Neon version of cft1st_128()
The performance gain on a Nexus 7 reported by audioproc is ~2%
See comments regarding the output.
R=bjornv@webrtc.org, cd@webrtc.org
Review URL: https://webrtc-codereview.appspot.com/21679004
Patch from Scott LaVarnway <slavarnw@gmail.com>.
git-svn-id: http://webrtc.googlecode.com/svn/trunk@6564 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/modules/audio_processing/aec/Android.mk b/webrtc/modules/audio_processing/aec/Android.mk
index 181e87d..b86ef5f 100644
--- a/webrtc/modules/audio_processing/aec/Android.mk
+++ b/webrtc/modules/audio_processing/aec/Android.mk
@@ -53,6 +53,7 @@
ifeq ($(WEBRTC_BUILD_NEON_LIBS),true)
LOCAL_SRC_FILES += \
- aec_core_neon.c
+ aec_core_neon.c \
+ aec_rdft_neon.c
endif # ifeq ($(WEBRTC_BUILD_NEON_LIBS),true)
diff --git a/webrtc/modules/audio_processing/aec/aec_rdft.c b/webrtc/modules/audio_processing/aec/aec_rdft.c
index 7731b37..5b1c221 100644
--- a/webrtc/modules/audio_processing/aec/aec_rdft.c
+++ b/webrtc/modules/audio_processing/aec/aec_rdft.c
@@ -287,6 +287,9 @@
float wk1r, wk1i, wk2r, wk2i, wk3r, wk3i;
float x0r, x0i, x1r, x1i, x2r, x2i, x3r, x3i;
+ // The processing of the first set of elements was simplified in C to avoid
+ // some operations (multiplication by zero or one, addition of two elements
+ // multiplied by the same weight, ...).
x0r = a[0] + a[2];
x0i = a[1] + a[3];
x1r = a[0] - a[2];
@@ -660,6 +663,9 @@
#if defined(MIPS_FPU_LE)
aec_rdft_init_mips();
#endif
+#if defined(WEBRTC_DETECT_ARM_NEON) || defined(WEBRTC_ARCH_ARM_NEON)
+ aec_rdft_init_neon();
+#endif
// init library constants.
makewt_32();
makect_32();
diff --git a/webrtc/modules/audio_processing/aec/aec_rdft.h b/webrtc/modules/audio_processing/aec/aec_rdft.h
index 795c57d..9430160 100644
--- a/webrtc/modules/audio_processing/aec/aec_rdft.h
+++ b/webrtc/modules/audio_processing/aec/aec_rdft.h
@@ -60,5 +60,8 @@
#if defined(MIPS_FPU_LE)
void aec_rdft_init_mips(void);
#endif
+#if defined(WEBRTC_DETECT_ARM_NEON) || defined(WEBRTC_ARCH_ARM_NEON)
+void aec_rdft_init_neon(void);
+#endif
#endif // WEBRTC_MODULES_AUDIO_PROCESSING_AEC_MAIN_SOURCE_AEC_RDFT_H_
diff --git a/webrtc/modules/audio_processing/aec/aec_rdft_neon.c b/webrtc/modules/audio_processing/aec/aec_rdft_neon.c
new file mode 100644
index 0000000..79b23e2
--- /dev/null
+++ b/webrtc/modules/audio_processing/aec/aec_rdft_neon.c
@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
+ *
+ * Use of this source code is governed by a BSD-style license
+ * that can be found in the LICENSE file in the root of the source
+ * tree. An additional intellectual property rights grant can be found
+ * in the file PATENTS. All contributing project authors may
+ * be found in the AUTHORS file in the root of the source tree.
+ */
+
+/*
+ * The rdft AEC algorithm, neon version of speed-critical functions.
+ *
+ * Based on the sse2 version.
