char *pic16_get_op(pCodeOp *pcop,char *buffer, size_t size)
{
regs *r;
- static char b[50];
+ static char b[128];
char *s;
int use_buffer = 1; // copy the string to the passed buffer pointer
pic16_pCodeInsertAfter(ppc, npci);
/* extra instructions to handle invertion */
- pcnext = pic16_newpCode(POC_GOTO, pic16_popGetLabel(tlbl->key));
+ pcnext = pic16_newpCode(POC_BRA, pic16_popGetLabel(tlbl->key));
pic16_pCodeInsertAfter(npci, pcnext);
pic16_pCodeInsertAfter(pc->prev, new_pc);
} while (pc);
}
+/** ADDITIONS BY RAPHAEL NEIDER, 2004-11-16: GOTO OPTIMIZATIONS **/
+
+/* Returns the (maximum of the) number of bytes used by the specified pCode. */
+int instrSize (pCode *pc)
+{
+ if (!pc) return 0;
+
+ if (isPCAD(pc)) {
+ if (!PCAD(pc)->directive || strlen (PCAD(pc)->directive) < 3) return 0;
+ return 4; // assumes only regular instructions using <= 4 bytes
+ }
+
+ if (isPCI(pc)) return PCI(pc)->isize;
+
+ return 0;
+}
+
+/* Returns 1 if pc is referenced by the given label (either
+ * pc is the label itself or is an instruction with an attached
+ * label).
+ * Returns 0 if pc is not preceeded by the specified label.
+ */
+int isLabel (pCode *pc, char *label)
+{
+ if (!pc) return 0;
+
+ // label attached to the pCode?
+ if (isPCI(pc) || isPCAD(pc) || isPCW(pc) || pc->type == PC_INFO) {
+ pBranch *lab = NULL;
+ lab = PCI(pc)->label;
+
+ while (lab) {
+ if (isPCL(lab->pc) && strcmp(PCL(lab->pc)->label, label) == 0) {
+ return 1;
+ }
+ lab = lab->next;
+ } // while
+ } // if
+
+ // is inline assembly label?
+ if (isPCAD(pc) && PCAD(pc)->directive == NULL && PCAD(pc)->arg) {
+ // do not compare trailing ':'
+ if (strncmp (PCAD(pc)->arg, label, strlen (label)) == 0) {
+ return 1;
+ }
+ } // if
+
+ // is pCodeLabel?
+ if (isPCL(pc)) {
+ if (strcmp(PCL(pc)->label,label) == 0) {
+ return 1;
+ }
+ } // if
+
+ // no label/no label attached/wrong label(s)
+ return 0;
+}
+
+/* Returns the distance to the given label in terms of words.
+ * Labels are searched only within -max .. max words from pc.
+ * Returns max if the label could not be found or
+ * its distance from pc in (-max..+max).
+ */
+int findpCodeLabel (pCode *pc, char *label, int max, pCode **target) {
+ int dist = instrSize(pc);
+ pCode *curr = pc;
+
+ // search backwards
+ while (dist < max && curr && !isLabel (curr, label)) {
+ curr = curr->prev;
+ dist += instrSize(curr); // sizeof (instruction)
+ } // while
+ if (curr && dist < max) {
+ if (target != NULL) *target = curr;
+ return -dist;
+ }
+
+ dist = 0;
+ curr = pic16_findNextInstruction (pc->next);
+ //search forwards
+ while (dist < max && curr && !isLabel (curr, label)) {
+ dist += instrSize(curr); // sizeof (instruction)
+ curr = curr->next;
+ } // while
+ if (curr && dist < max) {
+ if (target != NULL) *target = curr;
+ return dist;
+ }
+
