From 21508003c9ae46ad9b7308b125ea8881e81bc01a Mon Sep 17 00:00:00 2001
From: twinaphex <libretro@gmail.com>
Date: Mon, 30 Jan 2017 18:15:41 +0100
Subject: [PATCH] Create sinc_resampler_common

---
 Makefile.common                               |   1 +
 griffin/griffin.c                             |   1 +
 .../audio/resampler/drivers/sinc_resampler.c  | 354 +-----------------
 .../resampler/drivers/sinc_resampler_common.c |  99 +++++
 .../resampler/drivers/sinc_resampler_common.h | 322 ++++++++++++++++
 5 files changed, 427 insertions(+), 350 deletions(-)
 create mode 100644 libretro-common/audio/resampler/drivers/sinc_resampler_common.c
 create mode 100644 libretro-common/audio/resampler/drivers/sinc_resampler_common.h

diff --git a/Makefile.common b/Makefile.common
index 47443fdd51..143babf270 100644
--- a/Makefile.common
+++ b/Makefile.common
@@ -231,6 +231,7 @@ OBJ += frontend/frontend.o \
        $(LIBRETRO_COMM_DIR)/audio/resampler/audio_resampler.o \
        $(LIBRETRO_COMM_DIR)/audio/dsp_filter.o \
        $(LIBRETRO_COMM_DIR)/audio/resampler/drivers/sinc_resampler.o \
+       $(LIBRETRO_COMM_DIR)/audio/resampler/drivers/sinc_resampler_common.o \
        $(LIBRETRO_COMM_DIR)/audio/resampler/drivers/nearest_resampler.o \
        $(LIBRETRO_COMM_DIR)/audio/resampler/drivers/null_resampler.o \
        location/drivers/nulllocation.o \
diff --git a/griffin/griffin.c b/griffin/griffin.c
index 639ce86bb3..0a9bc92d5a 100644
--- a/griffin/griffin.c
+++ b/griffin/griffin.c
@@ -573,6 +573,7 @@ AUDIO RESAMPLER
 ============================================================ */
 #include "../libretro-common/audio/resampler/audio_resampler.c"
 #include "../libretro-common/audio/resampler/drivers/sinc_resampler.c"
+#include "../libretro-common/audio/resampler/drivers/sinc_resampler_common.c"
 #include "../libretro-common/audio/resampler/drivers/nearest_resampler.c"
 #include "../libretro-common/audio/resampler/drivers/null_resampler.c"
 #ifdef HAVE_CC_RESAMPLER
diff --git a/libretro-common/audio/resampler/drivers/sinc_resampler.c b/libretro-common/audio/resampler/drivers/sinc_resampler.c
index 2237dfc5ce..6b0da074e4 100644
--- a/libretro-common/audio/resampler/drivers/sinc_resampler.c
+++ b/libretro-common/audio/resampler/drivers/sinc_resampler.c
@@ -27,351 +27,13 @@
 #include <math.h>
 #include <string.h>
 
-#ifdef __SSE__
-#include <xmmintrin.h>
-#endif
-
 #include <retro_inline.h>
 #include <filters.h>
 #include <memalign.h>
 
 #include <audio/audio_resampler.h>
 
-/* Rough SNR values for upsampling:
- * LOWEST: 40 dB
- * LOWER: 55 dB
- * NORMAL: 70 dB
- * HIGHER: 110 dB
- * HIGHEST: 140 dB
- */
-
-/* TODO, make all this more configurable. */
-#if defined(SINC_LOWEST_QUALITY)
-#define SINC_WINDOW_LANCZOS
-#define CUTOFF 0.98
-#define PHASE_BITS 12
-#define SINC_COEFF_LERP 0
-#define SUBPHASE_BITS 10
-#define SIDELOBES 2
-#define ENABLE_AVX 0
-#elif defined(SINC_LOWER_QUALITY)
-#define SINC_WINDOW_LANCZOS
-#define CUTOFF 0.98
-#define PHASE_BITS 12
-#define SUBPHASE_BITS 10
-#define SINC_COEFF_LERP 0
-#define SIDELOBES 4
-#define ENABLE_AVX 0
-#elif defined(SINC_HIGHER_QUALITY)
-#define SINC_WINDOW_KAISER
-#define SINC_WINDOW_KAISER_BETA 10.5
-#define CUTOFF 0.90
-#define PHASE_BITS 10
-#define SUBPHASE_BITS 14
-#define SINC_COEFF_LERP 1
-#define SIDELOBES 32
-#define ENABLE_AVX 1
-#elif defined(SINC_HIGHEST_QUALITY)
-#define SINC_WINDOW_KAISER
-#define SINC_WINDOW_KAISER_BETA 14.5
-#define CUTOFF 0.962
-#define PHASE_BITS 10
-#define SUBPHASE_BITS 14
-#define SINC_COEFF_LERP 1
-#define SIDELOBES 128
-#define ENABLE_AVX 1
-#else
-#define SINC_WINDOW_KAISER
-#define SINC_WINDOW_KAISER_BETA 5.5
-#define CUTOFF 0.825
-#define PHASE_BITS 8
-#define SUBPHASE_BITS 16
-#define SINC_COEFF_LERP 1
-#define SIDELOBES 8
-#define ENABLE_AVX 0
-#endif
-
-/* For the little amount of taps we're using,
- * SSE1 is faster than AVX for some reason.
