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

   1 /*****************************************************************************/
   2 /*                                                                           */
   3 /*                                codeinfo.c                                 */
   4 /*                                                                           */
   5 /*                  Additional information about 6502 code                   */
   6 /*                                                                           */
   7 /*                                                                           */
   8 /*                                                                           */
   9 /* (C) 2001      Ullrich von Bassewitz                                       */
  10 /*               Wacholderweg 14                                             */
  11 /*               D-70597 Stuttgart                                           */
  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 <stdlib.h>
  37 #include <string.h>
  38
  39 /* common */
  40 #include "coll.h"
  41
  42 /* cc65 */
  43 #include "codeent.h"
  44 #include "codeseg.h"
  45 #include "datatype.h"
  46 #include "error.h"
  47 #include "symtab.h"
  48 #include "codeinfo.h"
  49
  50
  51
  52 /*****************************************************************************/
  53 /*                                   Data                                    */
  54 /*****************************************************************************/
  55
  56
  57
  58 /* Table listing the function names and code info values for known internally
  59  * used functions. This table should get auto-generated in the future.
  60  */
  61 typedef struct FuncInfo FuncInfo;
  62 struct FuncInfo {
  63     const char*     Name;       /* Function name */
  64     unsigned short  Use;        /* Register usage */
  65     unsigned short  Chg;        /* Changed/destroyed registers */
  66 };
  67
  68 static const FuncInfo FuncInfoTable[] = {
  69     { "addysp",         REG_Y,                REG_NONE                       },
  70     { "aslax1",         REG_AX,               REG_AX | REG_TMP1              },
  71     { "aslax2",         REG_AX,               REG_AX | REG_TMP1              },
  72     { "aslax3",         REG_AX,               REG_AX | REG_TMP1              },
  73     { "aslax4",         REG_AX,               REG_AX | REG_TMP1              },
  74     { "bnega",          REG_A,                REG_AX                         },
  75     { "bnegax",         REG_AX,               REG_AX                         },
  76     { "bnegeax",        REG_EAX,              REG_EAX                        },
  77     { "booleq",         REG_NONE,             REG_AX                         },
  78     { "boolge",         REG_NONE,             REG_AX                         },
  79     { "boolgt",         REG_NONE,             REG_AX                         },
  80     { "boolle",         REG_NONE,             REG_AX                         },
  81     { "boollt",         REG_NONE,             REG_AX                         },
  82     { "boolne",         REG_NONE,             REG_AX                         },
  83     { "booluge",        REG_NONE,             REG_AX                         },
  84     { "boolugt",        REG_NONE,             REG_AX                         },
  85     { "boolule",        REG_NONE,             REG_AX                         },
  86     { "boolult",        REG_NONE,             REG_AX                         },
  87     { "complax",        REG_AX,               REG_AX                         },
  88     { "decax1",         REG_AX,               REG_AX                         },
  89     { "decax2",         REG_AX,               REG_AX                         },
  90     { "decax3",         REG_AX,               REG_AX                         },
  91     { "decax4",         REG_AX,               REG_AX                         },
  92     { "decax5",         REG_AX,               REG_AX                         },
  93     { "decax6",         REG_AX,               REG_AX                         },
  94     { "decax7",         REG_AX,               REG_AX                         },
  95     { "decax8",         REG_AX,               REG_AX                         },
  96     { "decaxy",         REG_AXY,              REG_AX | REG_TMP1              },
  97     { "deceaxy",        REG_EAXY,             REG_EAX                        },
  98     { "decsp1",         REG_NONE,             REG_Y                          },
  99     { "decsp2",         REG_NONE,             REG_A                          },
