1) lpc.c, FLAC__lpc_quantize_coefficients(): This function declares "const int nshift = -(*shift)" variable when *shift is less than 0. Then nshift is used in the loop:
for(i = 0; i < order; i++) {
error += lp_coeff[i] / (1 << nshift);
This patch adds "const int pshift = *shift" variable.
Pros:
* more symmetry for two branches
* compiler doesn't know that lp_coeff[] and *shift
don't alias, so the code for
error += lp_coeff[i] * (1 << *shift);
is less efficient than for
error += lp_coeff[i] * (1 << pshift);
Cons:
* the speed increase is probably negligible
2)
There's the following code in stream_decoder.c:
if(order <= 8)
decoder->private_->local_lpc_restore_signal_16bit_order8( ... );
else
decoder->private_->local_lpc_restore_signal_16bit( ... );
but local_lpc_restore_signal_16bit is equal to ..._order8 for all
architectures except powerpc/altivec.
The patch hides local_lpc_restore_signal_16bit_order8 under
#ifdef FLAC__CPU_PPC / #endif directives.
Pros:
* one branch less
Cons:
* the same as for the 1st patch: the speed increase is probably negligible
lpc_shift.patch
Description: Binary data
ppc_order8.patch
Description: Binary data
_______________________________________________ flac-dev mailing list flac-dev@xiph.org http://lists.xiph.org/mailman/listinfo/flac-dev
