/*****************************************************************************/
/* */
-/* coptstop.c */
+/* coptstop.c */
/* */
-/* Optimize operations that take operands via the stack */
+/* Optimize operations that take operands via the stack */
/* */
/* */
/* */
-/* (C) 2001-2002 Ullrich von Bassewitz */
-/* Wacholderweg 14 */
-/* D-70597 Stuttgart */
-/* EMail: uz@cc65.org */
+/* (C) 2001-2019, Ullrich von Bassewitz */
+/* Roemerstrasse 52 */
+/* D-70794 Filderstadt */
+/* EMail: uz@cc65.org */
/* */
/* */
/* This software is provided 'as-is', without any expressed or implied */
#include <stdlib.h>
-#include <ctype.h>
+
+/* common */
+#include "chartype.h"
/* cc65 */
#include "codeent.h"
#include "codeinfo.h"
#include "coptstop.h"
+#include "error.h"
+
+
+
+/*****************************************************************************/
+/* Load tracking data */
+/*****************************************************************************/
+
+
+
+/* LoadRegInfo flags set by DirectOp */
+typedef enum {
+ LI_NONE = 0x00,
+ LI_DIRECT = 0x01, /* Direct op may be used */
+ LI_RELOAD_Y = 0x02, /* Reload index register Y */
+ LI_REMOVE = 0x04, /* Load may be removed */
+ LI_DONT_REMOVE = 0x08, /* Load may not be removed */
+ LI_DUP_LOAD = 0x10, /* Duplicate load */
+} LI_FLAGS;
+
+/* Structure that tells us how to load the lhs values */
+typedef struct LoadRegInfo LoadRegInfo;
+struct LoadRegInfo {
+ LI_FLAGS Flags; /* Tells us how to load */
+ int LoadIndex; /* Index of load insn, -1 if invalid */
+ CodeEntry* LoadEntry; /* The actual entry, 0 if invalid */
+ int XferIndex; /* Index of transfer insn */
+ CodeEntry* XferEntry; /* The actual transfer entry */
+ int Offs; /* Stack offset if data is on stack */
+};
+
+/* Now combined for both registers */
+typedef struct LoadInfo LoadInfo;
+struct LoadInfo {
+ LoadRegInfo A; /* Info for A register */
+ LoadRegInfo X; /* Info for X register */
+ LoadRegInfo Y; /* Info for Y register */
+};
-/* Structure that holds the needed data */
+/* Flags for the functions */
+typedef enum {
+ OP_NONE = 0x00, /* Nothing special */
+ OP_A_KNOWN = 0x01, /* Value of A must be known */
+ OP_X_ZERO = 0x02, /* X must be zero */
+ OP_LHS_LOAD = 0x04, /* Must have load insns for LHS */
+ OP_LHS_LOAD_DIRECT = 0x0C, /* Must have direct load insn for LHS */
+ OP_RHS_LOAD = 0x10, /* Must have load insns for RHS */
+ OP_RHS_LOAD_DIRECT = 0x30, /* Must have direct load insn for RHS */
+} OP_FLAGS;
+
+/* Structure forward decl */
typedef struct StackOpData StackOpData;
+
+/* Structure that describes an optimizer subfunction for a specific op */
+typedef unsigned (*OptFunc) (StackOpData* D);
+typedef struct OptFuncDesc OptFuncDesc;
+struct OptFuncDesc {
+ const char* Name; /* Name of the replaced runtime function */
+ OptFunc Func; /* Function pointer */
+ unsigned UnusedRegs; /* Regs that must not be used later */
+ OP_FLAGS Flags; /* Flags */
+};
+
+/* Structure that holds the needed data */
struct StackOpData {
- CodeSeg* Code; /* Pointer to code segment */
- unsigned Flags; /* Flags to remember things */
- unsigned PushIndex; /* Index of call to pushax in codeseg */
- unsigned OpIndex; /* Index of actual operation */
- CodeEntry* PrevEntry; /* Entry before the call to pushax */
- CodeEntry* PushEntry; /* Pointer to entry with call to pushax */
- CodeEntry* OpEntry; /* Pointer to entry with op */
- CodeEntry* NextEntry; /* Entry after the op */
- const char* ZPLo; /* Lo byte of zero page loc to use */
- const char* ZPHi; /* Hi byte of zero page loc to use */
- unsigned IP; /* Insertion point used by some routines */
+ CodeSeg* Code; /* Pointer to code segment */
+ unsigned Flags; /* Flags to remember things */
+
+ /* Pointer to optimizer subfunction description */
+ const OptFuncDesc* OptFunc;
+
+ /* ZP register usage inside the sequence */
