Use bsr() in frequency shift calculations

src/engine/bsr.h

@@ -61,25 +61,52 @@ static inline int bsr32(unsigned int v) {
 #else
 
 static inline int bsr(unsigned short v) {
-  unsigned short mask = 0x8000;
+  if (v==0) return -1;
-  for (int i = 16; i >= 0; --i) {
+  if (v&0x8000) return 16;
-    if (v&mask)
+  int o=16;
-      return i;
+  if (!(v&0xff00)) {
-    mask>>=1;
+    o-=8;
+    v<<=8;
+    if (v&0x8000) return o;
   }
-
+  if (!(v&0xf000)) {
-  return -1;
+    o-=4;
+    v<<=4;
+    if (v&0x8000) return o;
+  }
+  if (!(v&0xc000)) {
+    o-=2;
+    v<<=2;
+    if (v&0x8000) return o;
+  }
+  return (v&0x8000) ? o : o-1;
 }
 
 static inline int bsr32(unsigned int v) {
-  unsigned int mask = 0x80000000;
+  if (v==0) return -1;
-  for (int i = 32; i >= 0; --i) {
+  if (v&0x80000000) return 32;
-    if (v&mask)
+  int o=32;
-      return i;
+  if (!(v&0xffff0000)) {
-    mask>>=1;
+    o-=16;
+    v<<=16;
+    if (v&0x80000000) return o;
   }
-
+  if (!(v&0xff000000)) {
-  return -1;
+    o-=8;
+    v<<=8;
+    if (v&0x80000000) return o;
+  }
+  if (!(v&0xf0000000)) {
+    o-=4;
+    v<<=4;
+    if (v&0x80000000) return o;
+  }
+  if (!(v&0xc0000000)) {
+    o-=2;
+    v<<=2;
+    if (v&0x80000000) return o;
+  }
+  return (v&0x80000000) ? o : o-1;
 }
 
 #endif

src/engine/platform/esfm.cpp

@@ -19,6 +19,7 @@
 
 #include "esfm.h"
 #include "../engine.h"
+#include "../bsr.h"
 #include "../../ta-log.h"
 #include <string.h>
 #include <stdio.h>
@@ -366,21 +367,19 @@ void DivPlatformESFM::tick(bool sysTick) {
 }
 
 int DivPlatformESFM::octave(int freq) {
-  int result=1;
+  if (freq>0x3ff) {
-  while (freq>0x3ff) {
+    return 1<<(bsr32(freq)-10);
-    freq>>=1;
-    result<<=1;
   }
-  return result;
+  return 1;
 }
 
 int DivPlatformESFM::toFreq(int freq) {
   int block=0;
-  while (freq>0x3ff) {
+  if (freq>0x3ff) {
-    freq>>=1;
+    block=bsr32(freq)-10;
-    block++;
+    freq>>=block;
   }
-  return ((block&7)<<10)|(freq&0x3ff);
+  return (block<<10)|(freq&0x3ff);
 }
 
