Files
sdk/runtime/vm/bitmap.cc
T
kmillikin@google.com 94a5b82f60 Make stackmaps store their actual length.
This allows stackmaps with varying lengths in the same function, necessary
for the way we plan to support bitmaps for saved live registers.

R=vegorov@google.com
BUG=

Review URL: https://chromiumcodereview.appspot.com//10837303

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@11019 260f80e4-7a28-3924-810f-c04153c831b5
2012-08-21 08:43:32 +00:00

91 lines
2.4 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.
#include "vm/bitmap.h"
#include "platform/assert.h"
#include "vm/object.h"
namespace dart {
bool BitmapBuilder::Get(intptr_t bit_offset) const {
if (!InRange(bit_offset)) {
return false;
}
return GetBit(bit_offset);
}
void BitmapBuilder::Set(intptr_t bit_offset, bool value) {
while (!InRange(bit_offset)) {
intptr_t new_size = size_in_bytes_ + kIncrementSizeInBytes;
ASSERT(new_size > 0);
uint8_t* new_bit_list =
Isolate::Current()->current_zone()->Alloc<uint8_t>(new_size);
ASSERT(new_bit_list != NULL);
ASSERT(bit_list_ != NULL);
uint8_t* old_bit_list = bit_list_;
memmove(new_bit_list, old_bit_list, size_in_bytes_);
memset((new_bit_list + size_in_bytes_), 0, kIncrementSizeInBytes);
size_in_bytes_ = new_size;
bit_list_ = new_bit_list;
}
SetBit(bit_offset, value);
}
// Return the bit offset of the highest bit set.
intptr_t BitmapBuilder::Maximum() const {
intptr_t bound = SizeInBits();
for (intptr_t i = (bound - 1); i >= 0; i--) {
if (Get(i)) return i;
}
return Stackmap::kNoMaximum;
}
// Return the bit offset of the lowest bit set.
intptr_t BitmapBuilder::Minimum() const {
intptr_t bound = SizeInBits();
for (intptr_t i = 0; i < bound; i++) {
if (Get(i)) return i;
}
return Stackmap::kNoMinimum;
}
void BitmapBuilder::SetRange(intptr_t min, intptr_t max, bool value) {
for (intptr_t i = min; i <= max; i++) {
Set(i, value);
}
}
bool BitmapBuilder::GetBit(intptr_t bit_offset) const {
ASSERT(InRange(bit_offset));
int byte_offset = bit_offset >> kBitsPerByteLog2;
int bit_remainder = bit_offset & (kBitsPerByte - 1);
uint8_t mask = 1U << bit_remainder;
ASSERT(bit_list_ != NULL);
return ((bit_list_[byte_offset] & mask) != 0);
}
void BitmapBuilder::SetBit(intptr_t bit_offset, bool value) {
ASSERT(InRange(bit_offset));
int byte_offset = bit_offset >> kBitsPerByteLog2;
int bit_remainder = bit_offset & (kBitsPerByte - 1);
uint8_t mask = 1U << bit_remainder;
uint8_t* byte_addr;
ASSERT(bit_list_ != NULL);
byte_addr = &(bit_list_[byte_offset]);
if (value) {
*byte_addr |= mask;
} else {
*byte_addr &= ~mask;
}
}
} // namespace dart