1 /*****************************************************************************/
5 /* Code segment structure */
9 /* (C) 2001 Ullrich von Bassewitz */
11 /* D-70597 Stuttgart */
12 /* EMail: uz@cc65.org */
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. */
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: */
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 */
32 /*****************************************************************************/
59 /*****************************************************************************/
60 /* Helper functions */
61 /*****************************************************************************/
65 static void CS_MoveLabelsToEntry (CodeSeg* S, CodeEntry* E)
66 /* Move all labels from the label pool to the given entry and remove them
70 /* Transfer the labels if we have any */
72 unsigned LabelCount = CollCount (&S->Labels);
73 for (I = 0; I < LabelCount; ++I) {
76 CodeLabel* L = CollAt (&S->Labels, I);
78 /* Attach it to the entry */
79 CE_AttachLabel (E, L);
82 /* Delete the transfered labels */
83 CollDeleteAll (&S->Labels);
88 static void CS_MoveLabelsToPool (CodeSeg* S, CodeEntry* E)
89 /* Move the labels of the code entry E to the label pool of the code segment */
91 unsigned LabelCount = CE_GetLabelCount (E);
92 while (LabelCount--) {
93 CodeLabel* L = CE_GetLabel (E, LabelCount);
95 CollAppend (&S->Labels, L);
97 CollDeleteAll (&E->Labels);
102 static CodeLabel* CS_FindLabel (CodeSeg* S, const char* Name, unsigned Hash)
103 /* Find the label with the given name. Return the label or NULL if not found */
105 /* Get the first hash chain entry */
106 CodeLabel* L = S->LabelHash[Hash];
108 /* Search the list */
110 if (strcmp (Name, L->Name) == 0) {
121 static CodeLabel* CS_NewCodeLabel (CodeSeg* S, const char* Name, unsigned Hash)
122 /* Create a new label and insert it into the label hash table */
124 /* Create a new label */
125 CodeLabel* L = NewCodeLabel (Name, Hash);
127 /* Enter the label into the hash table */
128 L->Next = S->LabelHash[L->Hash];
129 S->LabelHash[L->Hash] = L;
131 /* Return the new label */
137 static void CS_RemoveLabelFromHash (CodeSeg* S, CodeLabel* L)
138 /* Remove the given code label from the hash list */
140 /* Get the first entry in the hash chain */
141 CodeLabel* List = S->LabelHash[L->Hash];
144 /* First, remove the label from the hash chain */
146 /* First entry in hash chain */
147 S->LabelHash[L->Hash] = L->Next;
149 /* Must search through the chain */
150 while (List->Next != L) {
151 /* If we've reached the end of the chain, something is *really* wrong */
152 CHECK (List->Next != 0);
156 /* The next entry is the one, we have been searching for */
157 List->Next = L->Next;
163 /*****************************************************************************/
164 /* Functions for parsing instructions */
165 /*****************************************************************************/
169 static const char* SkipSpace (const char* S)
170 /* Skip white space and return an updated pointer */
172 while (IsSpace (*S)) {
180 static const char* ReadToken (const char* L, const char* Term,
181 char* Buf, unsigned BufSize)
182 /* Read the next token into Buf, return the updated line pointer. The
183 * token is terminated by one of the characters given in term.
186 /* Read/copy the token */
188 unsigned ParenCount = 0;
189 while (*L && (ParenCount > 0 || strchr (Term, *L) == 0)) {
195 } else if (*L == '(') {
201 /* Terminate the buffer contents */
204 /* Return the updated line pointer */
210 static CodeEntry* ParseInsn (CodeSeg* S, LineInfo* LI, const char* L)
211 /* Parse an instruction nnd generate a code entry from it. If the line contains
212 * errors, output an error message and return NULL.
213 * For simplicity, we don't accept the broad range of input a "real" assembler
214 * does. The instruction and the argument are expected to be separated by
215 * white space, for example.