 void DivPlatformESFM::muteChannel(int ch, bool mute) {

src/engine/platform/opl.cpp

@@ -19,6 +19,7 @@
 
 #include "opl.h"
 #include "../engine.h"
+#include "../bsr.h"
 #include "../../ta-log.h"
 #include <string.h>
 #include <math.h>
@@ -1386,39 +1387,12 @@ void DivPlatformOPL::tick(bool sysTick) {
         double off=(s->centerRate>=1)?((double)s->centerRate/8363.0):1.0;
         chan[i].freq=(int)(off*parent->calcFreq(chan[i].baseFreq,chan[i].pitch,chan[i].fixedArp?chan[i].baseNoteOverride:chan[i].arpOff,chan[i].fixedArp,false,2,chan[i].pitch2,chipClock,(524288*768)));
         if (chan[i].freq<0x400) chan[i].freq=0x400;
-        if (chan[i].freq>0x3ffffff) chan[i].freq=0x3ffffff;
-        if (chan[i].freq>=0x2000000) {
-          chan[i].freqH=15;
-        } else if (chan[i].freq>=0x1000000) {
-          chan[i].freqH=14;
-        } else if (chan[i].freq>=0x800000) {
-          chan[i].freqH=13;
-        } else if (chan[i].freq>=0x400000) {
-          chan[i].freqH=12;
-        } else if (chan[i].freq>=0x200000) {
-          chan[i].freqH=11;
-        } else if (chan[i].freq>=0x100000) {
-          chan[i].freqH=10;
-        } else if (chan[i].freq>=0x80000) {
-          chan[i].freqH=9;
-        } else if (chan[i].freq>=0x40000) {
-          chan[i].freqH=8;
-        } else if (chan[i].freq>=0x20000) {
-          chan[i].freqH=7;
-        } else if (chan[i].freq>=0x10000) {
-          chan[i].freqH=6;
-        } else if (chan[i].freq>=0x8000) {
-          chan[i].freqH=5;
-        } else if (chan[i].freq>=0x4000) {
-          chan[i].freqH=4;
-        } else if (chan[i].freq>=0x2000) {
-          chan[i].freqH=3;
-        } else if (chan[i].freq>=0x1000) {
-          chan[i].freqH=2;
-        } else if (chan[i].freq>=0x800) {
-          chan[i].freqH=1;
-        } else {
         chan[i].freqH=0;
+        if (chan[i].freq>0x3ffffff) {
+          chan[i].freq=0x3ffffff;
+          chan[i].freqH=15;
+        } else if (chan[i].freq>=0x800) {
+          chan[i].freqH=bsr32(chan[i].freq)-11;
         }
         chan[i].freqL=(chan[i].freq>>chan[i].freqH)&0x3ff;
         chan[i].freqH=8^chan[i].freqH;
@@ -1528,44 +1502,15 @@ void DivPlatformOPL::tick(bool sysTick) {
 #define OPLL_C_NUM 686
 
 int DivPlatformOPL::octave(int freq) {
-  if (freq>=OPLL_C_NUM*64) {
+  freq/=OPLL_C_NUM;
-    return 128;
+  if (freq==0) return 1;
-  } else if (freq>=OPLL_C_NUM*32) {
+  return 1<<bsr(freq);
-    return 64;
-  } else if (freq>=OPLL_C_NUM*16) {
-    return 32;
-  } else if (freq>=OPLL_C_NUM*8) {
-    return 16;
-  } else if (freq>=OPLL_C_NUM*4) {
-    return 8;
-  } else if (freq>=OPLL_C_NUM*2) {
-    return 4;
-  } else if (freq>=OPLL_C_NUM) {
-    return 2;
-  } else {
-    return 1;
-  }
-  return 1;
 }
 
 int DivPlatformOPL::toFreq(int freq) {
-  if (freq>=OPLL_C_NUM*64) {
+  int block=freq/OPLL_C_NUM;
-    return 0x1c00|((freq>>7)&0x3ff);
+  if (block>0) block=bsr(block);
-  } else if (freq>=OPLL_C_NUM*32) {
+  return (block<<10)|((freq>>block)&0x3ff);
-    return 0x1800|((freq>>6)&0x3ff);
-  } else if (freq>=OPLL_C_NUM*16) {
-    return 0x1400|((freq>>5)&0x3ff);
-  } else if (freq>=OPLL_C_NUM*8) {
-    return 0x1000|((freq>>4)&0x3ff);
-  } else if (freq>=OPLL_C_NUM*4) {
-    return 0xc00|((freq>>3)&0x3ff);
-  } else if (freq>=OPLL_C_NUM*2) {
-    return 0x800|((freq>>2)&0x3ff);
-  } else if (freq>=OPLL_C_NUM) {
-    return 0x400|((freq>>1)&0x3ff);
-  } else {
-    return freq&0x3ff;
-  }
 }
 
 void DivPlatformOPL::muteChannel(int ch, bool mute) {

src/engine/platform/opll.cpp

@@ -19,6 +19,7 @@
 
 #include "opll.h"
 #include "../engine.h"
+#include "../bsr.h"
 #include "../../ta-log.h"
 #include <string.h>
 #include <math.h>
@@ -352,44 +353,15 @@ void DivPlatformOPLL::tick(bool sysTick) {
 #define OPLL_C_NUM 343
 
