git.sur5r.net Git - cc65/blob - src/cc65/coptptrstore.h

   1 /*****************************************************************************/
   2 /*                                                                           */
   3 /*                               coptptrstore.h                              */
   4 /*                                                                           */
   5 /*                      Optimize stores through pointers                     */
   6 /*                                                                           */
   7 /*                                                                           */
   8 /*                                                                           */
   9 /* (C) 2012,      Ullrich von Bassewitz                                      */
  10 /*                Roemerstrasse 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 COPTPTRSTORE_H
  37 #define COPTPTRSTORE_H
  38
  39
  40
  41 /* cc65 */
  42 #include "codeseg.h"
  43
  44
  45
  46 /*****************************************************************************/
  47 /*                                   Code                                    */
  48 /*****************************************************************************/
  49
  50
  51
  52 unsigned OptPtrStore1 (CodeSeg* S);
  53 /* Search for the sequence:
  54  *
  55  *      clc
  56  *      adc     xxx
  57  *      bcc     L
  58  *      inx
  59  * L:   jsr     pushax
  60  *      ldx     #$00
  61  *      lda     yyy
  62  *      ldy     #$00
  63  *      jsr     staspidx
  64  *
  65  * and replace it by:
  66  *
  67  *      sta     ptr1
  68  *      stx     ptr1+1
  69  *      ldy     xxx
  70  *      ldx     #$00
  71  *      lda     yyy
  72  *      sta     (ptr1),y
  73  *
  74  * or by
  75  *
  76  *      ldy     xxx
  77  *      ldx     #$00
  78  *      lda     yyy
  79  *      sta     (zp),y
  80  *
  81  * or by
  82  *
  83  *      ldy     xxx
  84  *      ldx     #$00
  85  *      lda     yyy
  86  *      sta     label,y
  87  *
  88  * or by
  89  *
  90  *      ldy     xxx
  91  *      ldx     #$00
  92  *      lda     yyy
  93  *      sta     $xxxx,y
  94  *
  95  * depending on the two instructions preceeding the sequence above.
  96  */
  97
  98 unsigned OptPtrStore2 (CodeSeg* S);
  99 /* Search for the sequence:
 100  *
 101  *      clc
 102  *      adc     xxx
 103  *      bcc     L
 104  *      inx
 105  * L:   jsr     pushax
 106  *      ldy     yyy
 107  *      ldx     #$00
 108  *      lda     (sp),y
 109  *      ldy     #$00
 110  *      jsr     staspidx
 111  *
 112  * and replace it by:
 113  *
 114  *      sta     ptr1
 115  *      stx     ptr1+1
 116  *      ldy     yyy-2
 117  *      ldx     #$00
 118  *      lda     (sp),y
 119  *      ldy     xxx
 120  *      sta     (ptr1),y
 121  *
 122  * or by
 123  *
 124  *      ldy     yyy-2
 125  *      ldx     #$00
 126  *      lda     (sp),y
 127  *      ldy     xxx
 128  *      sta     (zp),y
 129  *
 130  * or by
 131  *
 132  *      ldy     yyy-2
 133  *      ldx     #$00
 134  *      lda     (sp),y
 135  *      ldy     xxx
 136  *      sta     label,y
 137  *
 138  * or by
 139  *
 140  *      ldy     yyy-2
 141  *      ldx     #$00
 142  *      lda     (sp),y
 143  *      ldy     xxx
 144  *      sta     $xxxx,y
 145  *
 146  * depending on the code preceeding the sequence above.
 147  */
 148
 149 unsigned OptPtrStore3 (CodeSeg* S);
 150 /* Search for the sequence:
 151  *
 152  *      jsr     pushax
 153  *      ldy     xxx
 154  *      jsr     ldauidx
 155  *      subop
 156  *      ldy     yyy
 157  *      jsr     staspidx
 158  *
 159  * and replace it by:
 160  *
 161  *      sta     ptr1
 162  *      stx     ptr1+1
 163  *      ldy     xxx
 164  *      ldx     #$00
 165  *      lda     (ptr1),y
 166  *      subop
 167  *      ldy     yyy
 168  *      sta     (ptr1),y
 169  *
 170  * In case a/x is loaded from the register bank before the pushax, we can even
 171  * use the register bank instead of ptr1.
 172  *
 173  */
 174
 175
 176
 177 /* End of coptptrstore.h */
 178 #endif
 179
 180
 181
 182