- * AVX code is kept here though as by increasing number
- * of sinc taps, the AVX code is clearly faster than SSE1.
- */
-
-#if defined(__AVX__) && ENABLE_AVX
-#include <immintrin.h>
-#endif
-
-#define PHASES (1 << (PHASE_BITS + SUBPHASE_BITS))
-
-#define TAPS (SIDELOBES * 2)
-#define SUBPHASE_MASK ((1 << SUBPHASE_BITS) - 1)
-#define SUBPHASE_MOD (1.0f / (1 << SUBPHASE_BITS))
-
-typedef struct rarch_sinc_resampler
-{
-   float *phase_table;
-   float *buffer_l;
-   float *buffer_r;
-
-   unsigned taps;
-
-   unsigned ptr;
-   uint32_t time;
-
-   /* A buffer for phase_table, buffer_l and buffer_r 
-    * are created in a single calloc().
-    * Ensure that we get as good cache locality as we can hope for. */
-   float *main_buffer;
-} rarch_sinc_resampler_t;
-
-#if defined(SINC_WINDOW_LANCZOS)
-#define window_function(idx)  (lanzcos_window_function(idx))
-#elif defined(SINC_WINDOW_KAISER)
-#define window_function(idx)  (kaiser_window_function(idx, SINC_WINDOW_KAISER_BETA))
-#else
-#error "No SINC window function defined."
-#endif
-
-static void init_sinc_table(rarch_sinc_resampler_t *resamp, double cutoff,
-      float *phase_table, int phases, int taps, bool calculate_delta)
-{
-   int i, j;
-   double    window_mod = window_function(0.0); /* Need to normalize w(0) to 1.0. */
-   int           stride = calculate_delta ? 2 : 1;
-   double     sidelobes = taps / 2.0;
-
-   for (i = 0; i < phases; i++)
-   {
-      for (j = 0; j < taps; j++)
-      {
-         double sinc_phase;
-         float val;
-         int               n = j * phases + i;
-         double window_phase = (double)n / (phases * taps); /* [0, 1). */
-         window_phase        = 2.0 * window_phase - 1.0; /* [-1, 1) */
-         sinc_phase          = sidelobes * window_phase;
-         val                 = cutoff * sinc(M_PI * sinc_phase * cutoff) * 
-            window_function(window_phase) / window_mod;
-         phase_table[i * stride * taps + j] = val;
-      }
-   }
-
-   if (calculate_delta)
-   {
-      int phase;
-      int p;
-
-      for (p = 0; p < phases - 1; p++)
-      {
-         for (j = 0; j < taps; j++)
-         {
-            float delta = phase_table[(p + 1) * stride * taps + j] - 
-               phase_table[p * stride * taps + j];
-            phase_table[(p * stride + 1) * taps + j] = delta;
-         }
-      }
-
-      phase = phases - 1;
-      for (j = 0; j < taps; j++)
-      {
-         float val, delta;
-         double sinc_phase;
-         int n               = j * phases + (phase + 1);
-         double window_phase = (double)n / (phases * taps); /* (0, 1]. */
-         window_phase        = 2.0 * window_phase - 1.0; /* (-1, 1] */
-         sinc_phase          = sidelobes * window_phase;
-
-         val                 = cutoff * sinc(M_PI * sinc_phase * cutoff) * 
-            window_function(window_phase) / window_mod;
-         delta = (val - phase_table[phase * stride * taps + j]);
-         phase_table[(phase * stride + 1) * taps + j] = delta;
-      }
-   }
-}
-
