gnu: libmad: Fix MIPS assembler code to work with new GCC.

* gnu/packages/patches/libmad-mips-newgcc.patch: New file.
* gnu/packages/mp3.scm (libmad): Add patch.
* gnu-system.am (dist_patch_DATA): Add patch.

gnu-system.am

@@ -240,6 +240,7 @@ dist_patch_DATA =						\
   gnu/packages/patches/hop-bigloo-4.0b.patch			\
   gnu/packages/patches/libevent-dns-tests.patch			\
   gnu/packages/patches/libffi-mips-n32-fix.patch		\
+  gnu/packages/patches/libmad-mips-newgcc.patch			\
   gnu/packages/patches/libtheora-config-guess.patch		\
   gnu/packages/patches/libtool-skip-tests.patch			\
   gnu/packages/patches/libtool-skip-tests-for-mips.patch	\

gnu/packages/mp3.scm

@@ -44,7 +44,8 @@
                                 version ".tar.gz"))
             (sha256
              (base32
-              "14460zhacxhswnzb36qfpd1f2wbk10qvksvm6wyq5hpvdgnw7ymv"))))
+              "14460zhacxhswnzb36qfpd1f2wbk10qvksvm6wyq5hpvdgnw7ymv"))
+            (patches (list (search-patch "libmad-mips-newgcc.patch")))))
    (build-system gnu-build-system)
    (arguments
     `(#:phases

gnu/packages/patches/libmad-mips-newgcc.patch

@@ -0,0 +1,16 @@
+Fix MIPS assembly code to work with newer GCC, where the "=h"
+constraint is no longer supported.
+
+--- libmad/fixed.h.orig	2004-02-16 21:02:03.000000000 -0500
++++ libmad/fixed.h	2011-10-29 18:47:21.000000000 -0400
+@@ -304,8 +304,8 @@
+  * significant bit depends on OPT_ACCURACY via mad_f_scale64().
+  */
+ #  define MAD_F_MLX(hi, lo, x, y)  \
+-    asm ("mult	%2,%3"  \
+-	 : "=l" (lo), "=h" (hi)  \
++    asm ("mult	%2,%3\n\tmfhi  %1"  \
++	 : "=l" (lo), "=r" (hi)  \
+ 	 : "%r" (x), "r" (y))
+ 
+ # if defined(HAVE_MADD_ASM)