 int DivPlatformOPLL::octave(int freq) {
-  if (freq>=OPLL_C_NUM*64) {
+  freq/=OPLL_C_NUM;
-    return 128;
+  if (freq==0) return 1;
-  } else if (freq>=OPLL_C_NUM*32) {
+  return 1<<bsr(freq);
-    return 64;
-  } else if (freq>=OPLL_C_NUM*16) {
-    return 32;
-  } else if (freq>=OPLL_C_NUM*8) {
-    return 16;
-  } else if (freq>=OPLL_C_NUM*4) {
-    return 8;
-  } else if (freq>=OPLL_C_NUM*2) {
-    return 4;
-  } else if (freq>=OPLL_C_NUM) {
-    return 2;
-  } else {
-    return 1;
-  }
-  return 1;
 }
 
 int DivPlatformOPLL::toFreq(int freq) {
-  if (freq>=OPLL_C_NUM*64) {
+  int block=freq/OPLL_C_NUM;
-    return 0xe00|((freq>>7)&0x1ff);
+  if (block>0) block=bsr(block);
-  } else if (freq>=OPLL_C_NUM*32) {
+  return (block<<9)|((freq>>block)&0x1ff);
-    return 0xc00|((freq>>6)&0x1ff);
-  } else if (freq>=OPLL_C_NUM*16) {
-    return 0xa00|((freq>>5)&0x1ff);
-  } else if (freq>=OPLL_C_NUM*8) {
-    return 0x800|((freq>>4)&0x1ff);
-  } else if (freq>=OPLL_C_NUM*4) {
-    return 0x600|((freq>>3)&0x1ff);
-  } else if (freq>=OPLL_C_NUM*2) {
-    return 0x400|((freq>>2)&0x1ff);
-  } else if (freq>=OPLL_C_NUM) {
-    return 0x200|((freq>>1)&0x1ff);
-  } else {
-    return freq&0x1ff;
-  }
 }
 
 void DivPlatformOPLL::muteChannel(int ch, bool mute) {

src/engine/platform/saa.cpp

@@ -19,6 +19,7 @@
 
 #include "saa.h"
 #include "../engine.h"
+#include "../bsr.h"
 #include "sound/saa1099.h"
 #include <string.h>
 #include <math.h>
@@ -155,22 +156,9 @@ void DivPlatformSAA1099::tick(bool sysTick) {
     if (chan[i].freqChanged || chan[i].keyOn || chan[i].keyOff) {
       chan[i].freq=parent->calcFreq(chan[i].baseFreq,chan[i].pitch,chan[i].fixedArp?chan[i].baseNoteOverride:chan[i].arpOff,chan[i].fixedArp,true,0,chan[i].pitch2,chipClock,CHIP_DIVIDER);
       if (chan[i].freq>65535) chan[i].freq=65535;
-      if (chan[i].freq>=32768) {
-        chan[i].freqH=7;
-      } else if (chan[i].freq>=16384) {
-        chan[i].freqH=6;
-      } else if (chan[i].freq>=8192) {
-        chan[i].freqH=5;
-      } else if (chan[i].freq>=4096) {
-        chan[i].freqH=4;
-      } else if (chan[i].freq>=2048) {
-        chan[i].freqH=3;
-      } else if (chan[i].freq>=1024) {
-        chan[i].freqH=2;
-      } else if (chan[i].freq>=512) {
-        chan[i].freqH=1;
-      } else {
       chan[i].freqH=0;
+      if (chan[i].freq>511) {
+        chan[i].freqH=bsr((unsigned short)chan[i].freq)-9;
       }
       chan[i].freqL=0xff-(chan[i].freq>>chan[i].freqH);
       chan[i].freqH=7-chan[i].freqH;

src/gui/fmPreview.cpp

@@ -27,6 +27,7 @@ extern "C" {
 #include "../../extern/Nuked-OPLL/opll.h"
 }
 #include "../engine/platform/sound/ymfm/ymfm_opz.h"
+#include "../engine/bsr.h"
 
 #define OPN_WRITE(addr,val) \
   OPN2_Write((ym3438_t*)fmPreviewOPN,0,(addr)); \
@@ -388,9 +389,9 @@ void FurnaceGUI::renderFMPreviewESFM(const DivInstrumentFM& params, const DivIns
         double fbase=(mult0?2048.0:1024.0)*pow(2.0,(float)offset/(128.0*12.0));
         int bf=round(fbase);
         int block=0;
-        while (bf>0x3ff) {
+        if (bf>0x3ff) {
-          bf>>=1;
+          block=bsr32(bf)-10;
-          block++;
+          bf>>=block;
         }
         freqL=bf&0xff;
         freqH=((block&7)<<2)|((bf>>8)&3);