gcc 4.4 did this: The MIPS port no longer recognizes the h  asm constraint. It was necessary to remove this constraint in order to avoid generating unpredictable code sequences. 

so the libmad build with gcc-4.5.0 was failing.

Found a solution here:

http://us.generation-nt.com/answer/bug-568418-libmad0-dev-mpg321-compilation-errors-mips-mipsel-architectures-help-169033451.html

Upstream-Status: Pending

2010/07/29
Nitin A Kamble <nitin.a.kamble@intel.com>

--- a/fixed.h
+++ b/fixed.h
@@ -297,6 +297,15 @@ mad_fixed_t mad_f_mul_inline(mad_fixed_t
 
 /* --- MIPS ---------------------------------------------------------------- */
 
+# elif defined(FPM_MIPS) && (defined(__clang__) || __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 4))
+    typedef unsigned int u64_di_t __attribute__ ((mode (DI)));
+#   define MAD_F_MLX(hi, lo, x, y) \
+    do { \
+        u64_di_t __ll = (u64_di_t) (x) * (y); \
+        hi = __ll >> 32; \
+        lo = __ll; \
+     } while (0)
+
 # elif defined(FPM_MIPS)
 
 /*