-#if !(defined(__AVX__) && ENABLE_AVX) && !defined(__SSE__)
-static INLINE void process_sinc_C(rarch_sinc_resampler_t *resamp,
-      float *out_buffer)
-{
-   unsigned i;
-   float sum_l              = 0.0f;
-   float sum_r              = 0.0f;
-   const float *buffer_l    = resamp->buffer_l + resamp->ptr;
-   const float *buffer_r    = resamp->buffer_r + resamp->ptr;
-   unsigned taps            = resamp->taps;
-   unsigned phase           = resamp->time >> SUBPHASE_BITS;
-#if SINC_COEFF_LERP
-   const float *phase_table = resamp->phase_table + phase * taps * 2;
-   const float *delta_table = phase_table + taps;
-   float delta              = (float)
-      (resamp->time & SUBPHASE_MASK) * SUBPHASE_MOD;
-#else
-   const float *phase_table = resamp->phase_table + phase * taps;
-#endif
-
-   for (i = 0; i < taps; i++)
-   {
-#if SINC_COEFF_LERP
-      float sinc_val = phase_table[i] + delta_table[i] * delta;
-#else
-      float sinc_val = phase_table[i];
-#endif
-      sum_l         += buffer_l[i] * sinc_val;
-      sum_r         += buffer_r[i] * sinc_val;
-   }
-
-   out_buffer[0] = sum_l;
-   out_buffer[1] = sum_r;
-}
-#endif
-
-#if defined(__AVX__) && ENABLE_AVX
-#define process_sinc_func process_sinc
-static void process_sinc(rarch_sinc_resampler_t *resamp, float *out_buffer)
-{
-   unsigned i;
-   __m256 sum_l             = _mm256_setzero_ps();
-   __m256 sum_r             = _mm256_setzero_ps();
-
-   const float *buffer_l    = resamp->buffer_l + resamp->ptr;
-   const float *buffer_r    = resamp->buffer_r + resamp->ptr;
-
-   unsigned taps            = resamp->taps;
-   unsigned phase           = resamp->time >> SUBPHASE_BITS;
-#if SINC_COEFF_LERP
-   const float *phase_table = resamp->phase_table + phase * taps * 2;
-   const float *delta_table = phase_table + taps;
-   __m256 delta             = _mm256_set1_ps((float)
-         (resamp->time & SUBPHASE_MASK) * SUBPHASE_MOD);
-#else
-   const float *phase_table = resamp->phase_table + phase * taps;
-#endif
-
-   for (i = 0; i < taps; i += 8)
-   {
-      __m256 buf_l  = _mm256_loadu_ps(buffer_l + i);
-      __m256 buf_r  = _mm256_loadu_ps(buffer_r + i);
-
-#if SINC_COEFF_LERP
-      __m256 deltas = _mm256_load_ps(delta_table + i);
-      __m256 sinc   = _mm256_add_ps(_mm256_load_ps(phase_table + i),
-            _mm256_mul_ps(deltas, delta));
-#else
-      __m256 sinc   = _mm256_load_ps(phase_table + i);
-#endif
-      sum_l         = _mm256_add_ps(sum_l, _mm256_mul_ps(buf_l, sinc));
-      sum_r         = _mm256_add_ps(sum_r, _mm256_mul_ps(buf_r, sinc));
-   }
-
-   /* hadd on AVX is weird, and acts on low-lanes 
-    * and high-lanes separately. */
-   __m256 res_l = _mm256_hadd_ps(sum_l, sum_l);
-   __m256 res_r = _mm256_hadd_ps(sum_r, sum_r);
-   res_l        = _mm256_hadd_ps(res_l, res_l);
-   res_r        = _mm256_hadd_ps(res_r, res_r);
-   res_l        = _mm256_add_ps(_mm256_permute2f128_ps(res_l, res_l, 1), res_l);
-   res_r        = _mm256_add_ps(_mm256_permute2f128_ps(res_r, res_r, 1), res_r);
-
-   /* This is optimized to mov %xmmN, [mem].
