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Special version of 'bitrv2' when len is 128:

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* 5.5% AEC overall speedup for the straight C path.
* 8.6% AEC overall speedup for the SSE2 path.
Review URL: https://webrtc-codereview.appspot.com/480001

git-svn-id: http://webrtc.googlecode.com/svn/trunk@2004 4adac7df-926f-26a2-2b94-8c16560cd09d
This commit is contained in:
cd@webrtc.org 2012-04-10 21:25:17 +00:00
parent 5d8c102899
commit 85b4a1b715
1 changed files with 79 additions and 9 deletions
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88
src/modules/audio_processing/aec/aec_rdft.c
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@ -42,8 +42,8 @@ ALIGN16_BEG float ALIGN16_END cftmdl_wk1r[4];
static int ip[16];
static void bitrv2_32or128(int n, int *ip, float *a) {
// n is 32 or 128
static void bitrv2_32(int *ip, float *a) {
const int n = 32;
int j, j1, k, k1, m, m2;
float xr, xi, yr, yi;
@ -116,6 +116,80 @@ static void bitrv2_32or128(int n, int *ip, float *a) {
}
}
static void bitrv2_128(float *a) {
/*
Following things have been attempted but are no faster:
(a) Storing the swap indexes in a LUT (index calculations are done
for 'free' while waiting on memory/L1).
(b) Consolidate the load/store of two consecutive floats by a 64 bit
integer (execution is memory/L1 bound).
(c) Do a mix of floats and 64 bit integer to maximize register
utilization (execution is memory/L1 bound).
(d) Replacing ip[i] by ((k<<31)>>25) + ((k >> 1)<<5).
(e) Hard-coding of the offsets to completely eliminates index
calculations.
*/
unsigned int j, j1, k, k1;
float xr, xi, yr, yi;
static const int ip[4] = {0, 64, 32, 96};
for (k = 0; k < 4; k++) {
for (j = 0; j < k; j++) {
j1 = 2 * j + ip[k];
k1 = 2 * k + ip[j];
xr = a[j1 + 0];
xi = a[j1 + 1];
yr = a[k1 + 0];
yi = a[k1 + 1];
a[j1 + 0] = yr;
a[j1 + 1] = yi;
a[k1 + 0] = xr;
a[k1 + 1] = xi;
j1 += 8;
k1 += 16;
xr = a[j1 + 0];
xi = a[j1 + 1];
yr = a[k1 + 0];
yi = a[k1 + 1];
a[j1 + 0] = yr;
a[j1 + 1] = yi;
a[k1 + 0] = xr;
a[k1 + 1] = xi;
j1 += 8;
k1 -= 8;
xr = a[j1 + 0];
xi = a[j1 + 1];
yr = a[k1 + 0];
yi = a[k1 + 1];
a[j1 + 0] = yr;
a[j1 + 1] = yi;
a[k1 + 0] = xr;
a[k1 + 1] = xi;
j1 += 8;
k1 += 16;
xr = a[j1 + 0];
xi = a[j1 + 1];
yr = a[k1 + 0];
yi = a[k1 + 1];
a[j1 + 0] = yr;
a[j1 + 1] = yi;
a[k1 + 0] = xr;
a[k1 + 1] = xi;
}
j1 = 2 * k + 8 + ip[k];
k1 = j1 + 8;
xr = a[j1 + 0];
xi = a[j1 + 1];
yr = a[k1 + 0];
yi = a[k1 + 1];
a[j1 + 0] = yr;
a[j1 + 1] = yi;
a[k1 + 0] = xr;
a[k1 + 1] = xi;
}
}
static void makewt_32(void) {
const int nw = 32;
int j, nwh;
@ -137,7 +211,7 @@ static void makewt_32(void) {
rdft_w[nw - j] = y;
rdft_w[nw - j + 1] = x;
}
bitrv2_32or128(nw, ip + 2, rdft_w);
bitrv2_32(ip + 2, rdft_w);
// pre-calculate constants used by cft1st_128 and cftmdl_128...
cftmdl_wk1r[0] = rdft_w[2];
@ -544,10 +618,8 @@ static void rftbsub_128_C(float *a) {
}
void aec_rdft_forward_128(float *a) {
const int n = 128;
float xi;
bitrv2_32or128(n, ip + 2, a);
bitrv2_128(a);
cftfsub_128(a);
rftfsub_128(a);
xi = a[0] - a[1];
@ -556,12 +628,10 @@ void aec_rdft_forward_128(float *a) {
}
void aec_rdft_inverse_128(float *a) {
const int n = 128;
a[1] = 0.5f * (a[0] - a[1]);
a[0] -= a[1];
rftbsub_128(a);
bitrv2_32or128(n, ip + 2, a);
bitrv2_128(a);
cftbsub_128(a);
}