+ unsigned ZPUsage;
+
+ /* Register load information for lhs and rhs */
+ LoadInfo Lhs;
+ LoadInfo Rhs;
+
+ /* Several indices of insns in the code segment */
+ int PushIndex; /* Index of call to pushax in codeseg */
+ int OpIndex; /* Index of actual operation */
+
+ /* Pointers to insns in the code segment */
+ CodeEntry* PrevEntry; /* Entry before the call to pushax */
+ CodeEntry* PushEntry; /* Pointer to entry with call to pushax */
+ CodeEntry* OpEntry; /* Pointer to entry with op */
+ CodeEntry* NextEntry; /* Entry after the op */
+
+ const char* ZPLo; /* Lo byte of zero page loc to use */
+ const char* ZPHi; /* Hi byte of zero page loc to use */
+ unsigned IP; /* Insertion point used by some routines */
};
-/* Flags returned by DirectOp */
-#define OP_DIRECT 0x01 /* Direct op may be used */
-#define OP_RELOAD_Y 0x02 /* Must reload index register Y */
+
+
+/*****************************************************************************/
+/* Load tracking code */
+/*****************************************************************************/
+
+
+
+static void ClearLoadRegInfo (LoadRegInfo* RI)
+/* Clear a LoadRegInfo struct */
+{
+ RI->Flags = LI_NONE;
+ RI->LoadIndex = -1;
+ RI->XferIndex = -1;
+ RI->Offs = 0;
+}
+
+
+
+static void FinalizeLoadRegInfo (LoadRegInfo* RI, CodeSeg* S)
+/* Prepare a LoadRegInfo struct for use */
+{
+ /* Get the entries */
+ if (RI->LoadIndex >= 0) {
+ RI->LoadEntry = CS_GetEntry (S, RI->LoadIndex);
+ } else {
+ RI->LoadEntry = 0;
+ }
+ if (RI->XferIndex >= 0) {
+ RI->XferEntry = CS_GetEntry (S, RI->XferIndex);
+ } else {
+ RI->XferEntry = 0;
+ }
+}
+
+
+
+static void ClearLoadInfo (LoadInfo* LI)
+/* Clear a LoadInfo struct */
+{
+ ClearLoadRegInfo (&LI->A);
+ ClearLoadRegInfo (&LI->X);
+ ClearLoadRegInfo (&LI->Y);
+}
+
+
+
+static void AdjustLoadRegInfo (LoadRegInfo* RI, int Index, int Change)
+/* Adjust a load register info struct after deleting or inserting an entry
+** with a given index
+*/
+{
+ CHECK (abs (Change) == 1);
+ if (Change < 0) {
+ /* Deletion */
+ if (Index < RI->LoadIndex) {
+ --RI->LoadIndex;
+ } else if (Index == RI->LoadIndex) {
+ /* Has been removed */
+ RI->LoadIndex = -1;
+ RI->LoadEntry = 0;
+ }
+ if (Index < RI->XferIndex) {
+ --RI->XferIndex;
+ } else if (Index == RI->XferIndex) {
+ /* Has been removed */
+ RI->XferIndex = -1;
+ RI->XferEntry = 0;
+ }
+ } else {
+ /* Insertion */
+ if (Index <= RI->LoadIndex) {
+ ++RI->LoadIndex;
+ }
+ if (Index <= RI->XferIndex) {
+ ++RI->XferIndex;
+ }
+ }
+}
+
+
+
+static void FinalizeLoadInfo (LoadInfo* LI, CodeSeg* S)
+/* Prepare a LoadInfo struct for use */
+{
+ /* Get the entries */
+ FinalizeLoadRegInfo (&LI->A, S);
+ FinalizeLoadRegInfo (&LI->X, S);
+ FinalizeLoadRegInfo (&LI->Y, S);
+}
+
+
+
+static void AdjustLoadInfo (LoadInfo* LI, int Index, int Change)
+/* Adjust a load info struct after deleting entry with a given index */
+{
+ AdjustLoadRegInfo (&LI->A, Index, Change);
+ AdjustLoadRegInfo (&LI->X, Index, Change);
+ AdjustLoadRegInfo (&LI->Y, Index, Change);
+}
+
+
+
+static void HonourUseAndChg (LoadRegInfo* RI, unsigned Reg, const CodeEntry* E)
+/* Honour use and change flags for an instruction */
+{
+ if (E->Chg & Reg) {
+ ClearLoadRegInfo (RI);
+ } else if ((E->Use & Reg) && RI->LoadIndex >= 0) {
+ RI->Flags |= LI_DONT_REMOVE;
+ }
+}
+
+
+
+static void TrackLoads (LoadInfo* LI, CodeEntry* E, int I)
+/* Track loads for a code entry */
+{
+ if (E->Info & OF_LOAD) {
+
+ LoadRegInfo* RI = 0;
+
+ /* Determine, which register was loaded */
+ if (E->Chg & REG_A) {
+ RI = &LI->A;
+ } else if (E->Chg & REG_X) {
+ RI = &LI->X;
+ } else if (E->Chg & REG_Y) {
+ RI = &LI->Y;
+ }
+ CHECK (RI != 0);
+
+ /* If we had a load or xfer op before, this is a duplicate load which
+ ** can cause problems if it encountered between the pushax and the op,
+ ** so remember it.