-    * There doesn't seem to be any _mm256_store_ss intrinsic. */
-   _mm_store_ss(out_buffer + 0, _mm256_extractf128_ps(res_l, 0));
-   _mm_store_ss(out_buffer + 1, _mm256_extractf128_ps(res_r, 0));
-}
-#elif defined(__SSE__)
-#define process_sinc_func process_sinc
-static void process_sinc(rarch_sinc_resampler_t *resamp, float *out_buffer)
-{
-   unsigned i;
-   __m128 sum;
-   __m128 sum_l             = _mm_setzero_ps();
-   __m128 sum_r             = _mm_setzero_ps();
-
-   const float *buffer_l    = resamp->buffer_l + resamp->ptr;
-   const float *buffer_r    = resamp->buffer_r + resamp->ptr;
-
-   unsigned taps            = resamp->taps;
-   unsigned phase           = resamp->time >> SUBPHASE_BITS;
-#if SINC_COEFF_LERP
-   const float *phase_table = resamp->phase_table + phase * taps * 2;
-   const float *delta_table = phase_table + taps;
-   __m128 delta             = _mm_set1_ps((float)
-         (resamp->time & SUBPHASE_MASK) * SUBPHASE_MOD);
-#else
-   const float *phase_table = resamp->phase_table + phase * taps;
-#endif
-
-   for (i = 0; i < taps; i += 4)
-   {
-      __m128 buf_l = _mm_loadu_ps(buffer_l + i);
-      __m128 buf_r = _mm_loadu_ps(buffer_r + i);
-
-#if SINC_COEFF_LERP
-      __m128 deltas = _mm_load_ps(delta_table + i);
-      __m128 _sinc  = _mm_add_ps(_mm_load_ps(phase_table + i),
-            _mm_mul_ps(deltas, delta));
-#else
-      __m128 _sinc = _mm_load_ps(phase_table + i);
-#endif
-      sum_l        = _mm_add_ps(sum_l, _mm_mul_ps(buf_l, _sinc));
-      sum_r        = _mm_add_ps(sum_r, _mm_mul_ps(buf_r, _sinc));
-   }
-
-   /* Them annoying shuffles.
-    * sum_l = { l3, l2, l1, l0 }
-    * sum_r = { r3, r2, r1, r0 }
-    */
-
-   sum = _mm_add_ps(_mm_shuffle_ps(sum_l, sum_r,
-            _MM_SHUFFLE(1, 0, 1, 0)),
-         _mm_shuffle_ps(sum_l, sum_r, _MM_SHUFFLE(3, 2, 3, 2)));
-
-   /* sum   = { r1, r0, l1, l0 } + { r3, r2, l3, l2 }
-    * sum   = { R1, R0, L1, L0 }
-    */
-
-   sum = _mm_add_ps(_mm_shuffle_ps(sum, sum, _MM_SHUFFLE(3, 3, 1, 1)), sum);
-
-   /* sum   = {R1, R1, L1, L1 } + { R1, R0, L1, L0 }
-    * sum   = { X,  R,  X,  L } 
-    */
-
-   /* Store L */
-   _mm_store_ss(out_buffer + 0, sum);
-
-   /* movehl { X, R, X, L } == { X, R, X, R } */
-   _mm_store_ss(out_buffer + 1, _mm_movehl_ps(sum, sum));
-}
-#elif defined(__ARM_NEON__)
-
-#if SINC_COEFF_LERP
-#error "NEON asm does not support SINC lerp."
-#endif
-
-/* Need to make this function pointer as Android doesn't 
- * have built-in targets for NEON and plain ARMv7a.
- */
-static void (*process_sinc_func)(rarch_sinc_resampler_t *resamp,
-      float *out_buffer);
-
-/* Assumes that taps >= 8, and that taps is a multiple of 8. */
-void process_sinc_neon_asm(float *out, const float *left, 
-      const float *right, const float *coeff, unsigned taps);
-
-static void process_sinc_neon(rarch_sinc_resampler_t *resamp,
-      float *out_buffer)
-{
-   const float *buffer_l    = resamp->buffer_l + resamp->ptr;
-   const float *buffer_r    = resamp->buffer_r + resamp->ptr;
-
-   unsigned phase           = resamp->time >> SUBPHASE_BITS;
-   unsigned taps            = resamp->taps;
-   const float *phase_table = resamp->phase_table + phase * taps;
-
-   process_sinc_neon_asm(out_buffer, buffer_l, buffer_r, phase_table, taps);
-}
-#else /* Plain ol' C99 */
-#define process_sinc_func process_sinc_C
-#endif
+#include "sinc_resampler_common.h"
 
 static void resampler_sinc_process(void *re_, struct resampler_data *data)
 {
@@ -411,14 +73,6 @@ static void resampler_sinc_process(void *re_, struct resampler_data *data)
    data->output_frames = out_frames;
 }
 
-static void resampler_sinc_free(void *re)
-{
-   rarch_sinc_resampler_t *resampler = (rarch_sinc_resampler_t*)re;
-   if (resampler)
-      memalign_free(resampler->main_buffer);
-   free(resampler);
-}
-
 static void *resampler_sinc_new(const struct resampler_config *config,
       double bandwidth_mod, resampler_simd_mask_t mask)
 {
@@ -464,7 +118,7 @@ static void *resampler_sinc_new(const struct resampler_config *config,
    re->buffer_l    = re->main_buffer + phase_elems;
    re->buffer_r    = re->buffer_l + 2 * re->taps;
 
-   init_sinc_table(re, cutoff, re->phase_table,