 100     { "decsp3",         REG_NONE,             REG_A                          },
 101     { "decsp4",         REG_NONE,             REG_A                          },
 102     { "decsp5",         REG_NONE,             REG_A                          },
 103     { "decsp6",         REG_NONE,             REG_A                          },
 104     { "decsp7",         REG_NONE,             REG_A                          },
 105     { "decsp8",         REG_NONE,             REG_A                          },
 106     { "incax1",         REG_AX,               REG_AX                         },
 107     { "incax2",         REG_AX,               REG_AX                         },
 108     { "incsp1",         REG_NONE,             REG_NONE                       },
 109     { "incsp2",         REG_NONE,             REG_Y                          },
 110     { "incsp3",         REG_NONE,             REG_Y                          },
 111     { "incsp4",         REG_NONE,             REG_Y                          },
 112     { "incsp5",         REG_NONE,             REG_Y                          },
 113     { "incsp6",         REG_NONE,             REG_Y                          },
 114     { "incsp7",         REG_NONE,             REG_Y                          },
 115     { "incsp8",         REG_NONE,             REG_Y                          },
 116     { "laddeq",         REG_EAXY|REG_PTR1_LO, REG_EAXY | REG_PTR1_HI         },
 117     { "laddeq1",        REG_Y | REG_PTR1_LO,  REG_EAXY | REG_PTR1_HI         },
 118     { "laddeqa",        REG_AY | REG_PTR1_LO, REG_EAXY | REG_PTR1_HI         },
 119     { "ldaidx",         REG_AXY,              REG_AX | REG_PTR1              },
 120     { "ldauidx",        REG_AXY,              REG_AX | REG_PTR1              },
 121     { "ldax0sp",        REG_Y,                REG_AX                         },
 122     { "ldaxi",          REG_AX,               REG_AXY | REG_PTR1             },
 123     { "ldaxidx",        REG_AXY,              REG_AXY | REG_PTR1             },
 124     { "ldaxysp",        REG_Y,                REG_AXY                        },
 125     { "leaasp",         REG_A,                REG_AX                         },
 126     { "lsubeq",         REG_EAXY|REG_PTR1_LO, REG_EAXY | REG_PTR1_HI         },
 127     { "lsubeq0sp",      REG_EAX,              REG_EAXY                       },
 128     { "lsubeq1",        REG_Y | REG_PTR1_LO,  REG_EAXY | REG_PTR1_HI         },
 129     { "lsubeqa",        REG_AY | REG_PTR1_LO, REG_EAXY | REG_PTR1_HI         },
 130     { "lsubeqysp",      REG_EAXY,             REG_EAXY                       },
 131     { "negax",          REG_AX,               REG_AX                         },
 132     { "pusha",          REG_A,                REG_Y                          },
 133     { "pusha0",         REG_A,                REG_XY                         },
 134     { "pushax",         REG_AX,               REG_Y                          },
 135     { "pusheax",        REG_EAX,              REG_Y                          },
 136     { "pushw0sp",       REG_NONE,             REG_AXY                        },
 137     { "pushwysp",       REG_Y,                REG_AXY                        },
 138     { "shlax1",         REG_AX,               REG_AX | REG_TMP1              },
 139     { "shlax2",         REG_AX,               REG_AX | REG_TMP1              },
 140     { "shlax3",         REG_AX,               REG_AX | REG_TMP1              },
 141     { "shlax4",         REG_AX,               REG_AX | REG_TMP1              },
 142     { "shrax1",         REG_AX,               REG_AX | REG_TMP1              },
 143     { "shrax2",         REG_AX,               REG_AX | REG_TMP1              },
 144     { "shrax3",         REG_AX,               REG_AX | REG_TMP1              },
 145     { "shrax4",         REG_AX,               REG_AX | REG_TMP1              },
 146     { "shreax1",        REG_EAX,              REG_AX | REG_TMP1              },
 147     { "shreax2",        REG_EAX,              REG_AX | REG_TMP1              },
 148     { "shreax3",        REG_EAX,              REG_AX | REG_TMP1              },
 149     { "shreax4",        REG_EAX,              REG_AX | REG_TMP1              },
 150     { "staspidx",       REG_A | REG_Y,        REG_Y | REG_TMP1 | REG_PTR1    },
 151     { "stax0sp",        REG_AX,               REG_Y                          },
 152     { "staxysp",        REG_AXY,              REG_Y                          },
 153     { "subeq0sp",       REG_AX,               REG_AXY                        },