220 am_t AM = 0; /* Initialize to keep gcc silent */
227 L = ReadToken (L, " \t", Mnemo, sizeof (Mnemo));
229 /* Try to find the opcode description for the mnemonic */
230 OPC = FindOP65 (Mnemo);
232 /* If we didn't find the opcode, print an error and bail out */
234 Error ("ASM code error: %s is not a valid mnemonic", Mnemo);
238 /* Skip separator white space */
241 /* Get the addressing mode */
252 StrCopy (Arg, sizeof (Arg), L+1);
258 L = ReadToken (L+1, ",)", Arg, sizeof (Arg));
260 /* Check for errors */
262 Error ("ASM code error: syntax error");
266 /* Check the different indirect modes */
268 /* Expect zp x indirect */
270 if (toupper (*L) != 'X') {
271 Error ("ASM code error: `X' expected");
276 Error ("ASM code error: `)' expected");
281 Error ("ASM code error: syntax error");
285 } else if (*L == ')') {
286 /* zp indirect or zp indirect, y */
290 if (toupper (*L) != 'Y') {
291 Error ("ASM code error: `Y' expected");
296 Error ("ASM code error: syntax error");
300 } else if (*L == '\0') {
303 Error ("ASM code error: syntax error");
319 /* Absolute, maybe indexed */
320 L = ReadToken (L, ",", Arg, sizeof (Arg));
322 /* Absolute, zeropage or branch */
323 if ((OPC->Info & OF_BRA) != 0) {
326 } else if (IsZPName (Arg)) {
331 } else if (*L == ',') {
335 Error ("ASM code error: syntax error");
341 if (IsZPName (Arg)) {
346 } else if (Reg == 'Y') {
349 Error ("ASM code error: syntax error");
353 Error ("ASM code error: syntax error");
362 /* If the instruction is a branch, check for the label and generate it
363 * if it does not exist. Ignore anything but local labels here.
366 if (AM == AM65_BRA && Arg[0] == 'L') {
368 /* Generate the hash over the label, then search for the label */
369 unsigned Hash = HashStr (Arg) % CS_LABEL_HASH_SIZE;
370 Label = CS_FindLabel (S, Arg, Hash);
372 /* If we don't have the label, it's a forward ref - create it */
374 /* Generate a new label */
375 Label = CS_NewCodeLabel (S, Arg, Hash);
379 /* We do now have the addressing mode in AM. Allocate a new CodeEntry
380 * structure and initialize it.
382 E = NewCodeEntry (OPC->OPC, AM, Arg, Label, LI);
384 /* Return the new code entry */
390 /*****************************************************************************/
392 /*****************************************************************************/
396 CodeSeg* NewCodeSeg (const char* SegName, SymEntry* Func)
397 /* Create a new code segment, initialize and return it */
401 /* Allocate memory */
402 CodeSeg* S = xmalloc (sizeof (CodeSeg));
404 /* Initialize the fields */
405 S->SegName = xstrdup (SegName);
407 InitCollection (&S->Entries);
408 InitCollection (&S->Labels);
409 for (I = 0; I < sizeof(S->LabelHash) / sizeof(S->LabelHash[0]); ++I) {
413 /* If we have a function given, get the return type of the function.
414 * Assume ANY return type besides void will use the A and X registers.
416 if (S->Func && !IsTypeVoid (GetFuncReturn (Func->Type))) {
417 S->ExitRegs = REG_AX;
419 S->ExitRegs = REG_NONE;
422 /* Return the new struct */
428 void CS_AddEntry (CodeSeg* S, struct CodeEntry* E)
429 /* Add an entry to the given code segment */
431 /* Transfer the labels if we have any */
432 CS_MoveLabelsToEntry (S, E);
434 /* Add the entry to the list of code entries in this segment */
435 CollAppend (&S->Entries, E);
440 void CS_AddVLine (CodeSeg* S, LineInfo* LI, const char* Format, va_list ap)
441 /* Add a line to the given code segment */
447 /* Format the line */
449 xvsprintf (Buf, sizeof (Buf), Format, ap);
451 /* Skip whitespace */
454 /* Check which type of instruction we have */
455 E = 0; /* Assume no insn created */
459 /* Empty line, just ignore it */
463 /* Comment or hint, ignore it for now */
467 /* Control instruction */
468 ReadToken (L, " \t", Token, sizeof (Token));
469 Error ("ASM code error: Pseudo instruction `%s' not supported", Token);
473 E = ParseInsn (S, LI, L);
477 /* If we have a code entry, transfer the labels and insert it */
485 void CS_AddLine (CodeSeg* S, LineInfo* LI, const char* Format, ...)
486 /* Add a line to the given code segment */
489 va_start (ap, Format);
490 CS_AddVLine (S, LI, Format, ap);
496 void CS_InsertEntry (CodeSeg* S, struct CodeEntry* E, unsigned Index)
497 /* Insert the code entry at the index given. Following code entries will be
498 * moved to slots with higher indices.
