[pulseaudio-discuss] [PATCH 22/23] core: mix: Add optimized mix code path for ARM NEON

Peter Meerwald pmeerw at pmeerw.net
Wed Feb 13 08:27:09 PST 2013


From: Peter Meerwald <p.meerwald at bct-electronic.com>

Signed-off-by: Peter Meerwald <pmeerw at pmeerw.net>
---
 src/Makefile.am          |    6 ++-
 src/pulsecore/cpu-arm.c  |    4 +-
 src/pulsecore/cpu-arm.h  |    1 +
 src/pulsecore/mix_neon.c |   94 ++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 102 insertions(+), 3 deletions(-)
 create mode 100644 src/pulsecore/mix_neon.c

diff --git a/src/Makefile.am b/src/Makefile.am
index 0a2fbd2..6614b9c 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -890,10 +890,12 @@ libpulsecore_ at PA_MAJORMINOR@_la_LDFLAGS = $(AM_LDFLAGS) -avoid-version
 libpulsecore_ at PA_MAJORMINOR@_la_LIBADD = $(AM_LIBADD) $(LIBLTDL) $(LIBSAMPLERATE_LIBS) $(LIBSPEEX_LIBS) $(LIBSNDFILE_LIBS) $(WINSOCK_LIBS) $(LTLIBICONV) libpulsecommon- at PA_MAJORMINOR@.la libpulse.la libpulsecore-foreign.la
 
 if HAVE_NEON
-noinst_LTLIBRARIES += libpulsecore_sconv_neon.la
+noinst_LTLIBRARIES += libpulsecore_sconv_neon.la libpulsecore_mix_neon.la
 libpulsecore_sconv_neon_la_SOURCES = pulsecore/sconv_neon.c
 libpulsecore_sconv_neon_la_CFLAGS = $(AM_CFLAGS) $(NEON_CFLAGS)
-libpulsecore_ at PA_MAJORMINOR@_la_LIBADD += libpulsecore_sconv_neon.la
+libpulsecore_mix_neon_la_SOURCES = pulsecore/mix_neon.c
+libpulsecore_mix_neon_la_CFLAGS = $(AM_CFLAGS) $(NEON_CFLAGS)
+libpulsecore_ at PA_MAJORMINOR@_la_LIBADD += libpulsecore_sconv_neon.la libpulsecore_mix_neon.la
 endif
 
 if HAVE_ORC
diff --git a/src/pulsecore/cpu-arm.c b/src/pulsecore/cpu-arm.c
index 05668f1..1378124 100644
--- a/src/pulsecore/cpu-arm.c
+++ b/src/pulsecore/cpu-arm.c
@@ -143,8 +143,10 @@ pa_bool_t pa_cpu_init_arm(pa_cpu_arm_flag_t *flags) {
     if (*flags & PA_CPU_ARM_V6)
         pa_volume_func_init_arm(*flags);
 #ifdef HAVE_NEON
-    if (*flags & PA_CPU_ARM_NEON)
+    if (*flags & PA_CPU_ARM_NEON) {
         pa_convert_func_init_neon(*flags);
+        pa_mix_func_init_neon(*flags);
+    }
 #endif
 
     return TRUE;
diff --git a/src/pulsecore/cpu-arm.h b/src/pulsecore/cpu-arm.h
index d2d3f5c..d9dc3d5 100644
--- a/src/pulsecore/cpu-arm.h
+++ b/src/pulsecore/cpu-arm.h
@@ -47,6 +47,7 @@ void pa_volume_func_init_arm(pa_cpu_arm_flag_t flags);
 
 #ifdef HAVE_NEON
 void pa_convert_func_init_neon(pa_cpu_arm_flag_t flags);
+void pa_mix_func_init_neon(pa_cpu_arm_flag_t flags);
 #endif
 
