MACRO                                                                  
&N       SWAPREG &R1,&R2                                                        
* ******************************************************************* *         
*                                                                     *         
*                          S W A P R E G                              *         
*                                                                     *         
*        Swaps the contents of two registers.                         *         
*                                                                     *         
         LCLC  &REG1,&REG2,&REG3,&LAB                                           
         AIF   (K'&N EQ 0).LABEND                                               
&LAB     SETC  '&N'                                                             
&LAB     DS    0H                                                               
.LABEND  ANOP                                                                   
         AIF   (K'&R1 NE 0).REG1OK                                              
         MNOTE 8,'***** No registers specified ***********************'         
         AGO   .END                                                             
.REG1OK  ANOP                                                                   
         AIF   ('&R1'(1,1) NE 'R').NUMB                                         
&REG1    SETC  '&R1'(2,2)                                                       
         AGO   .COMP                                                            
.NUMB    ANOP                                                                   
&REG1    SETC  '&R1'                                                            
.COMP    ANOP                                                                   
         AIF   ('&REG1' GT '15').E1                                             
&REG1    SETC  '&R1'                                                            
         AIF   (K'&R2 NE 0).REG2OK                                              
         MNOTE 8,'***** No second register specified *****************'         
         AGO   .END                                                             
.REG2OK  ANOP                                                                   
         AIF   ('&R2'(1,1) NE 'R').NUMB2                                        
&REG2    SETC  '&R2'(2,2)                                                       
         AGO   .COMP2                                                           
.NUMB2   ANOP                                                                   
&REG2    SETC  '&R2'                                                            
.COMP2   ANOP                                                                   
         AIF   ('&REG2' GT '15').E1                                             
&REG2    SETC  '&R2'                                                            
         AIF   ('&REG1' EQ '&REG2').E2                                          
.CONT    ANOP                                                                   
&REG3    SETC  '&REG1           * Exchange registers &REG1 and &REG2'           
         CR    &REG1,&REG2      * See if registers are the smae       *         
         BE    *+10             * Skip if they are                    *         
         XR    &REG1,&REG2      *                                     *         
         XR    &REG2,&REG3      * Swap them                           *         
         XR    &REG1,&REG2      *                                     *         
*                                                                     *         
*  Copyright - Abbydale Systems LLC.                                  *         
* ******************************************************************* *         
         MEXIT                                                                  
.E2      MNOTE 8,'Duplicate register specification'                             
         AGO   .END                                                             
.E1      MNOTE 8,'Improper register specified, No statements generated'         
.END     ANOP                                                                   
         MEND