add NEON optimization

13 files changed, 359 insertions, 40 deletions

diff --git a/curses/Makefile.am b/curses/Makefile.am
index 586f76d..d4c7585 100644
--- a/curses/Makefile.am
+++ b/curses/Makefile.am
@@ -9,6 +9,7 @@ LIBOPNA_SOURCES=../libopna/opnaadpcm.c \
                 ../libopna/opna.c
 
 FMDRIVER_SOURCES=../fmdriver/fmdriver_fmp.c \
+                 ../fmdriver/fmdriver_common.c \
                  ../fmdriver/ppz8.c
 fmpc_SOURCES=main.c \
              $(LIBOPNA_SOURCES) \
diff --git a/fmdsp/fmdsp-vramlookup-c.c b/fmdsp/fmdsp-vramlookup-c.c
new file mode 100644
index 0000000..f900c8d
--- /dev/null
+++ b/fmdsp/fmdsp-vramlookup-c.c
@@ -0,0 +1,14 @@
+#include "fmdsp/fmdsp.h"
+
+void fmdsp_vramlookup_c(uint8_t *vram32, const uint8_t *vram, const uint8_t *palette, int stride) {
+  for (int y = 0; y < PC98_H; y++) {
+    for (int x = 0; x < PC98_W; x++) {
+      uint8_t r = palette[vram[y*PC98_W+x]*3+0];
+      uint8_t g = palette[vram[y*PC98_W+x]*3+1];
+      uint8_t b = palette[vram[y*PC98_W+x]*3+2];
+      uint32_t data = (((uint32_t)r)<<16) | (((uint32_t)g)<<8) | ((uint32_t)b);
+      uint32_t *row = (uint32_t *)(vram32 + y*stride);
+      row[x] = data;
+    }
+  }
+}
diff --git a/fmdsp/fmdsp-vramlookup-neon.s b/fmdsp/fmdsp-vramlookup-neon.s
new file mode 100644
index 0000000..3cfb957
--- /dev/null
+++ b/fmdsp/fmdsp-vramlookup-neon.s
@@ -0,0 +1,83 @@
+@ neon register map
+@  0,  3,  6,  9, 12, 15, 18, 21  b
+@  1,  4,  7, 10, 13, 16, 19, 22  g
+@  2,  5,  9, 11, 14, 17, 20, 23  r
+
+@ 16, 17, 18, 19, 20, 21, 22, 23  vram
+
+@ 26, 27 r palette
+@ 28, 29 g palette
+@ 30, 31 b palette
+
+.global fmdsp_vramlookup_neon
+
+@ r0: uint8_t *vram32
+@   4 bytes aligned
+@   b, g, r, 0,
+@ r1: const uint8_t *vram
+@ r2: const uint8_t *palette
+@   r0, g0, b0, r1, g1, b1, ...
+@ r3: int stride
+fmdsp_vramlookup_neon:
+  push {lr}
+@ load palette
+  vld3.8 {d26, d28, d30}, [r2]!
+  vld1.8 {d27}, [r2]!
+  vld1.8 {d29}, [r2]!
+  vld1.8 {d31}, [r2]!
+
+  mov r14, #400
+.loopcol:
+  mov r2, r0
+  mov r12, #10
+.looprow:
+@ row address
+
+@ load vram
+  vld1.8 {d16-d19}, [r1]!
+  vld1.8 {d20-d23}, [r1]!
+
+@ lookup
+  vtbl.8 d0,  {d30-d31}, d16
+  vtbl.8 d1,  {d28-d29}, d16
+  vtbl.8 d2,  {d26-d27}, d16
+  vtbl.8 d3,  {d30-d31}, d17
+  vtbl.8 d4,  {d28-d29}, d17
+  vtbl.8 d5,  {d26-d27}, d17
+  vtbl.8 d6,  {d30-d31}, d18
+  vtbl.8 d7,  {d28-d29}, d18
+  vtbl.8 d8,  {d26-d27}, d18
+  vtbl.8 d9,  {d30-d31}, d19
+  vtbl.8 d10, {d28-d29}, d19
+  vtbl.8 d11, {d26-d27}, d19
+  vtbl.8 d12, {d30-d31}, d20
+  vtbl.8 d13, {d28-d29}, d20
+  vtbl.8 d14, {d26-d27}, d20
+  vtbl.8 d15, {d30-d31}, d21
+  vtbl.8 d16, {d28-d29}, d21
+  vtbl.8 d17, {d26-d27}, d21
+  vtbl.8 d18, {d30-d31}, d22
+  vtbl.8 d19, {d28-d29}, d22
+  vtbl.8 d20, {d26-d27}, d22
+  vtbl.8 d21, {d30-d31}, d23
+  vtbl.8 d22, {d28-d29}, d23
+  vtbl.8 d23, {d26-d27}, d23
+
+@ store vram32
+  vst4.8 {d0-d3},   [r2]!
+  vst4.8 {d3-d6},   [r2]!
+  vst4.8 {d6-d9},   [r2]!
+  vst4.8 {d9-d12},  [r2]!
+  vst4.8 {d12-d15}, [r2]!
+  vst4.8 {d15-d18}, [r2]!
+  vst4.8 {d18-d21}, [r2]!
+  vst4.8 {d21-d24}, [r2]!
+
+  subs r12, #1
+  bne .looprow
+
+  add r0, r3
+  subs r14, #1
+  bne .loopcol
+
+  pop {pc}
diff --git a/fmdsp/fmdsp.c b/fmdsp/fmdsp.c
index 3d082af..2f708dd 100644
--- a/fmdsp/fmdsp.c
+++ b/fmdsp/fmdsp.c
@@ -5,6 +5,8 @@
 #include <stdio.h>
 #include "libopna/opna.h"
 