 154     { "subeqysp",       REG_AXY,              REG_AXY                        },
 155     { "tsteax",         REG_EAX,              REG_Y                          },
 156     { "tosadda0",       REG_A,                REG_AXY                        },
 157     { "tosaddax",       REG_AX,               REG_AXY                        },
 158     { "tosicmp",        REG_AX,               REG_AXY | REG_SREG             },
 159     { "tosdiva0",       REG_AX,               REG_ALL                        },
 160     { "tosdivax",       REG_AX,               REG_ALL                        },
 161     { "tosdiveax",      REG_EAX,              REG_ALL                        },
 162     { "toseqeax",       REG_EAX,              REG_AXY | REG_PTR1             },
 163     { "tosgeeax",       REG_EAX,              REG_AXY | REG_PTR1             },
 164     { "tosgteax",       REG_EAX,              REG_AXY | REG_PTR1             },
 165     { "toslcmp",        REG_EAX,              REG_A | REG_Y | REG_PTR1       },
 166     { "tosleeax",       REG_EAX,              REG_AXY | REG_PTR1             },
 167     { "toslteax",       REG_EAX,              REG_AXY | REG_PTR1             },
 168     { "tosmula0",       REG_AX,               REG_ALL                        },
 169     { "tosmulax",       REG_AX,               REG_ALL                        },
 170     { "tosmuleax",      REG_EAX,              REG_ALL                        },
 171     { "tosneeax",       REG_EAX,              REG_AXY | REG_PTR1             },
 172     { "tosshreax",      REG_EAX,              REG_EAXY | REG_PTR1 | REG_PTR2 },
 173     { "tossuba0",       REG_A,                REG_AXY                        },
 174     { "tossubax",       REG_AX,               REG_AXY                        },
 175     { "tossubeax",      REG_EAX,              REG_EAXY                       },
 176     { "tosugeeax",      REG_EAX,              REG_AXY | REG_PTR1             },
 177     { "tosugteax",      REG_EAX,              REG_AXY | REG_PTR1             },
 178     { "tosuleeax",      REG_EAX,              REG_AXY | REG_PTR1             },
 179     { "tosulteax",      REG_EAX,              REG_AXY | REG_PTR1             },
 180     { "tosumula0",      REG_AX,               REG_ALL                        },
 181     { "tosumulax",      REG_AX,               REG_ALL                        },
 182     { "tosumuleax",     REG_EAX,              REG_ALL                        },
 183     { "utsteax",        REG_EAX,              REG_Y                          },
 184 };
 185 #define FuncInfoCount   (sizeof(FuncInfoTable) / sizeof(FuncInfoTable[0]))
 186
 187 /* Table with names of zero page locations used by the compiler */
 188 static const ZPInfo ZPInfoTable[] = {
 189     {   0, "ptr1",      REG_PTR1_LO,    REG_PTR1        },
 190     {   0, "ptr1+1",    REG_PTR1_HI,    REG_PTR1        },
 191     {   0, "ptr2",      REG_PTR2_LO,    REG_PTR2        },
 192     {   0, "ptr2+1",    REG_PTR2_HI,    REG_PTR2        },
 193     {   4, "ptr3",      REG_NONE,       REG_NONE        },
 194     {   4, "ptr4",      REG_NONE,       REG_NONE        },
 195     {   7, "regbank",   REG_NONE,       REG_NONE        },
 196     {   0, "regsave",   REG_SAVE_LO,    REG_SAVE        },
 197     {   0, "regsave+1", REG_SAVE_HI,    REG_SAVE        },
 198     {   0, "sp",        REG_SP_LO,      REG_SP          },
 199     {   0, "sp+1",      REG_SP_HI,      REG_SP          },
 200     {   0, "sreg",      REG_SREG_LO,    REG_SREG        },
 201     {   0, "sreg+1",    REG_SREG_HI,    REG_SREG        },
 202     {   0, "tmp1",      REG_TMP1,       REG_TMP1        },
 203     {   0, "tmp2",      REG_NONE,       REG_NONE        },
 204     {   0, "tmp3",      REG_NONE,       REG_NONE        },
 205     {   0, "tmp4",      REG_NONE,       REG_NONE        },
 206 };
 207 #define ZPInfoCount     (sizeof(ZPInfoTable) / sizeof(ZPInfoTable[0]))
 208
 209
 210
 211 /*****************************************************************************/
 212 /*                                   Code                                    */
 213 /*****************************************************************************/
 214
 215
 216
 217 static int CompareFuncInfo (const void* Key, const void* Info)
 218 /* Compare function for bsearch */
 219 {
 220     return strcmp (Key, ((const FuncInfo*) Info)->Name);
 221 }
 222
 223
 224
 225 void GetFuncInfo (const char* Name, unsigned short* Use, unsigned short* Chg)
 226 /* For the given function, lookup register information and store it into
 227  * the given variables. If the function is unknown, assume it will use and
 228  * load all registers.
