--- /dev/null
+#include "io.h"
+
+int main(void)
+{
+ long long achi, acli, rs, rt;
+ long long acho, aclo;
+ long long resulth, resultl;
+
+ rs = 0x00BBAACC;
+ rt = 0x0B1C3D2F;
+ achi = 0x00004433;
+ acli = 0xFFCC0011;
+ resulth = 0xFFFFFFFFFFF81F29;
+ resultl = 0xFFFFFFFFB355089D;
+
+ __asm
+ ("mthi %2, $ac1\n\t"
+ "mtlo %3, $ac1\n\t"
+ "msubu $ac1, %4, %5\n\t"
+ "mfhi %0, $ac1\n\t"
+ "mflo %1, $ac1\n\t"
+ : "=r"(acho), "=r"(aclo)
+ : "r"(achi), "r"(acli), "r"(rs), "r"(rt)
+ );
+ if ((acho != resulth) || (aclo != resultl)) {
+ printf("msubu wrong\n");
+
+ return -1;
+ }
+
+ return 0;
+}