+ */
+ if (RI->LoadIndex >= 0 || RI->XferIndex >= 0) {
+ RI->Flags |= LI_DUP_LOAD;
+ }
+
+ /* Remember the load */
+ RI->LoadIndex = I;
+ RI->XferIndex = -1;
+
+ /* Set load flags */
+ RI->Flags &= ~(LI_DIRECT | LI_RELOAD_Y);
+ if (E->AM == AM65_IMM || E->AM == AM65_ZP || E->AM == AM65_ABS) {
+ /* These insns are all ok and replaceable */
+ RI->Flags |= LI_DIRECT;
+ } else if (E->AM == AM65_ZP_INDY &&
+ RegValIsKnown (E->RI->In.RegY) &&
+ strcmp (E->Arg, "sp") == 0) {
+ /* A load from the stack with known offset is also ok, but in this
+ ** case we must reload the index register later. Please note that
+ ** a load indirect via other zero page locations is not ok, since
+ ** these locations may change between the push and the actual
+ ** operation.
+ */
+ RI->Offs = (unsigned char) E->RI->In.RegY;
+ RI->Flags |= (LI_DIRECT | LI_RELOAD_Y);
+ }
+
+
+ } else if (E->Info & OF_XFR) {
+
+ /* Determine source and target of the transfer and handle the TSX insn */
+ LoadRegInfo* Src;
+ LoadRegInfo* Tgt;
+ switch (E->OPC) {
+ case OP65_TAX: Src = &LI->A; Tgt = &LI->X; break;
+ case OP65_TAY: Src = &LI->A; Tgt = &LI->Y; break;
+ case OP65_TXA: Src = &LI->X; Tgt = &LI->A; break;
+ case OP65_TYA: Src = &LI->Y; Tgt = &LI->A; break;
+ case OP65_TSX: ClearLoadRegInfo (&LI->X); return;
+ case OP65_TXS: return;
+ default: Internal ("Unknown XFR insn in TrackLoads");
+ }
+
+ /* If we had a load or xfer op before, this is a duplicate load which
+ ** can cause problems if it encountered between the pushax and the op,
+ ** so remember it.
+ */
+ if (Tgt->LoadIndex >= 0 || Tgt->XferIndex >= 0) {
+ Tgt->Flags |= LI_DUP_LOAD;
+ }
+
+ /* Transfer the data */
+ Tgt->LoadIndex = Src->LoadIndex;
+ Tgt->XferIndex = I;
+ Tgt->Offs = Src->Offs;
+ Tgt->Flags &= ~(LI_DIRECT | LI_RELOAD_Y);
+ Tgt->Flags |= Src->Flags & (LI_DIRECT | LI_RELOAD_Y);
+
+ } else if (CE_IsCallTo (E, "ldaxysp") && RegValIsKnown (E->RI->In.RegY)) {
+
+ /* If we had a load or xfer op before, this is a duplicate load which
+ ** can cause problems if it encountered between the pushax and the op,
+ ** so remember it for both registers involved.
+ */
+ if (LI->A.LoadIndex >= 0 || LI->A.XferIndex >= 0) {
+ LI->A.Flags |= LI_DUP_LOAD;
+ }
+ if (LI->X.LoadIndex >= 0 || LI->X.XferIndex >= 0) {
+ LI->X.Flags |= LI_DUP_LOAD;
+ }
+
+ /* Both registers set, Y changed */
+ LI->A.LoadIndex = I;
+ LI->A.XferIndex = -1;
+ LI->A.Flags |= (LI_DIRECT | LI_RELOAD_Y);
+ LI->A.Offs = (unsigned char) E->RI->In.RegY - 1;
+
+ LI->X.LoadIndex = I;
+ LI->X.XferIndex = -1;
+ LI->X.Flags |= (LI_DIRECT | LI_RELOAD_Y);
+ LI->X.Offs = (unsigned char) E->RI->In.RegY;
+
+ ClearLoadRegInfo (&LI->Y);
+ } else {
+ HonourUseAndChg (&LI->A, REG_A, E);
+ HonourUseAndChg (&LI->X, REG_X, E);
+ HonourUseAndChg (&LI->Y, REG_Y, E);
+ }
+}
+
+
+
+/*****************************************************************************/
+/* Helpers */
+/*****************************************************************************/
+
+
+
+static void InsertEntry (StackOpData* D, CodeEntry* E, int Index)
+/* Insert a new entry. Depending on Index, D->PushIndex and D->OpIndex will
+** be adjusted by this function.
+*/
+{
+ /* Insert the entry into the code segment */
+ CS_InsertEntry (D->Code, E, Index);
+
+ /* Adjust register loads if necessary */
+ AdjustLoadInfo (&D->Lhs, Index, 1);
+ AdjustLoadInfo (&D->Rhs, Index, 1);
+
+ /* Adjust the indices if necessary */
+ if (D->PushEntry && Index <= D->PushIndex) {
+ ++D->PushIndex;
+ }
+ if (D->OpEntry && Index <= D->OpIndex) {
+ ++D->OpIndex;
+ }
+}
+
+
+
+static void DelEntry (StackOpData* D, int Index)
+/* Delete an entry. Depending on Index, D->PushIndex and D->OpIndex will be
+** adjusted by this function, and PushEntry/OpEntry may get invalidated.
