1 /*-------------------------------------------------------------------------
3 pcode.h - post code generation
4 Written By - Scott Dattalo scott@dattalo.com
6 This program is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by the
8 Free Software Foundation; either version 2, or (at your option) any
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
20 -------------------------------------------------------------------------*/
28 The post code generation is an assembler optimizer. The assembly code
29 produced by all of the previous steps is fully functional. This step
30 will attempt to analyze the flow of the assembly code and agressively
31 optimize it. The peep hole optimizer attempts to do the same thing.
32 As you may recall, the peep hole optimizer replaces blocks of assembly
33 with more optimal blocks (e.g. removing redundant register loads).
34 However, the peep hole optimizer has to be somewhat conservative since
35 an assembly program has implicit state information that's unavailable
36 when only a few instructions are examined.
37 Consider this example:
43 The movf seems redundant since we know that the W register already
44 contains the same value of t1. So a peep hole optimizer is tempted to
45 remove the "movf". However, this is dangerous since the movf affects
46 the flags in the status register (specifically the Z flag) and subsequent
47 code may depend upon this. Look at these two examples:
51 movf t1,w ; Can't remove this movf
57 movf t1,w ; This movf can be removed
58 xorwf t2,w ; since xorwf will over write Z
68 /***********************************************************************
71 * The DFPRINTF macro will call fprintf if PCODE_DEBUG is defined.
72 * The macro is used like:
74 * DPRINTF(("%s #%d\n","test", 1));
76 * The double parenthesis (()) are necessary
78 ***********************************************************************/
82 #define DFPRINTF(args) (fprintf args)
84 #define DFPRINTF(args) ;
88 /***********************************************************************
89 * PIC status bits - this will move into device dependent headers
90 ***********************************************************************/
94 #define PIC_RP0_BIT 5 /* Register Bank select bits RP1:0 : */
95 #define PIC_RP1_BIT 6 /* 00 - bank 0, 01 - bank 1, 10 - bank 2, 11 - bank 3 */
96 #define PIC_IRP_BIT 7 /* Indirect register page select */
98 /***********************************************************************
99 * PIC INTCON bits - this will move into device dependent headers
100 ***********************************************************************/
101 #define PIC_RBIF_BIT 0 /* Port B level has changed flag */
102 #define PIC_INTF_BIT 1 /* Port B bit 0 interrupt on edge flag */
103 #define PIC_T0IF_BIT 2 /* TMR0 has overflowed flag */
104 #define PIC_RBIE_BIT 3 /* Port B level has changed - Interrupt Enable */
105 #define PIC_INTE_BIT 4 /* Port B bit 0 interrupt on edge - Int Enable */
106 #define PIC_T0IE_BIT 5 /* TMR0 overflow Interrupt Enable */
107 #define PIC_PIE_BIT 6 /* Peripheral Interrupt Enable */
108 #define PIC_GIE_BIT 7 /* Global Interrupt Enable */
110 /***********************************************************************
112 ***********************************************************************/
118 /***********************************************************************
120 * PIC_OPTYPE - Operand types that are specific to the PIC architecture
122 * If a PIC assembly instruction has an operand then here is where we
123 * associate a type to it. For example,
127 * The movf has two operands: 'reg' and the W register. 'reg' is some
128 * arbitrary general purpose register, hence it has the type PO_GPR_REGISTER.
129 * The W register, which is the PIC's accumulator, has the type PO_W.