501 /* Insert the entry into the collection */
502 CollInsert (&S->Entries, E, Index);
507 void CS_DelEntry (CodeSeg* S, unsigned Index)
508 /* Delete an entry from the code segment. This includes moving any associated
509 * labels, removing references to labels and even removing the referenced labels
510 * if the reference count drops to zero.
513 /* Get the code entry for the given index */
514 CodeEntry* E = CS_GetEntry (S, Index);
516 /* If the entry has a labels, we have to move this label to the next insn.
517 * If there is no next insn, move the label into the code segement label
518 * pool. The operation is further complicated by the fact that the next
519 * insn may already have a label. In that case change all reference to
520 * this label and delete the label instead of moving it.
522 unsigned Count = CE_GetLabelCount (E);
525 /* The instruction has labels attached. Check if there is a next
528 if (Index == CS_GetEntryCount (S)-1) {
530 /* No next instruction, move to the codeseg label pool */
531 CS_MoveLabelsToPool (S, E);
535 /* There is a next insn, get it */
536 CodeEntry* N = CS_GetEntry (S, Index+1);
538 /* Move labels to the next entry */
539 CS_MoveLabels (S, E, N);
544 /* If this insn references a label, remove the reference. And, if the
545 * the reference count for this label drops to zero, remove this label.
548 /* Remove the reference */
549 CS_RemoveLabelRef (S, E);
552 /* Delete the pointer to the insn */
553 CollDelete (&S->Entries, Index);
555 /* Delete the instruction itself */
561 void CS_DelEntries (CodeSeg* S, unsigned Start, unsigned Count)
562 /* Delete a range of code entries. This includes removing references to labels,
563 * labels attached to the entries and so on.
566 /* Start deleting the entries from the rear, because this involves less
570 CS_DelEntry (S, Start + Count);
576 void CS_MoveEntries (CodeSeg* S, unsigned Start, unsigned Count, unsigned NewPos)
577 /* Move a range of entries from one position to another. Start is the index
578 * of the first entry to move, Count is the number of entries and NewPos is
579 * the index of the target entry. The entry with the index Start will later
580 * have the index NewPos. All entries with indices NewPos and above are
581 * moved to higher indices. If the code block is moved to the end of the
582 * current code, and if pending labels exist, these labels will get attached
583 * to the first instruction of the moved block (the first one after the
587 /* If NewPos is at the end of the code segment, move any labels from the
588 * label pool to the first instruction of the moved range.
590 if (NewPos == CS_GetEntryCount (S)) {
591 CS_MoveLabelsToEntry (S, CS_GetEntry (S, Start));
594 /* Move the code block to the destination */
595 CollMoveMultiple (&S->Entries, Start, Count, NewPos);
600 struct CodeEntry* CS_GetPrevEntry (CodeSeg* S, unsigned Index)
601 /* Get the code entry preceeding the one with the index Index. If there is no
602 * preceeding code entry, return NULL.
606 /* This is the first entry */
609 /* Previous entry available */
610 return CollAtUnchecked (&S->Entries, Index-1);
616 struct CodeEntry* CS_GetNextEntry (CodeSeg* S, unsigned Index)
617 /* Get the code entry following the one with the index Index. If there is no
618 * following code entry, return NULL.
621 if (Index >= CollCount (&S->Entries)-1) {
622 /* This is the last entry */
625 /* Code entries left */
626 return CollAtUnchecked (&S->Entries, Index+1);
632 int CS_GetEntries (CodeSeg* S, struct CodeEntry** List,
633 unsigned Start, unsigned Count)
634 /* Get Count code entries into List starting at index start. Return true if
635 * we got the lines, return false if not enough lines were available.
638 /* Check if enough entries are available */
639 if (Start + Count > CollCount (&S->Entries)) {
643 /* Copy the entries */
645 *List++ = CollAtUnchecked (&S->Entries, Start++);
648 /* We have the entries */
654 unsigned CS_GetEntryIndex (CodeSeg* S, struct CodeEntry* E)
655 /* Return the index of a code entry */
657 int Index = CollIndex (&S->Entries, E);
664 CodeLabel* CS_AddLabel (CodeSeg* S, const char* Name)
665 /* Add a code label for the next instruction to follow */
667 /* Calculate the hash from the name */
668 unsigned Hash = HashStr (Name) % CS_LABEL_HASH_SIZE;
670 /* Try to find the code label if it does already exist */
671 CodeLabel* L = CS_FindLabel (S, Name, Hash);
673 /* Did we find it? */
675 /* We found it - be sure it does not already have an owner */
676 CHECK (L->Owner == 0);
678 /* Not found - create a new one */
679 L = CS_NewCodeLabel (S, Name, Hash);
682 /* Safety. This call is quite costly, but safety is better */
683 if (CollIndex (&S->Labels, L) >= 0) {
684 Internal ("AddCodeLabel: Label `%s' already defined", Name);
687 /* We do now have a valid label. Remember it for later */
688 CollAppend (&S->Labels, L);
690 /* Return the label */
696 CodeLabel* CS_GenLabel (CodeSeg* S, struct CodeEntry* E)
697 /* If the code entry E does already have a label, return it. Otherwise
698 * create a new label, attach it to E and return it.