+ if (target != NULL) *target = NULL;
+ return max;
+}
+
+/* Returns -1 if pc does NOT denote an instruction like
+ * BTFS[SC] STATUS,i
+ * Otherwise we return
+ * (a) 0x10 + i for BTFSS
+ * (b) 0x00 + i for BTFSC
+ */
+int isSkipOnStatus (pCode *pc)
+{
+ int res = -1;
+ pCodeOp *pcop;
+ if (!pc || !isPCI(pc)) return -1;
+ if (PCI(pc)->op == POC_BTFSS) res = 0x10;
+ else if (PCI(pc)->op == POC_BTFSC) res = 0x00;
+ else return -1;
+
+ pcop = PCI(pc)->pcop;
+
+ if (pcop->type == PO_STATUS || (pcop->type == PO_GPR_BIT && strcmp(pcop->name, "STATUS") == 0)) {
+ return res + ((pCodeOpRegBit *)pcop)->bit;
+ }
+
+ return -1;
+}
+
+/* Returns 1 if pc is one of BC, BZ, BOV, BN, BNC, BNZ, BNOV or BNN,
+ * returns 0 otherwise. */
+int isConditionalBranch (pCode *pc)
+{
+ if (!pc || !isPCI_BRANCH(pc)) return 0;
+
+ switch (PCI(pc)->op) {
+ case POC_BC:
+ case POC_BZ:
+ case POC_BOV:
+ case POC_BN:
+ case POC_BNC:
+ case POC_BNZ:
+ case POC_BNOV:
+ case POC_BNN:
+ return 1;
+
+ default:
+ break;
+ } // switch
+
+ return 0;
+}
+
+/* Returns 1 if pc has a label attached to it.
+ * This can be either a label stored in the pCode itself (.label)
+ * or a label making up its own pCode preceding this pc.
+ * Returns 0 if pc cannot be reached directly via a label.
+ */
+int hasNoLabel (pCode *pc)
+{
+ pCode *prev;
+ if (!pc) return 1;
+
+ // are there any label pCodes between pc and the previous instruction?
+ prev = pic16_findPrevInstruction (pc->prev);
+ while (pc && pc != prev) {
+ // pCode with attached label?
+ if ((isPCI(pc) || isPCAD(pc) || isPCW(pc) || pc->type == PC_INFO)
+ && PCI(pc)->label) {
+ return 0;
+ }
+ // is inline assembly label?
+ if (isPCAD(pc) && PCAD(pc)->directive == NULL) return 0;
+ if (isPCW(pc) && PCW(pc)->label) return 0;
+
+ // pCodeLabel?
+ if (isPCL(pc)) return 0;
+
+ pc = pc->prev;
+ } // if
+
+ // no label found
+ return 1;
+}
+
+/* Replaces the old pCode with the new one, moving the labels,
+ * C source line and probably flow information to the new pCode.
+ */
+void pic16_pCodeReplace (pCode *oldPC, pCode *newPC) {
+ if (!oldPC || !newPC || !isPCI(oldPC) || !isPCI(newPC))
+ return;
+
+ /* first move all labels from old to new */
+ PCI(newPC)->label = pic16_pBranchAppend (PCI(oldPC)->label, PCI(newPC)->label);
+ PCI(oldPC)->label = NULL;
+
+ /* move C source line (if possible) */
+ if (PCI(oldPC)->cline && !PCI(newPC)->cline)
+ PCI(newPC)->cline = PCI(oldPC)->cline;
+
+ /* insert new pCode into pBlock */
+ pic16_pCodeInsertAfter (oldPC, newPC);
+ pic16_unlinkpCode (oldPC);
+
+ /* TODO: update flow (newPC->from, newPC->to) */
+ PCI(newPC)->pcflow = PCI(oldPC)->pcflow;
+
+ /* destruct replaced pCode */
+ oldPC->destruct (oldPC);
+}
+
+/* Returns the inverted conditional branch (if any) or NULL.
+ * pcop must be set to the new jump target.