+fmdsp_vramlookup_type fmdsp_vramlookup_func = fmdsp_vramlookup_c;
+
 static void vramblit(uint8_t *vram, int x, int y,
                      const uint8_t *data, int w, int h) {
   for (int yi = 0; yi < h; yi++) {
@@ -727,17 +729,9 @@ void fmdsp_update(struct fmdsp *fmdsp,
   }
   fmdsp_palette_fade(fmdsp);
 }
+
 void fmdsp_vrampalette(struct fmdsp *fmdsp, const uint8_t *vram, uint8_t *vram32, int stride) {
-  for (int y = 0; y < PC98_H; y++) {
-    for (int x = 0; x < PC98_W; x++) {
-      uint8_t r = fmdsp->palette[vram[y*PC98_W+x]*3+0];
-      uint8_t g = fmdsp->palette[vram[y*PC98_W+x]*3+1];
-      uint8_t b = fmdsp->palette[vram[y*PC98_W+x]*3+2];
-      uint32_t data = (((uint32_t)r)<<16) | (((uint32_t)g)<<8) | ((uint32_t)b);
-      uint32_t *row = (uint32_t *)(vram32 + y*stride);
-      row[x] = data;
-    }
-  }
+  fmdsp_vramlookup_func(vram32, vram, fmdsp->palette, stride);
 }
 
