>(V)) {
    const MDNode *MD = dyn_cast<MDNode>(V);
    std::vector<Value*> Elts;
    Elts.reserve(MD->getNumOperands());
    for (unsigned i = 0; i != MD->getNumOperands(); i++)
      Elts.push_back(MapValue(MD->getOperand(i), VM));
    return VM[V] = MDNode::get(V->getContext(), Elts.data(), Elts.size());
  }

  Constant *C = const_cast<Constant*>(dyn_cast<Constant>(V));
  if (C == 0) return 0;
  
  if (isa<ConstantInt>(C) || isa<ConstantFP>(C) ||
      isa<ConstantPointerNull>(C) || isa<ConstantAggregateZero>(C) ||
      isa<UndefValue>(C) || isa<MDString>(C))
    return VMSlot = C;           // Primitive constants map directly
  
  if (ConstantArray *CA = dyn_cast<ConstantArray>(C)) {
    for (User::op_iterator b = CA->op_begin(), i = b, e = CA->op_end();
         i != e; ++i) {
      Value *MV = MapValue(*i, VM);
      if (MV != *i) {
        // This array must contain a reference to a global, make a new array
        // and return it.
        //
        std::vector<Constant*> Values;
        Values.reserve(CA->getNumOperands());
        for (User::op_iterator j = b; j != i; ++j)
          Values.push_back(cast<Constant>(*j));
        Values.push_back(cast<Constant>(MV));
        for (++i; i != e; ++i)
          Values.push_back(cast<Constant>(MapValue(*i, VM)));
        return VM[V] = ConstantArray::get(CA->getType(), Values);
      }
    }
    return VM[V] = C;
  }
  
  if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) {
    for (User::op_iterator b = CS->op_begin(), i = b, e = CS->op_end();
         i != e; ++i) {
      Value *MV = MapValue(*i, VM);
      if (MV != *i) {
        // This struct must contain a reference to a global, make a new struct
        // and return it.
        //
        std::vector<Constant*> Values;
        Values.reserve(CS->getNumOperands());
        for (User::op_iterator j = b; j != i; ++j)
          Values.push_back(cast<Constant>(*j));
        Values.push_back(cast<Constant>(MV));
        for (++i; i != e; ++i)
          Values.push_back(cast<Constant>(MapValue(*i, VM)));
        return VM[V] = ConstantStruct::get(CS->getType(), Values);
      }
    }
    return VM[V] = C;
  }
  
  if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
    std::vector<Constant*> Ops;
    for (User::op_iterator i = CE->op_begin(), e = CE->op_end(); i != e; ++i)
      Ops.push_back(cast<Constant>(MapValue(*i, VM)));
    return VM[V] = CE->getWithOperands(Ops);
  }
  
  if (ConstantVector *CV = dyn_cast<ConstantVector>(C)) {
    for (User::op_iterator b = CV->op_begin(), i = b, e = CV->op_end();
         i != e; ++i) {
      Value *MV = MapValue(*i, VM);
      if (MV != *i) {
        // This vector value must contain a reference to a global, make a new
        // vector constant and return it.
        //
        std::vector<Constant*> Values;
        Values.reserve(CV->getNumOperands());
        for (User::op_iterator j = b; j != i; ++j)
          Values.push_back(cast<Constant>(*j));
        Values.push_back(cast<Constant>(MV));
        for (++i; i != e; ++i)
          Values.push_back(cast<Constant>(MapValue(*i, VM)));
        return VM[V] = ConstantVector::get(Values);
      }
    }
    return VM[V] = C;
  }
  
  if (BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
    Function *F = cast<Function>(MapValue(BA->getFunction(), VM));
    BasicBlock *BB = cast_or_null<BasicBlock>(MapValue(BA->getBasicBlock(),VM));
    return VM[V] = BlockAddress::get(F, BB ? BB : BA->getBasicBlock());
  }
  
  llvm_unreachable("Unknown type of constant!");
  return 0;
}

/// RemapInstruction - Convert the instruction operands from referencing the
/// current values into those specified by ValueMap.
///
void llvm::RemapInstruction(Instruction *I, ValueMapTy &ValueMap) {
  for (User::op_iterator op = I->op_begin(), E = I->op_end(); op != E; ++op) {
    Value *V = MapValue(*op, ValueMap);
    assert(V && "Referenced value not in value map!");
    *op = V;
  }
}