 #endif /* foocpuarmhfoo */
diff --git a/src/pulsecore/mix_neon.c b/src/pulsecore/mix_neon.c
new file mode 100644
index 0000000..ff05ccf
--- /dev/null
+++ b/src/pulsecore/mix_neon.c
@@ -0,0 +1,94 @@
+/***
+  This file is part of PulseAudio.
+
+  Copyright 2013 Peter Meerwald <pmeerw at pmeerw.net>
+
+  PulseAudio is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License as published
+  by the Free Software Foundation; either version 2.1 of the License,
+  or (at your option) any later version.
+
+  PulseAudio is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <pulsecore/macro.h>
+#include <pulsecore/endianmacros.h>
+
+#include "cpu-arm.h"
+#include "mix.h"
+
+#include <arm_neon.h>
+
+static pa_do_mix_func_t fallback;
+
+/* special case: mix s16ne streams, 2 channels each */
+static void pa_mix_ch2_s16ne_neon(pa_mix_info streams[], unsigned nstreams, uint8_t *data, unsigned length) {
+    const unsigned mask = sizeof(int16_t) * 8 - 1;
+    const uint8_t *end = data + (length & ~mask);
+
+    while (data < end) {
+        int32x4_t sum0, sum1;
+        unsigned i;
+
+        __asm__ __volatile__ (
+            "veor.s32 %q[sum0], %q[sum0]     \n\t"
+            "veor.s32 %q[sum1], %q[sum1]     \n\t"
+            : [sum0] "=w" (sum0), [sum1] "=w" (sum1)
+            :
+            : "cc" /* clobber list */
+        );
+
+        for (i = 0; i < nstreams; i++) {
+            pa_mix_info *m = streams + i;
+            int32_t cv0 = m->linear[0].i;
+            int32_t cv1 = m->linear[1].i;
+
+            __asm__ __volatile__ (
+                "vld2.s16    {d0,d2}, [%[ptr]]!      \n\t"
+                "vmov.s32    d4[0], %[cv0]           \n\t"
+                "vmov.s32    d4[1], %[cv1]           \n\t"
+                "vshll.s16   q0, d0, #15             \n\t"
+                "vshll.s16   q1, d2, #15             \n\t"
+                "vqdmulh.s32 q0, q0, d4[0]           \n\t"
+                "vqdmulh.s32 q1, q1, d4[1]           \n\t"
+                "vqadd.s32   %q[sum0], %q[sum0], q0  \n\t"
+                "vqadd.s32   %q[sum1], %q[sum1], q1  \n\t"
+                : [ptr] "+r" (m->ptr), [sum0] "+w" (sum0), [sum1] "+w" (sum1)
+                : [cv0] "r" (cv0), [cv1] "r" (cv1)
+                : "memory", "cc", "q0", "q1", "d4" /* clobber list */
+            );
+        }
+
+        __asm__ __volatile__ (
+            "vqmovn.s32 d0, %q[sum0]         \n\t"
+            "vqmovn.s32 d1, %q[sum1]         \n\t"
+            "vst2.s16   {d0,d1}, [%[data]]!  \n\t"
+            : [data] "+r" (data)
+            : [sum0] "w" (sum0), [sum1] "w" (sum1)
+            : "memory", "cc", "q0" /* clobber list */
+        );
+    }
+
+    fallback(streams, nstreams, 2, data, length & mask);
+}
+
+static void pa_mix_s16ne_neon(pa_mix_info streams[], unsigned nstreams, unsigned nchannels, void *data, unsigned length) {
+    if (nchannels == 2)
+        pa_mix_ch2_s16ne_neon(streams, nstreams, data, length);
+    else
+        fallback(streams, nstreams, nchannels, data, length);
+}
+
+void pa_mix_func_init_neon(pa_cpu_arm_flag_t flags) {
+    pa_log_info("Initialising ARM NEON optimized mixing functions.");
+
+    fallback = pa_get_mix_func(PA_SAMPLE_S16NE);
+    pa_set_mix_func(PA_SAMPLE_S16NE, (pa_do_mix_func_t) pa_mix_s16ne_neon);
+}
-- 
1.7.9.5



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