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Optimization of 'rftbsub':

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* scalar optimization, vectorization.
* 0.5% AEC overall speedup for the straight C path.
* 2.8% AEC overall speedup for the SSE2 path.
Review URL: http://webrtc-codereview.appspot.com/48008

git-svn-id: http://webrtc.googlecode.com/svn/trunk@137 4adac7df-926f-26a2-2b94-8c16560cd09d
This commit is contained in:
cduvivier@google.com 2011-06-30 19:19:37 +00:00
parent 8ec2231979
commit 9d94116697
3 changed files with 116 additions and 26 deletions
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44
modules/audio_processing/aec/main/source/aec_rdft.c
View File

@ -449,36 +449,32 @@ static void rftfsub_128_C(float *a, float *c) {
}
}
static void rftbsub_128(float *a, int nc, float *c) {
const int n = 128;
int j, k, kk, ks, m;
static void rftbsub_128_C(float *a, float *c) {
int j1, j2, k1, k2;
float wkr, wki, xr, xi, yr, yi;
a[1] = -a[1];
m = n >> 1;
ks = 2 * nc / m;
kk = 0;
for (j = 2; j < m; j += 2) {
k = n - j;
kk += ks;
wkr = 0.5f - c[nc - kk];
wki = c[kk];
xr = a[j] - a[k];
xi = a[j + 1] + a[k + 1];
for (j1 = 1, j2 = 2; j2 < 64; j1 += 1, j2 += 2) {
k2 = 128 - j2;
k1 = 32 - j1;
wkr = 0.5f - c[k1];
wki = c[j1];
xr = a[j2 + 0] - a[k2 + 0];
xi = a[j2 + 1] + a[k2 + 1];
yr = wkr * xr + wki * xi;
yi = wkr * xi - wki * xr;
a[j] -= yr;
a[j + 1] = yi - a[j + 1];
a[k] += yr;
a[k + 1] = yi - a[k + 1];
a[j2 + 0] = a[j2 + 0] - yr;
a[j2 + 1] = yi - a[j2 + 1];
a[k2 + 0] = yr + a[k2 + 0];
a[k2 + 1] = yi - a[k2 + 1];
}
a[m + 1] = -a[m + 1];
a[65] = -a[65];
}
void aec_rdft_128(int isgn, float *a, int *ip, float *w)
{
const int n = 128;
int nw, nc;
int nw;
float xi;
nw = ip[0];
@ -486,9 +482,7 @@ void aec_rdft_128(int isgn, float *a, int *ip, float *w)
nw = n >> 2;
makewt(ip, w);
}
nc = ip[1];
if (n > (nc << 2)) {
nc = n >> 2;
if (n > (ip[1] << 2)) {
makect_32(ip, w + nw);
}
if (isgn >= 0) {
@ -501,17 +495,19 @@ void aec_rdft_128(int isgn, float *a, int *ip, float *w)
} else {
a[1] = 0.5f * (a[0] - a[1]);
a[0] -= a[1];
rftbsub_128(a, nc, w + nw);
rftbsub_128(a, w + nw);
bitrv2_32or128(n, ip + 2, a);
cftbsub_128(a, w);
}
}
// code path selection
rftfsub_128_t rftfsub_128;
rft_sub_128_t rftfsub_128;
rft_sub_128_t rftbsub_128;
void aec_rdft_init(void) {
rftfsub_128 = rftfsub_128_C;
rftbsub_128 = rftbsub_128_C;
if (WebRtc_GetCPUInfo(kSSE2)) {
#if defined(__SSE2__)
aec_rdft_init_sse2();

5
modules/audio_processing/aec/main/source/aec_rdft.h
View File

@ -9,8 +9,9 @@
*/
// code path selection function pointers
typedef void (*rftfsub_128_t)(float *a, float *c);
extern rftfsub_128_t rftfsub_128;
typedef void (*rft_sub_128_t)(float *a, float *c);
extern rft_sub_128_t rftfsub_128;
extern rft_sub_128_t rftbsub_128;
// entry points
void aec_rdft_init(void);