131 ***********************************************************************/
137 PO_NONE=0, // No operand e.g. NOP
138 PO_W, // The 'W' register
139 PO_STATUS, // The 'STATUS' register
140 PO_FSR, // The "file select register" (in 18c it's one of three)
141 PO_INDF, // The Indirect register
142 PO_INTCON, // Interrupt Control register
143 PO_GPR_REGISTER, // A general purpose register
144 PO_GPR_BIT, // A bit of a general purpose register
145 PO_GPR_TEMP, // A general purpose temporary register
146 PO_GPR_POINTER, // A general purpose pointer
147 PO_SFR_REGISTER, // A special function register (e.g. PORTA)
148 PO_PCL, // Program counter Low register
149 PO_PCLATH, // Program counter Latch high register
150 PO_LITERAL, // A constant
151 PO_IMMEDIATE, // (8051 legacy)
152 PO_DIR, // Direct memory (8051 legacy)
153 PO_CRY, // bit memory (8051 legacy)
154 PO_BIT, // bit operand.
155 PO_STR, // (8051 legacy)
157 PO_WILD // Wild card operand in peep optimizer
161 /***********************************************************************
165 * This is not a list of the PIC's opcodes per se, but instead
166 * an enumeration of all of the different types of pic opcodes.
168 ***********************************************************************/
172 POC_WILD=-1, /* Wild card - used in the pCode peep hole optimizer
173 * to represent ANY pic opcode */
230 /***********************************************************************
231 * PC_TYPE - pCode Types
232 ***********************************************************************/
236 PC_COMMENT=0, /* pCode is a comment */
237 PC_INLINE, /* user's inline code */
238 PC_OPCODE, /* PORT dependent opcode */
239 PC_LABEL, /* assembly label */
240 PC_FLOW, /* flow analysis */
241 PC_FUNCTION, /* Function start or end */
242 PC_WILD, /* wildcard - an opcode place holder used
243 * in the pCode peep hole optimizer */
244 PC_CSOURCE, /* C-Source Line */
245 PC_ASMDIR, /* Assembler directive */
246 PC_BAD /* Mark the pCode object as being bad */
249 /************************************************/
250 /*************** Structures ********************/
251 /************************************************/
252 /* These are here as forward references - the
253 * full definition of these are below */
255 struct pCodeWildBlock;
256 struct pCodeRegLives;
258 /*************************************************
261 The first step in optimizing pCode is determining
262 the program flow. This information is stored in
263 single-linked lists in the for of 'from' and 'to'
264 objects with in a pcode. For example, most instructions
265 don't involve any branching. So their from branch
266 points to the pCode immediately preceding them and
267 their 'to' branch points to the pcode immediately
268 following them. A skip instruction is an example of
269 a pcode that has multiple (in this case two) elements
270 in the 'to' branch. A 'label' pcode is an where there
271 may be multiple 'from' branches.
272 *************************************************/
274 typedef struct pBranch
276 struct pCode *pc; // Next pCode in a branch
277 struct pBranch *next; /* If more than one branch
278 * the next one is here */
282 /*************************************************
285 pCode Operand structure.
286 For those assembly instructions that have arguments,
287 the pCode will have a pCodeOp in which the argument
288 can be stored. For example
292 'some_register' will be stored/referenced in a pCodeOp
294 *************************************************/
296 typedef struct pCodeOp
303 typedef struct pCodeOpBit
307 unsigned int inBitSpace: 1; /* True if in bit space, else
308 just a bit of a register */
311 typedef struct pCodeOpLit
317 typedef struct pCodeOpImmd
320 int offset; /* low,med, or high byte of immediate value */
321 int index; /* add this to the immediate value */
322 unsigned _const:1; /* is in code space */
323 unsigned _function:1; /* is a (pointer to a) function */
325 int rIdx; /* If this immd points to a register */
326 struct regs *r; /* then this is the reg. */
330 typedef struct pCodeOpLabel
334 int offset; /* low or high byte of label */
337 typedef struct pCodeOpReg
339 pCodeOp pcop; // Can be either GPR or SFR
340 int rIdx; // Index into the register table
342 int instance; // byte # of Multi-byte registers
346 typedef struct pCodeOpRegBit
348 pCodeOpReg pcor; // The Register containing this bit
349 int bit; // 0-7 bit number.
350 PIC_OPTYPE subtype; // The type of this register.
351 unsigned int inBitSpace: 1; /* True if in bit space, else
352 just a bit of a register */
356 typedef struct pCodeOpRegPtr
358 pCodeOpReg pcor; // The Register containing this bit
360 // PIC_OPTYPE subtype; // The type of this register.
