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   1 /*****************************************************************************/
   2 /*                                                                           */
   3 /*                                 coptadd.h                                 */
   4 /*                                                                           */
   5 /*                        Optimize addition sequences                        */
   6 /*                                                                           */
   7 /*                                                                           */
   8 /*                                                                           */
   9 /* (C) 2001-2005, Ullrich von Bassewitz                                      */
  10 /*                Römerstrasse 52                                            */
  11 /*                D-70794 Filderstadt                                        */
  12 /* EMail:         uz@cc65.org                                                */
  13 /*                                                                           */
  14 /*                                                                           */
  15 /* This software is provided 'as-is', without any expressed or implied       */
  16 /* warranty.  In no event will the authors be held liable for any damages    */
  17 /* arising from the use of this software.                                    */
  18 /*                                                                           */
  19 /* Permission is granted to anyone to use this software for any purpose,     */
  20 /* including commercial applications, and to alter it and redistribute it    */
  21 /* freely, subject to the following restrictions:                            */
  22 /*                                                                           */
  23 /* 1. The origin of this software must not be misrepresented; you must not   */
  24 /*    claim that you wrote the original software. If you use this software   */
  25 /*    in a product, an acknowledgment in the product documentation would be  */
  26 /*    appreciated but is not required.                                       */
  27 /* 2. Altered source versions must be plainly marked as such, and must not   */
  28 /*    be misrepresented as being the original software.                      */
  29 /* 3. This notice may not be removed or altered from any source              */
  30 /*    distribution.                                                          */
  31 /*                                                                           */
  32 /*****************************************************************************/
  33
  34
  35
  36 #ifndef COPTADD_H
  37 #define COPTADD_H
  38
  39
  40
  41 /* cc65 */
  42 #include "codeseg.h"
  43
  44
  45
  46 /*****************************************************************************/
  47 /*                            Optimize additions                             */
  48 /*****************************************************************************/
  49
  50
  51
  52 unsigned OptAdd1 (CodeSeg* S);
  53 /* Search for the sequence
  54  *
  55  *      jsr     pushax
  56  *      ldy     xxx
  57  *      ldx     #$00
  58  *      lda     (sp),y
  59  *      jsr     tosaddax
  60  *
  61  * and replace it by:
  62  *
  63  *      ldy     xxx-2
  64  *      clc
  65  *      adc     (sp),y
  66  *      bcc     L
  67  *      inx
  68  * L:
  69  */
  70
  71 unsigned OptAdd2 (CodeSeg* S);
  72 /* Search for the sequence
  73  *
  74  *      ldy     #xx
  75  *      lda     (sp),y
  76  *      tax
  77  *      dey
  78  *      lda     (sp),y
  79  *      ldy     #$yy
  80  *      jsr     addeqysp
  81  *
  82  * and replace it by:
  83  *
  84  *      ldy     #xx-1
  85  *      lda     (sp),y
  86  *      ldy     #yy
  87  *      clc
  88  *      adc     (sp),y
  89  *      sta     (sp),y
  90  *      ldy     #xx
  91  *      lda     (sp),y
  92  *      ldy     #yy+1
  93  *      adc     (sp),y
  94  *      sta     (sp),y
  95  *
  96  * provided that a/x is not used later.
  97  */
  98
  99 unsigned OptAdd3 (CodeSeg* S);
 100 /* Search for the sequence
 101  *
 102  *      jsr     pushax
 103  *      ldx     #$00
 104  *      lda     xxx
 105  *      jsr     tosaddax
 106  *
 107  * and replace it by
 108  *
 109  *      clc
 110  *      adc     xxx
 111  *      bcc     L1
 112  *      inx
 113  * L1:
 114  */
 115
 116 unsigned OptAdd4 (CodeSeg* S);
 117 /* Search for the sequence
 118  *
 119  *      jsr     pushax
 120  *      lda     xxx
 121  *      ldx     yyy
 122  *      jsr     tosaddax
 123  *
 124  * and replace it by
 125  *
 126  *      clc
 127  *      adc     xxx
 128  *      pha
 129  *      txa
 130  *      adc     yyy
 131  *      tax
 132  *      pla
 133  */
 134
 135 unsigned OptAdd5 (CodeSeg* S);
 136 /* Search for a call to incaxn and replace it by an 8 bit add if the X register
 137  * is not used later.
 138  */
 139
 140 unsigned OptAdd6 (CodeSeg* S);
 141 /* Search for the sequence
 142  *
 143  *      adc     ...
 144  *      bcc     L
 145  *      inx
 146  * L:
 147  *
 148  * and remove the handling of the high byte if X is not used later.
 149  */
 150
 151
 152
 153 /* End of coptadd.h */
 154
 155 #endif
 156
 157
 158