+*/
+{
+ /* Delete the entry from the code segment */
+ CS_DelEntry (D->Code, Index);
+
+ /* Adjust register loads if necessary */
+ AdjustLoadInfo (&D->Lhs, Index, -1);
+ AdjustLoadInfo (&D->Rhs, Index, -1);
+
+ /* Adjust the other indices if necessary */
+ if (Index < D->PushIndex) {
+ --D->PushIndex;
+ } else if (Index == D->PushIndex) {
+ D->PushEntry = 0;
+ }
+ if (Index < D->OpIndex) {
+ --D->OpIndex;
+ } else if (Index == D->OpIndex) {
+ D->OpEntry = 0;
+ }
+}
+
+
+
+static void AdjustStackOffset (StackOpData* D, unsigned Offs)
+/* Adjust the offset for all stack accesses in the range PushIndex to OpIndex.
+** OpIndex is adjusted according to the insertions.
+*/
+{
+ /* Walk over all entries */
+ int I = D->PushIndex + 1;
+ while (I < D->OpIndex) {
+
+ CodeEntry* E = CS_GetEntry (D->Code, I);
+
+ int NeedCorrection = 0;
+ if ((E->Use & REG_SP) != 0) {
+
+ /* Check for some things that should not happen */
+ CHECK (E->AM == AM65_ZP_INDY || E->RI->In.RegY >= (short) Offs);
+ CHECK (strcmp (E->Arg, "sp") == 0);
+
+ /* We need to correct this one */
+ NeedCorrection = 1;
+
+ } else if (CE_IsCallTo (E, "ldaxysp")) {
+
+ /* We need to correct this one */
+ NeedCorrection = 1;
+
+ }
+
+ if (NeedCorrection) {
+
+ /* Get the code entry before this one. If it's a LDY, adjust the
+ ** value.
+ */
+ CodeEntry* P = CS_GetPrevEntry (D->Code, I);
+ if (P && P->OPC == OP65_LDY && CE_IsConstImm (P)) {
+
+ /* The Y load is just before the stack access, adjust it */
+ CE_SetNumArg (P, P->Num - Offs);
+
+ } else {
+
+ /* Insert a new load instruction before the stack access */
+ const char* Arg = MakeHexArg (E->RI->In.RegY - Offs);
+ CodeEntry* X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, E->LI);
+ InsertEntry (D, X, I++);
+
+ }
+
+ /* If we need the value of Y later, be sure to reload it */
+ if (RegYUsed (D->Code, I+1)) {
+ const char* Arg = MakeHexArg (E->RI->In.RegY);
+ CodeEntry* X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, E->LI);
+ InsertEntry (D, X, I+1);
+
+ /* Skip this instruction in the next round */
+ ++I;
+ }
+ }
+
+ /* Next entry */
+ ++I;
+ }
+
+ /* If we have rhs load insns that load from stack, we'll have to adjust
+ ** the offsets for these also.
+ */
+ if (D->Rhs.A.Flags & LI_RELOAD_Y) {
+ D->Rhs.A.Offs -= Offs;
+ }
+ if (D->Rhs.X.Flags & LI_RELOAD_Y) {
+ D->Rhs.X.Offs -= Offs;
+ }
+}
+
+
+
+static void AddStoreA (StackOpData* D)
+/* Add a store to zero page after the push insn */
+{
+ CodeEntry* X = NewCodeEntry (OP65_STA, AM65_ZP, D->ZPLo, 0, D->PushEntry->LI);
+ InsertEntry (D, X, D->PushIndex+1);
+}
+
+
+
+static void AddStoreX (StackOpData* D)
+/* Add a store to zero page after the push insn */
+{
+ CodeEntry* X = NewCodeEntry (OP65_STX, AM65_ZP, D->ZPHi, 0, D->PushEntry->LI);
+ InsertEntry (D, X, D->PushIndex+1);
+}
+
+
+
+static void ReplacePushByStore (StackOpData* D)
+/* Replace the call to the push subroutine by a store into the zero page
+** location (actually, the push is not replaced, because we need it for
+** later, but the name is still ok since the push will get removed at the
+** end of each routine).
+*/
+{
+ /* Store the value into the zeropage instead of pushing it. Check high
+ ** byte first so that the store is later in A/X order.
+ */
+ if ((D->Lhs.X.Flags & LI_DIRECT) == 0) {
+ AddStoreX (D);
+ }
+ if ((D->Lhs.A.Flags & LI_DIRECT) == 0) {
+ AddStoreA (D);
+ }
+}
+
+
+
+static void AddOpLow (StackOpData* D, opc_t OPC, LoadInfo* LI)
+/* Add an op for the low byte of an operator. This function honours the
+** OP_DIRECT and OP_RELOAD_Y flags and generates the necessary instructions.
