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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
commit36d22d82aa202bb199967e9512281e9a53db42c9 (patch)
tree105e8c98ddea1c1e4784a60a5a6410fa416be2de /js/src/util/BitArray.h
parentInitial commit. (diff)
downloadfirefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz
firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'js/src/util/BitArray.h')
-rw-r--r--js/src/util/BitArray.h71
1 files changed, 71 insertions, 0 deletions
diff --git a/js/src/util/BitArray.h b/js/src/util/BitArray.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * A bit array is an array of bits represented by an array of words (size_t).
+ */
+
+#ifndef util_BitArray_h
+#define util_BitArray_h
+
+#include "mozilla/Assertions.h"
+
+#include <limits.h>
+#include <stddef.h>
+
+namespace js {
+
+static const size_t BitArrayElementBits = sizeof(size_t) * CHAR_BIT;
+
+static inline unsigned NumWordsForBitArrayOfLength(size_t length) {
+ return (length + (BitArrayElementBits - 1)) / BitArrayElementBits;
+}
+
+static inline unsigned BitArrayIndexToWordIndex(size_t length,
+ size_t bitIndex) {
+ unsigned wordIndex = bitIndex / BitArrayElementBits;
+ MOZ_ASSERT(wordIndex < length);
+ return wordIndex;
+}
+
+static inline size_t BitArrayIndexToWordMask(size_t i) {
+ return size_t(1) << (i % BitArrayElementBits);
+}
+
+static inline bool IsBitArrayElementSet(const size_t* array, size_t length,
+ size_t i) {
+ return array[BitArrayIndexToWordIndex(length, i)] &
+ BitArrayIndexToWordMask(i);
+}
+
+static inline bool IsAnyBitArrayElementSet(const size_t* array, size_t length) {
+ unsigned numWords = NumWordsForBitArrayOfLength(length);
+ for (unsigned i = 0; i < numWords; ++i) {
+ if (array[i]) {
+ return true;
+ }
+ }
+ return false;
+}
+
+static inline void SetBitArrayElement(size_t* array, size_t length, size_t i) {
+ array[BitArrayIndexToWordIndex(length, i)] |= BitArrayIndexToWordMask(i);
+}
+
+static inline void ClearBitArrayElement(size_t* array, size_t length,
+ size_t i) {
+ array[BitArrayIndexToWordIndex(length, i)] &= ~BitArrayIndexToWordMask(i);
+}
+
+static inline void ClearAllBitArrayElements(size_t* array, size_t length) {
+ for (unsigned i = 0; i < length; ++i) {
+ array[i] = 0;
+ }
+}
+
+} /* namespace js */
+
+#endif /* util_BitArray_h */