361 // unsigned int inBitSpace: 1; /* True if in bit space, else
365 typedef struct pCodeOpStr /* Only used here for the name of fn being called or jumped to */
368 unsigned isPublic: 1; /* True if not static ie extern */
371 typedef struct pCodeOpWild
375 struct pCodeWildBlock *pcwb;
377 int id; /* index into an array of char *'s that will match
378 * the wild card. The array is in *pcp. */
379 pCodeOp *subtype; /* Pointer to the Operand type into which this wild
380 * card will be expanded */
381 pCodeOp *matched; /* When a wild matches, we'll store a pointer to the
382 * opcode we matched */
387 /*************************************************
390 Here is the basic build block of a PIC instruction.
391 Each pic instruction will get allocated a pCode.
392 A linked list of pCodes makes a program.
394 **************************************************/
400 struct pCode *prev; // The pCode objects are linked together
401 struct pCode *next; // in doubly linked lists.
403 unsigned id; // unique ID number for all pCodes to assist in debugging
404 int seq; // sequence number
406 struct pBlock *pb; // The pBlock that contains this pCode.
408 /* "virtual functions"
409 * The pCode structure is like a base class
410 * in C++. The subsequent structures that "inherit"
411 * the pCode structure will initialize these function
412 * pointers to something useful */
413 // void (*analyze) (struct pCode *_this);
414 void (*destruct)(struct pCode *_this);
415 void (*print) (FILE *of,struct pCode *_this);
420 /*************************************************
422 **************************************************/
424 typedef struct pCodeComment
434 /*************************************************
436 **************************************************/
438 typedef struct pCodeCSource
450 /*************************************************
453 The Flow object is used as marker to separate
454 the assembly code into contiguous chunks. In other
455 words, everytime an instruction cause or potentially
456 causes a branch, a Flow object will be inserted into
457 the pCode chain to mark the beginning of the next
460 **************************************************/
462 typedef struct pCodeFlow
467 pCode *end; /* Last pCode in this flow. Note that
468 the first pCode is pc.next */
470 /* set **uses; * map the pCode instruction inCond and outCond conditions
471 * in this array of set's. The reason we allocate an
472 * array of pointers instead of declaring each type of
473 * usage is because there are port dependent usage definitions */
474 //int nuses; /* number of uses sets */
476 set *from; /* flow blocks that can send control to this flow block */
477 set *to; /* flow blocks to which this one can send control */
478 struct pCodeFlow *ancestor; /* The most immediate "single" pCodeFlow object that
479 * executes prior to this one. In many cases, this
480 * will be just the previous */
482 int inCond; /* Input conditions - stuff assumed defined at entry */
483 int outCond; /* Output conditions - stuff modified by flow block */
485 int firstBank; /* The first and last bank flags are the first and last */
486 int lastBank; /* register banks used within one flow object */
491 set *registers;/* Registers used in this flow */
496 /*************************************************
499 The Flow Link object is used to record information
500 about how consecutive excutive Flow objects are related.
501 The pCodeFlow objects demarcate the pCodeInstructions
502 into contiguous chunks. The FlowLink records conflicts
503 in the discontinuities. For example, if one Flow object
504 references a register in bank 0 and the next Flow object
505 references a register in bank 1, then there is a discontinuity
506 in the banking registers.
509 typedef struct pCodeFlowLink
511 pCodeFlow *pcflow; /* pointer to linked pCodeFlow object */
513 int bank_conflict; /* records bank conflicts */
518 /*************************************************
521 Here we describe all the facets of a PIC instruction
522 (expansion for the 18cxxx is also provided).