+ */
+
+
+#include "webrtc/modules/audio_processing/aec/aec_rdft.h"
+
+#include <arm_neon.h>
+
+static const ALIGN16_BEG float ALIGN16_END
+ k_swap_sign[4] = {-1.f, 1.f, -1.f, 1.f};
+
+static void cft1st_128_neon(float* a) {
+ const float32x4_t vec_swap_sign = vld1q_f32((float32_t*)k_swap_sign);
+ int j, k2;
+
+ for (k2 = 0, j = 0; j < 128; j += 16, k2 += 4) {
+ float32x4_t a00v = vld1q_f32(&a[j + 0]);
+ float32x4_t a04v = vld1q_f32(&a[j + 4]);
+ float32x4_t a08v = vld1q_f32(&a[j + 8]);
+ float32x4_t a12v = vld1q_f32(&a[j + 12]);
+ float32x4_t a01v = vcombine_f32(vget_low_f32(a00v), vget_low_f32(a08v));
+ float32x4_t a23v = vcombine_f32(vget_high_f32(a00v), vget_high_f32(a08v));
+ float32x4_t a45v = vcombine_f32(vget_low_f32(a04v), vget_low_f32(a12v));
+ float32x4_t a67v = vcombine_f32(vget_high_f32(a04v), vget_high_f32(a12v));
+ const float32x4_t wk1rv = vld1q_f32(&rdft_wk1r[k2]);
+ const float32x4_t wk1iv = vld1q_f32(&rdft_wk1i[k2]);
+ const float32x4_t wk2rv = vld1q_f32(&rdft_wk2r[k2]);
+ const float32x4_t wk2iv = vld1q_f32(&rdft_wk2i[k2]);
+ const float32x4_t wk3rv = vld1q_f32(&rdft_wk3r[k2]);
+ const float32x4_t wk3iv = vld1q_f32(&rdft_wk3i[k2]);
+ float32x4_t x0v = vaddq_f32(a01v, a23v);
+ const float32x4_t x1v = vsubq_f32(a01v, a23v);
+ const float32x4_t x2v = vaddq_f32(a45v, a67v);
+ const float32x4_t x3v = vsubq_f32(a45v, a67v);
+ const float32x4_t x3w = vrev64q_f32(x3v);
+ float32x4_t x0w;
+ a01v = vaddq_f32(x0v, x2v);
+ x0v = vsubq_f32(x0v, x2v);
+ x0w = vrev64q_f32(x0v);
+ a45v = vmulq_f32(wk2rv, x0v);
+ a45v = vmlaq_f32(a45v, wk2iv, x0w);
+ x0v = vmlaq_f32(x1v, x3w, vec_swap_sign);
+ x0w = vrev64q_f32(x0v);
+ a23v = vmulq_f32(wk1rv, x0v);
+ a23v = vmlaq_f32(a23v, wk1iv, x0w);
+ x0v = vmlsq_f32(x1v, x3w, vec_swap_sign);
+ x0w = vrev64q_f32(x0v);
+ a67v = vmulq_f32(wk3rv, x0v);
+ a67v = vmlaq_f32(a67v, wk3iv, x0w);
+ a00v = vcombine_f32(vget_low_f32(a01v), vget_low_f32(a23v));
+ a04v = vcombine_f32(vget_low_f32(a45v), vget_low_f32(a67v));
+ a08v = vcombine_f32(vget_high_f32(a01v), vget_high_f32(a23v));
+ a12v = vcombine_f32(vget_high_f32(a45v), vget_high_f32(a67v));
+ vst1q_f32(&a[j + 0], a00v);
+ vst1q_f32(&a[j + 4], a04v);
+ vst1q_f32(&a[j + 8], a08v);
+ vst1q_f32(&a[j + 12], a12v);
+ }
+}
+
+void aec_rdft_init_neon(void) {
+ cft1st_128 = cft1st_128_neon;
+}
+
diff --git a/webrtc/modules/audio_processing/audio_processing.gypi b/webrtc/modules/audio_processing/audio_processing.gypi
index b1d18c5..98d437f 100644
--- a/webrtc/modules/audio_processing/audio_processing.gypi
+++ b/webrtc/modules/audio_processing/audio_processing.gypi
@@ -200,6 +200,7 @@
],
'sources': [
'aec/aec_core_neon.c',
+ 'aec/aec_rdft_neon.c',
'aecm/aecm_core_neon.c',
'ns/nsx_core_neon.c',
],