+   sinc_init_table(re, cutoff, re->phase_table,
          1 << PHASE_BITS, re->taps, SINC_COEFF_LERP);
 
 #if defined(__ARM_NEON__) 
@@ -475,14 +129,14 @@ static void *resampler_sinc_new(const struct resampler_config *config,
    return re;
 
 error:
-   resampler_sinc_free(re);
+   sinc_free(re);
    return NULL;
 }
 
 retro_resampler_t sinc_resampler = {
    resampler_sinc_new,
    resampler_sinc_process,
-   resampler_sinc_free,
+   sinc_free,
    RESAMPLER_API_VERSION,
    "sinc",
    "sinc"
diff --git a/libretro-common/audio/resampler/drivers/sinc_resampler_common.c b/libretro-common/audio/resampler/drivers/sinc_resampler_common.c
new file mode 100644
index 0000000000..4bb628ea88
--- /dev/null
+++ b/libretro-common/audio/resampler/drivers/sinc_resampler_common.c
@@ -0,0 +1,99 @@
+/* Copyright  (C) 2010-2017 The RetroArch team
+ *
+ * ---------------------------------------------------------------------------------------
+ * The following license statement only applies to this file (sinc_resampler_common.c).
+ * ---------------------------------------------------------------------------------------
+ *
+ * Permission is hereby granted, free of charge,
+ * to any person obtaining a copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+ * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/* Bog-standard windowed SINC implementation. */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <math.h>
+#include <string.h>
+
+#include <memalign.h>
+
+#include <audio/audio_resampler.h>
+
+#include "sinc_resampler_common.h"
+
+void sinc_init_table(rarch_sinc_resampler_t *resamp, double cutoff,
+      float *phase_table, int phases, int taps, bool calculate_delta)
+{
+   int i, j;
+   double    window_mod = window_function(0.0); /* Need to normalize w(0) to 1.0. */
+   int           stride = calculate_delta ? 2 : 1;
+   double     sidelobes = taps / 2.0;
+
+   for (i = 0; i < phases; i++)
+   {
+      for (j = 0; j < taps; j++)
+      {
+         double sinc_phase;
+         float val;
+         int               n = j * phases + i;
+         double window_phase = (double)n / (phases * taps); /* [0, 1). */
+         window_phase        = 2.0 * window_phase - 1.0; /* [-1, 1) */
+         sinc_phase          = sidelobes * window_phase;
+         val                 = cutoff * sinc(M_PI * sinc_phase * cutoff) * 
+            window_function(window_phase) / window_mod;
+         phase_table[i * stride * taps + j] = val;
+      }
+   }
+
+   if (calculate_delta)
+   {
+      int phase;
+      int p;
+
+      for (p = 0; p < phases - 1; p++)
+      {
+         for (j = 0; j < taps; j++)
+         {
+            float delta = phase_table[(p + 1) * stride * taps + j] - 
+               phase_table[p * stride * taps + j];
+            phase_table[(p * stride + 1) * taps + j] = delta;
+         }
+      }
+
+      phase = phases - 1;
+      for (j = 0; j < taps; j++)
+      {
+         float val, delta;
+         double sinc_phase;
+         int n               = j * phases + (phase + 1);
+         double window_phase = (double)n / (phases * taps); /* (0, 1]. */
+         window_phase        = 2.0 * window_phase - 1.0; /* (-1, 1] */
+         sinc_phase          = sidelobes * window_phase;
+
+         val                 = cutoff * sinc(M_PI * sinc_phase * cutoff) * 
+            window_function(window_phase) / window_mod;
+         delta = (val - phase_table[phase * stride * taps + j]);
+         phase_table[(phase * stride + 1) * taps + j] = delta;
+      }
+   }
+}
+
+void sinc_free(void *data)
+{
+   rarch_sinc_resampler_t *resamp = (rarch_sinc_resampler_t*)data;
+   if (resamp)
+      memalign_free(resamp->main_buffer);
+   free(resamp);
+}
diff --git a/libretro-common/audio/resampler/drivers/sinc_resampler_common.h b/libretro-common/audio/resampler/drivers/sinc_resampler_common.h
new file mode 100644
index 0000000000..fb4afa7fbb
--- /dev/null
+++ b/libretro-common/audio/resampler/drivers/sinc_resampler_common.h
@@ -0,0 +1,322 @@
+/* Copyright  (C) 2010-2017 The RetroArch team
+ *
+ * ---------------------------------------------------------------------------------------
+ * The following license statement only applies to this file (sinc_resampler_common.h).