524 **************************************************/
526 typedef struct pCodeInstruction
531 PIC_OPCODE op; // The opcode of the instruction.
533 char const * const mnemonic; // Pointer to mnemonic string
535 pBranch *from; // pCodes that execute before this one
536 pBranch *to; // pCodes that execute after
537 pBranch *label; // pCode instructions that have labels
539 pCodeOp *pcop; /* Operand, if this instruction has one */
540 pCodeFlow *pcflow; /* flow block to which this instruction belongs */
541 pCodeCSource *cline; /* C Source from which this instruction was derived */
543 unsigned int num_ops; /* Number of operands (0,1,2 for mid range pics) */
544 unsigned int isModReg: 1; /* If destination is W or F, then 1==F */
545 unsigned int isBitInst: 1; /* e.g. BCF */
546 unsigned int isBranch: 1; /* True if this is a branching instruction */
547 unsigned int isSkip: 1; /* True if this is a skip instruction */
548 unsigned int isLit: 1; /* True if this instruction has an literal operand */
550 PIC_OPCODE inverted_op; /* Opcode of instruction that's the opposite of this one */
551 unsigned int inCond; // Input conditions for this instruction
552 unsigned int outCond; // Output conditions for this instruction
557 /*************************************************
559 **************************************************/
561 typedef struct pCodeAsmDir
563 pCodeInstruction pci;
570 /*************************************************
572 **************************************************/
574 typedef struct pCodeLabel
585 /*************************************************
587 **************************************************/
589 typedef struct pCodeFunction
595 char *fname; /* If NULL, then this is the end of
596 a function. Otherwise, it's the
597 start and the name is contained
600 pBranch *from; // pCodes that execute before this one
601 pBranch *to; // pCodes that execute after
602 pBranch *label; // pCode instructions that have labels
604 int ncalled; /* Number of times function is called */
605 unsigned isPublic:1; /* True if the fn is not static and can be called from another module (ie a another c or asm file) */
610 /*************************************************
612 **************************************************/
614 typedef struct pCodeWild
617 pCodeInstruction pci;
619 int id; /* Index into the wild card array of a peepBlock
620 * - this wild card will get expanded into that pCode
621 * that is stored at this index */
623 /* Conditions on wild pcode instruction */
624 int mustBeBitSkipInst:1;
625 int mustNotBeBitSkipInst:1;
626 int invertBitSkipInst:1;
628 pCodeOp *operand; // Optional operand
629 pCodeOp *label; // Optional label
633 /*************************************************
636 Here are PIC program snippets. There's a strong
637 correlation between the eBBlocks and pBlocks.
638 SDCC subdivides a C program into managable chunks.
639 Each chunk becomes a eBBlock and ultimately in the
642 **************************************************/
644 typedef struct pBlock
646 memmap *cmemmap; /* The snippet is from this memmap */
647 char dbName; /* if cmemmap is NULL, then dbName will identify the block */
648 pCode *pcHead; /* A pointer to the first pCode in a link list of pCodes */
649 pCode *pcTail; /* A pointer to the last pCode in a link list of pCodes */
651 struct pBlock *next; /* The pBlocks will form a doubly linked list */
654 set *function_entries; /* dll of functions in this pblock */
660 unsigned visited:1; /* set true if traversed in call tree */
662 unsigned seq; /* sequence number of this pBlock */
666 /*************************************************
669 The collection of pBlock program snippets are
670 placed into a linked list that is implemented
671 in the pFile structure.
673 The pcode optimizer will parse the pFile.
675 **************************************************/
679 pBlock *pbHead; /* A pointer to the first pBlock */
680 pBlock *pbTail; /* A pointer to the last pBlock */
682 pBranch *functions; /* A SLL of functions in this pFile */
688 /*************************************************
691 The pCodeWildBlock object keeps track of the wild
692 variables, operands, and opcodes that exist in
694 **************************************************/
695 typedef struct pCodeWildBlock {
697 struct pCodePeep *pcp; // pointer back to ... I don't like this...
699 int nvars; // Number of wildcard registers in target.
700 char **vars; // array of pointers to them
702 int nops; // Number of wildcard operands in target.
