Index: apps/plugins/pdbox/PDa/src/m_fixed.h
===================================================================
--- apps/plugins/pdbox/PDa/src/m_fixed.h	(revision 26504)
+++ apps/plugins/pdbox/PDa/src/m_fixed.h	(working copy)
@@ -1,6 +1,10 @@
 #ifndef __M_FIXED_H__
 #define __M_FIXED_H__
 
+#ifdef ROCKBOX
+#include "plugin.h"
+#endif
+
 typedef int t_sample;
 
 #define t_fixed int
@@ -11,10 +15,24 @@
 
 
 /* fixed point multiplication and division */
-
-#define mult(a,b) (long long)(((long long) (a) * (long long) (b))>>fix1)
-#define idiv(a,b) ((((long long) (a) )<<fix1)/(long long) (b) )
-
+#if defined(ROCKBOX) && defined(CPU_ARM)
+    #define mult(A,B) \
+         ({ \
+            t_fixed lo; \
+            t_fixed hi; \
+            asm volatile ( \
+               "smull %[lo], %[hi], %[x], %[y] \n\t"   /* multiply */ \
+               "mov   %[lo], %[lo], lsr %[shr] \n\t"   /* lo >>= fix1 */ \
+               "orr   %[lo], %[lo], %[hi], lsl %[shl]" /* lo |= (hi << (32-fix1)) */ \
+               : [lo]"=&r"(lo), [hi]"=&r"(hi) \
+               : [x]"r"(A), [y]"r"(B), [shr]"r"(fix1), [shl]"r"(32-fix1)); \
+            lo; \
+         })
+    #define idiv(a,b) ((((long long) (a) )<<fix1)/(long long) (b) )
+#else
+    #define mult(a,b) (long long)(((long long) (a) * (long long) (b))>>fix1)
+    #define idiv(a,b) ((((long long) (a) )<<fix1)/(long long) (b) )
+#endif
 /* conversion macros */
 
 #define itofix(a) ((a) << fix1)