xref: /csrg-svn/sys/tahoe/align/Aadwc.c (revision 45760)
1*45760Sbostic /*-
2*45760Sbostic  * Copyright (c) 1986 The Regents of the University of California.
3*45760Sbostic  * All rights reserved.
4*45760Sbostic  *
5*45760Sbostic  * This code is derived from software contributed to Berkeley by
6*45760Sbostic  * Computer Consoles Inc.
7*45760Sbostic  *
8*45760Sbostic  * %sccs.include.redist.c%
9*45760Sbostic  *
10*45760Sbostic  *	@(#)Aadwc.c	7.1 (Berkeley) 12/06/90
11*45760Sbostic  */
1229586Ssam 
1345699Sbostic #include "align.h"
adwc(infop)1429586Ssam adwc(infop)	process_info *infop;
1529586Ssam /*
1629586Ssam /*	Add with carry.
1729586Ssam /*	Note : the play with 'tmp' just before the 'asm' line makes
1829586Ssam /*		sure that when the adwc opcode is executed, the current
1929586Ssam /*		carry in psl is the same as the 'offending' process'.
2029586Ssam /*		Don't change unless you know exactly what you're doing.
2129586Ssam /*
2229586Ssam /*****************************/
2329586Ssam {
2429586Ssam 	register	long	Register_12;	/* Has to be first reg ! */
2529586Ssam 	register	long	Register_11;
2629586Ssam 	register	long	Register_10;
2729586Ssam 	register 	long	tmp;
2829586Ssam 
2929586Ssam 	Register_12 = operand(infop,0)->data;
3029586Ssam 	Register_11 = operand(infop,1)->data;
3129586Ssam 	if (carry)	/* If process' carry set */
3229586Ssam 		tmp = -1;
3329586Ssam 	else tmp = 0;
3429586Ssam 	tmp++;		/* 0 => carry set.  1 => carry clear */
3529586Ssam 
3629586Ssam 	Register_10=psl;
3729586Ssam 	Set_psl(r10);	/* restore the user psl */
3829586Ssam 	asm("	adwc	r11,r12");
3929586Ssam 	asm("	movpsl	r11");
4029586Ssam 	New_cc (Register_11);
4129586Ssam 
4229586Ssam 	write_back(infop, Register_12, operand(infop,1) );
4329586Ssam }
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