+void CS_DelCodeAfter (CodeSeg* S, unsigned Last)
+/* Delete all entries including the given one */
+{
+ /* Get the number of entries in this segment */
+ unsigned Count = CS_GetEntryCount (S);
+
+ /* First pass: Delete all references to labels. If the reference count
+ * for a label drops to zero, delete it.
+ */
+ unsigned C = Count;
+ while (Last < C--) {
+
+ /* Get the next entry */
+ CodeEntry* E = CS_GetEntry (S, C);
+
+ /* Check if this entry has a label reference */
+ if (E->JumpTo) {
+ /* If the label is a label in the label pool and this is the last
+ * reference to the label, remove the label from the pool.
+ */
+ CodeLabel* L = E->JumpTo;
+ int Index = CollIndex (&S->Labels, L);
+ if (Index >= 0 && CollCount (&L->JumpFrom) == 1) {
+ /* Delete it from the pool */
+ CollDelete (&S->Labels, Index);
+ }
+
+ /* Remove the reference to the label */
+ CS_RemoveLabelRef (S, E);
+ }
+
+ }
+
+ /* Second pass: Delete the instructions. If a label attached to an
+ * instruction still has references, it must be references from outside
+ * the deleted area. Don't delete the label in this case, just make it
+ * ownerless and move it to the label pool.
+ */
+ C = Count;
+ while (Last < C--) {
+
+ /* Get the next entry */
+ CodeEntry* E = CS_GetEntry (S, C);
+
+ /* Check if this entry has a label attached */
+ if (CE_HasLabel (E)) {
+ /* Move the labels to the pool and clear the owner pointer */
+ CS_MoveLabelsToPool (S, E);
+ }
+
+ /* Delete the pointer to the entry */
+ CollDelete (&S->Entries, C);
+
+ /* Delete the entry itself */
+ FreeCodeEntry (E);
+ }
+}
+
+
+
+void CS_ResetMarks (CodeSeg* S, unsigned First, unsigned Last)
+/* Remove all user marks from the entries in the given range */
+{
+ while (First <= Last) {
+ CE_ResetMark (CS_GetEntry (S, First++));
+ }
+}
+
+
+
+int CS_IsBasicBlock (CodeSeg* S, unsigned First, unsigned Last)
+/* Check if the given code segment range is a basic block. That is, check if
+ * First is the only entrance and Last is the only exit. This means that no
+ * jump/branch inside the block may jump to an insn below First or after(!)
+ * Last, and that no insn may jump into this block from the outside.
+ */
+{
+ unsigned I;
+
+ /* Don't accept invalid ranges */
+ CHECK (First <= Last);
+
+ /* First pass: Walk over the range and remove all marks from the entries */
+ CS_ResetMarks (S, First, Last);
+
+ /* Second pass: Walk over the range checking all labels. Note: There may be
+ * label on the first insn which is ok.
+ */
+ I = First + 1;
+ while (I <= Last) {
+
+ /* Get the next entry */
+ CodeEntry* E = CS_GetEntry (S, I);
+
+ /* Check if this entry has one or more labels, if so, check which
+ * entries jump to this label.
+ */
+ unsigned LabelCount = CE_GetLabelCount (E);
+ unsigned LabelIndex;
+ for (LabelIndex = 0; LabelIndex < LabelCount; ++LabelIndex) {
+
+ /* Get this label */
+ CodeLabel* L = CE_GetLabel (E, LabelIndex);
+
+ /* Walk over all entries that jump to this label. Check for each
+ * of the entries if it is out of the range.
+ */
+ unsigned RefCount = CL_GetRefCount (L);
+ unsigned RefIndex;
+ for (RefIndex = 0; RefIndex < RefCount; ++RefIndex) {
+
+ /* Get the code entry that jumps here */
+ CodeEntry* Ref = CL_GetRef (L, RefIndex);
+
+ /* Walk over out complete range and check if we find the
+ * refering entry. This is cheaper than using CS_GetEntryIndex,
+ * because CS_GetEntryIndex will search the complete code
+ * segment and not just our range.