+ */
+pCode *getNegatedBcc (pCode *bcc, pCodeOp *pcop)
+{
+ pCode *newBcc;
+
+ if (!bcc || !isPCI(bcc)) return NULL;
+
+ switch (PCI(bcc)->op) {
+ case POC_BC: newBcc = pic16_newpCode (POC_BNC , pcop); break;
+ case POC_BZ: newBcc = pic16_newpCode (POC_BNZ , pcop); break;
+ case POC_BOV: newBcc = pic16_newpCode (POC_BNOV, pcop); break;
+ case POC_BN: newBcc = pic16_newpCode (POC_BNN , pcop); break;
+ case POC_BNC: newBcc = pic16_newpCode (POC_BC , pcop); break;
+ case POC_BNZ: newBcc = pic16_newpCode (POC_BZ , pcop); break;
+ case POC_BNOV: newBcc = pic16_newpCode (POC_BOV , pcop); break;
+ case POC_BNN: newBcc = pic16_newpCode (POC_BN , pcop); break;
+ default:
+ newBcc = NULL;
+ }
+ return newBcc;
+}
+
+#define MAX_DIST_GOTO 0x7FFFFFFF
+#define MAX_DIST_BRA 1020 // maximum offset (in bytes) possible with BRA
+#define MAX_DIST_BCC 120 // maximum offset (in bytes) possible with Bcc
+#define MAX_JUMPCHAIN_DEPTH 16 // number of GOTOs to follow in resolveJumpChain() (to prevent endless loops)
+#define IS_GOTO(arg) ((arg) && isPCI(arg) && (PCI(arg)->op == POC_GOTO || PCI(arg)->op == POC_BRA))
+
+/* Follows GOTO/BRA instructions to their target instructions, stores the
+ * final destination (not a GOTO or BRA instruction) in target and returns
+ * the distance from the original pc to *target.
+ */
+int resolveJumpChain (pCode *pc, pCode **target, pCodeOp **pcop) {
+ pCode *curr = pc;
+ pCode *last = NULL;
+ pCodeOp *lastPCOP = NULL;
+ int dist = 0;
+ int depth = 0;
+
+ //fprintf (stderr, "%s:%d: -=-", __FUNCTION__, __LINE__);
+
+ /* only follow unconditional branches, except for the initial pCode (which may be a conditional branch) */
+ while (curr && (last != curr) && (depth++ < MAX_JUMPCHAIN_DEPTH) && isPCI(curr)
+ && (PCI(curr)->op == POC_GOTO || PCI(curr)->op == POC_BRA || (curr == pc && isConditionalBranch(curr)))) {
+ last = curr;
+ lastPCOP = PCI(curr)->pcop;
+ dist = findpCodeLabel (pc, PCI(curr)->pcop->name, MAX_DIST_GOTO, &curr);
+ //fprintf (stderr, "last:%p, curr:%p, label:%s\n", last, curr, PCI(last)->pcop->name);
+ } // while
+
+ if (target) *target = last;
+ if (pcop) *pcop = lastPCOP;
+ return dist;
+}
+
+/* Returns pc if it is not a OPT_JUMPTABLE_BEGIN INFO pCode.
+ * Otherwise the first pCode after the jumptable (after
+ * the OPT_JUMPTABLE_END tag) is returned.
+ */
+pCode *skipJumptables (pCode *pc, int *isJumptable)
+{
+ *isJumptable = 0;
+ if (!pc) return NULL;
+
+ while (pc->type == PC_INFO && PCINF(pc)->type == INF_OPTIMIZATION && PCOO(PCINF(pc)->oper1)->type == OPT_JUMPTABLE_BEGIN) {
+ *isJumptable = 1;
+ //fprintf (stderr, "SKIPPING jumptable\n");
+ do {
+ //pc->print(stderr, pc);
+ pc = pc->next;
+ } while (pc && (pc->type != PC_INFO || PCINF(pc)->type != INF_OPTIMIZATION
+ || PCOO(PCINF(pc)->oper1)->type != OPT_JUMPTABLE_END));
+ //fprintf (stderr, "<<JUMPTAB:\n");
+ // skip OPT_END as well
+ if (pc) pc = pc->next;
+ } // while
+
+ return pc;
+}
+
+pCode *pic16_findNextInstructionSkipJumptables (pCode *pc, int *isJumptable)
+{
+ int isJumptab;
+ *isJumptable = 0;
+ while (pc && !isPCI(pc) && !isPCAD(pc) && !isPCW(pc)) {
+ // set pc to the first pCode after a jumptable, leave pc untouched otherwise
+ pc = skipJumptables (pc, &isJumptab);
+ if (isJumptab) {
+ // pc is the first pCode after the jumptable
+ *isJumptable = 1;
+ } else {
+ // pc has not been changed by skipJumptables()
+ pc = pc->next;
+ }
+ } // while
+
+ return pc;
+}
+
+/* Turn GOTOs into BRAs if distance between GOTO and label
+ * is less than 1024 bytes.
