Neon version of FilterAdaptation()
The performance gain on a Nexus 7 reported by audioproc is ~5.2%.
The output is bit exact.
Measured total of 15% speed gain on N7 compared to C.
R=bjornv@webrtc.org, cd@webrtc.org
Review URL: https://webrtc-codereview.appspot.com/17699004
Patch from Scott LaVarnway <slavarnw@gmail.com>.
git-svn-id: http://webrtc.googlecode.com/svn/trunk@6480 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/modules/audio_processing/aec/aec_core_neon.c b/webrtc/modules/audio_processing/aec/aec_core_neon.c
index d751a4b..cec0a7e 100644
--- a/webrtc/modules/audio_processing/aec/aec_core_neon.c
+++ b/webrtc/modules/audio_processing/aec/aec_core_neon.c
@@ -18,6 +18,7 @@
#include <arm_neon.h>
#include <math.h>
+#include <string.h> // memset
#include "webrtc/modules/audio_processing/aec/aec_core_internal.h"
#include "webrtc/modules/audio_processing/aec/aec_rdft.h"
@@ -25,6 +26,85 @@
enum { kShiftExponentIntoTopMantissa = 8 };
enum { kFloatExponentShift = 23 };
+__inline static float MulRe(float aRe, float aIm, float bRe, float bIm) {
+ return aRe * bRe - aIm * bIm;
+}
+
+static void FilterAdaptationNEON(AecCore* aec,
+ float* fft,
+ float ef[2][PART_LEN1]) {
+ int i;
+ const int num_partitions = aec->num_partitions;
+ for (i = 0; i < num_partitions; i++) {
+ int xPos = (i + aec->xfBufBlockPos) * PART_LEN1;
+ int pos = i * PART_LEN1;
+ int j;
+ // Check for wrap
+ if (i + aec->xfBufBlockPos >= num_partitions) {
+ xPos -= num_partitions * PART_LEN1;
+ }
+
+ // Process the whole array...
+ for (j = 0; j < PART_LEN; j += 4) {
+ // Load xfBuf and ef.
+ const float32x4_t xfBuf_re = vld1q_f32(&aec->xfBuf[0][xPos + j]);
+ const float32x4_t xfBuf_im = vld1q_f32(&aec->xfBuf[1][xPos + j]);
+ const float32x4_t ef_re = vld1q_f32(&ef[0][j]);
+ const float32x4_t ef_im = vld1q_f32(&ef[1][j]);
+ // Calculate the product of conjugate(xfBuf) by ef.
+ // re(conjugate(a) * b) = aRe * bRe + aIm * bIm
+ // im(conjugate(a) * b)= aRe * bIm - aIm * bRe
+ const float32x4_t a = vmulq_f32(xfBuf_re, ef_re);
+ const float32x4_t e = vmlaq_f32(a, xfBuf_im, ef_im);
+ const float32x4_t c = vmulq_f32(xfBuf_re, ef_im);
+ const float32x4_t f = vmlsq_f32(c, xfBuf_im, ef_re);
+ // Interleave real and imaginary parts.
+ const float32x4x2_t g_n_h = vzipq_f32(e, f);
+ // Store
+ vst1q_f32(&fft[2 * j + 0], g_n_h.val[0]);
+ vst1q_f32(&fft[2 * j + 4], g_n_h.val[1]);
+ }
+ // ... and fixup the first imaginary entry.
+ fft[1] = MulRe(aec->xfBuf[0][xPos + PART_LEN],
+ -aec->xfBuf[1][xPos + PART_LEN],
+ ef[0][PART_LEN],
+ ef[1][PART_LEN]);
+
+ aec_rdft_inverse_128(fft);
+ memset(fft + PART_LEN, 0, sizeof(float) * PART_LEN);
+
+ // fft scaling
+ {
+ const float scale = 2.0f / PART_LEN2;
+ const float32x4_t scale_ps = vmovq_n_f32(scale);
+ for (j = 0; j < PART_LEN; j += 4) {
+ const float32x4_t fft_ps = vld1q_f32(&fft[j]);
+ const float32x4_t fft_scale = vmulq_f32(fft_ps, scale_ps);
+ vst1q_f32(&fft[j], fft_scale);
+ }
+ }
+ aec_rdft_forward_128(fft);
+
+ {
+ const float wt1 = aec->wfBuf[1][pos];
+ aec->wfBuf[0][pos + PART_LEN] += fft[1];
+ for (j = 0; j < PART_LEN; j += 4) {
+ float32x4_t wtBuf_re = vld1q_f32(&aec->wfBuf[0][pos + j]);
+ float32x4_t wtBuf_im = vld1q_f32(&aec->wfBuf[1][pos + j]);
+ const float32x4_t fft0 = vld1q_f32(&fft[2 * j + 0]);
+ const float32x4_t fft4 = vld1q_f32(&fft[2 * j + 4]);
+ const float32x4x2_t fft_re_im = vuzpq_f32(fft0, fft4);
+ wtBuf_re = vaddq_f32(wtBuf_re, fft_re_im.val[0]);
+ wtBuf_im = vaddq_f32(wtBuf_im, fft_re_im.val[1]);
+
+ vst1q_f32(&aec->wfBuf[0][pos + j], wtBuf_re);
+ vst1q_f32(&aec->wfBuf[1][pos + j], wtBuf_im);
+ }
+ aec->wfBuf[1][pos] = wt1;
+ }
+ }
+}
+
extern const float WebRtcAec_weightCurve[65];
extern const float WebRtcAec_overDriveCurve[65];
@@ -218,6 +298,7 @@
}
void WebRtcAec_InitAec_neon(void) {
+ WebRtcAec_FilterAdaptation = FilterAdaptationNEON;
WebRtcAec_OverdriveAndSuppress = OverdriveAndSuppressNEON;
}