 void fmdsp_dispstyle_set(struct fmdsp *fmdsp, enum FMDSP_DISPSTYLE style) {
diff --git a/fmdsp/fmdsp.h b/fmdsp/fmdsp.h
index cce2310..a7e4aab 100644
--- a/fmdsp/fmdsp.h
+++ b/fmdsp/fmdsp.h
@@ -49,6 +49,16 @@ void fmdsp_vrampalette(struct fmdsp *fmdsp, const uint8_t *vram, uint8_t *vram32
 void fmdsp_font_from_fontrom(uint8_t *font, const uint8_t *fontrom);
 void fmdsp_palette_set(struct fmdsp *fmdsp, int p);
 void fmdsp_dispstyle_set(struct fmdsp *fmdsp, enum FMDSP_DISPSTYLE style);
+
+typedef void (*fmdsp_vramlookup_type)(uint8_t *vram32,
+                                      const uint8_t *vram,
+                                      const uint8_t *palette,
+                                      int stride);
+extern fmdsp_vramlookup_type fmdsp_vramlookup_func;
+void fmdsp_vramlookup_c(uint8_t *vram32,
+                        const uint8_t *vram,
+                        const uint8_t *palette,
+                        int stride);
 #ifdef __cplusplus
 }
 #endif
diff --git a/gtk/Makefile.am b/gtk/Makefile.am
index 174f5e9..0a9a95b 100644
--- a/gtk/Makefile.am
+++ b/gtk/Makefile.am
@@ -1,11 +1,12 @@
 bin_PROGRAMS=fmplayer
 
 LIBOPNA_SRC=../libopna/opnaadpcm.c \
-                ../libopna/opnadrum.c \
-                ../libopna/opnafm.c \
-                ../libopna/opnassg.c \
-                ../libopna/opnatimer.c \
-                ../libopna/opna.c
+            ../libopna/opnadrum.c \
+            ../libopna/opnafm.c \
+            ../libopna/opnassg.c \
+            ../libopna/opnassg-sinc-c.c \
+            ../libopna/opnatimer.c \
+            ../libopna/opna.c
 
 FMDRIVER_SRC=../fmdriver/fmdriver_fmp.c \
              ../fmdriver/fmdriver_pmd.c \
@@ -13,9 +14,16 @@ FMDRIVER_SRC=../fmdriver/fmdriver_fmp.c \
              ../fmdriver/ppz8.c
 
 FMDSP_SRC=../fmdsp/fmdsp.c \
+          ../fmdsp/fmdsp-vramlookup-c.c \
           ../fmdsp/font_rom.c \
           ../fmdsp/font_fmdsp_small.c
 
+if ENABLE_NEON
+LIBOPNA_SRC+=../libopna/opnassg-sinc-neon.s
+FMDSP_SRC+=../fmdsp/fmdsp-vramlookup-neon.s
+fmplayer_CCASFLAGS=-march=armv8-a -mfpu=crypto-neon-fp-armv8
+endif
+
 fmplayer_SOURCES=main.c \
                  toneview.c \
                  oscilloview.c \
diff --git a/gtk/configure.ac b/gtk/configure.ac
index 8e13a34..2727888 100644
--- a/gtk/configure.ac
+++ b/gtk/configure.ac
@@ -2,10 +2,17 @@ AC_INIT([fmplayer], [0.1.0])
 AM_INIT_AUTOMAKE([-Wall -Werror foreign subdir-objects])
 AM_SILENT_RULES([yes])
 AC_PROG_CC_C99
+AM_PROG_AS
 
 dnl AM_PATH_SDL2([2.0.5])
 PKG_CHECK_MODULES([PORTAUDIO], [portaudio-2.0])
 PKG_CHECK_MODULES([GTK3], [gtk+-3.0 cairo])
 
+AC_ARG_ENABLE([neon], AS_HELP_STRING([--enable-neon], [Enable NEON optimized functions for SSG sinc filtering and fmdsp palette lookup. Tested on Cortex-A53 (Raspberry PI 3)]))
+AM_CONDITIONAL([ENABLE_NEON], [test "x$enable_neon" = "xyes"])
+AS_IF([test "x$enable_neon" = "xyes"], [
+  AC_DEFINE([ENABLE_NEON])
+])
+
 AC_CONFIG_FILES([Makefile])
 AC_OUTPUT
diff --git a/gtk/main.c b/gtk/main.c
index af0d2db..fc72d62 100644
--- a/gtk/main.c
+++ b/gtk/main.c
@@ -53,6 +53,7 @@ static struct {
   void *vram32;
   int vram32_stride;
   const char *current_uri;
+  bool oscillo_should_update;
   struct oscillodata oscillodata_audiothread[LIBOPNA_OSCILLO_TRACK_COUNT];
 } g;
 