703 if (CE_HasLabel (E)) {
705 /* Get the label from this entry */
706 L = CE_GetLabel (E, 0);
711 const char* Name = LocalLabelName (GetLocalLabel ());
713 /* Generate the hash over the name */
714 unsigned Hash = HashStr (Name) % CS_LABEL_HASH_SIZE;
716 /* Create a new label */
717 L = CS_NewCodeLabel (S, Name, Hash);
719 /* Attach this label to the code entry */
720 CE_AttachLabel (E, L);
724 /* Return the label */
730 void CS_DelLabel (CodeSeg* S, CodeLabel* L)
731 /* Remove references from this label and delete it. */
735 /* First, remove the label from the hash chain */
736 CS_RemoveLabelFromHash (S, L);
738 /* Remove references from insns jumping to this label */
739 Count = CollCount (&L->JumpFrom);
740 for (I = 0; I < Count; ++I) {
741 /* Get the insn referencing this label */
742 CodeEntry* E = CollAt (&L->JumpFrom, I);
743 /* Remove the reference */
746 CollDeleteAll (&L->JumpFrom);
748 /* Remove the reference to the owning instruction if it has one. The
749 * function may be called for a label without an owner when deleting
750 * unfinished parts of the code. This is unfortunate since it allows
751 * errors to slip through.
754 CollDeleteItem (&L->Owner->Labels, L);
757 /* All references removed, delete the label itself */
763 void CS_MergeLabels (CodeSeg* S)
764 /* Merge code labels. That means: For each instruction, remove all labels but
765 * one and adjust references accordingly.
770 /* Walk over all code entries */
771 for (I = 0; I < CS_GetEntryCount (S); ++I) {
776 /* Get a pointer to the next entry */
777 CodeEntry* E = CS_GetEntry (S, I);
779 /* If this entry has zero labels, continue with the next one */
780 unsigned LabelCount = CE_GetLabelCount (E);
781 if (LabelCount == 0) {
785 /* We have at least one label. Use the first one as reference label. */
786 RefLab = CE_GetLabel (E, 0);
788 /* Walk through the remaining labels and change references to these
789 * labels to a reference to the one and only label. Delete the labels
790 * that are no longer used. To increase performance, walk backwards
793 for (J = LabelCount-1; J >= 1; --J) {
795 /* Get the next label */
796 CodeLabel* L = CE_GetLabel (E, J);
798 /* Move all references from this label to the reference label */
799 CL_MoveRefs (L, RefLab);
801 /* Remove the label completely. */
805 /* The reference label is the only remaining label. Check if there
806 * are any references to this label, and delete it if this is not
809 if (CollCount (&RefLab->JumpFrom) == 0) {
810 /* Delete the label */
811 CS_DelLabel (S, RefLab);
818 void CS_MoveLabels (CodeSeg* S, struct CodeEntry* Old, struct CodeEntry* New)
819 /* Move all labels from Old to New. The routine will move the labels itself
820 * if New does not have any labels, and move references if there is at least
821 * a label for new. If references are moved, the old label is deleted
825 /* Get the number of labels to move */
826 unsigned OldLabelCount = CE_GetLabelCount (Old);
828 /* Does the new entry have itself a label? */
829 if (CE_HasLabel (New)) {
831 /* The new entry does already have a label - move references */
832 CodeLabel* NewLabel = CE_GetLabel (New, 0);
833 while (OldLabelCount--) {
835 /* Get the next label */
836 CodeLabel* OldLabel = CE_GetLabel (Old, OldLabelCount);
838 /* Move references */
839 CL_MoveRefs (OldLabel, NewLabel);
841 /* Delete the label */
842 CS_DelLabel (S, OldLabel);
848 /* The new entry does not have a label, just move them */
849 while (OldLabelCount--) {
851 /* Move the label to the new entry */
852 CE_MoveLabel (CE_GetLabel (Old, OldLabelCount), New);
861 void CS_RemoveLabelRef (CodeSeg* S, struct CodeEntry* E)
862 /* Remove the reference between E and the label it jumps to. The reference
863 * will be removed on both sides and E->JumpTo will be 0 after that. If
864 * the reference was the only one for the label, the label will get
868 /* Get a pointer to the label and make sure it exists */
869 CodeLabel* L = E->JumpTo;
872 /* Delete the entry from the label */
