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Improve endswapping (especially purge ntohl).

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This commit is contained in:
Erik de Castro Lopo
2012-02-04 22:06:23 +11:00
parent a3f43aaa7c
commit a5d1d4f0c5
4 changed files with 58 additions and 87 deletions
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60
src/libFLAC/bitreader.c
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@@ -33,24 +33,13 @@
# include <config.h>
#endif
#include <stdlib.h> /* for malloc() */
#include <string.h> /* for memcpy(), memset() */
#ifdef _MSC_VER
# include <winsock.h> /* for ntohl() */
# if _MSC_VER >= 1310
# include <winsock2.h> /* for ntohl(), sometimes it is not in winsock.h */
# endif
#elif defined FLAC__SYS_DARWIN
# include <machine/endian.h> /* for ntohl() */
#elif defined __MINGW32__
# include <winsock.h> /* for ntohl() */
#else
# include <netinet/in.h> /* for ntohl() */
#endif
#include <stdlib.h>
#include <string.h>
#include "private/bitmath.h"
#include "private/bitreader.h"
#include "private/crc.h"
#include "FLAC/assert.h"
#include "share/endswap.h"
/* Things should be fastest when this matches the machine word size */
/* WATCHOUT: if you change this you must also change the following #defines down to COUNT_ZERO_MSBS below to match */
@@ -64,11 +53,7 @@ typedef FLAC__uint32 brword;
#if WORDS_BIGENDIAN
#define SWAP_BE_WORD_TO_HOST(x) (x)
#else
#ifdef _MSC_VER
#define SWAP_BE_WORD_TO_HOST(x) local_swap32_(x)
#else
#define SWAP_BE_WORD_TO_HOST(x) ntohl(x)
#endif
#define SWAP_BE_WORD_TO_HOST(x) ENDSWAP_INT(x)
#endif
/* counts the # of zero MSBs in a word */
#define COUNT_ZERO_MSBS(word) ( \
@@ -152,36 +137,6 @@ struct FLAC__BitReader {
FLAC__CPUInfo cpu_info;
};
#ifdef _MSC_VER
/* OPT: an MSVC built-in would be better */
/* OPT: use _byteswap_ulong intrinsic? */
static _inline FLAC__uint32 local_swap32_(FLAC__uint32 x)
{
x = ((x<<8)&0xFF00FF00) | ((x>>8)&0x00FF00FF);
return (x>>16) | (x<<16);
}
#ifdef _WIN64
#else
static void local_swap32_block_(FLAC__uint32 *start, FLAC__uint32 len)
{
__asm {
mov edx, start
mov ecx, len
test ecx, ecx
loop1:
jz done1
mov eax, [edx]
bswap eax
mov [edx], eax
add edx, 4
dec ecx
jmp short loop1
done1:
}
}
#endif
#endif
static FLaC__INLINE void crc16_update_word_(FLAC__BitReader *br, brword word)
{
register unsigned crc = br->read_crc16;
@@ -270,13 +225,6 @@ FLAC__bool bitreader_read_from_client_(FLAC__BitReader *br)
#if WORDS_BIGENDIAN
#else
end = (br->words*FLAC__BYTES_PER_WORD + br->bytes + bytes + (FLAC__BYTES_PER_WORD-1)) / FLAC__BYTES_PER_WORD;
# if defined(_MSC_VER) && !defined(_WIN64) && (FLAC__BYTES_PER_WORD == 4)
if(br->cpu_info.type == FLAC__CPUINFO_TYPE_IA32 && br->cpu_info.data.ia32.bswap) {
start = br->words;
local_swap32_block_(br->buffer + start, end - start);
}
else
# endif
for(start = br->words; start < end; start++)
br->buffer[start] = SWAP_BE_WORD_TO_HOST(br->buffer[start]);
#endif