@@ -97,17 +98,21 @@ static int pastream_cb(const void *inptr, void *outptr, unsigned long frames,
   struct opna_timer *timer = (struct opna_timer *)userdata;
   int16_t *buf = (int16_t *)outptr;
   memset(outptr, 0, sizeof(int16_t)*frames*2);
-  opna_timer_mix_oscillo(timer, buf, frames, g.oscillodata_audiothread);
+  opna_timer_mix_oscillo(timer, buf, frames,
+                         g.oscillo_should_update ?
+                         g.oscillodata_audiothread : 0);
 
   if (!atomic_flag_test_and_set_explicit(
       &toneview_g.flag, memory_order_acquire)) {
     tonedata_from_opna(&toneview_g.tonedata, &g.opna);
     atomic_flag_clear_explicit(&toneview_g.flag, memory_order_release);
   }
-  if (!atomic_flag_test_and_set_explicit(
-    &oscilloview_g.flag, memory_order_acquire)) {
-    memcpy(oscilloview_g.oscillodata, g.oscillodata_audiothread, sizeof(oscilloview_g.oscillodata));
-    atomic_flag_clear_explicit(&oscilloview_g.flag, memory_order_release);
+  if (g.oscillo_should_update) {
+    if (!atomic_flag_test_and_set_explicit(
+      &oscilloview_g.flag, memory_order_acquire)) {
+      memcpy(oscilloview_g.oscillodata, g.oscillodata_audiothread, sizeof(oscilloview_g.oscillodata));
+      atomic_flag_clear_explicit(&oscilloview_g.flag, memory_order_release);
+    }
   }
   return paContinue;
 }
@@ -479,7 +484,14 @@ static void drag_data_recv_cb(
   gtk_drag_finish(ctx, TRUE, FALSE, time);
 }
 