873 CollDeleteItem (&L->JumpFrom, E);
875 /* The entry jumps no longer to L */
878 /* If there are no more references, delete the label */
879 if (CollCount (&L->JumpFrom) == 0) {
886 void CS_MoveLabelRef (CodeSeg* S, struct CodeEntry* E, CodeLabel* L)
887 /* Change the reference of E to L instead of the current one. If this
888 * was the only reference to the old label, the old label will get
892 /* Get the old label */
893 CodeLabel* OldLabel = E->JumpTo;
895 /* Be sure that code entry references a label */
896 PRECONDITION (OldLabel != 0);
898 /* Remove the reference to our label */
899 CS_RemoveLabelRef (S, E);
901 /* Use the new label */
907 void CS_DelCodeAfter (CodeSeg* S, unsigned Last)
908 /* Delete all entries including the given one */
910 /* Get the number of entries in this segment */
911 unsigned Count = CS_GetEntryCount (S);
913 /* First pass: Delete all references to labels. If the reference count
914 * for a label drops to zero, delete it.
919 /* Get the next entry */
920 CodeEntry* E = CS_GetEntry (S, C);
922 /* Check if this entry has a label reference */
924 /* If the label is a label in the label pool and this is the last
925 * reference to the label, remove the label from the pool.
927 CodeLabel* L = E->JumpTo;
928 int Index = CollIndex (&S->Labels, L);
929 if (Index >= 0 && CollCount (&L->JumpFrom) == 1) {
930 /* Delete it from the pool */
931 CollDelete (&S->Labels, Index);
934 /* Remove the reference to the label */
935 CS_RemoveLabelRef (S, E);
940 /* Second pass: Delete the instructions. If a label attached to an
941 * instruction still has references, it must be references from outside
942 * the deleted area. Don't delete the label in this case, just make it
943 * ownerless and move it to the label pool.
948 /* Get the next entry */
949 CodeEntry* E = CS_GetEntry (S, C);
951 /* Check if this entry has a label attached */
952 if (CE_HasLabel (E)) {
953 /* Move the labels to the pool and clear the owner pointer */
954 CS_MoveLabelsToPool (S, E);
957 /* Delete the pointer to the entry */
958 CollDelete (&S->Entries, C);
960 /* Delete the entry itself */
967 void CS_Output (const CodeSeg* S, FILE* F)
968 /* Output the code segment data to a file */
973 /* Get the number of entries in this segment */
974 unsigned Count = CS_GetEntryCount (S);
976 /* If the code segment is empty, bail out here */
981 /* Output the segment directive */
982 fprintf (F, ".segment\t\"%s\"\n\n", S->SegName);
984 /* If this is a segment for a function, enter a function */
986 fprintf (F, ".proc\t_%s\n\n", S->Func->Name);
989 /* Output all entries, prepended by the line information if it has changed */
991 for (I = 0; I < Count; ++I) {
992 /* Get the next entry */
993 const CodeEntry* E = CollConstAt (&S->Entries, I);
994 /* Check if the line info has changed. If so, output the source line
995 * if the option is enabled and output debug line info if the debug
999 /* Line info has changed, remember the new line info */
1002 /* Add the source line as a comment */
1004 fprintf (F, ";\n; %s\n;\n", LI->Line);
1007 /* Add line debug info */
1009 fprintf (F, "\t.dbg\tline, \"%s\", %u\n",
1010 GetInputName (LI), GetInputLine (LI));
1013 /* Output the code */
1017 /* If debug info is enabled, terminate the last line number information */
1019 fprintf (F, "\t.dbg\tline\n");
1022 /* If this is a segment for a function, leave the function */
1024 fprintf (F, "\n.endproc\n\n");
1030 void CS_FreeRegInfo (CodeSeg* S)
1031 /* Free register infos for all instructions */
1034 for (I = 0; I < CS_GetEntryCount (S); ++I) {
1035 CE_FreeRegInfo (CS_GetEntry(S, I));
1041 void CS_GenRegInfo (CodeSeg* S)
1042 /* Generate register infos for all instructions */
1046 RegContents* CurrentRegs;
1049 /* Be sure to delete all register infos */
1052 /* On entry, the register contents are unknown */
1053 RC_Invalidate (&Regs);
1054 CurrentRegs = &Regs;
1056 /* First pass. Walk over all insns an note just the changes from one
1057 * insn to the next one.