+ */
+ unsigned J;
+ for (J = First; J <= Last; ++J) {
+ if (Ref == CS_GetEntry (S, J)) {
+ break;
+ }
+ }
+ if (J > Last) {
+ /* We did not find the entry. This means that the jump to
+ * out code segment entry E came from outside the range,
+ * which in turn means that the given range is not a basic
+ * block.
+ */
+ CS_ResetMarks (S, First, Last);
+ return 0;
+ }
+
+ /* If we come here, we found the entry. Mark it, so we know
+ * that the branch to the label is in range.
+ */
+ CE_SetMark (Ref);
+ }
+ }
+
+ /* Next entry */
+ ++I;
+ }
+
+ /* Third pass: Walk again over the range and check all branches. If we
+ * find a branch that is not marked, its target is not inside the range
+ * (since we checked all the labels in the range before).
+ */
+ I = First;
+ while (I <= Last) {
+
+ /* Get the next entry */
+ CodeEntry* E = CS_GetEntry (S, I);
+
+ /* Check if this is a branch and if so, if it has a mark */
+ if (E->Info & (OF_UBRA | OF_CBRA)) {
+ if (!CE_HasMark (E)) {
+ /* No mark means not a basic block. Before bailing out, be sure
+ * to remove the marks from the remaining entries.
+ */
+ CS_ResetMarks (S, I+1, Last);
+ return 0;
+ }
+
+ /* Remove the mark */
+ CE_ResetMark (E);
+ }
+
+ /* Next entry */
+ ++I;
+ }
+
+ /* Done - this is a basic block */
+ return 1;
+}
+
+
+
+void CS_OutputPrologue (const CodeSeg* S, FILE* F)
+/* If the given code segment is a code segment for a function, output the
+ * assembler prologue into the file. That is: Output a comment header, switch
+ * to the correct segment and enter the local function scope. If the code
+ * segment is global, do nothing.
+ */
+{
+ /* Get the function associated with the code segment */
+ SymEntry* Func = S->Func;
+
+ /* If the code segment is associated with a function, print a function
+ * header and enter a local scope. Be sure to switch to the correct
+ * segment before outputing the function label.
+ */
+ if (Func) {
+ CS_PrintFunctionHeader (S, F);
+ fprintf (F, ".segment\t\"%s\"\n\n.proc\t_%s\n\n", S->SegName, Func->Name);
+ }
+
+}
+
+
+
+void CS_OutputEpilogue (const CodeSeg* S, FILE* F)
+/* If the given code segment is a code segment for a function, output the
+ * assembler epilogue into the file. That is: Close the local function scope.
+ */
+{
+ if (S->Func) {
+ fprintf (F, "\n.endproc\n\n");
+ }
+}
+
+
+
+void CS_Output (const CodeSeg* S, FILE* F)
+/* Output the code segment data to a file */
+{
+ unsigned I;
+ const LineInfo* LI;
+
+ /* Get the number of entries in this segment */
+ unsigned Count = CS_GetEntryCount (S);
+
+ /* If the code segment is empty, bail out here */
+ if (Count == 0) {
+ return;
+ }
+
+ /* Output the segment directive */
+ fprintf (F, ".segment\t\"%s\"\n\n", S->SegName);
+
+ /* Output all entries, prepended by the line information if it has changed */
+ LI = 0;
+ for (I = 0; I < Count; ++I) {
+ /* Get the next entry */
+ const CodeEntry* E = CollConstAt (&S->Entries, I);
+ /* Check if the line info has changed. If so, output the source line
+ * if the option is enabled and output debug line info if the debug
+ * option is enabled.
+ */
+ if (E->LI != LI) {
+ /* Line info has changed, remember the new line info */
+ LI = E->LI;
+
+ /* Add the source line as a comment. Beware: When line continuation
+ * was used, the line may contain newlines.