+ * ---------------------------------------------------------------------------------------
+ *
+ * Permission is hereby granted, free of charge,
+ * to any person obtaining a copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+ * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef _LIBRETRO_SDK_SINC_RESAMPLER_COMMON_H
+#define _LIBRETRO_SDK_SINC_RESAMPLER_COMMON_H
+
+#include <retro_common_api.h>
+#include <filters.h>
+
+#ifdef __SSE__
+#include <xmmintrin.h>
+#endif
+
+#if defined(__AVX__) && ENABLE_AVX
+#include <immintrin.h>
+#endif
+
+RETRO_BEGIN_DECLS
+
+typedef struct rarch_sinc_resampler
+{
+   float *phase_table;
+   float *buffer_l;
+   float *buffer_r;
+
+   unsigned taps;
+
+   unsigned ptr;
+   uint32_t time;
+
+   /* A buffer for phase_table, buffer_l and buffer_r 
+    * are created in a single calloc().
+    * Ensure that we get as good cache locality as we can hope for. */
+   float *main_buffer;
+} rarch_sinc_resampler_t;
+
+/* Rough SNR values for upsampling:
+ * LOWEST: 40 dB
+ * LOWER: 55 dB
+ * NORMAL: 70 dB
+ * HIGHER: 110 dB
+ * HIGHEST: 140 dB
+ */
+
+/* TODO, make all this more configurable. */
+#if defined(SINC_LOWEST_QUALITY)
+#define SINC_WINDOW_LANCZOS
+#define CUTOFF 0.98
+#define PHASE_BITS 12
+#define SINC_COEFF_LERP 0
+#define SUBPHASE_BITS 10
+#define SIDELOBES 2
+#define ENABLE_AVX 0
+#elif defined(SINC_LOWER_QUALITY)
+#define SINC_WINDOW_LANCZOS
+#define CUTOFF 0.98
+#define PHASE_BITS 12
+#define SUBPHASE_BITS 10
+#define SINC_COEFF_LERP 0
+#define SIDELOBES 4
+#define ENABLE_AVX 0
+#elif defined(SINC_HIGHER_QUALITY)
+#define SINC_WINDOW_KAISER
+#define SINC_WINDOW_KAISER_BETA 10.5
+#define CUTOFF 0.90
+#define PHASE_BITS 10
+#define SUBPHASE_BITS 14
+#define SINC_COEFF_LERP 1
+#define SIDELOBES 32
+#define ENABLE_AVX 1
+#elif defined(SINC_HIGHEST_QUALITY)
+#define SINC_WINDOW_KAISER
+#define SINC_WINDOW_KAISER_BETA 14.5
+#define CUTOFF 0.962
+#define PHASE_BITS 10
+#define SUBPHASE_BITS 14
+#define SINC_COEFF_LERP 1
+#define SIDELOBES 128
+#define ENABLE_AVX 1
+#else
+#define SINC_WINDOW_KAISER
+#define SINC_WINDOW_KAISER_BETA 5.5
+#define CUTOFF 0.825
+#define PHASE_BITS 8
+#define SUBPHASE_BITS 16
+#define SINC_COEFF_LERP 1
+#define SIDELOBES 8
+#define ENABLE_AVX 0
+#endif
+
+#if defined(SINC_WINDOW_LANCZOS)
+#define window_function(idx)  (lanzcos_window_function(idx))
+#elif defined(SINC_WINDOW_KAISER)
+#define window_function(idx)  (kaiser_window_function(idx, SINC_WINDOW_KAISER_BETA))
+#else
+#error "No SINC window function defined."
+#endif
+
+/* For the little amount of taps we're using,
+ * SSE1 is faster than AVX for some reason.
+ * AVX code is kept here though as by increasing number
+ * of sinc taps, the AVX code is clearly faster than SSE1.