 229  */
 230 {
 231     /* If the function name starts with an underline, it is an external
 232      * function. Search for it in the symbol table. If the function does
 233      * not start with an underline, it may be a runtime support function.
 234      * Search for it in the list of builtin functions.
 235      */
 236     if (Name[0] == '_') {
 237
 238         /* Search in the symbol table, skip the leading underscore */
 239         SymEntry* E = FindGlobalSym (Name+1);
 240
 241         /* Did we find it in the top level table? */
 242         if (E && IsTypeFunc (E->Type)) {
 243
 244             /* A function may use the A or A/X registers if it is a fastcall
 245              * function. If it is not a fastcall function but a variadic one,
 246              * it will use the Y register (the parameter size is passed here).
 247              * In all other cases, no registers are used. However, we assume
 248              * that any function will destroy all registers.
 249              */
 250             FuncDesc* D = E->V.F.Func;
 251             if ((D->Flags & FD_FASTCALL) != 0 && D->ParamCount > 0) {
 252                 /* Will use registers depending on the last param */
 253                 SymEntry* LastParam = D->SymTab->SymTail;
 254                 if (SizeOf (LastParam->Type) == 1) {
 255                     *Use = REG_A;
 256                 } else {
 257                     *Use = REG_AX;
 258                 }
 259             } else if ((D->Flags & FD_VARIADIC) != 0) {
 260                 *Use = REG_Y;
 261             } else {
 262                 /* Will not use any registers */
 263                 *Use = REG_NONE;
 264             }
 265
 266             /* Will destroy all registers */
 267             *Chg = REG_ALL;
 268
 269             /* Done */
 270             return;
 271         }
 272
 273     } else {
 274
 275         /* Search for the function in the list of builtin functions */
 276         const FuncInfo* Info = bsearch (Name, FuncInfoTable, FuncInfoCount,
 277                                         sizeof(FuncInfo), CompareFuncInfo);
 278
 279         /* Do we know the function? */
 280         if (Info) {
 281             /* Use the information we have */
 282             *Use = Info->Use;
 283             *Chg = Info->Chg;
 284             return;
 285         }
 286     }
 287
 288     /* Function not found - assume that the primary register is input, and all
 289      * registers are changed
 290      */
 291     *Use = REG_EAXY;
 292     *Chg = REG_ALL;
 293 }
 294
 295
 296
 297 static int CompareZPInfo (const void* Name, const void* Info)
 298 /* Compare function for bsearch */
 299 {
 300     /* Cast the pointers to the correct data type */
 301     const char* N   = (const char*) Name;
 302     const ZPInfo* E = (const ZPInfo*) Info;
 303
 304     /* Do the compare. Be careful because of the length (Info may contain
 305      * more than just the zeropage name).