+ */
+ if (AddSource) {
+ const char* L = LI->Line;
+ fputs (";\n; ", F);
+ while (*L) {
+ if (*L == '\n') {
+ fputs ("\n; ", F);
+ } else {
+ fputc (*L, F);
+ }
+ ++L;
+ }
+ fputs ("\n;\n", F);
+ }
+
+ /* Add line debug info */
+ if (DebugInfo) {
+ fprintf (F, "\t.dbg\tline, \"%s\", %u\n",
+ GetInputName (LI), GetInputLine (LI));
+ }
+ }
+ /* Output the code */
+ CE_Output (E, F);
+ }
+
+ /* If debug info is enabled, terminate the last line number information */
+ if (DebugInfo) {
+ fprintf (F, "\t.dbg\tline\n");
+ }
+}
+
+
+
+void CS_FreeRegInfo (CodeSeg* S)
+/* Free register infos for all instructions */
+{
+ unsigned I;
+ for (I = 0; I < CS_GetEntryCount (S); ++I) {
+ CE_FreeRegInfo (CS_GetEntry(S, I));
+ }
+}
+
+
+
+void CS_GenRegInfo (CodeSeg* S)
+/* Generate register infos for all instructions */
+{
+ unsigned I;
+ RegContents Regs; /* Initial register contents */
+ RegContents* CurrentRegs; /* Current register contents */
+ int WasJump; /* True if last insn was a jump */
+ int Done; /* All runs done flag */
+
+ /* Be sure to delete all register infos */
+ CS_FreeRegInfo (S);
+
+ /* We may need two runs to get back references right */
+ do {
+
+ /* Assume we're done after this run */
+ Done = 1;
+
+ /* On entry, the register contents are unknown */
+ RC_Invalidate (&Regs);
+ CurrentRegs = &Regs;
+
+ /* Walk over all insns and note just the changes from one insn to the
+ * next one.
+ */
+ WasJump = 0;
+ for (I = 0; I < CS_GetEntryCount (S); ++I) {
+
+ CodeEntry* P;
+
+ /* Get the next instruction */
+ CodeEntry* E = CollAtUnchecked (&S->Entries, I);
+
+ /* If the instruction has a label, we need some special handling */
+ unsigned LabelCount = CE_GetLabelCount (E);
+ if (LabelCount > 0) {
+
+ /* Loop over all entry points that jump here. If these entry
+ * points already have register info, check if all values are
+ * known and identical. If all values are identical, and the
+ * preceeding instruction was not an unconditional branch, check
+ * if the register value on exit of the preceeding instruction
+ * is also identical. If all these values are identical, the
+ * value of a register is known, otherwise it is unknown.
+ */
+ CodeLabel* Label = CE_GetLabel (E, 0);
+ unsigned Entry;
+ if (WasJump) {
+ /* Preceeding insn was an unconditional branch */
+ CodeEntry* J = CL_GetRef(Label, 0);
+ if (J->RI) {
+ Regs = J->RI->Out2;
+ } else {
+ RC_Invalidate (&Regs);
+ }
+ Entry = 1;
+ } else {
+ Regs = *CurrentRegs;
+ Entry = 0;
+ }
+
+ while (Entry < CL_GetRefCount (Label)) {
+ /* Get this entry */
+ CodeEntry* J = CL_GetRef (Label, Entry);
+ if (J->RI == 0) {
+ /* No register info for this entry. This means that the
+ * instruction that jumps here is at higher addresses and
+ * the jump is a backward jump. We need a second run to
+ * get the register info right in this case. Until then,
+ * assume unknown register contents.
+ */
+ Done = 0;
+ RC_Invalidate (&Regs);
+ break;
+ }
+ if (J->RI->Out2.RegA != Regs.RegA) {
+ Regs.RegA = UNKNOWN_REGVAL;
+ }
+ if (J->RI->Out2.RegX != Regs.RegX) {
+ Regs.RegX = UNKNOWN_REGVAL;
+ }
+ if (J->RI->Out2.RegY != Regs.RegY) {
+ Regs.RegY = UNKNOWN_REGVAL;
+ }
+ if (J->RI->Out2.SRegLo != Regs.SRegLo) {
+ Regs.SRegLo = UNKNOWN_REGVAL;
+ }
+ if (J->RI->Out2.SRegHi != Regs.SRegHi) {
+ Regs.SRegHi = UNKNOWN_REGVAL;
+ }
+ if (J->RI->Out2.Tmp1 != Regs.Tmp1) {
+ Regs.Tmp1 = UNKNOWN_REGVAL;
+ }
+ ++Entry;
+ }
+
+ /* Use this register info */
+ CurrentRegs = &Regs;
+
+ }
+
+ /* Generate register info for this instruction */
+ CE_GenRegInfo (E, CurrentRegs);
+
+ /* Remember for the next insn if this insn was an uncondition branch */
+ WasJump = (E->Info & OF_UBRA) != 0;
+
+ /* Output registers for this insn are input for the next */
+ CurrentRegs = &E->RI->Out;
+
+ /* If this insn is a branch on zero flag, we may have more info on
+ * register contents for one of both flow directions, but only if
+ * there is a previous instruction.