+ */
+
+#define PHASES (1 << (PHASE_BITS + SUBPHASE_BITS))
+
+#define TAPS (SIDELOBES * 2)
+#define SUBPHASE_MASK ((1 << SUBPHASE_BITS) - 1)
+#define SUBPHASE_MOD (1.0f / (1 << SUBPHASE_BITS))
+
+#if !(defined(__AVX__) && ENABLE_AVX) && !defined(__SSE__)
+static INLINE void process_sinc_C(rarch_sinc_resampler_t *resamp,
+      float *out_buffer)
+{
+   unsigned i;
+   float sum_l              = 0.0f;
+   float sum_r              = 0.0f;
+   const float *buffer_l    = resamp->buffer_l + resamp->ptr;
+   const float *buffer_r    = resamp->buffer_r + resamp->ptr;
+   unsigned taps            = resamp->taps;
+   unsigned phase           = resamp->time >> SUBPHASE_BITS;
+#if SINC_COEFF_LERP
+   const float *phase_table = resamp->phase_table + phase * taps * 2;
+   const float *delta_table = phase_table + taps;
+   float delta              = (float)
+      (resamp->time & SUBPHASE_MASK) * SUBPHASE_MOD;
+#else
+   const float *phase_table = resamp->phase_table + phase * taps;
+#endif
+
+   for (i = 0; i < taps; i++)
+   {
+#if SINC_COEFF_LERP
+      float sinc_val = phase_table[i] + delta_table[i] * delta;
+#else
+      float sinc_val = phase_table[i];
+#endif
+      sum_l         += buffer_l[i] * sinc_val;
+      sum_r         += buffer_r[i] * sinc_val;
+   }
+
+   out_buffer[0] = sum_l;
+   out_buffer[1] = sum_r;
+}
+#endif
+
+#if defined(__AVX__) && ENABLE_AVX
+#define process_sinc_func process_sinc
+static INLINE void process_sinc(rarch_sinc_resampler_t *resamp, float *out_buffer)
+{
+   unsigned i;
+   __m256 sum_l             = _mm256_setzero_ps();
+   __m256 sum_r             = _mm256_setzero_ps();
+
+   const float *buffer_l    = resamp->buffer_l + resamp->ptr;
+   const float *buffer_r    = resamp->buffer_r + resamp->ptr;
+
+   unsigned taps            = resamp->taps;
+   unsigned phase           = resamp->time >> SUBPHASE_BITS;
+#if SINC_COEFF_LERP
+   const float *phase_table = resamp->phase_table + phase * taps * 2;
+   const float *delta_table = phase_table + taps;
+   __m256 delta             = _mm256_set1_ps((float)
+         (resamp->time & SUBPHASE_MASK) * SUBPHASE_MOD);
+#else
+   const float *phase_table = resamp->phase_table + phase * taps;
+#endif
+
+   for (i = 0; i < taps; i += 8)
+   {
+      __m256 buf_l  = _mm256_loadu_ps(buffer_l + i);
+      __m256 buf_r  = _mm256_loadu_ps(buffer_r + i);
+
+#if SINC_COEFF_LERP
+      __m256 deltas = _mm256_load_ps(delta_table + i);
+      __m256 sinc   = _mm256_add_ps(_mm256_load_ps(phase_table + i),
+            _mm256_mul_ps(deltas, delta));
+#else
+      __m256 sinc   = _mm256_load_ps(phase_table + i);
+#endif
+      sum_l         = _mm256_add_ps(sum_l, _mm256_mul_ps(buf_l, sinc));
+      sum_r         = _mm256_add_ps(sum_r, _mm256_mul_ps(buf_r, sinc));
+   }
+
+   /* hadd on AVX is weird, and acts on low-lanes 
+    * and high-lanes separately. */
+   __m256 res_l = _mm256_hadd_ps(sum_l, sum_l);
+   __m256 res_r = _mm256_hadd_ps(sum_r, sum_r);
+   res_l        = _mm256_hadd_ps(res_l, res_l);
+   res_r        = _mm256_hadd_ps(res_r, res_r);
+   res_l        = _mm256_add_ps(_mm256_permute2f128_ps(res_l, res_l, 1), res_l);
+   res_r        = _mm256_add_ps(_mm256_permute2f128_ps(res_r, res_r, 1), res_r);
+
+   /* This is optimized to mov %xmmN, [mem].