+** All code is inserted at the current insertion point.
+*/
+{
+ CodeEntry* X;
+
+ if ((LI->A.Flags & LI_DIRECT) != 0) {
+ /* Op with a variable location. If the location is on the stack, we
+ ** need to reload the Y register.
+ */
+ if ((LI->A.Flags & LI_RELOAD_Y) == 0) {
+
+ /* opc ... */
+ CodeEntry* LoadA = LI->A.LoadEntry;
+ X = NewCodeEntry (OPC, LoadA->AM, LoadA->Arg, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ } else {
+
+ /* ldy #offs */
+ const char* Arg = MakeHexArg (LI->A.Offs);
+ X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* opc (sp),y */
+ X = NewCodeEntry (OPC, AM65_ZP_INDY, "sp", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ }
+
+ /* In both cases, we can remove the load */
+ LI->A.Flags |= LI_REMOVE;
+
+ } else {
+
+ /* Op with temp storage */
+ X = NewCodeEntry (OPC, AM65_ZP, D->ZPLo, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ }
+}
+
+
+
+static void AddOpHigh (StackOpData* D, opc_t OPC, LoadInfo* LI, int KeepResult)
+/* Add an op for the high byte of an operator. Special cases (constant values
+** or similar) have to be checked separately, the function covers only the
+** generic case. Code is inserted at the insertion point.
+*/
+{
+ CodeEntry* X;
+
+ if (KeepResult) {
+ /* pha */
+ X = NewCodeEntry (OP65_PHA, AM65_IMP, 0, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+ }
+
+ /* txa */
+ X = NewCodeEntry (OP65_TXA, AM65_IMP, 0, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ if ((LI->X.Flags & LI_DIRECT) != 0) {
+
+ if ((LI->X.Flags & LI_RELOAD_Y) == 0) {
+
+ /* opc xxx */
+ CodeEntry* LoadX = LI->X.LoadEntry;
+ X = NewCodeEntry (OPC, LoadX->AM, LoadX->Arg, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ } else {
+
+ /* ldy #const */
+ const char* Arg = MakeHexArg (LI->X.Offs);
+ X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* opc (sp),y */
+ X = NewCodeEntry (OPC, AM65_ZP_INDY, "sp", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+ }
+
+ /* In both cases, we can remove the load */
+ LI->X.Flags |= LI_REMOVE;
+
+ } else {
+ /* opc zphi */
+ X = NewCodeEntry (OPC, AM65_ZP, D->ZPHi, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+ }
+
+ if (KeepResult) {
+ /* tax */
+ X = NewCodeEntry (OP65_TAX, AM65_IMP, 0, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* pla */
+ X = NewCodeEntry (OP65_PLA, AM65_IMP, 0, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+ }
+}
+
+
+
+static void RemoveRegLoads (StackOpData* D, LoadInfo* LI)
+/* Remove register load insns */
+{
+ /* Both registers may be loaded with one insn, but DelEntry will in this
+ ** case clear the other one.
+ */
+ if ((LI->A.Flags & (LI_REMOVE | LI_DONT_REMOVE)) == LI_REMOVE) {
+ if (LI->A.LoadIndex >= 0) {
+ DelEntry (D, LI->A.LoadIndex);
+ }
+ if (LI->A.XferIndex >= 0) {
+ DelEntry (D, LI->A.XferIndex);
+ }
+ }
+ if ((LI->X.Flags & (LI_REMOVE | LI_DONT_REMOVE)) == LI_REMOVE) {
+ if (LI->X.LoadIndex >= 0) {
+ DelEntry (D, LI->X.LoadIndex);
+ }
+ if (LI->X.XferIndex >= 0) {
+ DelEntry (D, LI->X.XferIndex);
+ }
+ }
+}
+
+
+
+static void RemoveRemainders (StackOpData* D)
+/* Remove the code that is unnecessary after translation of the sequence */
+{
+ /* Remove the register loads for lhs and rhs */
+ RemoveRegLoads (D, &D->Lhs);
+ RemoveRegLoads (D, &D->Rhs);
+
+ /* Remove the push and the operator routine */
+ DelEntry (D, D->OpIndex);
+ DelEntry (D, D->PushIndex);
+}
+
+
+
+static int IsRegVar (StackOpData* D)
+/* If the value pushed is that of a zeropage variable, replace ZPLo and ZPHi
+** in the given StackOpData struct by the variable and return true. Otherwise
+** leave D untouched and return false.