+ */
+ if ((E->Info & OF_ZBRA) != 0 && (P = CS_GetPrevEntry (S, I)) != 0) {
+
+ /* Get the branch condition */
+ bc_t BC = GetBranchCond (E->OPC);
+
+ /* Check the previous instruction */
+ switch (P->OPC) {
+
+ case OP65_ADC:
+ case OP65_AND:
+ case OP65_DEA:
+ case OP65_EOR:
+ case OP65_INA:
+ case OP65_LDA:
+ case OP65_ORA:
+ case OP65_PLA:
+ case OP65_SBC:
+ /* A is zero in one execution flow direction */
+ if (BC == BC_EQ) {
+ E->RI->Out2.RegA = 0;
+ } else {
+ E->RI->Out.RegA = 0;
+ }
+ break;
+
+ case OP65_CMP:
+ /* If this is an immidiate compare, the A register has
+ * the value of the compare later.
+ */
+ if (CE_KnownImm (P)) {
+ if (BC == BC_EQ) {
+ E->RI->Out2.RegA = (unsigned char)P->Num;
+ } else {
+ E->RI->Out.RegA = (unsigned char)P->Num;
+ }
+ }
+ break;
+
+ case OP65_CPX:
+ /* If this is an immidiate compare, the X register has
+ * the value of the compare later.
+ */
+ if (CE_KnownImm (P)) {
+ if (BC == BC_EQ) {
+ E->RI->Out2.RegX = (unsigned char)P->Num;
+ } else {
+ E->RI->Out.RegX = (unsigned char)P->Num;
+ }
+ }
+ break;
+
+ case OP65_CPY:
+ /* If this is an immidiate compare, the Y register has
+ * the value of the compare later.
+ */
+ if (CE_KnownImm (P)) {
+ if (BC == BC_EQ) {
+ E->RI->Out2.RegY = (unsigned char)P->Num;
+ } else {
+ E->RI->Out.RegY = (unsigned char)P->Num;
+ }
+ }
+ break;
+
+ case OP65_DEX:
+ case OP65_INX:
+ case OP65_LDX:
+ case OP65_PLX:
+ /* X is zero in one execution flow direction */
+ if (BC == BC_EQ) {
+ E->RI->Out2.RegX = 0;
+ } else {
+ E->RI->Out.RegX = 0;
+ }
+ break;
+
+ case OP65_DEY:
+ case OP65_INY:
+ case OP65_LDY:
+ case OP65_PLY:
+ /* X is zero in one execution flow direction */
+ if (BC == BC_EQ) {
+ E->RI->Out2.RegY = 0;
+ } else {
+ E->RI->Out.RegY = 0;
+ }
+ break;
+
+ case OP65_TAX:
+ case OP65_TXA:
+ /* If the branch is a beq, both A and X are zero at the
+ * branch target, otherwise they are zero at the next
+ * insn.
+ */
+ if (BC == BC_EQ) {
+ E->RI->Out2.RegA = E->RI->Out2.RegX = 0;
+ } else {
+ E->RI->Out.RegA = E->RI->Out.RegX = 0;
+ }
+ break;
+
+ case OP65_TAY:
+ case OP65_TYA:
+ /* If the branch is a beq, both A and Y are zero at the
+ * branch target, otherwise they are zero at the next
+ * insn.
+ */
+ if (BC == BC_EQ) {
+ E->RI->Out2.RegA = E->RI->Out2.RegY = 0;
+ } else {
+ E->RI->Out.RegA = E->RI->Out.RegY = 0;
+ }
+ break;
+
+ default:
+ break;
+
+ }
+ }
+ }
+ } while (!Done);
+
+}
+
+