 306      */
 307     if (E->Len == 0) {
 308         /* Do a full compare */
 309         return strcmp (N, E->Name);
 310     } else {
 311         /* Only compare the first part */
 312         int Res = strncmp (N, E->Name, E->Len);
 313         if (Res == 0 && (N[E->Len] != '\0' && N[E->Len] != '+')) {
 314             /* Name is actually longer than Info->Name */
 315             Res = -1;
 316         }
 317         return Res;
 318     }
 319 }
 320
 321
 322
 323 const ZPInfo* GetZPInfo (const char* Name)
 324 /* If the given name is a zero page symbol, return a pointer to the info
 325  * struct for this symbol, otherwise return NULL.
 326  */
 327 {
 328     /* Search for the zp location in the list */
 329     return bsearch (Name, ZPInfoTable, ZPInfoCount,
 330                     sizeof(ZPInfo), CompareZPInfo);
 331 }
 332
 333
 334
 335 static unsigned GetRegInfo2 (CodeSeg* S,
 336                              CodeEntry* E,
 337                              int Index,
 338                              Collection* Visited,
 339                              unsigned Used,
 340                              unsigned Unused,
 341                              unsigned Wanted)
 342 /* Recursively called subfunction for GetRegInfo. */
 343 {
 344     /* Follow the instruction flow recording register usage. */
 345     while (1) {
 346
 347         unsigned R;
 348
 349         /* Check if we have already visited the current code entry. If so,
 350          * bail out.
 351          */
 352         if (CE_HasMark (E)) {
 353             break;
 354         }
 355
 356         /* Mark this entry as already visited */
 357         CE_SetMark (E);
 358         CollAppend (Visited, E);
 359
 360         /* Evaluate the used registers */
 361         R = E->Use;
 362         if (E->OPC == OP65_RTS ||
 363             ((E->Info & OF_BRA) != 0 && E->JumpTo == 0)) {
 364             /* This instruction will leave the function */
 365             R |= S->ExitRegs;
 366         }
 367         if (R != REG_NONE) {
 368             /* We are not interested in the use of any register that has been
 369              * used before.
 370              */
 371             R &= ~Unused;
 372             /* Remember the remaining registers */
 373             Used |= R;
 374         }
 375
 376         /* Evaluate the changed registers */
 377         if ((R = E->Chg) != REG_NONE) {
 378             /* We are not interested in the use of any register that has been
 379              * used before.
 380              */
 381             R &= ~Used;
 382             /* Remember the remaining registers */
 383             Unused |= R;
 384         }
 385
 386         /* If we know about all registers now, bail out */
 387         if (((Used | Unused) & Wanted) == Wanted) {
 388             break;
 389         }
 390
 391         /* If the instruction is an RTS or RTI, we're done */
 392         if ((E->Info & OF_RET) != 0) {
 393             break;
 394         }
 395
 396         /* If we have an unconditional branch, follow this branch if possible,
 397          * otherwise we're done.
 398          */
 399         if ((E->Info & OF_UBRA) != 0) {
 400
 401             /* Does this jump have a valid target? */
 402             if (E->JumpTo) {
 403
 404                 /* Unconditional jump */
 405                 E     = E->JumpTo->Owner;
 406                 Index = -1;             /* Invalidate */
 407
 408             } else {
 409                 /* Jump outside means we're done */
 410                 break;
 411             }
 412
 413         /* In case of conditional branches, follow the branch if possible and
 414          * follow the normal flow (branch not taken) afterwards. If we cannot
 415          * follow the branch, we're done.
