Index: clisp-2.49.20180218+really2.49.92/src/ari_asm_mips-macro.c
===================================================================
--- clisp-2.49.20180218+really2.49.92.orig/src/ari_asm_mips-macro.c
+++ clisp-2.49.20180218+really2.49.92/src/ari_asm_mips-macro.c
@@ -37,9 +37,14 @@
         .ent asm_mulu32_
         DECLARE_FUNCTION(asm_mulu32_)
 asm_mulu32_:
+#if __mips_isa_rev >= 6
+        muhu $3,$5,$4
+        mulu $2,$5,$4
+#else
         multu $5,$4
         mfhi $3
         mflo $2
+#endif
         sw $3,($6)
         j $31
         .end asm_mulu32_
Index: clisp-2.49.20180218+really2.49.92/src/ari_asm_mips64-macro.c
===================================================================
--- clisp-2.49.20180218+really2.49.92.orig/src/ari_asm_mips64-macro.c
+++ clisp-2.49.20180218+really2.49.92/src/ari_asm_mips64-macro.c
@@ -37,9 +37,14 @@
         .ent asm_mulu32_
         DECLARE_FUNCTION(asm_mulu32_)
 asm_mulu32_:
+#if __mips_isa_rev >= 6
+        muhu $3,$5,$4
+        mulu $2,$5,$4
+#else
         multu $5,$4
         mfhi $3
         mflo $2
+#endif
         sw $3,($6)
         j $31
         .end asm_mulu32_