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 /* End of coptptrstore.h */
 177
 178 #endif