Introduce likely() and unlikely() macros, use to give gcc hints about which branch is likely to be taken in a conditional, use them in the midi player for a small speedup, use instead of similar EXPECT macros in tremor and use in mpegplayer

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@19162 a1c6a512-1295-4272-9138-f99709370657

5 files changed, 32 insertions, 42 deletions

diff --git a/apps/codecs/libtremor/codebook.c b/apps/codecs/libtremor/codebook.c
index 8c319ab49e..5ffd0e308b 100644
--- a/apps/codecs/libtremor/codebook.c
+++ b/apps/codecs/libtremor/codebook.c
@@ -154,9 +154,9 @@ STIN long decode_packed_entry_number(codebook *book,
   long lo,hi;
   long lok = oggpack_look(b,book->dec_firsttablen);
  
-  if (EXPECT(lok >= 0, 1)) {
+  if (likely(lok >= 0)) {
     long entry = book->dec_firsttable[lok];
-    if(EXPECT(entry&0x80000000UL, 0)){
+    if(unlikely(entry&0x80000000UL)){
       lo=(entry>>15)&0x7fff;
       hi=book->used_entries-(entry&0x7fff);
     }else{
@@ -218,7 +218,7 @@ static long decode_packed_block(codebook *book, oggpack_buffer *b,
       bitend = ((adr&3)+b->headend)*8;
       while (bufptr<bufend){
         long entry, lo, hi;
-        if (EXPECT(cachesize<book->dec_maxlength, 0)) {
+        if (unlikely(cachesize<book->dec_maxlength)) {
           if (bit-cachesize+32>=bitend)
             break;
           bit-=cachesize;
@@ -230,13 +230,13 @@ static long decode_packed_block(codebook *book, oggpack_buffer *b,
         }
 
         entry=book->dec_firsttable[cache&((1<<book->dec_firsttablen)-1)];
-        if(EXPECT(entry&0x80000000UL, 0)){
+        if(unlikely(entry&0x80000000UL)){
           lo=(entry>>15)&0x7fff;
           hi=book->used_entries-(entry&0x7fff);
           {
             ogg_uint32_t testword=bitreverse((ogg_uint32_t)cache);
             
-            while(EXPECT(hi-lo>1, 1)){
+            while(likely(hi-lo>1)){
               long p=(hi-lo)>>1;
               if (book->codelist[lo+p]>testword)
                 hi-=p;
diff --git a/apps/codecs/libtremor/misc.h b/apps/codecs/libtremor/misc.h
index 7d8b846381..e94236c2a8 100644
--- a/apps/codecs/libtremor/misc.h
+++ b/apps/codecs/libtremor/misc.h
@@ -275,17 +275,5 @@ static inline ogg_int32_t VFLOAT_ADD(ogg_int32_t a,ogg_int32_t ap,
   return(a);
 }
 
-#ifdef __GNUC__
-#if __GNUC__ >= 3
-#define EXPECT(a, b) __builtin_expect((a), (b))
-#else
-#define EXPECT(a, b) (a)
-#endif
-#else
-#define EXPECT(a, b) (a)
 #endif
 
-#endif
-
-
-
diff --git a/apps/plugins/midi/synth.c b/apps/plugins/midi/synth.c
index 0819722030..bae6149860 100644
--- a/apps/plugins/midi/synth.c
+++ b/apps/plugins/midi/synth.c
@@ -296,7 +296,7 @@ static inline void synthVoice(struct SynthObject * so, int32_t * out, unsigned i
     while(samples-- > 0)
     {
         /* Is voice being ramped? */
-        if(so->state == STATE_RAMPDOWN)
+        if(unlikely(so->state == STATE_RAMPDOWN))
         {
             if(so->decay != 0)  /* Ramp has been started */
             {
@@ -318,12 +318,12 @@ static inline void synthVoice(struct SynthObject * so, int32_t * out, unsigned i
 
         s2 = getSample((cp_temp >> FRACTSIZE)+1, wf);
 
-        if(mode_mask28)
+        if(likely(mode_mask28))
         {
             /* LOOP_REVERSE|LOOP_PINGPONG  = 24  */
-            if(mode_mask24 && so->loopState == STATE_LOOPING && (cp_temp < start_loop))
+            if(unlikely(mode_mask24 && so->loopState == STATE_LOOPING && (cp_temp < start_loop)))
             {
-                if(mode_mask_looprev)
+                if(unlikely(mode_mask_looprev))
                 {
                     cp_temp += diff_loop;
                     s2=getSample((cp_temp >> FRACTSIZE), wf);
@@ -334,10 +334,10 @@ static inline void synthVoice(struct SynthObject * so, int32_t * out, unsigned i
                 }
             }
 
-            if(cp_temp >= end_loop)
+            if(unlikely(cp_temp >= end_loop))
             {
                 so->loopState = STATE_LOOPING;
-                if(!mode_mask24)
+                if(unlikely(!mode_mask24))
                 {
                     cp_temp -= diff_loop;
                     s2=getSample((cp_temp >> FRACTSIZE), wf);
@@ -350,7 +350,7 @@ static inline void synthVoice(struct SynthObject * so, int32_t * out, unsigned i
         }
 