+void opna_ssg_sinc_calc_neon(unsigned, const int16_t *, int32_t *);
+void fmdsp_vramlookup_neon(uint8_t *, const uint8_t *, const uint8_t *, int);
+
 int main(int argc, char **argv) {
+#ifdef ENABLE_NEON
+  opna_ssg_sinc_calc_func = opna_ssg_sinc_calc_neon;
+  fmdsp_vramlookup_func = fmdsp_vramlookup_neon;
+#endif
   load_fontrom();
   gtk_init(&argc, &argv);
   GtkWidget *w = gtk_window_new(GTK_WINDOW_TOPLEVEL);
diff --git a/libopna/opna.c b/libopna/opna.c
index 1b0aa6c..567c913 100644
--- a/libopna/opna.c
+++ b/libopna/opna.c
@@ -37,8 +37,9 @@ void opna_mix_oscillo(struct opna *opna, int16_t *buf, unsigned samples, struct
     }
   }
   unsigned offset = OSCILLO_SAMPLE_COUNT - samples;
-  opna_fm_mix(&opna->fm, buf, samples, &oscillo[0], offset);
-  opna_ssg_mix_55466(&opna->ssg, &opna->resampler, buf, samples, &oscillo[6], offset);
+  opna_fm_mix(&opna->fm, buf, samples, oscillo ? &oscillo[0] : 0, offset);
+  opna_ssg_mix_55466(&opna->ssg, &opna->resampler, buf, samples,
+                     oscillo ? &oscillo[6] : 0, offset);
   opna_drum_mix(&opna->drum, buf, samples);
   opna_adpcm_mix(&opna->adpcm, buf, samples);
 }
diff --git a/libopna/opnassg-sinc-c.c b/libopna/opnassg-sinc-c.c
new file mode 100644
index 0000000..bf93039
--- /dev/null
+++ b/libopna/opnassg-sinc-c.c
@@ -0,0 +1,13 @@
+#include "libopna/opnassg.h"
+
+void opna_ssg_sinc_calc_c(unsigned resampler_index, const int16_t *inbuf, int32_t *outbuf) {
+  for (int c = 0; c < 3; c++) {
+    int32_t chsample = 0;
+    for (int j = 0; j < OPNA_SSG_SINCTABLELEN; j++) {
+      unsigned sincindex = j;
+      if (!(resampler_index&1)) sincindex += OPNA_SSG_SINCTABLELEN;
+      chsample += inbuf[(((resampler_index)>>1)+j)*3+c] * opna_ssg_sinctable[sincindex];
+    }
+    outbuf[c] = chsample;
+  }
+}
diff --git a/libopna/opnassg-sinc-neon.s b/libopna/opnassg-sinc-neon.s
new file mode 100644
index 0000000..19dc3c6
--- /dev/null
+++ b/libopna/opnassg-sinc-neon.s
@@ -0,0 +1,118 @@
+@ neon register map:
+@  0,  3,  6,  9, 12, 15 ssg1
+@  1,  4,  7, 10, 13, 16 ssg2
+@  2,  5,  8, 11, 14, 17 ssg3
+@ 18, 19, 20, 21, 22, 23 sinc
+@ 24-25 (q12): ssg1 out
+@ 26-27 (q13): ssg2 out
+@ 28-29 (q14): ssg3 out
+
+.global opna_ssg_sinc_calc_neon
+@ r0: resampler_index
+@ r1: const int16_t *inbuf
+@ r2: int32_t *outbuf
+
+opna_ssg_sinc_calc_neon:
+  push {r4-r10,lr}
+@ sinc table to r3
