1 files changed, 17 insertions, 1 deletions

diff --git a/lib/mpi/longlong.h b/lib/mpi/longlong.h
index 57fd45ab7af1..08c60d10747f 100644
--- a/lib/mpi/longlong.h
+++ b/lib/mpi/longlong.h
@@ -671,7 +671,23 @@ do {						\
         **************  MIPS/64  **************
         ***************************************/
 #if (defined(__mips) && __mips >= 3) && W_TYPE_SIZE == 64
-#if (__GNUC__ >= 5) || (__GNUC__ >= 4 && __GNUC_MINOR__ >= 4)
+#if defined(__mips_isa_rev) && __mips_isa_rev >= 6
+/*
+ * GCC ends up emitting a __multi3 intrinsic call for MIPS64r6 with the plain C
+ * code below, so we special case MIPS64r6 until the compiler can do better.
+ */
+#define umul_ppmm(w1, w0, u, v)                                         \
+do {                                                                    \
+        __asm__ ("dmulu %0,%1,%2"                                       \
+                 : "=d" ((UDItype)(w0))                                 \
+                 : "d" ((UDItype)(u)),                                  \
+                   "d" ((UDItype)(v)));                                 \
+        __asm__ ("dmuhu %0,%1,%2"                                       \
+                 : "=d" ((UDItype)(w1))                                 \
+                 : "d" ((UDItype)(u)),                                  \
+                   "d" ((UDItype)(v)));                                 \
+} while (0)
+#elif (__GNUC__ >= 5) || (__GNUC__ >= 4 && __GNUC_MINOR__ >= 4)
 #define umul_ppmm(w1, w0, u, v) \
 do {                                                                    \
         typedef unsigned int __ll_UTItype __attribute__((mode(TI)));    \