93
modules/audio_processing/aec/main/source/aec_rdft_sse2.c
View File

@ -109,6 +109,99 @@ static void rftfsub_128_SSE2(float *a, float *c) {
}
}
static void rftbsub_128_SSE2(float *a, float *c) {
int j1, j2, k1, k2;
float wkr, wki, xr, xi, yr, yi;
static const ALIGN16_BEG float ALIGN16_END k_half[4] =
{0.5f, 0.5f, 0.5f, 0.5f};
const __m128 mm_half = _mm_load_ps(k_half);
a[1] = -a[1];
// Vectorized code (four at once).
// Note: commented number are indexes for the first iteration of the loop.
for (j1 = 1, j2 = 2; j2 + 7 < 64; j1 += 4, j2 += 8) {
// Load 'wk'.
const __m128 c_j1 = _mm_loadu_ps(&c[ j1]); // 1, 2, 3, 4,
const __m128 c_k1 = _mm_loadu_ps(&c[29 - j1]); // 28, 29, 30, 31,
const __m128 wkrt = _mm_sub_ps(mm_half, c_k1); // 28, 29, 30, 31,
const __m128 wkr_ =
_mm_shuffle_ps(wkrt, wkrt, _MM_SHUFFLE(0, 1, 2, 3)); // 31, 30, 29, 28,
const __m128 wki_ = c_j1; // 1, 2, 3, 4,
// Load and shuffle 'a'.
const __m128 a_j2_0 = _mm_loadu_ps(&a[0 + j2]); // 2, 3, 4, 5,
const __m128 a_j2_4 = _mm_loadu_ps(&a[4 + j2]); // 6, 7, 8, 9,
const __m128 a_k2_0 = _mm_loadu_ps(&a[122 - j2]); // 120, 121, 122, 123,
const __m128 a_k2_4 = _mm_loadu_ps(&a[126 - j2]); // 124, 125, 126, 127,
const __m128 a_j2_p0 = _mm_shuffle_ps(a_j2_0, a_j2_4,
_MM_SHUFFLE(2, 0, 2 ,0)); // 2, 4, 6, 8,
const __m128 a_j2_p1 = _mm_shuffle_ps(a_j2_0, a_j2_4,
_MM_SHUFFLE(3, 1, 3 ,1)); // 3, 5, 7, 9,
const __m128 a_k2_p0 = _mm_shuffle_ps(a_k2_4, a_k2_0,
_MM_SHUFFLE(0, 2, 0 ,2)); // 126, 124, 122, 120,
const __m128 a_k2_p1 = _mm_shuffle_ps(a_k2_4, a_k2_0,
_MM_SHUFFLE(1, 3, 1 ,3)); // 127, 125, 123, 121,
// Calculate 'x'.
const __m128 xr_ = _mm_sub_ps(a_j2_p0, a_k2_p0);
// 2-126, 4-124, 6-122, 8-120,
const __m128 xi_ = _mm_add_ps(a_j2_p1, a_k2_p1);
// 3-127, 5-125, 7-123, 9-121,
// Calculate product into 'y'.
// yr = wkr * xr + wki * xi;
// yi = wkr * xi - wki * xr;
const __m128 a_ = _mm_mul_ps(wkr_, xr_);
const __m128 b_ = _mm_mul_ps(wki_, xi_);
const __m128 c_ = _mm_mul_ps(wkr_, xi_);
const __m128 d_ = _mm_mul_ps(wki_, xr_);
const __m128 yr_ = _mm_add_ps(a_, b_); // 2-126, 4-124, 6-122, 8-120,
const __m128 yi_ = _mm_sub_ps(c_, d_); // 3-127, 5-125, 7-123, 9-121,
// Update 'a'.
// a[j2 + 0] = a[j2 + 0] - yr;
// a[j2 + 1] = yi - a[j2 + 1];
// a[k2 + 0] = yr + a[k2 + 0];
// a[k2 + 1] = yi - a[k2 + 1];
const __m128 a_j2_p0n = _mm_sub_ps(a_j2_p0, yr_); // 2, 4, 6, 8,
const __m128 a_j2_p1n = _mm_sub_ps(yi_, a_j2_p1); // 3, 5, 7, 9,
const __m128 a_k2_p0n = _mm_add_ps(a_k2_p0, yr_); // 126, 124, 122, 120,
const __m128 a_k2_p1n = _mm_sub_ps(yi_, a_k2_p1); // 127, 125, 123, 121,
// Shuffle in right order and store.
// Shuffle in right order and store.
const __m128 a_j2_0n = _mm_unpacklo_ps(a_j2_p0n, a_j2_p1n);
// 2, 3, 4, 5,
const __m128 a_j2_4n = _mm_unpackhi_ps(a_j2_p0n, a_j2_p1n);
// 6, 7, 8, 9,
const __m128 a_k2_0nt = _mm_unpackhi_ps(a_k2_p0n, a_k2_p1n);
// 122, 123, 120, 121,
const __m128 a_k2_4nt = _mm_unpacklo_ps(a_k2_p0n, a_k2_p1n);
// 126, 127, 124, 125,
const __m128 a_k2_0n = _mm_shuffle_ps(a_k2_0nt, a_k2_0nt,
_MM_SHUFFLE(1, 0, 3 ,2)); // 120, 121, 122, 123,
const __m128 a_k2_4n = _mm_shuffle_ps(a_k2_4nt, a_k2_4nt,
_MM_SHUFFLE(1, 0, 3 ,2)); // 124, 125, 126, 127,
_mm_storeu_ps(&a[0 + j2], a_j2_0n);
_mm_storeu_ps(&a[4 + j2], a_j2_4n);
_mm_storeu_ps(&a[122 - j2], a_k2_0n);
_mm_storeu_ps(&a[126 - j2], a_k2_4n);
}
// Scalar code for the remaining items.
for (; j2 < 64; j1 += 1, j2 += 2) {
k2 = 128 - j2;
k1 = 32 - j1;
wkr = 0.5f - c[k1];
wki = c[j1];
xr = a[j2 + 0] - a[k2 + 0];
xi = a[j2 + 1] + a[k2 + 1];
yr = wkr * xr + wki * xi;
yi = wkr * xi - wki * xr;
a[j2 + 0] = a[j2 + 0] - yr;
a[j2 + 1] = yi - a[j2 + 1];
a[k2 + 0] = yr + a[k2 + 0];
a[k2 + 1] = yi - a[k2 + 1];
}
a[65] = -a[65];
}
void aec_rdft_init_sse2(void) {
rftfsub_128 = rftfsub_128_SSE2;
rftbsub_128 = rftbsub_128_SSE2;
}