+ *
+ * This method is especially useful if GOTOs after BTFS[SC]
+ * can be turned into BRAs as GOTO would cost another NOP
+ * if skipped.
+ */
+void pic16_OptimizeJumps ()
+{
+ pCode *pc;
+ pCode *pc_prev = NULL;
+ pCode *pc_next = NULL;
+ pBlock *pb;
+ pCode *target;
+ int change, iteration, isJumptab;
+ int isHandled = 0;
+ char *label;
+ int opt=0, toofar=0, opt_cond = 0, cond_toofar=0, opt_reorder = 0, opt_gotonext = 0, opt_gotochain = 0;
+
+ if (!the_pFile) return;
+
+ //fprintf (stderr, "%s:%d: %s\n", __FILE__, __LINE__, __FUNCTION__);
+
+ for (pb = the_pFile->pbHead; pb != NULL; pb = pb->next) {
+ int matchedInvertRule = 1;
+ iteration = 1;
+ do {
+ //fprintf (stderr, "%s:%d: iterating over pBlock %p\n", __FUNCTION__, __LINE__, pb);
+ change = 0;
+ pc = pic16_findNextInstruction (pb->pcHead);
+
+ while (pc) {
+ pc_next = pic16_findNextInstructionSkipJumptables (pc->next, &isJumptab);
+ if (isJumptab) {
+ // skip jumptable, i.e. start over with no pc_prev!
+ pc_prev = NULL;
+ pc = pc_next;
+ continue;
+ } // if
+
+ /* (1) resolve chained jumps
+ * Do not perform this until pattern (4) is no longer present! Otherwise we will
+ * (a) leave dead code in and
+ * (b) skip over the dead code with an (unneccessary) jump.
+ */
+ if (!matchedInvertRule && (IS_GOTO(pc) || isConditionalBranch(pc))) {
+ pCodeOp *lastTargetOp = NULL;
+ int newDist = resolveJumpChain (pc, &target, &lastTargetOp);
+ int maxDist = MAX_DIST_BCC;
+ if (PCI(pc)->op == POC_BRA) maxDist = MAX_DIST_BRA;
+ if (PCI(pc)->op == POC_GOTO) maxDist = MAX_DIST_GOTO;
+
+ /* be careful NOT to make the jump instruction longer (might break previously shortened jumps!) */
+ if (lastTargetOp && newDist <= maxDist && lastTargetOp != PCI(pc)->pcop
+ && strcmp (lastTargetOp->name, PCI(pc)->pcop->name) != 0) {
+ //fprintf (stderr, "(1) ");pc->print(stderr, pc); fprintf (stderr, " --> %s\n", lastTargetOp->name);
+ if (pic16_pcode_verbose) { pic16_pCodeInsertAfter (pc->prev, pic16_newpCodeCharP("(1) jump chain resolved")); }
+ PCI(pc)->pcop->name = lastTargetOp->name;
+ change++;
+ opt_gotochain++;
+ } // if
+ } // if
+
+
+ if (IS_GOTO(pc)) {
+ int dist;
+ int condBraType = isSkipOnStatus(pc_prev);
+ label = PCI(pc)->pcop->name;
+ dist = findpCodeLabel(pc, label, MAX_DIST_BRA, &target);
+ if (dist < 0) dist = -dist;
+ //fprintf (stderr, "distance: %d (", dist); pc->print(stderr, pc);fprintf (stderr, ")\n");
+ isHandled = 0;
+
+
+ /* (2) remove "GOTO label; label:" */
+ if (isLabel (pc_next, label)) {
+ //fprintf (stderr, "(2) GOTO next instruction: ");pc->print(stderr, pc);fprintf (stderr, " --> ");pc_next->print(stderr, pc_next); fprintf(stderr, "\n");
+ // first remove all preceeding SKIP instructions
+ while (pc_prev && isPCI_SKIP(pc_prev)) {
+ // attach labels on this instruction to pc_next
