Diff: mbd_os/features/FEATURE_COMMON_PAL/nanostack-libservice/source/libBits/common_functions.c

Revision:

1:55a6170b404f

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbd_os/features/FEATURE_COMMON_PAL/nanostack-libservice/source/libBits/common_functions.c	Sat Sep 17 16:32:05 2016 +0000
@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2014-2015 ARM Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ * Licensed under the Apache License, Version 2.0 (the License); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an AS IS BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * Most functions can be inlined, and definitions are in common_functions.h.
+ * Define COMMON_FUNCTIONS_FN before including it to generate external definitions.
+ */
+#define COMMON_FUNCTIONS_FN extern
+
+#include "common_functions.h"
+
+#include <string.h>
+
+/* Returns mask for <split_value> (0-8) most-significant bits of a byte */
+static inline uint8_t context_split_mask(uint_fast8_t split_value)
+{
+    return (uint8_t) - (0x100u >> split_value);
+}
+
+bool bitsequal(const uint8_t *a, const uint8_t *b, uint_fast8_t bits)
+{
+    uint_fast8_t bytes = bits / 8;
+    bits %= 8;
+
+    if (memcmp(a, b, bytes)) {
+        return false;
+    }
+
+    if (bits) {
+        uint_fast8_t split_bit = context_split_mask(bits);
+        if ((a[bytes] & split_bit) != (b[bytes] & split_bit)) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+uint8_t *bitcopy(uint8_t *restrict dst, const uint8_t *restrict src, uint_fast8_t bits)
+{
+    uint_fast8_t bytes = bits / 8;
+    bits %= 8;
+
+    if (bytes) {
+        dst = (uint8_t *) memcpy(dst, src, bytes) + bytes;
+        src += bytes;
+    }
+
+    if (bits) {
+        uint_fast8_t split_bit = context_split_mask(bits);
+        *dst = (*src & split_bit) | (*dst & ~ split_bit);
+    }
+
+    return dst;
+}
+
+uint8_t *bitcopy0(uint8_t *restrict dst, const uint8_t *restrict src, uint_fast8_t bits)
+{
+    uint_fast8_t bytes = bits / 8;
+    bits %= 8;
+
+    if (bytes) {
+        dst = (uint8_t *) memcpy(dst, src, bytes) + bytes;
+        src += bytes;
+    }
+
+    if (bits) {
+        uint_fast8_t split_bit = context_split_mask(bits);
+        *dst = (*src & split_bit);
+    }
+
+    return dst;
+}