--- /dev/null
+#include<stdio.h>
+#include<assert.h>
+
+int main()
+{
+ int rt, rs, ach, acl, dsp;
+ int result;
+
+ ach = 0x05;
+ acl = 0xB4CB;
+ dsp = 0x07;
+ rs = 0x03;
+ result = 0x00007FFF;
+
+ __asm
+ ("wrdsp %1, 0x01\n\t"
+ "mthi %3, $ac1\n\t"
+ "mtlo %4, $ac1\n\t"
+ "extrv_s.h %0, $ac1, %2\n\t"
+ "rddsp %1\n\t"
+ : "=r"(rt), "+r"(dsp)
+ : "r"(rs), "r"(ach), "r"(acl)
+ );
+ dsp = (dsp >> 23) & 0x01;
+ assert(dsp == 1);
+ assert(result == rt);
+
+ rs = 0x08;
+ ach = 0xffffffff;
+ acl = 0x12344321;
+ result = 0xFFFF8000;
+ __asm
+ ("wrdsp %1, 0x01\n\t"
+ "mthi %3, $ac1\n\t"
+ "mtlo %4, $ac1\n\t"
+ "extrv_s.h %0, $ac1, %2\n\t"
+ "rddsp %1\n\t"
+ : "=r"(rt), "+r"(dsp)
+ : "r"(rs), "r"(ach), "r"(acl)
+ );
+ dsp = (dsp >> 23) & 0x01;
+ assert(dsp == 1);
+ assert(result == rt);
+
+ /* Clear dsp */
+ dsp = 0;
+ __asm
+ ("wrdsp %0\n\t"
+ :
+ : "r"(dsp)
+ );
+
+ rs = 0x04;
+ ach = 0x00;
+ acl = 0x4321;
+ result = 0x432;
+ __asm
+ ("wrdsp %1, 0x01\n\t"
+ "mthi %3, $ac1\n\t"
+ "mtlo %4, $ac1\n\t"
+ "extrv_s.h %0, $ac1, %2\n\t"
+ "rddsp %1\n\t"
+ : "=r"(rt), "+r"(dsp)
+ : "r"(rs), "r"(ach), "r"(acl)
+ );
+ dsp = (dsp >> 23) & 0x01;
+ assert(dsp == 0);
+ assert(result == rt);
+
+ rs = 0x1C;
+ ach = 0x123;
+ acl = 0x87654321;
+ result = 0x1238;
+ __asm
+ ("wrdsp %1, 0x01\n\t"
+ "mthi %3, $ac1\n\t"
+ "mtlo %4, $ac1\n\t"
+ "extrv_s.h %0, $ac1, %2\n\t"
+ "rddsp %1\n\t"
+ : "=r"(rt), "+r"(dsp)
+ : "r"(rs), "r"(ach), "r"(acl)
+ );
+ dsp = (dsp >> 23) & 0x01;
+ assert(dsp == 0);
+ assert(result == rt);
+
+ return 0;
+}