1 files changed, 80 insertions, 0 deletions
diff --git a/private/mvdm/softpc.new/base/ccpu386/sub.c b/private/mvdm/softpc.new/base/ccpu386/sub.c
new file mode 100644
index 000000000..1b0c314ca
--- /dev/null
+++ b/private/mvdm/softpc.new/base/ccpu386/sub.c
@@ -0,0 +1,80 @@
+/*[
+
+sub.c
+
+LOCAL CHAR SccsID[]="@(#)sub.c	1.5 02/09/94";
+
+SUB CPU functions.
+------------------
+
+]*/
+
+
+#include <insignia.h>
+
+#include <host_def.h>
+#include <xt.h>
+#include <c_main.h>
+#include <c_addr.h>
+#include <c_bsic.h>
+#include <c_prot.h>
+#include <c_seg.h>
+#include <c_stack.h>
+#include <c_xcptn.h>
+#include	<c_reg.h>
+#include <sub.h>
+
+
+/*
+   =====================================================================
+   EXTERNAL FUNCTIONS START HERE.
+   =====================================================================
+ */
+
+
+/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+/* Generic - one size fits all 'sub'.                                 */
+/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+GLOBAL VOID
+SUB
+       	    	    	                    
+IFN3(
+	IU32 *, pop1,	/* pntr to dst/lsrc operand */
+	IU32, op2,	/* rsrc operand */
+	IUM8, op_sz	/* 8, 16 or 32-bit */
+    )
+
+
+   {
+   IU32 result;
+   IU32 carry;
+   IU32 msb;
+   IU32 op1_msb;
+   IU32 op2_msb;
+   IU32 res_msb;
+
+   msb = SZ2MSB(op_sz);
+
+   result = *pop1 - op2 & SZ2MASK(op_sz);	/* Do operation */
+   op1_msb = (*pop1  & msb) != 0;	/* Isolate all msb's */
+   op2_msb = (op2    & msb) != 0;
+   res_msb = (result & msb) != 0;
+   carry = *pop1 ^ op2 ^ result;	/* Isolate carries */
+					/* Determine flags */
+   /*
+      OF = (op1 == !op2) & (op1 ^ res)
+      ie if operand signs differ and res sign different to original
+      destination set OF.
+    */
+   SET_OF((op1_msb != op2_msb) & (op1_msb ^ res_msb));
+   /*
+      Formally:-     CF = !op1 & op2 | res & !op1 | res & op2
+      Equivalently:- CF = OF ^ op1 ^ op2 ^ res
+    */
+   SET_CF(((carry & msb) != 0) ^ GET_OF());
+   SET_PF(pf_table[result & BYTE_MASK]);
+   SET_ZF(result == 0);
+   SET_SF((result & msb) != 0);		/* SF = MSB */
+   SET_AF((carry & BIT4_MASK) != 0);	/* AF = Bit 4 carry */
+   *pop1 = result;			/* Return answer */
+   }