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

   1 /*****************************************************************************/
   2 /*                                                                           */
   3 /*                                copttest.h                                 */
   4 /*                                                                           */
   5 /*                          Optimize test sequences                          */
   6 /*                                                                           */
   7 /*                                                                           */
   8 /*                                                                           */
   9 /* (C) 2001-2009, 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 COPTTEST_H
  37 #define COPTTEST_H
  38
  39
  40
  41 /* cc65 */
  42 #include "codeseg.h"
  43
  44
  45
  46 /*****************************************************************************/
  47 /*                              Optimize tests                               */
  48 /*****************************************************************************/
  49
  50
  51
  52 unsigned OptTest1 (CodeSeg* S);
  53 /* Given a sequence
  54 **
  55 **     stx     xxx
  56 **     ora     xxx
  57 **     beq/bne ...
  58 **
  59 ** If X is zero, the sequence may be changed to
  60 **
  61 **     cmp     #$00
  62 **     beq/bne ...
  63 **
  64 ** which may be optimized further by another step.
  65 **
  66 ** If A is zero, the sequence may be changed to
  67 **
  68 **     txa
  69 **     beq/bne ...
  70 */
  71
  72 unsigned OptTest2 (CodeSeg* S);
  73 /* Search for an inc/dec operation followed by a load and a conditional
  74 ** branch based on the flags from the load. Remove the load if the insn
  75 ** isn't used later.
  76 */
  77
  78
  79
  80 /* End of copttest.h */
  81
  82 #endif