 416          */
 417         } else if ((E->Info & OF_CBRA) != 0) {
 418
 419             if (E->JumpTo) {
 420
 421                 /* Recursively determine register usage at the branch target */
 422                 unsigned U1;
 423                 unsigned U2;
 424
 425                 U1 = GetRegInfo2 (S, E->JumpTo->Owner, -1, Visited, Used, Unused, Wanted);
 426                 if (U1 == REG_ALL) {
 427                     /* All registers used, no need for second call */
 428                     return REG_AXY;
 429                 }
 430                 if (Index < 0) {
 431                     Index = CS_GetEntryIndex (S, E);
 432                 }
 433                 if ((E = CS_GetEntry (S, ++Index)) == 0) {
 434                     Internal ("GetRegInfo2: No next entry!");
 435                 }
 436                 U2 = GetRegInfo2 (S, E, Index, Visited, Used, Unused, Wanted);
 437                 return U1 | U2;         /* Used in any of the branches */
 438
 439             } else {
 440                 /* Jump to global symbol */
 441                 break;
 442             }
 443
 444         } else {
 445
 446             /* Just go to the next instruction */
 447             if (Index < 0) {
 448                 Index = CS_GetEntryIndex (S, E);
 449             }
 450             E = CS_GetEntry (S, ++Index);
 451             if (E == 0) {
 452                 /* No next entry */
 453                 Internal ("GetRegInfo2: No next entry!");
 454             }
 455
 456         }
 457
 458     }
 459
 460     /* Return to the caller the complement of all unused registers */
 461     return Used;
 462 }
 463
 464
 465
 466 static unsigned GetRegInfo1 (CodeSeg* S,
 467                              CodeEntry* E,
 468                              int Index,
 469                              Collection* Visited,
 470                              unsigned Used,
 471                              unsigned Unused,
 472                              unsigned Wanted)
 473 /* Recursively called subfunction for GetRegInfo. */
 474 {
 475     /* Remember the current count of the line collection */
 476     unsigned Count = CollCount (Visited);
 477
 478     /* Call the worker routine */
 479     unsigned R = GetRegInfo2 (S, E, Index, Visited, Used, Unused, Wanted);
 480
 481     /* Restore the old count, unmarking all new entries */
 482     unsigned NewCount = CollCount (Visited);
 483     while (NewCount-- > Count) {
 484         CodeEntry* E = CollAt (Visited, NewCount);
 485         CE_ResetMark (E);
 486         CollDelete (Visited, NewCount);
 487     }
 488
 489     /* Return the registers used */
 490     return R;
 491 }
 492
 493
 494
 495 unsigned GetRegInfo (struct CodeSeg* S, unsigned Index, unsigned Wanted)
 496 /* Determine register usage information for the instructions starting at the
 497  * given index.
 498  */
 499 {
 500     CodeEntry*      E;
 501     Collection      Visited;    /* Visited entries */
 502     unsigned        R;
 503
 504     /* Get the code entry for the given index */
 505     if (Index >= CS_GetEntryCount (S)) {
 506         /* There is no such code entry */
 507         return REG_NONE;
 508     }
 509     E = CS_GetEntry (S, Index);
 510
 511     /* Initialize the data structure used to collection information */
 512     InitCollection (&Visited);
 513
 514     /* Call the recursive subfunction */
 515     R = GetRegInfo1 (S, E, Index, &Visited, REG_NONE, REG_NONE, Wanted);
 516
 517     /* Delete the line collection */
 518     DoneCollection (&Visited);
 519
 520     /* Return the registers used */
 521     return R;
 522 }
 523
 524
 525
 526 int RegAUsed (struct CodeSeg* S, unsigned Index)
 527 /* Check if the value in A is used. */
 528 {
 529     return (GetRegInfo (S, Index, REG_A) & REG_A) != 0;
 530 }
 531
 532
 533
 534 int RegXUsed (struct CodeSeg* S, unsigned Index)
 535 /* Check if the value in X is used. */
 536 {
 537     return (GetRegInfo (S, Index, REG_X) & REG_X) != 0;
 538 }
 539
 540
 541
 542 int RegYUsed (struct CodeSeg* S, unsigned Index)
 543 /* Check if the value in Y is used. */
 544 {
 545     return (GetRegInfo (S, Index, REG_Y) & REG_Y) != 0;
 546 }
 547
 548
 549
 550 int RegAXUsed (struct CodeSeg* S, unsigned Index)
 551 /* Check if the value in A or(!) the value in X are used. */
 552 {
 553     return (GetRegInfo (S, Index, REG_AX) & REG_AX) != 0;
 554 }
 555
 556
 557