703 pCodeOp **wildpCodeOps; // array of pointers to the pCodeOp's.
705 int nwildpCodes; // Number of wildcard pCodes in target/replace
706 pCode **wildpCodes; // array of pointers to the pCode's.
710 /*************************************************
713 The pCodePeep object mimics the peep hole optimizer
714 in the main SDCC src (e.g. SDCCpeeph.c). Essentially
715 there is a target pCode chain and a replacement
716 pCode chain. The target chain is compared to the
717 pCode that is generated by gen.c. If a match is
718 found then the pCode is replaced by the replacement
720 **************************************************/
721 typedef struct pCodePeep {
722 pCodeWildBlock target; // code we'd like to optimize
723 pCodeWildBlock replace; // and this is what we'll optimize it with.
726 //pBlock replace; // and this is what we'll optimize it with.
730 /* (Note: a wildcard register is a place holder. Any register
731 * can be replaced by the wildcard when the pcode is being
732 * compared to the target. */
734 /* Post Conditions. A post condition is a condition that
735 * must be either true or false before the peep rule is
736 * accepted. For example, a certain rule may be accepted
737 * if and only if the Z-bit is not used as an input to
738 * the subsequent instructions in a pCode chain.
740 unsigned int postFalseCond;
741 unsigned int postTrueCond;
745 /*************************************************
747 pCode peep command definitions
749 Here are some special commands that control the
750 way the peep hole optimizer behaves
752 **************************************************/
754 enum peepCommandTypes{
761 /*************************************************
762 peepCommand structure stores the peep commands.
764 **************************************************/
766 typedef struct peepCommand {
771 /*************************************************
774 **************************************************/
775 #define PCODE(x) ((pCode *)(x))
776 #define PCI(x) ((pCodeInstruction *)(x))
777 #define PCL(x) ((pCodeLabel *)(x))
778 #define PCF(x) ((pCodeFunction *)(x))
779 #define PCFL(x) ((pCodeFlow *)(x))
780 #define PCFLINK(x)((pCodeFlowLink *)(x))
781 #define PCW(x) ((pCodeWild *)(x))
782 #define PCCS(x) ((pCodeCSource *)(x))
783 #define PCAD(x) ((pCodeAsmDir *)(x))
785 #define PCOP(x) ((pCodeOp *)(x))
786 //#define PCOB(x) ((pCodeOpBit *)(x))
787 #define PCOL(x) ((pCodeOpLit *)(x))
788 #define PCOI(x) ((pCodeOpImmd *)(x))
789 #define PCOLAB(x) ((pCodeOpLabel *)(x))
790 #define PCOR(x) ((pCodeOpReg *)(x))
791 #define PCORB(x) ((pCodeOpRegBit *)(x))
792 #define PCOS(x) ((pCodeOpStr *)(x))
793 #define PCOW(x) ((pCodeOpWild *)(x))
795 #define PBR(x) ((pBranch *)(x))
797 #define PCWB(x) ((pCodeWildBlock *)(x))
799 #define isPCOLAB(x) ((PCOP(x)->type) == PO_LABEL)
800 #define isPCOS(x) ((PCOP(x)->type) == PO_STR)
804 macros for checking pCode types
806 #define isPCI(x) ((PCODE(x)->type == PC_OPCODE))
807 #define isPCFL(x) ((PCODE(x)->type == PC_FLOW))
808 #define isPCF(x) ((PCODE(x)->type == PC_FUNCTION))
809 #define isPCL(x) ((PCODE(x)->type == PC_LABEL))
810 #define isPCW(x) ((PCODE(x)->type == PC_WILD))
811 #define isPCCS(x) ((PCODE(x)->type == PC_CSOURCE))
814 macros for checking pCodeInstruction types
