SQLite

Check-in [e42ed9b4ad]
Login

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Overview
Comment:An example showing how to improve performance of sqlite3VdbeSerialPut() using the GCC intrinsic function __builtin_bswap64().
Downloads: Tarball | ZIP archive
Timelines: family | ancestors | builtin-bswap64
Files: files | file ages | folders
SHA1: e42ed9b4adbf4a5cd4ce572d1015f3d2414053aa
User & Date: drh 2017-01-16 11:54:30.181
Context
2017-01-16
11:54
An example showing how to improve performance of sqlite3VdbeSerialPut() using the GCC intrinsic function __builtin_bswap64(). (Leaf check-in: e42ed9b4ad user: drh tags: builtin-bswap64)
2017-01-13
18:24
Fix a problem preventing resumption of RBU operations after recovering from a process or system failure that occurs during the incremental-checkpoint phase. (check-in: 97914266cb user: dan tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/vdbeaux.c.
︙︙
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354










3355
3356
3357
3358
3359
3360
3361
3362

**
** Return the number of bytes actually written into buf[].  The number
** of bytes in the zero-filled tail is included in the return value only
** if those bytes were zeroed in buf[].
*/ 
u32 sqlite3VdbeSerialPut(u8 *buf, Mem *pMem, u32 serial_type){
  u32 len;

  /* Integer and Real */
  if( serial_type<=7 && serial_type>0 ){
    u64 v;
    u32 i;
    if( serial_type==7 ){
      assert( sizeof(v)==sizeof(pMem->u.r) );
      memcpy(&v, &pMem->u.r, sizeof(v));
      swapMixedEndianFloat(v);
    }else{
      v = pMem->u.i;
    }
    len = i = sqlite3SmallTypeSizes[serial_type];
    assert( i>0 );
    do{
      buf[--i] = (u8)(v&0xFF);
      v >>= 8;
    }while( i );
    return len;
  }

  /* String or blob */
  if( serial_type>=12 ){
    assert( pMem->n + ((pMem->flags & MEM_Zero)?pMem->u.nZero:0)
             == (int)sqlite3VdbeSerialTypeLen(serial_type) );
    len = pMem->n;
    if( len>0 ) memcpy(buf, pMem->z, len);
    return len;
  }

  /* NULL or constants 0 or 1 */










  return 0;
}

/* Input "x" is a sequence of unsigned characters that represent a
** big-endian integer.  Return the equivalent native integer
*/
#define ONE_BYTE_INT(x)    ((i8)(x)[0])
#define TWO_BYTE_INT(x)    (256*(i8)((x)[0])|(x)[1])








<
<
<
|
|
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<










|
>
>
>
>
>
>
>
>
>
>
|








3317
3318
3319
3320
3321
3322
3323



3324
3325















3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354

**
** Return the number of bytes actually written into buf[].  The number
** of bytes in the zero-filled tail is included in the return value only
** if those bytes were zeroed in buf[].
*/ 
u32 sqlite3VdbeSerialPut(u8 *buf, Mem *pMem, u32 serial_type){
  u32 len;



  u64 v;
  u32 i;
















  /* String or blob */
  if( serial_type>=12 ){
    assert( pMem->n + ((pMem->flags & MEM_Zero)?pMem->u.nZero:0)
             == (int)sqlite3VdbeSerialTypeLen(serial_type) );
    len = pMem->n;
    if( len>0 ) memcpy(buf, pMem->z, len);
    return len;
  }

  /* Integer and Real */
  if( serial_type==7 ){
    assert( sizeof(v)==sizeof(pMem->u.r) );
    memcpy(&v, &pMem->u.r, sizeof(v));
    swapMixedEndianFloat(v);
  }else{
    v = pMem->u.i;
  }
  len = i = sqlite3SmallTypeSizes[serial_type];
  v = __builtin_bswap64(v);
  memcpy(buf, &((char*)&v)[8-i], i);
  return len;
}

/* Input "x" is a sequence of unsigned characters that represent a
** big-endian integer.  Return the equivalent native integer
*/
#define ONE_BYTE_INT(x)    ((i8)(x)[0])
#define TWO_BYTE_INT(x)    (256*(i8)((x)[0])|(x)[1])
︙︙