mirror of
https://github.com/dart-lang/sdk
synced 2024-09-05 00:13:50 +00:00
bc16959fc7
The original revision is in patchset 1. Three bugs are fixed: 1. Fix SIMARM_X64 build: no need to generate trampolines for AOT or simulated JIT. 2. Hot-reload: Fix hot-reload: don't invalidate Code for force-optimized functions. 3. Windows: Provide shadow space to runtime routines. Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-mac-debug-simarm_x64-try,vm-kernel-precomp-mac-release-simarm_x64-try,vm-kernel-reload-linux-debug-x64-try,vm-kernel-reload-rollback-linux-debug-x64-try,vm-kernel-win-debug-ia32-try,vm-kernel-win-debug-x64-try,vm-kernel-win-release-ia32-try,vm-kernel-win-release-x64-try Change-Id: I326009cfacb51a84e9de4ddf9ff2d6d415460f91 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/113829 Commit-Queue: Samir Jindel <sjindel@google.com> Reviewed-by: Martin Kustermann <kustermann@google.com>
69 lines
2.1 KiB
C++
69 lines
2.1 KiB
C++
// Copyright (c) 2011, 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 RUNTIME_VM_BITFIELD_H_
|
|
#define RUNTIME_VM_BITFIELD_H_
|
|
|
|
#include "platform/assert.h"
|
|
#include "platform/globals.h"
|
|
|
|
namespace dart {
|
|
|
|
static const uword kUwordOne = 1U;
|
|
|
|
// BitField is a template for encoding and decoding a value of type T
|
|
// inside a storage of type S.
|
|
template <typename S, typename T, int position, int size>
|
|
class BitField {
|
|
public:
|
|
static_assert((sizeof(S) * kBitsPerByte) >= (position + size),
|
|
"BitField does not fit into the type.");
|
|
|
|
static const intptr_t kNextBit = position + size;
|
|
|
|
// Tells whether the provided value fits into the bit field.
|
|
static bool is_valid(T value) {
|
|
return (static_cast<S>(value) & ~((kUwordOne << size) - 1)) == 0;
|
|
}
|
|
|
|
// Returns a S mask of the bit field.
|
|
static constexpr S mask() { return (kUwordOne << size) - 1; }
|
|
|
|
// Returns a S mask of the bit field which can be applied directly to
|
|
// to the raw unshifted bits.
|
|
static constexpr S mask_in_place() {
|
|
return ((kUwordOne << size) - 1) << position;
|
|
}
|
|
|
|
// Returns the shift count needed to right-shift the bit field to
|
|
// the least-significant bits.
|
|
static constexpr int shift() { return position; }
|
|
|
|
// Returns the size of the bit field.
|
|
static constexpr int bitsize() { return size; }
|
|
|
|
// Returns an S with the bit field value encoded.
|
|
static S encode(T value) {
|
|
ASSERT(is_valid(value));
|
|
return static_cast<S>(value) << position;
|
|
}
|
|
|
|
// Extracts the bit field from the value.
|
|
static T decode(S value) {
|
|
return static_cast<T>((value >> position) & ((kUwordOne << size) - 1));
|
|
}
|
|
|
|
// Returns an S with the bit field value encoded based on the
|
|
// original value. Only the bits corresponding to this bit field
|
|
// will be changed.
|
|
static S update(T value, S original) {
|
|
ASSERT(is_valid(value));
|
|
return (static_cast<S>(value) << position) | (~mask_in_place() & original);
|
|
}
|
|
};
|
|
|
|
} // namespace dart
|
|
|
|
#endif // RUNTIME_VM_BITFIELD_H_
|