+    * There doesn't seem to be any _mm256_store_ss intrinsic. */
+   _mm_store_ss(out_buffer + 0, _mm256_extractf128_ps(res_l, 0));
+   _mm_store_ss(out_buffer + 1, _mm256_extractf128_ps(res_r, 0));
+}
+#elif defined(__SSE__)
+#define process_sinc_func process_sinc
+static INLINE void process_sinc(rarch_sinc_resampler_t *resamp, float *out_buffer)
+{
+   unsigned i;
+   __m128 sum;
+   __m128 sum_l             = _mm_setzero_ps();
+   __m128 sum_r             = _mm_setzero_ps();
+
+   const float *buffer_l    = resamp->buffer_l + resamp->ptr;
+   const float *buffer_r    = resamp->buffer_r + resamp->ptr;
+
+   unsigned taps            = resamp->taps;
+   unsigned phase           = resamp->time >> SUBPHASE_BITS;
+#if SINC_COEFF_LERP
+   const float *phase_table = resamp->phase_table + phase * taps * 2;
+   const float *delta_table = phase_table + taps;
+   __m128 delta             = _mm_set1_ps((float)
+         (resamp->time & SUBPHASE_MASK) * SUBPHASE_MOD);
+#else
+   const float *phase_table = resamp->phase_table + phase * taps;
+#endif
+
+   for (i = 0; i < taps; i += 4)
+   {
+      __m128 buf_l = _mm_loadu_ps(buffer_l + i);
+      __m128 buf_r = _mm_loadu_ps(buffer_r + i);
+
+#if SINC_COEFF_LERP
+      __m128 deltas = _mm_load_ps(delta_table + i);
+      __m128 _sinc  = _mm_add_ps(_mm_load_ps(phase_table + i),
+            _mm_mul_ps(deltas, delta));
+#else
+      __m128 _sinc = _mm_load_ps(phase_table + i);
+#endif
+      sum_l        = _mm_add_ps(sum_l, _mm_mul_ps(buf_l, _sinc));
+      sum_r        = _mm_add_ps(sum_r, _mm_mul_ps(buf_r, _sinc));
+   }
+
+   /* Them annoying shuffles.
+    * sum_l = { l3, l2, l1, l0 }
+    * sum_r = { r3, r2, r1, r0 }
+    */
+
+   sum = _mm_add_ps(_mm_shuffle_ps(sum_l, sum_r,
+            _MM_SHUFFLE(1, 0, 1, 0)),
+         _mm_shuffle_ps(sum_l, sum_r, _MM_SHUFFLE(3, 2, 3, 2)));
+
+   /* sum   = { r1, r0, l1, l0 } + { r3, r2, l3, l2 }
+    * sum   = { R1, R0, L1, L0 }
+    */
+
+   sum = _mm_add_ps(_mm_shuffle_ps(sum, sum, _MM_SHUFFLE(3, 3, 1, 1)), sum);
+
+   /* sum   = {R1, R1, L1, L1 } + { R1, R0, L1, L0 }
+    * sum   = { X,  R,  X,  L } 
+    */
+
+   /* Store L */
+   _mm_store_ss(out_buffer + 0, sum);
+
+   /* movehl { X, R, X, L } == { X, R, X, R } */
+   _mm_store_ss(out_buffer + 1, _mm_movehl_ps(sum, sum));
+}
+#elif defined(__ARM_NEON__)
+
+#if SINC_COEFF_LERP
+#error "NEON asm does not support SINC lerp."
+#endif
+
+/* Need to make this function pointer as Android doesn't 
+ * have built-in targets for NEON and plain ARMv7a.
+ */
+static void (*process_sinc_func)(rarch_sinc_resampler_t *resamp,
+      float *out_buffer);
+
+/* Assumes that taps >= 8, and that taps is a multiple of 8. */
+void process_sinc_neon_asm(float *out, const float *left, 
+      const float *right, const float *coeff, unsigned taps);
+
+static INLINE void process_sinc_neon(rarch_sinc_resampler_t *resamp,
+      float *out_buffer)
+{
+   const float *buffer_l    = resamp->buffer_l + resamp->ptr;
+   const float *buffer_r    = resamp->buffer_r + resamp->ptr;
+
+   unsigned phase           = resamp->time >> SUBPHASE_BITS;
+   unsigned taps            = resamp->taps;
+   const float *phase_table = resamp->phase_table + phase * taps;
+
+   process_sinc_neon_asm(out_buffer, buffer_l, buffer_r, phase_table, taps);
+}
+#else /* Plain ol' C99 */
+#define process_sinc_func process_sinc_C
+#endif
+
+
+void sinc_init_table(rarch_sinc_resampler_t *resamp, double cutoff,
+      float *phase_table, int phases, int taps, bool calculate_delta);
+
+void sinc_free(void *data);
+
+RETRO_END_DECLS
+
+#endif