816 #define isCALL(x) (isPCI(x) && (PCI(x)->op == POC_CALL))
817 #define isPCI_BRANCH(x) (isPCI(x) && PCI(x)->isBranch)
818 #define isPCI_SKIP(x) (isPCI(x) && PCI(x)->isSkip)
819 #define isPCI_LIT(x) (isPCI(x) && PCI(x)->isLit)
820 #define isPCI_BITSKIP(x)(isPCI_SKIP(x) && PCI(x)->isBitInst)
823 #define isSTATUS_REG(r) ((r)->pc_type == PO_STATUS)
825 /*-----------------------------------------------------------------*
827 *-----------------------------------------------------------------*/
829 pCode *newpCode (PIC_OPCODE op, pCodeOp *pcop); // Create a new pCode given an operand
830 pCode *newpCodeCharP(char *cP); // Create a new pCode given a char *
831 pCode *newpCodeInlineP(char *cP); // Create a new pCode given a char *
832 pCode *newpCodeFunction(char *g, char *f,int); // Create a new function
833 pCode *newpCodeLabel(char *name,int key); // Create a new label given a key
834 pCode *newpCodeCSource(int ln, char *f, const char *l); // Create a new symbol line
835 pCode *findNextInstruction(pCode *pci);
836 pCode *findNextpCode(pCode *pc, PC_TYPE pct);
837 pCode *pCodeInstructionCopy(pCodeInstruction *pci,int invert);
839 pBlock *newpCodeChain(memmap *cm,char c, pCode *pc); // Create a new pBlock
840 void printpBlock(FILE *of, pBlock *pb); // Write a pBlock to a file
841 void printpCode(FILE *of, pCode *pc); // Write a pCode to a file
842 void addpCode2pBlock(pBlock *pb, pCode *pc); // Add a pCode to a pBlock
843 void addpBlock(pBlock *pb); // Add a pBlock to a pFile
844 void copypCode(FILE *of, char dbName); // Write all pBlocks with dbName to *of
845 void movepBlock2Head(char dbName); // move pBlocks around
846 void AnalyzepCode(char dbName);
847 int OptimizepCode(char dbName);
848 void printCallTree(FILE *of);
849 void pCodePeepInit(void);
850 void pBlockConvert2ISR(pBlock *pb);
851 void pCodeInsertAfter(pCode *pc1, pCode *pc2);
852 void pCodeInsertBefore(pCode *pc1, pCode *pc2);
853 void pCodeDeleteChain(pCode *f,pCode *t);
855 pCode *newpCodeAsmDir(char *asdir, char *argfmt, ...);
857 pCodeOp *newpCodeOpLabel(char *name, int key);
858 pCodeOp *newpCodeOpImmd(char *name, int offset, int index, int code_space,int is_func);
859 pCodeOp *newpCodeOpLit(int lit);
860 pCodeOp *newpCodeOpBit(char *name, int bit,int inBitSpace);
861 pCodeOp *newpCodeOpRegFromStr(char *name);
862 pCodeOp *newpCodeOp(char *name, PIC_OPTYPE p);
863 pCodeOp *pCodeOpCopy(pCodeOp *pcop);
864 pCodeOp *popCopyReg(pCodeOpReg *pc);
866 int isPCinFlow(pCode *pc, pCode *pcflow);
867 struct regs * getRegFromInstruction(pCode *pc);
869 extern void pcode_test(void);
870 void resetpCodeStatistics (void);
871 void dumppCodeStatistics (FILE *of);
873 /*-----------------------------------------------------------------*
875 *-----------------------------------------------------------------*/
877 extern pCodeOpReg pc_status;
878 extern pCodeOpReg pc_intcon;
879 extern pCodeOpReg pc_indf;
880 extern pCodeOpReg pc_fsr;
881 extern pCodeOpReg pc_pcl;
882 extern pCodeOpReg pc_pclath;
883 extern pCodeOpReg pc_wsave; /* wsave, ssave and psave are used to save W, the Status and PCLATH*/
884 extern pCodeOpReg pc_ssave; /* registers during an interrupt */
885 extern pCodeOpReg pc_psave; /* registers during an interrupt */
888 #endif // __PCODE_H__
projects / fw / sdcc / blob