+*/
+{
+ CodeEntry* LoadA = D->Lhs.A.LoadEntry;
+ CodeEntry* LoadX = D->Lhs.X.LoadEntry;
+ unsigned Len;
+
+ /* Must have both load insns */
+ if (LoadA == 0 || LoadX == 0) {
+ return 0;
+ }
+
+ /* Must be loads from zp */
+ if (LoadA->AM != AM65_ZP || LoadX->AM != AM65_ZP) {
+ return 0;
+ }
+
+ /* Must be the same zp loc with high byte in X */
+ Len = strlen (LoadA->Arg);
+ if (strncmp (LoadA->Arg, LoadX->Arg, Len) != 0 ||
+ strcmp (LoadX->Arg + Len, "+1") != 0) {
+ return 0;
+ }
+
+ /* Use the zero page location directly */
+ D->ZPLo = LoadA->Arg;
+ D->ZPHi = LoadX->Arg;
+ return 1;
+}
+
+
+
+/*****************************************************************************/
+/* Actual optimization functions */
+/*****************************************************************************/
+
+
+
+static unsigned Opt_toseqax_tosneax (StackOpData* D, const char* BoolTransformer)
+/* Optimize the toseqax and tosneax sequences. */
+{
+ CodeEntry* X;
+ CodeLabel* L;
+
+ /* Create a call to the boolean transformer function and a label for this
+ ** insn. This is needed for all variants. Other insns are inserted *before*
+ ** the call.
+ */
+ X = NewCodeEntry (OP65_JSR, AM65_ABS, BoolTransformer, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->OpIndex + 1);
+ L = CS_GenLabel (D->Code, X);
+
+ /* If the lhs is direct (but not stack relative), encode compares with lhs
+ ** effectively reverting the order (which doesn't matter for ==).
+ */
+ if ((D->Lhs.A.Flags & (LI_DIRECT | LI_RELOAD_Y)) == LI_DIRECT &&
+ (D->Lhs.X.Flags & (LI_DIRECT | LI_RELOAD_Y)) == LI_DIRECT) {
+
+ CodeEntry* LoadX = D->Lhs.X.LoadEntry;
+ CodeEntry* LoadA = D->Lhs.A.LoadEntry;
+
+ D->IP = D->OpIndex+1;
+
+ /* cpx */
+ X = NewCodeEntry (OP65_CPX, LoadX->AM, LoadX->Arg, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* bne L */
+ X = NewCodeEntry (OP65_BNE, AM65_BRA, L->Name, L, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* cmp */
+ X = NewCodeEntry (OP65_CMP, LoadA->AM, LoadA->Arg, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* Lhs load entries can be removed */
+ D->Lhs.X.Flags |= LI_REMOVE;
+ D->Lhs.A.Flags |= LI_REMOVE;
+
+ } else if ((D->Rhs.A.Flags & (LI_DIRECT | LI_RELOAD_Y)) == LI_DIRECT &&
+ (D->Rhs.X.Flags & (LI_DIRECT | LI_RELOAD_Y)) == LI_DIRECT) {
+
+ CodeEntry* LoadX = D->Rhs.X.LoadEntry;
+ CodeEntry* LoadA = D->Rhs.A.LoadEntry;
+
+ D->IP = D->OpIndex+1;
+
+ /* cpx */
+ X = NewCodeEntry (OP65_CPX, LoadX->AM, LoadX->Arg, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* bne L */
+ X = NewCodeEntry (OP65_BNE, AM65_BRA, L->Name, L, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* cmp */
+ X = NewCodeEntry (OP65_CMP, LoadA->AM, LoadA->Arg, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* Rhs load entries can be removed */
+ D->Rhs.X.Flags |= LI_REMOVE;
+ D->Rhs.A.Flags |= LI_REMOVE;
+
+ } else if ((D->Rhs.A.Flags & LI_DIRECT) != 0 &&
+ (D->Rhs.X.Flags & LI_DIRECT) != 0) {
+
+ D->IP = D->OpIndex+1;
+
+ /* Add operand for low byte */
+ AddOpLow (D, OP65_CMP, &D->Rhs);
+
+ /* bne L */
+ X = NewCodeEntry (OP65_BNE, AM65_BRA, L->Name, L, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* Add operand for high byte */
+ AddOpHigh (D, OP65_CMP, &D->Rhs, 0);
+
+ } else {
+
+ /* Save lhs into zeropage, then compare */
+ AddStoreX (D);
+ AddStoreA (D);
+
+ D->IP = D->OpIndex+1;
+
+ /* cpx */
+ X = NewCodeEntry (OP65_CPX, AM65_ZP, D->ZPHi, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* bne L */
+ X = NewCodeEntry (OP65_BNE, AM65_BRA, L->Name, L, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* cmp */
+ X = NewCodeEntry (OP65_CMP, AM65_ZP, D->ZPLo, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ }
+
+ /* Remove the push and the call to the tosgeax function */
+ RemoveRemainders (D);
+
+ /* We changed the sequence */
+ return 1;
+}
+
+
+
+static unsigned Opt_tosshift (StackOpData* D, const char* Name)
+/* Optimize shift sequences. */
+{
+ CodeEntry* X;
+
+ /* Store the value into the zeropage instead of pushing it */
+ ReplacePushByStore (D);
+
+ /* If the lhs is direct (but not stack relative), we can just reload the
+ ** data later.
