git.sur5r.net Git - cc65/blob - src/cc65/coptc02.c

   1 /*****************************************************************************/
   2 /*                                                                           */
   3 /*                                 coptc02.h                                 */
   4 /*                                                                           */
   5 /*                       65C02 specific optimizations                        */
   6 /*                                                                           */
   7 /*                                                                           */
   8 /*                                                                           */
   9 /* (C) 2001-2012, Ullrich von Bassewitz                                      */
  10 /*                Roeerstrasse 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 #include <string.h>
  37
  38 /* cc65 */
  39 #include "codeent.h"
  40 #include "codeinfo.h"
  41 #include "error.h"
  42 #include "coptc02.h"
  43
  44
  45
  46 /*****************************************************************************/
  47 /*                                   Data                                    */
  48 /*****************************************************************************/
  49
  50
  51
  52 /*****************************************************************************/
  53 /*                             Helper functions                              */
  54 /*****************************************************************************/
  55
  56
  57
  58 /*****************************************************************************/
  59 /*                                   Code                                    */
  60 /*****************************************************************************/
  61
  62
  63
  64 unsigned Opt65C02Ind (CodeSeg* S)
  65 /* Try to use the indirect addressing mode where possible */
  66 {
  67     unsigned Changes = 0;
  68     unsigned I;
  69
  70     /* Walk over the entries */
  71     I = 0;
  72     while (I < CS_GetEntryCount (S)) {
  73
  74         /* Get next entry */
  75         CodeEntry* E = CS_GetEntry (S, I);
  76
  77         /* Check for addressing mode indirect indexed Y where Y is zero.
  78          * Note: All opcodes that are available as (zp),y are also available
  79          * as (zp), so we can ignore the actual opcode here.
  80          */
  81         if (E->AM == AM65_ZP_INDY && E->RI->In.RegY == 0) {
  82
  83             /* Replace it by indirect addressing mode */
  84             CodeEntry* X = NewCodeEntry (E->OPC, AM65_ZP_IND, E->Arg, 0, E->LI);
  85             CS_InsertEntry (S, X, I+1);
  86             CS_DelEntry (S, I);
  87
  88             /* We had changes */
  89             ++Changes;
  90
  91         }
  92
  93         /* Next entry */
  94         ++I;
  95
  96     }
  97
  98     /* Return the number of changes made */
  99     return Changes;
 100 }
 101
 102
 103
 104 unsigned Opt65C02BitOps (CodeSeg* S)
 105 /* Use special bit op instructions of the C02 */
 106 {
 107     unsigned Changes = 0;
 108     unsigned I;
 109
 110     /* Walk over the entries */
 111     I = 0;
 112     while (I < CS_GetEntryCount (S)) {
 113
 114         CodeEntry* L[3];
 115
 116         /* Get next entry */
 117         L[0] = CS_GetEntry (S, I);
 118
 119         /* Check for the sequence */
 120         if (L[0]->OPC == OP65_LDA                               &&
 121             (L[0]->AM == AM65_ZP || L[0]->AM == AM65_ABS)       &&
 122             !CS_RangeHasLabel (S, I+1, 2)                       &&
 123             CS_GetEntries (S, L+1, I+1, 2)                      &&
 124             (L[1]->OPC == OP65_AND || L[1]->OPC == OP65_ORA)    &&
 125             CE_IsConstImm (L[1])                                &&
 126             L[2]->OPC == OP65_STA                               &&
 127             L[2]->AM == L[0]->AM                                &&
 128             strcmp (L[2]->Arg, L[0]->Arg) == 0                  &&
 129             !RegAUsed (S, I+3)) {
 130
 131             char Buf[32];
 132             CodeEntry* X;
 133
 134             /* Use TRB for AND and TSB for ORA */
 135             if (L[1]->OPC == OP65_AND) {
 136
 137                 /* LDA #XX */
 138                 sprintf (Buf, "$%02X", (int) ((~L[1]->Num) & 0xFF));
 139                 X = NewCodeEntry (OP65_LDA, AM65_IMM, Buf, 0, L[1]->LI);
 140                 CS_InsertEntry (S, X, I+3);
 141
 142                 /* TRB */
 143                 X = NewCodeEntry (OP65_TRB, L[0]->AM, L[0]->Arg, 0, L[0]->LI);
 144                 CS_InsertEntry (S, X, I+4);
 145
 146             } else {
 147
 148                 /* LDA #XX */
 149                 sprintf (Buf, "$%02X", (int) L[1]->Num);
 150                 X = NewCodeEntry (OP65_LDA, AM65_IMM, Buf, 0, L[1]->LI);
 151                 CS_InsertEntry (S, X, I+3);
 152
 153                 /* TSB */
 154                 X = NewCodeEntry (OP65_TSB, L[0]->AM, L[0]->Arg, 0, L[0]->LI);
 155                 CS_InsertEntry (S, X, I+4);
 156             }
 157
 158             /* Delete the old stuff */
 159             CS_DelEntries (S, I, 3);
 160
 161             /* We had changes */
 162             ++Changes;
 163         }
 164
 165         /* Next entry */
 166         ++I;
 167
 168     }
 169
 170     /* Return the number of changes made */
 171     return Changes;
 172 }
 173
 174
 175
 176 unsigned Opt65C02Stores (CodeSeg* S)
 177 /* Use STZ where possible */
 178 {
 179     unsigned Changes = 0;
 180     unsigned I;
 181
 182     /* Walk over the entries */
 183     I = 0;
 184     while (I < CS_GetEntryCount (S)) {
 185
 186         /* Get next entry */
 187         CodeEntry* E = CS_GetEntry (S, I);
 188
 189         /* Check for a store with a register value of zero and an addressing
 190          * mode available with STZ.
 191          */
 192         if (((E->OPC == OP65_STA && E->RI->In.RegA == 0) ||
 193              (E->OPC == OP65_STX && E->RI->In.RegX == 0) ||
 194              (E->OPC == OP65_STY && E->RI->In.RegY == 0))       &&
 195             (E->AM == AM65_ZP  || E->AM == AM65_ABS ||
 196              E->AM == AM65_ZPX || E->AM == AM65_ABSX)) {
 197
 198             /* Replace by STZ */
 199             CodeEntry* X = NewCodeEntry (OP65_STZ, E->AM, E->Arg, 0, E->LI);
 200             CS_InsertEntry (S, X, I+1);
 201
 202             /* Delete the old stuff */
 203             CS_DelEntry (S, I);
 204
 205             /* We had changes */
 206             ++Changes;
 207         }
 208
 209         /* Next entry */
 210         ++I;
 211
 212     }
 213
 214     /* Return the number of changes made */
 215     return Changes;
 216 }
 217
 218
 219