yes, a mere 2 years later it is checked in!
speed improvement for me is roughly 17% testing flac files on
linux-i386.
Josh
--- Miroslav Lichvar <[EMAIL PROTECTED]> wrote:
> On Thu, Jan 30, 2003 at 10:35:29PM +0100, Miroslav Lichvar wrote:
> > Ok, here is a patch waiting for new CVS :). It works fine for me,
> but
> > please check it before commiting...
>
> Here is slightly better version of the patch.
>
> --
> Miroslav Lichvar
> > Index: src/libFLAC/bitbuffer.c
> ===================================================================
> RCS file: /cvsroot/flac/flac/src/libFLAC/bitbuffer.c,v
> retrieving revision 1.51
> diff -u -r1.51 bitbuffer.c
> --- src/libFLAC/bitbuffer.c 31 Jan 2003 23:34:57 -0000 1.51
> +++ src/libFLAC/bitbuffer.c 6 Feb 2003 17:08:42 -0000
> @@ -63,6 +63,25 @@
> */
> static const unsigned FLAC__BITBUFFER_DEFAULT_CAPACITY = ((65536 -
> 64) * 8) / FLAC__BITS_PER_BLURB; /* blurbs */
>
> +static const unsigned char byte_to_unary_table[] = {
> + 8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4,
> + 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
> + 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
> + 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
> + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
> + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
> + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
> + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
> + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
> +};
> +
> #if FLAC__BITS_PER_BLURB == 8
> #define FLAC__BITS_PER_BLURB_LOG2 3
> #define FLAC__BYTES_PER_BLURB 1
> @@ -70,6 +89,7 @@
> #define FLAC__BLURB_TOP_BIT_ONE ((FLAC__byte)0x80)
> #define BLURB_BIT_TO_MASK(b) (((FLAC__blurb)'\x80') >> (b))
> #define CRC16_UPDATE_BLURB(bb, blurb, crc)
> FLAC__CRC16_UPDATE((blurb), (crc));
> +#define FLAC__ALIGNED_BLURB_UNARY(blurb)
> (byte_to_unary_table[blurb])
> #elif FLAC__BITS_PER_BLURB == 32
> #define FLAC__BITS_PER_BLURB_LOG2 5
> #define FLAC__BYTES_PER_BLURB 4
> @@ -77,6 +97,7 @@
> #define FLAC__BLURB_TOP_BIT_ONE ((FLAC__uint32)0x80000000)
> #define BLURB_BIT_TO_MASK(b) (((FLAC__blurb)0x80000000) >> (b))
> #define CRC16_UPDATE_BLURB(bb, blurb, crc) crc16_update_blurb((bb),
> (blurb));
> +#define FLAC__ALIGNED_BLURB_UNARY(blurb) ((blurb) <= 0xff ?
> byte_to_unary_table[blurb] + 24 : ((blurb) <= 0xffff ?
> byte_to_unary_table[(blurb) >> 8] + 16 : ((blurb) <= 0xffffff ?
> byte_to_unary_table[(blurb) >> 16] + 8 : byte_to_unary_table[(blurb)
> >> 24])))
> #else
> /* ERROR, only sizes of 8 and 32 are supported */
> #endif
> @@ -2102,114 +2123,16 @@
> if(nvals == 0)
> return true;
>
> + cbits = bb->consumed_bits;
> i = bb->consumed_blurbs;
> - /*
> - * We unroll the main loop to take care of partially consumed
> blurbs here.
