Initial version

code/bin/instr.h

@@ -0,0 +1,21 @@
+/*
+ Copyright (c) 1992-1993 The Regents of the University of California.
+ All rights reserved.  See copyright.h for copyright notice and limitation 
+ of liability and disclaimer of warranty provisions.
+ */
+
+#include "copyright.h"
+
+/* Instruction formats */
+
+#define rd(i)		(((i) >> 11) & 0x1f)
+#define rt(i)		(((i) >> 16) & 0x1f)
+#define rs(i)		(((i) >> 21) & 0x1f)
+#define shamt(i)	(((i) >> 6) & 0x1f)
+#define immed(i)	(((i) & 0x8000) ? (i)|(-0x8000) : (i)&0x7fff)
+
+#define off26(i)        (((i)&((1<<26)-1))<<2)
+#define top4(i)         (((i)&(~((1<<28)-1))))
+#define off16(i)        (immed(i)<<2)
+
+#define extend(i, hibitmask)	(((i)&(hibitmask)) ? ((i)|(-(hibitmask))) : (i))