The MIPS port for GCC-4.4 no longer recognizes the h asm constraint.
Patch from: https://forum.openwrt.org/viewtopic.php?id=20520

--- libgcrypt/mpi/longlong.h-asdf	2009-08-04 09:58:51.000000000 +0930
+++ libgcrypt/mpi/longlong.h	2009-08-04 10:10:27.000000000 +0930
@@ -710,18 +710,35 @@
 #endif /* __m88110__ */
 #endif /* __m88000__ */
 
+/* Test for gcc >= maj.min, as per __GNUC_PREREQ in glibc */
+#if defined (__GNUC__) && defined (__GNUC_MINOR__)
+#define __GNUC_PREREQ(maj, min) \
+	((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
+#else
+#define __GNUC_PREREQ(maj, min)  0
+#endif
+
 /***************************************
  **************  MIPS  *****************
  ***************************************/
 #if defined (__mips__) && W_TYPE_SIZE == 32
-#if __GNUC__ > 2 || __GNUC_MINOR__ >= 7
+#if __GNUC_PREREQ (4,4)
+#define umul_ppmm(w1, w0, u, v) \
+  do {                                                                 \
+    UDItype __ll = (UDItype)(u) * (v);                                 \
+    w1 = __ll >> 32;                                                   \
+    w0 = __ll;                                                         \
+  } while (0)
+#endif
+#if !defined (umul_ppmm) && __GNUC_PREREQ (2,7)
 #define umul_ppmm(w1, w0, u, v) \
   __asm__ ("multu %2,%3"                                                \
 	   : "=l" ((USItype)(w0)),                                      \
 	     "=h" ((USItype)(w1))                                       \
 	   : "d" ((USItype)(u)),                                        \
 	     "d" ((USItype)(v)))
-#else
+#endif
+#if !defined (umul_ppmm)
 #define umul_ppmm(w1, w0, u, v) \
   __asm__ ("multu %2,%3 \n" \
 	   "mflo %0 \n"     \
@@ -739,14 +756,24 @@
  **************  MIPS/64  **************
  ***************************************/
 #if (defined (__mips) && __mips >= 3) && W_TYPE_SIZE == 64
-#if __GNUC__ > 2 || __GNUC_MINOR__ >= 7
+#if __GNUC_PREREQ (4,4)
+#define umul_ppmm(w1, w0, u, v) \
+  do {                                                                 \
+    typedef unsigned int __ll_UTItype __attribute__((mode(TI)));       \
+    __ll_UTItype __ll = (__ll_UTItype)(u) * (v);                       \
+    w1 = __ll >> 64;                                                   \
+    w0 = __ll;                                                         \
+  } while (0)
+#endif
+#if !defined (umul_ppmm) && __GNUC_PREREQ (2,7)
 #define umul_ppmm(w1, w0, u, v) \
   __asm__ ("dmultu %2,%3"                                               \
 	   : "=l" ((UDItype)(w0)),                                      \
 	     "=h" ((UDItype)(w1))                                       \
 	   : "d" ((UDItype)(u)),                                        \
 	     "d" ((UDItype)(v)))
-#else
+#endif
+#if !defined (umul_ppmm)
 #define umul_ppmm(w1, w0, u, v) \
   __asm__ ("dmultu %2,%3 \n"    \
 	   "mflo %0 \n"         \