/*
- * unaligned.h
+ * unaligned.h - inline functions for unaligned memory accesses
*
- * Inline functions for unaligned memory accesses.
+ * Copyright 2022 Eric Biggers
*
- * Author: Eric Biggers
- * Year: 2014, 2015
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following
+ * conditions:
*
- * The author dedicates this file to the public domain.
- * You can do whatever you want with this file.
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef _WIMLIB_UNALIGNED_H
#define _WIMLIB_UNALIGNED_H
+#include <string.h>
+
#include "wimlib/compiler.h"
#include "wimlib/endianness.h"
#include "wimlib/types.h"
#define DEFINE_UNALIGNED_TYPE(type) \
-struct type##_unaligned { \
- type v; \
-} _packed_attribute; \
- \
-static inline type \
+static forceinline type \
load_##type##_unaligned(const void *p) \
{ \
- return ((const struct type##_unaligned *)p)->v; \
+ type v; \
+ memcpy(&v, p, sizeof(v)); \
+ return v; \
} \
\
-static inline void \
-store_##type##_unaligned(type val, void *p) \
+static forceinline void \
+store_##type##_unaligned(type v, void *p) \
{ \
- ((struct type##_unaligned *)p)->v = val; \
+ memcpy(p, &v, sizeof(v)); \
}
DEFINE_UNALIGNED_TYPE(u16);
#define load_word_unaligned load_machine_word_t_unaligned
#define store_word_unaligned store_machine_word_t_unaligned
-static inline u16
-get_unaligned_u16_le(const void *p)
+static forceinline u16
+get_unaligned_le16(const u8 *p)
{
- u16 v;
-
- if (UNALIGNED_ACCESS_IS_FAST) {
- v = le16_to_cpu(load_le16_unaligned(p));
- } else {
- const u8 *p8 = p;
- v = 0;
- v |= (u16)p8[0] << 0;
- v |= (u16)p8[1] << 8;
- }
- return v;
+ if (UNALIGNED_ACCESS_IS_FAST)
+ return le16_to_cpu(load_le16_unaligned(p));
+ else
+ return ((u16)p[1] << 8) | p[0];
}
-static inline u32
-get_unaligned_u32_le(const void *p)
+static forceinline u32
+get_unaligned_le32(const u8 *p)
{
- u32 v;
-
- if (UNALIGNED_ACCESS_IS_FAST) {
- v = le32_to_cpu(load_le32_unaligned(p));
- } else {
- const u8 *p8 = p;
- v = 0;
- v |= (u32)p8[0] << 0;
- v |= (u32)p8[1] << 8;
- v |= (u32)p8[2] << 16;
- v |= (u32)p8[3] << 24;
- }
- return v;
+ if (UNALIGNED_ACCESS_IS_FAST)
+ return le32_to_cpu(load_le32_unaligned(p));
+ else
+ return ((u32)p[3] << 24) | ((u32)p[2] << 16) |
+ ((u32)p[1] << 8) | p[0];
}
-static inline void
-put_unaligned_u16_le(u16 v, void *p)
+static forceinline void
+put_unaligned_le16(u16 v, u8 *p)
{
if (UNALIGNED_ACCESS_IS_FAST) {
store_le16_unaligned(cpu_to_le16(v), p);
} else {
- u8 *p8 = p;
- p8[0] = (v >> 0) & 0xFF;
- p8[1] = (v >> 8) & 0xFF;
+ p[0] = (u8)(v >> 0);
+ p[1] = (u8)(v >> 8);
}
}
-static inline void
-put_unaligned_u32_le(u32 v, void *p)
+static forceinline void
+put_unaligned_le32(u32 v, u8 *p)
{
if (UNALIGNED_ACCESS_IS_FAST) {
store_le32_unaligned(cpu_to_le32(v), p);
} else {
- u8 *p8 = p;
- p8[0] = (v >> 0) & 0xFF;
- p8[1] = (v >> 8) & 0xFF;
- p8[2] = (v >> 16) & 0xFF;
- p8[3] = (v >> 24) & 0xFF;
+ p[0] = (u8)(v >> 0);
+ p[1] = (u8)(v >> 8);
+ p[2] = (u8)(v >> 16);
+ p[3] = (u8)(v >> 24);
}
}
-/*
- * Given a 32-bit value that was loaded with the platform's native endianness,
- * return a 32-bit value whose high-order 8 bits are 0 and whose low-order 24
- * bits contain the first 3 bytes, arranged in octets in a platform-dependent
- * order, at the memory location from which the input 32-bit value was loaded.
- */
-static inline u32
-loaded_u32_to_u24(u32 v)
-{
- if (CPU_IS_LITTLE_ENDIAN)
- return v & 0xFFFFFF;
- else
- return v >> 8;
-}
-
-/*
- * Load the next 3 bytes from the memory location @p into the 24 low-order bits
- * of a 32-bit value. The order in which the 3 bytes will be arranged as octets
- * in the 24 bits is platform-dependent. At least LOAD_U24_REQUIRED_NBYTES
- * bytes must be available at @p; note that this may be more than 3.
- */
-static inline u32
-load_u24_unaligned(const u8 *p)
-{
-#if UNALIGNED_ACCESS_IS_FAST
-# define LOAD_U24_REQUIRED_NBYTES 4
- return loaded_u32_to_u24(load_u32_unaligned(p));
-#else
-# define LOAD_U24_REQUIRED_NBYTES 3
- return ((u32)p[0] << 0) | ((u32)p[1] << 8) | ((u32)p[2] << 16);
-#endif
-}
-
-
#endif /* _WIMLIB_UNALIGNED_H */
git://wimlib.net / wimlib / blobdiff