+ */
+ if ((D->Lhs.A.Flags & (LI_DIRECT | LI_RELOAD_Y)) == LI_DIRECT &&
+ (D->Lhs.X.Flags & (LI_DIRECT | LI_RELOAD_Y)) == LI_DIRECT) {
+
+ CodeEntry* LoadX = D->Lhs.X.LoadEntry;
+ CodeEntry* LoadA = D->Lhs.A.LoadEntry;
+
+ /* Inline the shift */
+ D->IP = D->OpIndex+1;
+
+ /* tay */
+ X = NewCodeEntry (OP65_TAY, AM65_IMP, 0, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* lda */
+ X = NewCodeEntry (OP65_LDA, LoadA->AM, LoadA->Arg, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* ldx */
+ X = NewCodeEntry (OP65_LDX, LoadX->AM, LoadX->Arg, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* Lhs load entries can be removed */
+ D->Lhs.X.Flags |= LI_REMOVE;
+ D->Lhs.A.Flags |= LI_REMOVE;
+
+ } else {
+
+ /* Save lhs into zeropage and reload later */
+ AddStoreX (D);
+ AddStoreA (D);
+
+ /* Be sure to setup IP after adding the stores, otherwise it will get
+ ** messed up.
+ */
+ D->IP = D->OpIndex+1;
+
+ /* tay */
+ X = NewCodeEntry (OP65_TAY, AM65_IMP, 0, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* lda zp */
+ X = NewCodeEntry (OP65_LDA, AM65_ZP, D->ZPLo, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* ldx zp+1 */
+ X = NewCodeEntry (OP65_LDX, AM65_ZP, D->ZPHi, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ }
+
+ /* jsr shlaxy/aslaxy/whatever */
+ X = NewCodeEntry (OP65_JSR, AM65_ABS, Name, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* Remove the push and the call to the shift function */
+ RemoveRemainders (D);
+
+ /* We changed the sequence */
+ return 1;
+}
+
+
+
+static unsigned Opt___bzero (StackOpData* D)
+/* Optimize the __bzero sequence */
+{
+ CodeEntry* X;
+ const char* Arg;
+ CodeLabel* L;
+
+ /* Check if we're using a register variable */
+ if (!IsRegVar (D)) {
+ /* Store the value into the zeropage instead of pushing it */
+ AddStoreX (D);
+ AddStoreA (D);
+ }
+
+ /* If the return value of __bzero is used, we have to add code to reload
+ ** a/x from the pointer variable.
+ */
+ if (RegAXUsed (D->Code, D->OpIndex+1)) {
+ X = NewCodeEntry (OP65_LDA, AM65_ZP, D->ZPLo, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->OpIndex+1);
+ X = NewCodeEntry (OP65_LDX, AM65_ZP, D->ZPHi, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->OpIndex+2);
+ }
+
+ /* X is always zero, A contains the size of the data area to zero.
+ ** Note: A may be zero, in which case the operation is null op.
+ */
+ if (D->OpEntry->RI->In.RegA != 0) {
+
+ /* lda #$00 */
+ X = NewCodeEntry (OP65_LDA, AM65_IMM, "$00", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->OpIndex+1);
+
+ /* The value of A is known */
+ if (D->OpEntry->RI->In.RegA <= 0x81) {
+
+ /* Loop using the sign bit */
+
+ /* ldy #count-1 */
+ Arg = MakeHexArg (D->OpEntry->RI->In.RegA - 1);
+ X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->OpIndex+2);
+
+ /* L: sta (zp),y */
+ X = NewCodeEntry (OP65_STA, AM65_ZP_INDY, D->ZPLo, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->OpIndex+3);
+ L = CS_GenLabel (D->Code, X);
+
+ /* dey */
+ X = NewCodeEntry (OP65_DEY, AM65_IMP, 0, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->OpIndex+4);
+
+ /* bpl L */
+ X = NewCodeEntry (OP65_BPL, AM65_BRA, L->Name, L, D->OpEntry->LI);
+ InsertEntry (D, X, D->OpIndex+5);
+
+ } else {
+
+ /* Loop using an explicit compare */
+
+ /* ldy #$00 */
+ X = NewCodeEntry (OP65_LDY, AM65_IMM, "$00", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->OpIndex+2);
+
+ /* L: sta (zp),y */
+ X = NewCodeEntry (OP65_STA, AM65_ZP_INDY, D->ZPLo, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->OpIndex+3);
+ L = CS_GenLabel (D->Code, X);
+
+ /* iny */
+ X = NewCodeEntry (OP65_INY, AM65_IMP, 0, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->OpIndex+4);
+
+ /* cpy #count */
+ Arg = MakeHexArg (D->OpEntry->RI->In.RegA);
+ X = NewCodeEntry (OP65_CPY, AM65_IMM, Arg, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->OpIndex+5);
+
+ /* bne L */
+ X = NewCodeEntry (OP65_BNE, AM65_BRA, L->Name, L, D->OpEntry->LI);
+ InsertEntry (D, X, D->OpIndex+6);
+ }