> - */
> - if(bb->consumed_bits > 0) {
> - save_blurb = blurb = buffer[i];
> - cbits = bb->consumed_bits;
> - blurb <<= cbits;
> -
> - while(1) {
> - if(state == 0) {
> - if(blurb) {
> - for(j = 0; !(blurb &
> FLAC__BLURB_TOP_BIT_ONE); j++)
> - blurb <<= 1;
> - msbs += j;
> -
> - /* dispose of the unary end bit */
> - blurb <<= 1;
> - j++;
> - cbits += j;
> -
> - uval = 0;
> - lsbs_left = parameter;
> - state++;
> - if(cbits == FLAC__BITS_PER_BLURB) {
> - cbits = 0;
> - CRC16_UPDATE_BLURB(bb,
> save_blurb, bb->read_crc16);
> - break;
> - }
> - }
> - else {
> - msbs += FLAC__BITS_PER_BLURB - cbits;
> - cbits = 0;
> - CRC16_UPDATE_BLURB(bb, save_blurb,
> bb->read_crc16);
> - break;
> - }
> - }
> - else {
> - const unsigned available_bits =
> FLAC__BITS_PER_BLURB - cbits;
> - if(lsbs_left >= available_bits) {
> - uval <<= available_bits;
> - uval |= (blurb >> cbits);
> - cbits = 0;
> - CRC16_UPDATE_BLURB(bb, save_blurb,
> bb->read_crc16);
> -
> - if(lsbs_left == available_bits) {
> - /* compose the value */
> - uval |= (msbs << parameter);
> - if(uval & 1)
> - vals[val_i++] =
> -((int)(uval >> 1)) - 1;
> - else
> - vals[val_i++] =
> (int)(uval >> 1);
> - if(val_i == nvals)
> - break;
> -
> - msbs = 0;
> - state = 0;
> - }
> -
> - lsbs_left -= available_bits;
> - break;
> - }
> - else {
> - uval <<= lsbs_left;
> - uval |= (blurb >> (FLAC__BITS_PER_BLURB
> - lsbs_left));
> - blurb <<= lsbs_left;
> - cbits += lsbs_left;
> -
> - /* compose the value */
> - uval |= (msbs << parameter);
> - if(uval & 1)
> - vals[val_i++] = -((int)(uval >>
> 1)) - 1;
> - else
> - vals[val_i++] = (int)(uval >>
> 1);
> - if(val_i == nvals) {
> - /* back up one if we exited the
> for loop because we read all
> nvals but the end came in the middle of a blurb */
> - i--;
> - break;
> - }
> -
> - msbs = 0;
> - state = 0;
> - }
> - }
> - }
> - i++;
> -
> - bb->consumed_blurbs = i;
> - bb->consumed_bits = cbits;
> - bb->total_consumed_bits = (i << FLAC__BITS_PER_BLURB_LOG2) |
> cbits;
> - }
> -
> - /*
> - * Now that we are blurb-aligned the logic is slightly simpler
> - */
> while(val_i < nvals) {
> - for( ; i < bb->blurbs && val_i < nvals; i++) {
> - save_blurb = blurb = buffer[i];
> - cbits = 0;
> + for( ; i < bb->blurbs; i++) {
> + blurb = (save_blurb = buffer[i]) << cbits;
> while(1) {
> if(state == 0) {
> if(blurb) {
> - for(j = 0; !(blurb &
> FLAC__BLURB_TOP_BIT_ONE); j++)
> - blurb <<= 1;
> + j =
> FLAC__ALIGNED_BLURB_UNARY(blurb);
> msbs += j;
> -
> - /* dispose of the unary end bit
> */
> - blurb <<= 1;
> j++;
> cbits += j;
>
> @@ -2221,6 +2144,7 @@
> CRC16_UPDATE_BLURB(bb,
> save_blurb, bb->read_crc16);
> break;
> }
> + blurb <<= j;
> }
> else {
> msbs += FLAC__BITS_PER_BLURB -
> cbits;
> @@ -2240,12 +2164,11 @@
> if(lsbs_left == available_bits)
> {
> /* compose the value */
> uval |= (msbs <<
> parameter);
> - if(uval & 1)
> - vals[val_i++] =
> -((int)(uval >> 1)) - 1;
> - else
> - vals[val_i++] =
> (int)(uval >> 1);
> - if(val_i == nvals)
> - break;
> + vals[val_i++] =
> (int)(uval >> 1 ^ -(int)(uval & 1));
> + if(val_i == nvals) {
> + i++;
> + goto break2;
>
=== message truncated ===
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