+  movw r3, #:lower16:opna_ssg_sinctable
+  movt r3, #:upper16:opna_ssg_sinctable
+  tst r0, #1
+  addeq r3, #256
+
+@ add offset to ssg input buffer address
+  bic r0, #1
+  add r0, r0, lsl #1
+  add r1, r0
+
+@ initialize output register
+  vmov.i64 q12, #0
+  vmov.i64 q13, #0
+  vmov.i64 q14, #0
+
+@ sinc sample length
+  mov r0, #128
+
+.loop:
+@
+  subs r0, #24
+  blo .end
+
+@ load SSG channel data
+  vld3.16 {d0-d2}, [r1]!
+  vld3.16 {d3-d5}, [r1]!
+  vld3.16 {d6-d8}, [r1]!
+  vld3.16 {d9-d11}, [r1]!
+  vld3.16 {d12-d14}, [r1]!
+  vld3.16 {d15-d17}, [r1]!
+
+@ load sinc data
+  vld1.16 {d18-d21}, [r3]!
+  vld1.16 {d22-d23}, [r3]!
+
+@ multiply and accumulate
+  vmlal.s16 q12, d0,  d18
+  vmlal.s16 q13, d1,  d18
+  vmlal.s16 q14, d2,  d18
+  vmlal.s16 q12, d3,  d19
+  vmlal.s16 q13, d4,  d19
+  vmlal.s16 q14, d5,  d19
+  vmlal.s16 q12, d6,  d20
+  vmlal.s16 q13, d7,  d20
+  vmlal.s16 q14, d8,  d20
+  vmlal.s16 q12, d9,  d21
+  vmlal.s16 q13, d10, d21
+  vmlal.s16 q14, d11, d21
+  vmlal.s16 q12, d12, d22
+  vmlal.s16 q13, d13, d22
+  vmlal.s16 q14, d14, d22
+  vmlal.s16 q12, d15, d23
+  vmlal.s16 q13, d16, d23
+  vmlal.s16 q14, d17, d23
+  b .loop
+
+.end:
+@ 8 samples left
+  vld3.16 {d0-d2}, [r1]!
+  vld3.16 {d3-d5}, [r1]
+  vld1.16 {d18-d19}, [r3]
+
+  vmlal.s16 q12, d0, d18
+  vmlal.s16 q13, d1, d18
+  vmlal.s16 q14, d2, d18
+  vmlal.s16 q12, d3, d19
+  vmlal.s16 q13, d4, d19
+  vmlal.s16 q14, d5, d19
+
+@ extract data from result SIMD registers
+
+  vmov.32 r0,  d24[0]
+  vmov.32 r1,  d24[1]
+  vmov.32 r3,  d25[0]
+  vmov.32 r12, d25[1]
+
+  vmov.32 r14, d26[0]
+  vmov.32 r4,  d26[1]
+  vmov.32 r5,  d27[0]
+  vmov.32 r6,  d27[1]
+
+  vmov.32 r7,  d28[0]
+  vmov.32 r8,  d28[1]
+  vmov.32 r9,  d29[0]
+  vmov.32 r10, d29[1]
+
+  add r0, r1
+  add r3, r12
+
+  add r14, r4
+  add r5, r6
+
+  add r7, r8
+  add r9, r10
+
+  add r4, r0, r3
+  add r5, r14
+  add r6, r7, r9
+
+  stmia r2, {r4-r6}
+  pop {r4-r10,pc}
diff --git a/libopna/opnassg.c b/libopna/opnassg.c
index ec03437..4a12f76 100644
--- a/libopna/opnassg.c
+++ b/libopna/opnassg.c
@@ -1,5 +1,6 @@
 #include "opnassg.h"
 #include "oscillo/oscillo.h"
+#include <string.h>
 /*
 static const float voltable[32] = {
   0.0f,           0.0f,           0x1.ae89f9p-8f, 0x1.000000p-7f,
@@ -27,9 +28,6 @@ static const int16_t voltable[32] = {
    6494,  7723,  9185, 10922
 };
 