         /* Have we overrun? */
-        if(cp_temp >= num_samples)
+        if(unlikely(cp_temp >= num_samples))
         {
             cp_temp -= so->delta;
             s2 = getSample((cp_temp >> FRACTSIZE)+1, wf);
@@ -362,21 +362,21 @@ static inline void synthVoice(struct SynthObject * so, int32_t * out, unsigned i
 
         s1 +=((signed)((s2 - s1) * (cp_temp & ((1<<FRACTSIZE)-1)))>>FRACTSIZE);
 
-        if(so->curRate == 0)
+        if(unlikely(so->curRate == 0))
         {
             stopVoice(so);
 //          so->isUsed = false;
 
         }
 
-        if(so->ch != 9 && so->state != STATE_RAMPDOWN) /* Stupid ADSR code... and don't do ADSR for drums */
+        if(likely(so->ch != 9 && so->state != STATE_RAMPDOWN)) /* Stupid ADSR code... and don't do ADSR for drums */
         {
-            if(so->curOffset < so->targetOffset)
+            if(unlikely(so->curOffset < so->targetOffset))
             {
                 so->curOffset += (so->curRate);
-                if(so -> curOffset > so->targetOffset && so->curPoint != 2)
+                if(unlikely(so -> curOffset > so->targetOffset && so->curPoint != 2))
                 {
-                    if(so->curPoint != 5)
+                    if(unlikely(so->curPoint != 5))
                     {
                         setPoint(so, so->curPoint+1);
                     }
@@ -388,10 +388,9 @@ static inline void synthVoice(struct SynthObject * so, int32_t * out, unsigned i
             } else
             {
                 so->curOffset -= (so->curRate);
-                if(so -> curOffset < so->targetOffset && so->curPoint != 2)
+                if(unlikely(so -> curOffset < so->targetOffset && so->curPoint != 2))
                 {
-
-                    if(so->curPoint != 5)
+                    if(unlikely(so->curPoint != 5))
                     {
                         setPoint(so, so->curPoint+1);
                     }
@@ -404,7 +403,7 @@ static inline void synthVoice(struct SynthObject * so, int32_t * out, unsigned i
             }
         }
 
-        if(so->curOffset < 0)
+        if(unlikely(so->curOffset < 0))
         {
             so->curOffset = so->targetOffset;
             stopVoice(so);
@@ -417,7 +416,7 @@ static inline void synthVoice(struct SynthObject * so, int32_t * out, unsigned i
         s1 = s1 * volscale >> 14;
 
         /* need to set ramp beginning */
-        if(so->state == STATE_RAMPDOWN && so->decay == 0)
+        if(unlikely(so->state == STATE_RAMPDOWN && so->decay == 0))
         {
             so->decay = s1;
             if(so->decay == 0)
@@ -443,7 +442,7 @@ int32_t samp_buf[512] IBSS_ATTR;
 void synthSamples(int32_t *buf_ptr, unsigned int num_samples) ICODE_ATTR;
 void synthSamples(int32_t *buf_ptr, unsigned int num_samples)
 {
-    if (num_samples > 512)
+    if (unlikely(num_samples > 512))
         DEBUGF("num_samples is too big!\n");
     else
     {
@@ -463,6 +462,7 @@ void synthSamples(int32_t *buf_ptr, unsigned int num_samples)
 
         rb->memcpy(buf_ptr, samp_buf, num_samples*4);
     }
+
     /* TODO: Automatic Gain Control, anyone? */
     /* Or, should this be implemented on the DSP's output volume instead? */
 
diff --git a/apps/plugins/mpegplayer/attributes.h b/apps/plugins/mpegplayer/attributes.h
index 9d708061c0..7ad83a3e6e 100644
--- a/apps/plugins/mpegplayer/attributes.h
+++ b/apps/plugins/mpegplayer/attributes.h
@@ -32,10 +32,3 @@
 #define ATTR_ALIGN(align)
 #endif
 
-#ifdef HAVE_BUILTIN_EXPECT
-#define likely(x) __builtin_expect ((x) != 0, 1)
-#define unlikely(x) __builtin_expect ((x) != 0, 0)
-#else
-#define likely(x) (x)
-#define unlikely(x) (x)
-#endif
diff --git a/firmware/export/system.h b/firmware/export/system.h
index 71422e17d6..cce7df6884 100644
--- a/firmware/export/system.h
+++ b/firmware/export/system.h
@@ -168,6 +168,15 @@ int get_cpu_boost_counter(void);
 #define TYPE_FROM_MEMBER(type, memberptr, membername) \
     ((type *)((intptr_t)(memberptr) - OFFSETOF(type, membername)))
 
+/* Use to give gcc hints on which branch is most likely taken */
+#if defined(__GNUC__) && __GNUC__ >= 3
+#define likely(x)   __builtin_expect(!!(x), 1)
+#define unlikely(x) __builtin_expect(!!(x), 0)
+#else
+#define likely(x)   (x)
+#define unlikely(x) (x)
+#endif
+
 /* returns index of first set bit + 1 or 0 if no bits are set */
 int find_first_set_bit(uint32_t val);