Files
sdk/runtime/vm/bit_vector.h
T
fschneider@google.com ee4a0fd042 First step to SSA construction: Phi insertion.
This CL contains the phi insertion step of the SSA construction algorithmus: The phi instructions inserted are not functional yet. Renaming is not included yet.


I based it on Kevin's CL (http://codereview.chromium.org/10388161/), rebased and fixed a bug (added missing iterator.Advance()) there.

It also reintroduces the Definition IL class because Phi-instructions are also
definitions that are referenced by UseVal.

I also added the set of immediately dominated blocks to each basic block.
This will be needed for pre-order dominator-tree traversal in the renaming pass.
Review URL: https://chromiumcodereview.appspot.com//10539108

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@8604 260f80e4-7a28-3924-810f-c04153c831b5
2012-06-13 13:36:04 +00:00

91 lines
2.1 KiB
C++

// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#ifndef VM_BIT_VECTOR_H_
#define VM_BIT_VECTOR_H_
#include "vm/allocation.h"
#include "vm/isolate.h"
#include "vm/zone.h"
namespace dart {
// Bit vector implementation.
class BitVector: public ZoneAllocated {
public:
// Iterator for the elements of this BitVector.
class Iterator : public ValueObject {
public:
explicit Iterator(BitVector* target)
: target_(target),
bit_index_(-1),
word_index_(0),
current_word_(target->data_[0]) {
ASSERT(target->data_length_ > 0);
Advance();
}
~Iterator() { }
bool Done() const { return word_index_ >= target_->data_length_; }
void Advance();
intptr_t Current() const {
ASSERT(!Done());
return bit_index_;
}
private:
BitVector* target_;
intptr_t bit_index_;
intptr_t word_index_;
uword current_word_;
friend class BitVector;
};
explicit BitVector(intptr_t length)
: length_(length),
data_length_(SizeFor(length)),
data_(reinterpret_cast<uword*>(
Isolate::Current()->current_zone()->Allocate(
data_length_ * sizeof(uword)))) {
ASSERT(length > 0);
Clear();
}
static intptr_t SizeFor(intptr_t length) {
return 1 + ((length - 1) / kBitsPerWord);
}
void Add(intptr_t i) {
ASSERT(i >= 0 && i < length());
data_[i / kBitsPerWord] |= (static_cast<uword>(1) << (i % kBitsPerWord));
}
bool Contains(int i) const {
ASSERT(i >= 0 && i < length());
uword block = data_[i / kBitsPerWord];
return (block & (static_cast<uword>(1) << (i % kBitsPerWord))) != 0;
}
void Clear() {
for (intptr_t i = 0; i < data_length_; i++) {
data_[i] = 0;
}
}
intptr_t length() const { return length_; }
private:
intptr_t length_;
intptr_t data_length_;
uword* data_;
DISALLOW_COPY_AND_ASSIGN(BitVector);
};
} // namespace dart
#endif // VM_BIT_VECTOR_H_