-#define SINCTABLEBIT 7
-#define SINCTABLELEN (1<<SINCTABLEBIT)
-
 // GNU Octave
 // Fc = 7987200
 // Ff = Fc/144
@@ -39,7 +37,8 @@ static const int16_t voltable[32] = {
 // B = 128 * O / 2
 // FILTER=sinc(linspace(-127.5,127.5,256)*2/9/2).*rotdim(kaiser(256,B))
 // FILTERI=round(FILTER(1:128).*32768)
-static const int16_t sinctable[SINCTABLELEN] = {
+#if 0
+const int16_t opna_ssg_sinctable[OPNA_SSG_SINCTABLELEN*2] = {
       1,     0,    -1,    -2,    -3,    -5,    -6,    -6,
      -6,    -5,    -2,     2,     7,    11,    16,    19,
      20,    18,    13,     5,    -5,   -17,   -29,   -38,
@@ -56,8 +55,61 @@ static const int16_t sinctable[SINCTABLELEN] = {
    3306,  3714,  3690,  3185,  2206,   815,  -868, -2673,
   -4391, -5798, -6670, -6809, -6067, -4359, -1681,  1886,
    6178, 10957, 15928, 20765, 25133, 28724, 31275, 32600,
+  32600, 31275, 28724, 25133, 20765, 15928, 10957,  6178,
+   1886, -1681, -4359, -6067, -6809, -6670, -5798, -4391,
+  -2673,  -868,   815,  2206,  3185,  3690,  3714,  3306,
+   2557,  1585,   523,  -498, -1365, -1994, -2333, -2369,
+  -2125, -1655, -1032,  -343,   328,   902,  1322,  1552,
+   1580,  1421,  1108,   692,   230,  -220,  -607,  -889,
+  -1043, -1062,  -954,  -744,  -464,  -154,   147,   405,
+    593,   694,   705,   632,   491,   306,   101,   -96,
+   -264,  -385,  -450,  -455,  -406,  -315,  -195,   -64,
+     61,   166,   241,   280,   282,   251,   193,   119,
+     39,   -37,  -100,  -144,  -166,  -166,  -146,  -112,
+    -68,   -22,    21,    56,    80,    91,    90,    79,
+     60,    36,    12,   -11,   -29,   -40,   -45,   -44,
+    -38,   -29,   -17,    -5,     5,    13,    18,    20,
+     19,    16,    11,     7,     2,    -2,    -5,    -6,
+     -6,    -6,    -5,    -3,    -2,    -1,     0,     1,
+};
+#endif
+const int16_t opna_ssg_sinctable[OPNA_SSG_SINCTABLELEN*2] = {
+      1,    -1,    -3,    -6,    -6,    -2,     7,    16,
+     20,    13,    -5,   -29,   -44,   -40,   -11,    36,
+     79,    91,    56,   -22,  -112,  -166,  -144,   -37,
+    119,   251,   280,   166,   -64,  -315,  -455,  -385,
+    -96,   306,   632,   694,   405,  -154,  -744, -1062,
+   -889,  -220,   692,  1421,  1552,   902,  -343, -1655,
+  -2369, -1994,  -498,  1585,  3306,  3690,  2206,  -868,
+  -4391, -6670, -6067, -1681,  6178, 15928, 25133, 31275,
+  32600, 28724, 20765, 10957,  1886, -4359, -6809, -5798,
+  -2673,   815,  3185,  3714,  2557,   523, -1365, -2333,
+  -2125, -1032,   328,  1322,  1580,  1108,   230,  -607,
+  -1043,  -954,  -464,   147,   593,   705,   491,   101,
+   -264,  -450,  -406,  -195,    61,   241,   282,   193,
+     39,  -100,  -166,  -146,   -68,    21,    80,    90,
+     60,    12,   -29,   -45,   -38,   -17,     5,    18,
+     19,    11,     2,    -5,    -6,    -5,    -2,     0,
+      0,    -2,    -5,    -6,    -5,     2,    11,    19,
+     18,     5,   -17,   -38,   -45,   -29,    12,    60,
+     90,    80,    21,   -68,  -146,  -166,  -100,    39,
+    193,   282,   241,    61,  -195,  -406,  -450,  -264,
+    101,   491,   705,   593,   147,  -464,  -954, -1043,
+   -607,   230,  1108,  1580,  1322,   328, -1032, -2125,
+  -2333, -1365,   523,  2557,  3714,  3185,   815, -2673,
+  -5798, -6809, -4359,  1886, 10957, 20765, 28724, 32600,
+  31275, 25133, 15928,  6178, -1681, -6067, -6670, -4391,
+   -868,  2206,  3690,  3306,  1585,  -498, -1994, -2369,
+  -1655,  -343,   902,  1552,  1421,   692,  -220,  -889,
+  -1062,  -744,  -154,   405,   694,   632,   306,   -96,
+   -385,  -455,  -315,   -64,   166,   280,   251,   119,
+    -37,  -144,  -166,  -112,   -22,    56,    91,    79,
+     36,   -11,   -40,   -44,   -29,    -5,    13,    20,
+     16,     7,    -2,    -6,    -6,    -3,    -1,     1,
 };
 
