This patch can be controversial, by assuming floats are IEEE-754 and
particular behaviour of the FPU will get in the way.
Timing on Arrandale and Win32 (thus, x87 FPU is used in the reference).
sbr_qmf_pre_shuffle_c: 115 to 76
sbr_neg_odd_64_c: 84 to 55
sbr_qmf_post_shuffle_c: 112 to 83
Signed-off-by: Diego Biurrun <diego@biurrun.de>
#include "config.h"
#include "libavutil/attributes.h"
#include "config.h"
#include "libavutil/attributes.h"
+#include "libavutil/intfloat.h"
#include "sbrdsp.h"
static void sbr_sum64x5_c(float *z)
#include "sbrdsp.h"
static void sbr_sum64x5_c(float *z)
static void sbr_neg_odd_64_c(float *x)
{
static void sbr_neg_odd_64_c(float *x)
{
+ union av_intfloat32 *xi = (union av_intfloat32*) x;
- for (i = 1; i < 64; i += 2)
- x[i] = -x[i];
+ for (i = 1; i < 64; i += 4) {
+ xi[i + 0].i ^= 1U << 31;
+ xi[i + 2].i ^= 1U << 31;
+ }
}
static void sbr_qmf_pre_shuffle_c(float *z)
{
}
static void sbr_qmf_pre_shuffle_c(float *z)
{
+ union av_intfloat32 *zi = (union av_intfloat32*) z;
- z[64] = z[0];
- z[65] = z[1];
- for (k = 1; k < 32; k++) {
- z[64+2*k ] = -z[64 - k];
- z[64+2*k+1] = z[ k + 1];
+ zi[64].i = zi[0].i;
+ zi[65].i = zi[1].i;
+ for (k = 1; k < 31; k += 2) {
+ zi[64 + 2 * k + 0].i = zi[64 - k].i ^ (1U << 31);
+ zi[64 + 2 * k + 1].i = zi[ k + 1].i;
+ zi[64 + 2 * k + 2].i = zi[63 - k].i ^ (1U << 31);
+ zi[64 + 2 * k + 3].i = zi[ k + 2].i;
+ zi[64 + 2 * 31 + 0].i = zi[64 - 31].i ^ (1U << 31);
+ zi[64 + 2 * 31 + 1].i = zi[31 + 1].i;
}
static void sbr_qmf_post_shuffle_c(float W[32][2], const float *z)
{
}
static void sbr_qmf_post_shuffle_c(float W[32][2], const float *z)
{
+ const union av_intfloat32 *zi = (const union av_intfloat32*) z;
+ union av_intfloat32 *Wi = (union av_intfloat32*) W;
- for (k = 0; k < 32; k++) {
- W[k][0] = -z[63-k];
- W[k][1] = z[k];
+ for (k = 0; k < 32; k += 2) {
+ Wi[2 * k + 0].i = zi[63 - k].i ^ (1U << 31);
+ Wi[2 * k + 1].i = zi[ k + 0].i;
+ Wi[2 * k + 2].i = zi[62 - k].i ^ (1U << 31);
+ Wi[2 * k + 3].i = zi[ k + 1].i;
}
}
static void sbr_qmf_deint_neg_c(float *v, const float *src)
{
}
}
static void sbr_qmf_deint_neg_c(float *v, const float *src)
{
+ const union av_intfloat32 *si = (const union av_intfloat32*)src;
+ union av_intfloat32 *vi = (union av_intfloat32*)v;
int i;
for (i = 0; i < 32; i++) {
int i;
for (i = 0; i < 32; i++) {
- v[ i] = src[63 - 2*i ];
- v[63 - i] = -src[63 - 2*i - 1];
+ vi[ i].i = si[63 - 2 * i ].i;
+ vi[63 - i].i = si[63 - 2 * i - 1].i ^ (1U << 31);