1060 for (I = 0; I < CS_GetEntryCount (S); ++I) {
1064 /* Get the next instruction */
1065 CodeEntry* E = CollAtUnchecked (&S->Entries, I);
1067 /* If the instruction has a label, we need some special handling */
1068 unsigned LabelCount = CE_GetLabelCount (E);
1069 if (LabelCount > 0) {
1071 /* Loop over all entry points that jump here. If these entry
1072 * points already have register info, check if all values are
1073 * known and identical. If all values are identical, and the
1074 * preceeding instruction was not an unconditional branch, check
1075 * if the register value on exit of the preceeding instruction
1076 * is also identical. If all these values are identical, the
1077 * value of a register is known, otherwise it is unknown.
1079 CodeLabel* Label = CE_GetLabel (E, 0);
1082 /* Preceeding insn was an unconditional branch */
1083 CodeEntry* J = CL_GetRef(Label, 0);
1087 RC_Invalidate (&Regs);
1091 Regs = *CurrentRegs;
1095 while (Entry < CL_GetRefCount (Label)) {
1096 /* Get this entry */
1097 CodeEntry* J = CL_GetRef (Label, Entry);
1099 /* No register info for this entry, bail out */
1100 RC_Invalidate (&Regs);
1103 if (J->RI->Out2.RegA != Regs.RegA) {
1106 if (J->RI->Out2.RegX != Regs.RegX) {
1109 if (J->RI->Out2.RegY != Regs.RegY) {
1115 /* Use this register info */
1116 CurrentRegs = &Regs;
1120 /* Generate register info for this instruction */
1121 CE_GenRegInfo (E, CurrentRegs);
1123 /* Remember for the next insn if this insn was an uncondition branch */
1124 WasJump = (E->Info & OF_UBRA) != 0;
1126 /* Output registers for this insn are input for the next */
1127 CurrentRegs = &E->RI->Out;
1129 /* If this insn is a branch on zero flag, we may have more info on
1130 * register contents for one of both flow directions, but only if
1131 * there is a previous instruction.
1133 if ((E->Info & OF_ZBRA) != 0 && (P = CS_GetPrevEntry (S, I)) != 0) {
1135 /* Get the branch condition */
1136 bc_t BC = GetBranchCond (E->OPC);
1138 /* Check the previous instruction */
1150 /* A is zero in one execution flow direction */
1152 E->RI->Out2.RegA = 0;
1154 E->RI->Out.RegA = 0;
1159 /* If this is an immidiate compare, the A register has
1160 * the value of the compare later.
1162 if (CE_KnownImm (P)) {
1164 E->RI->Out2.RegA = (unsigned char)P->Num;
1166 E->RI->Out.RegA = (unsigned char)P->Num;
1172 /* If this is an immidiate compare, the X register has
1173 * the value of the compare later.
1175 if (CE_KnownImm (P)) {
1177 E->RI->Out2.RegX = (unsigned char)P->Num;
1179 E->RI->Out.RegX = (unsigned char)P->Num;
1185 /* If this is an immidiate compare, the Y register has
1186 * the value of the compare later.
1188 if (CE_KnownImm (P)) {
1190 E->RI->Out2.RegY = (unsigned char)P->Num;
1192 E->RI->Out.RegY = (unsigned char)P->Num;
1201 /* X is zero in one execution flow direction */
1203 E->RI->Out2.RegX = 0;
1205 E->RI->Out.RegX = 0;
1213 /* X is zero in one execution flow direction */
1215 E->RI->Out2.RegY = 0;
1217 E->RI->Out.RegY = 0;
1223 /* If the branch is a beq, both A and X are zero at the
1224 * branch target, otherwise they are zero at the next
1228 E->RI->Out2.RegA = E->RI->Out2.RegX = 0;
1230 E->RI->Out.RegA = E->RI->Out.RegX = 0;
1236 /* If the branch is a beq, both A and Y are zero at the
1237 * branch target, otherwise they are zero at the next
1241 E->RI->Out2.RegA = E->RI->Out2.RegY = 0;
1243 E->RI->Out.RegA = E->RI->Out.RegY = 0;