+opna_ssg_sinc_calc_func_type opna_ssg_sinc_calc_func = opna_ssg_sinc_calc_c;
+
 void opna_ssg_reset(struct opna_ssg *ssg) {
   for (int i = 0; i < 3; i++) {
     ssg->ch[i].tone_counter = 0;
@@ -78,7 +130,7 @@ void opna_ssg_reset(struct opna_ssg *ssg) {
 }
 
 void opna_ssg_resampler_reset(struct opna_ssg_resampler *resampler) {
-  for (int i = 0; i < SINCTABLELEN; i++) {
+  for (int i = 0; i < OPNA_SSG_SINCTABLELEN; i++) {
     resampler->buf[i] = 0;
   }
   resampler->index = 0;
@@ -215,7 +267,7 @@ void opna_ssg_generate_raw(struct opna_ssg *ssg, int16_t *buf, int samples) {
   }
 }
 
-#define BUFINDEX(n) ((((resampler->index)>>1)+n)&(SINCTABLELEN-1))
+#define BUFINDEX(n) ((((resampler->index)>>1)+n)&(OPNA_SSG_SINCTABLELEN-1))
 
 void opna_ssg_mix_55466(
   struct opna_ssg *ssg, struct opna_ssg_resampler *resampler,
@@ -246,18 +298,13 @@ void opna_ssg_mix_55466(
       resampler->index += 9;
     }
     int32_t sample = 0;
+    resampler->index &= (1u<<(OPNA_SSG_SINCTABLEBIT+1))-1;
+    memcpy(resampler->buf + OPNA_SSG_SINCTABLELEN*3, resampler->buf, OPNA_SSG_SINCTABLELEN*3*sizeof(*resampler->buf));
+    int32_t outbuf[3];
+    opna_ssg_sinc_calc_func(resampler->index, resampler->buf, outbuf);
     for (int ch = 0; ch < 3; ch++) {
-      int32_t chsample = 0;
-      for (int j = 0; j < SINCTABLELEN; j++) {
-        unsigned sincindex = j*2;
-        if (!(resampler->index&1)) sincindex++;
-        bool sincsign = sincindex & (1<<(SINCTABLEBIT));
-        unsigned sincmask = ((1<<(SINCTABLEBIT))-1);
-        sincindex = (sincindex & sincmask) ^ (sincsign ? sincmask : 0);
-        chsample += (resampler->buf[BUFINDEX(j)*3+ch] * sinctable[sincindex])>>2;
-      }
-      if (oscillo) oscillo[ch].buf[offset+i] = chsample >> 13;
-      if (!(ssg->mask & (1<<ch))) sample += chsample;
+      if (oscillo) oscillo[ch].buf[offset+i] = outbuf[ch] >> 15;
+      if (!(ssg->mask & (1<<ch))) sample += outbuf[ch] >> 2;
     }
     sample >>= 16;
     sample *= 13000;
diff --git a/libopna/opnassg.h b/libopna/opnassg.h
index 0321163..231db4d 100644
--- a/libopna/opnassg.h
+++ b/libopna/opnassg.h
@@ -8,6 +8,9 @@
 extern "C" {
 #endif
 
+#define OPNA_SSG_SINCTABLEBIT 7
+#define OPNA_SSG_SINCTABLELEN (1<<OPNA_SSG_SINCTABLEBIT)
+
 struct opna_ssg_ch {
   uint16_t tone_counter;
   bool out;
@@ -30,7 +33,7 @@ struct opna_ssg {
 };
 
 struct opna_ssg_resampler {
-  int16_t buf[(1<<7)*3];
+  int16_t buf[OPNA_SSG_SINCTABLELEN*3 * 2];
   unsigned index;
 };
 
@@ -58,6 +61,14 @@ unsigned opna_ssg_readreg(const struct opna_ssg *ssg, unsigned reg);
 int opna_ssg_channel_level(const struct opna_ssg *ssg, int ch);
 unsigned opna_ssg_tone_period(const struct opna_ssg *ssg, int ch);
 
+typedef void (*opna_ssg_sinc_calc_func_type)(unsigned resampler_index,
+                                             const int16_t *inbuf, int32_t *outbuf);
+extern opna_ssg_sinc_calc_func_type opna_ssg_sinc_calc_func;
+void opna_ssg_sinc_calc_c(unsigned resampler_index,
+                          const int16_t *inbuf, int32_t *outbuf);
+
+extern const int16_t opna_ssg_sinctable[OPNA_SSG_SINCTABLELEN*2];
+
 #ifdef __cplusplus
 }
 #endif