compiler.h: remove concept of different unaligned access speeds

[wimlib] / include / wimlib / decompress_common.h

diff --git a/include/wimlib/decompress_common.h b/include/wimlib/decompress_common.h
index 420f7f41e3adf8a207248241a41aee0db3ee3879..54241b36592495106ff7d2efc5970e3d84b52c20 100644 (file)
--- a/include/wimlib/decompress_common.h
+++ b/include/wimlib/decompress_common.h
@@ -10,6 +10,8 @@
 #ifndef _WIMLIB_DECOMPRESS_COMMON_H
 #define _WIMLIB_DECOMPRESS_COMMON_H
 
+#include <string.h>
+
 #include "wimlib/compiler.h"
 #include "wimlib/types.h"
 #include "wimlib/unaligned.h"
@@ -65,7 +67,7 @@ bitstream_ensure_bits(struct input_bitstream *is, const unsigned num_bits)
        if (unlikely(is->end - is->next < 2))
                goto overflow;
 
-       is->bitbuf |= (u32)get_unaligned_u16_le(is->next) << (16 - is->bitsleft);
+       is->bitbuf |= (u32)get_unaligned_le16(is->next) << (16 - is->bitsleft);
        is->next += 2;
        is->bitsleft += 16;
 
@@ -73,7 +75,7 @@ bitstream_ensure_bits(struct input_bitstream *is, const unsigned num_bits)
                if (unlikely(is->end - is->next < 2))
                        goto overflow;
 
-               is->bitbuf |= (u32)get_unaligned_u16_le(is->next);
+               is->bitbuf |= (u32)get_unaligned_le16(is->next);
                is->next += 2;
                is->bitsleft = 32;
        }
@@ -90,9 +92,7 @@ overflow:
 static inline u32
 bitstream_peek_bits(const struct input_bitstream *is, const unsigned num_bits)
 {
-       if (unlikely(num_bits == 0))
-               return 0;
-       return is->bitbuf >> (32 - num_bits);
+       return (is->bitbuf >> 1) >> (sizeof(is->bitbuf) * 8 - num_bits - 1);
 }
 
 /* Remove @num_bits from the bitstream.  There must be at least @num_bits
@@ -141,7 +141,7 @@ bitstream_read_u16(struct input_bitstream *is)
 
        if (unlikely(is->end - is->next < 2))
                return 0;
-       v = get_unaligned_u16_le(is->next);
+       v = get_unaligned_le16(is->next);
        is->next += 2;
        return v;
 }
@@ -154,23 +154,22 @@ bitstream_read_u32(struct input_bitstream *is)
 
        if (unlikely(is->end - is->next < 4))
                return 0;
-       v = get_unaligned_u32_le(is->next);
+       v = get_unaligned_le32(is->next);
        is->next += 4;
        return v;
 }
 
-/* Read an array of literal bytes embedded in the bitstream.  Return a pointer
- * to the resulting array, or NULL if the read overflows the input buffer.  */
-static inline const u8 *
-bitstream_read_bytes(struct input_bitstream *is, size_t count)
+/* Read into @dst_buffer an array of literal bytes embedded in the bitstream.
+ * Return either a pointer to the byte past the last written, or NULL if the
+ * read overflows the input buffer.  */
+static inline void *
+bitstream_read_bytes(struct input_bitstream *is, void *dst_buffer, size_t count)
 {
-       const u8 *p;
-
        if (unlikely(is->end - is->next < count))
                return NULL;
-       p = is->next;
+       memcpy(dst_buffer, is->next, count);
        is->next += count;
-       return p;
+       return (u8 *)dst_buffer + count;
 }
 
 /* Align the input bitstream on a coding-unit boundary.  */
@@ -262,7 +261,7 @@ repeat_byte(u8 b)
 {
        machine_word_t v;
 
-       BUILD_BUG_ON(WORDSIZE != 4 && WORDSIZE != 8);
+       STATIC_ASSERT(WORDSIZE == 4 || WORDSIZE == 8);
 
        v = b;
        v |= v << 8;
@@ -300,7 +299,7 @@ lz_copy(u8 *dst, u32 length, u32 offset, const u8 *winend, u32 min_length)
         * beyond the end of the output buffer, hence the check for (winend -
         * end >= WORDSIZE - 1).
         */
-       if (UNALIGNED_ACCESS_IS_VERY_FAST &&
+       if (UNALIGNED_ACCESS_IS_FAST &&
            likely(winend - end >= WORDSIZE - 1))
        {