+ //fprintf (stderr, "(2) preceeding SKIP removed: ");pc_prev->print(stderr, pc_prev);fprintf(stderr, "\n");
+ PCI(pc_next)->label = pic16_pBranchAppend (PCI(pc_prev)->label, PCI(pc_next)->label);
+ PCI(pc_prev)->label = NULL;
+ if (pic16_pcode_verbose) { pic16_pCodeInsertAfter (pc->prev, pic16_newpCodeCharP("(2) SKIP removed")); }
+ pic16_unlinkpCode (pc_prev);
+ pc_prev = pic16_findPrevInstruction (pc);
+ } // while
+ // now remove the redundant goto itself
+ PCI(pc_next)->label = pic16_pBranchAppend (PCI(pc)->label, PCI(pc_next)->label);
+ if (pic16_pcode_verbose) { pic16_pCodeInsertAfter (pc, pic16_newpCodeCharP("(2) GOTO next instruction removed")); }
+ pic16_unlinkpCode (pc);
+ pc = pic16_findPrevInstruction(pc_next->prev);
+ isHandled = 1; // do not perform further optimizations
+ opt_gotonext++;
+ change++;
+ } // if
+
+
+ /* (3) turn BTFSx STATUS,i; GOTO label into Bcc label if possible */
+ if (!isHandled && condBraType != -1 && hasNoLabel(pc)) {
+ if (dist < MAX_DIST_BCC) {
+ pCode *bcc = NULL;
+ switch (condBraType) {
+ case 0x00: bcc = pic16_newpCode (POC_BC, PCI(pc)->pcop);break;
+ // no BDC on DIGIT CARRY available
+ case 0x02: bcc = pic16_newpCode (POC_BZ, PCI(pc)->pcop);break;
+ case 0x03: bcc = pic16_newpCode (POC_BOV, PCI(pc)->pcop);break;
+ case 0x04: bcc = pic16_newpCode (POC_BN, PCI(pc)->pcop);break;
+ case 0x10: bcc = pic16_newpCode (POC_BNC, PCI(pc)->pcop);break;
+ // no BNDC on DIGIT CARRY available
+ case 0x12: bcc = pic16_newpCode (POC_BNZ, PCI(pc)->pcop);break;
+ case 0x13: bcc = pic16_newpCode (POC_BNOV, PCI(pc)->pcop);break;
+ case 0x14: bcc = pic16_newpCode (POC_BNN, PCI(pc)->pcop);break;
+ default:
+ // no replacement possible
+ bcc = NULL;
+ break;
+ } // switch
+ if (bcc) {
+ // ATTENTION: keep labels attached to BTFSx!
+ // HINT: GOTO is label free (checked above)
+ //fprintf (stderr, "%s:%d: (3) turning %s %s into %s %s\n", __FUNCTION__, __LINE__, PCI(pc)->mnemonic, label, PCI(bcc)->mnemonic, label);
+ isHandled = 1; // do not perform further optimizations
+ if (pic16_pcode_verbose) { pic16_pCodeInsertAfter(pc_prev->prev, pic16_newpCodeCharP("(3) conditional branch introduced")); }
+ pic16_pCodeReplace (pc_prev, bcc);
+ pc->destruct(pc);
+ pc = bcc;
+ opt_cond++;
+ change++;
+ } // if
+ } else {
+ //fprintf (stderr, "(%d, too far for Bcc)\n", dist);
+ cond_toofar++;
+ } // if
+ } // if
+
+ if (!isHandled) {
+ // (4) eliminate the following (common) tripel:
+ // <pred.>;
+ // labels1: Bcc label2;
+ // GOTO somewhere; ; <-- instruction referenced by pc
+ // label2: <cont.>
+ // and replace it by
+ // labels1: B#(cc) somewhere; ; #(cc) is the negated condition cc
+ // label2: <cont.>
+ // ATTENTION: all labels pointing to "Bcc label2" must be attached
+ // to <cont.> instead
+ // ATTENTION: This optimization is only valid if <pred.> is
+ // not a skip operation!
