Small Musepack optimisation.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@6685 a1c6a512-1295-4272-9138-f99709370657

apps/codecs/libmusepack/Makefile

@@ -14,7 +14,8 @@ ifdef APPEXTRA
 INCLUDES += -I$(APPSDIR)/$(APPEXTRA)
 endif
 
-CFLAGS = $(GCCOPTS) \
+MUSEPACKOPTS = -O2
+CFLAGS = $(GCCOPTS) $(MUSEPACKOPTS)\
 $(INCLUDES) $(TARGET) $(EXTRA_DEFINES) -DMEM=${MEMORYSIZE}
 
 # This sets up 'SRC' based on the files mentioned in SOURCES

apps/codecs/libmusepack/math.h

@@ -99,8 +99,24 @@ static inline MPC_SAMPLE_FORMAT MPC_MULTIPLY_EX(MPC_SAMPLE_FORMAT item1,MPC_SAMP
 #ifdef MPC_HAVE_MULHIGH
 #define MPC_MULTIPLY_FRACT(X,Y) _MulHigh(X,Y)
 #else
+#if CONFIG_CPU==MCF5249 && !defined(SIMULATOR)
+/* loses one bit of accuracy.
+   the rest of the macros won't be as easy as this... */
+#define MPC_MULTIPLY_FRACT(X,Y) \
+    ({ \
+        MPC_SAMPLE_FORMAT t; \
+        asm volatile ( \
+            "mac.l %[A], %[B], %%acc0\n\t" \
+            "movclr.l %%acc0, %[t]\n\t" \
+            "asr.l #1, %[t]\n\t" \
+            : [t] "=d" (t) \
+            : [A] "r" ((X)), [B] "r" ((Y))); \
+        t; \
+    })
+#else
 #define MPC_MULTIPLY_FRACT(X,Y) MPC_MULTIPLY_EX(X,Y,32)
 #endif
+#endif
 
 #define MPC_MAKE_FRACT_CONST(X) (MPC_SAMPLE_FORMAT)((X) * (double)(((mpc_int64_t)1)<<32) )
 #define MPC_MULTIPLY_FRACT_CONST(X,Y) MPC_MULTIPLY_FRACT(X,MPC_MAKE_FRACT_CONST(Y))