+ // ATTENTION: somewhere must be within MAX_DIST_BCC bytes!
+ // ATTENTION: no label may be attached to the GOTO instruction!
+ if (isConditionalBranch(pc_prev)
+ && (!isPCI_SKIP(pic16_findPrevInstruction(pc_prev->prev)))
+ && (dist < MAX_DIST_BCC)
+ && isLabel(pc_next,PCI(pc_prev)->pcop->name)
+ && hasNoLabel(pc)) {
+ pCode *newBcc = getNegatedBcc (pc_prev, PCI(pc)->pcop);
+
+ if (newBcc) {
+ //fprintf (stderr, "%s:%d: (4) turning %s %s into %s %s\n", __FUNCTION__, __LINE__, PCI(pc)->mnemonic, label, PCI(newBcc)->mnemonic, label);
+ isHandled = 1; // do not perform further optimizations
+ if (pic16_pcode_verbose) { pic16_pCodeInsertAfter(pc_prev->prev, pic16_newpCodeCharP("(4) conditional skipping branch inverted")); }
+ pic16_pCodeReplace (pc_prev, newBcc);
+ pc->destruct(pc);
+ pc = newBcc;
+ opt_reorder++;
+ change++;
+ matchedInvertRule++;
+ }
+ }
+ }
+
+ /* (5) now just turn GOTO into BRA */
+ if (!isHandled && (PCI(pc)->op == POC_GOTO)) {
+ if (dist < MAX_DIST_BRA) {
+ pCode *newBra = pic16_newpCode (POC_BRA, PCI(pc)->pcop);
+ //fprintf (stderr, "%s:%d: (5) turning %s %s into %s %s\n", __FUNCTION__, __LINE__, PCI(pc)->mnemonic, label, PCI(newBra)->mnemonic, label);
+ if (pic16_pcode_verbose) { pic16_pCodeInsertAfter(pc->prev, pic16_newpCodeCharP("(5) GOTO replaced by BRA")); }
+ pic16_pCodeReplace (pc, newBra);
+ pc = newBra;
+ opt++;
+ change++;
+ } else {
+ //fprintf (stderr, "(%d, too far for BRA)\n", dist);
+ toofar++;
+ }
+ } // if (!isHandled)
+ } // if
+
+ pc_prev = pc;
+ pc = pc_next;
+ } // while (pc)
+
+ pBlockRemoveUnusedLabels (pb);
+
+ // This line enables goto chain resolution!
+ if (matchedInvertRule > 1) matchedInvertRule = 1; else matchedInvertRule = 0;
+
+ iteration++;
+ } while (change); /* fixpoint iteration per pBlock */
+ } // for (pb)
+
+ // emit some statistics concerning goto-optimization
+ // (maybe this should be moved to the general statistics?)
+ if (pic16_debug_verbose || pic16_pcode_verbose) {
+ fprintf (stderr, "optimize-goto:\n"
+ "\t%5d GOTO->BRA; (%d GOTOs too far)\n"
+ "\t%5d BTFSx, GOTO->Bcc (%d too far)\n"
+ "\t%5d conditional \"skipping\" jumps inverted\n"
+ "\t%5d GOTOs to next instruction removed\n"
+ "\t%5d chained GOTOs resolved\n",
+ opt, toofar, opt_cond, cond_toofar, opt_reorder, opt_gotonext, opt_gotochain);
+ } // if
+ //fprintf (stderr, "%s:%d: %s\n", __FILE__, __LINE__, __FUNCTION__);
+}
+
+#undef IS_GOTO
+#undef MAX_JUMPCHAIN_DEPTH
+#undef MAX_DIST_GOTO
+#undef MAX_DIST_BRA
+#undef MAX_DIST_BCC
+/** END OF RAPHAEL NEIDER'S ADDITIONS **/
static void pBlockDestruct(pBlock *pb)
{
projects / fw / sdcc / blobdiff