+
+ }
+
+ /* Remove the push and the call to the __bzero function */
+ RemoveRemainders (D);
+
+ /* We changed the sequence */
+ return 1;
+}
+
+
+
+static unsigned Opt_staspidx (StackOpData* D)
+/* Optimize the staspidx sequence */
+{
+ CodeEntry* X;
+
+ /* Check if we're using a register variable */
+ if (!IsRegVar (D)) {
+ /* Store the value into the zeropage instead of pushing it */
+ AddStoreX (D);
+ AddStoreA (D);
+ }
+
+ /* Replace the store subroutine call by a direct op */
+ X = NewCodeEntry (OP65_STA, AM65_ZP_INDY, D->ZPLo, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->OpIndex+1);
+
+ /* Remove the push and the call to the staspidx function */
+ RemoveRemainders (D);
+
+ /* We changed the sequence */
+ return 1;
+}
+
+
+
+static unsigned Opt_staxspidx (StackOpData* D)
+/* Optimize the staxspidx sequence */
+{
+ CodeEntry* X;
+
+ /* Check if we're using a register variable */
+ if (!IsRegVar (D)) {
+ /* Store the value into the zeropage instead of pushing it */
+ AddStoreX (D);
+ AddStoreA (D);
+ }
+
+ /* Inline the store */
+
+ /* sta (zp),y */
+ X = NewCodeEntry (OP65_STA, AM65_ZP_INDY, D->ZPLo, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->OpIndex+1);
+
+ if (RegValIsKnown (D->OpEntry->RI->In.RegY)) {
+ /* Value of Y is known */
+ const char* Arg = MakeHexArg (D->OpEntry->RI->In.RegY + 1);
+ X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, D->OpEntry->LI);
+ } else {
+ X = NewCodeEntry (OP65_INY, AM65_IMP, 0, 0, D->OpEntry->LI);
+ }
+ InsertEntry (D, X, D->OpIndex+2);
+
+ if (RegValIsKnown (D->OpEntry->RI->In.RegX)) {
+ /* Value of X is known */
+ const char* Arg = MakeHexArg (D->OpEntry->RI->In.RegX);
+ X = NewCodeEntry (OP65_LDA, AM65_IMM, Arg, 0, D->OpEntry->LI);
+ } else {
+ /* Value unknown */
+ X = NewCodeEntry (OP65_TXA, AM65_IMP, 0, 0, D->OpEntry->LI);
+ }
+ InsertEntry (D, X, D->OpIndex+3);
+
+ /* sta (zp),y */
+ X = NewCodeEntry (OP65_STA, AM65_ZP_INDY, D->ZPLo, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->OpIndex+4);
+
+ /* If we remove staxspidx, we must restore the Y register to what the
+ ** function would return.
+ */
+ X = NewCodeEntry (OP65_LDY, AM65_IMM, "$00", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->OpIndex+5);
+
+ /* Remove the push and the call to the staxspidx function */
+ RemoveRemainders (D);
+
+ /* We changed the sequence */
+ return 1;
+}
+
+
+
+static unsigned Opt_tosaddax (StackOpData* D)
+/* Optimize the tosaddax sequence */
+{
+ CodeEntry* X;
+ CodeEntry* N;
+
+ /* We need the entry behind the add */
+ CHECK (D->NextEntry != 0);
+
+ /* Check if the X register is known and zero when the add is done, and
+ ** if the add is followed by
+ **
+ ** ldy #$00
+ ** jsr ldauidx ; or ldaidx
+ **
+ ** If this is true, the addition does actually add an offset to a pointer
+ ** before it is dereferenced. Since both subroutines take an offset in Y,
+ ** we can pass the offset (instead of #$00) and remove the addition
+ ** alltogether.
+ */
+ if (D->OpEntry->RI->In.RegX == 0 &&
+ D->NextEntry->OPC == OP65_LDY &&
+ CE_IsKnownImm (D->NextEntry, 0) &&
+ !CE_HasLabel (D->NextEntry) &&
+ (N = CS_GetNextEntry (D->Code, D->OpIndex + 1)) != 0 &&
+ (CE_IsCallTo (N, "ldauidx") ||
+ CE_IsCallTo (N, "ldaidx"))) {
+
+ int Signed = (strcmp (N->Arg, "ldaidx") == 0);
+
+ /* Store the value into the zeropage instead of pushing it */
+ AddStoreX (D);
+ AddStoreA (D);
+
+ /* Replace the ldy by a tay. Be sure to create the new entry before
+ ** deleting the ldy, since we will reference the line info from this
+ ** insn.
+ */
+ X = NewCodeEntry (OP65_TAY, AM65_IMP, 0, 0, D->NextEntry->LI);
+ DelEntry (D, D->OpIndex + 1);
+ InsertEntry (D, X, D->OpIndex + 1);
+
+ /* Replace the call to ldaidx/ldauidx. Since X is already zero, and
+ ** the ptr is in the zero page location, we just need to load from
+ ** the pointer, and fix X in case of ldaidx.
+ */
+ X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, D->ZPLo, 0, N->LI);
+ DelEntry (D, D->OpIndex + 2);
+ InsertEntry (D, X, D->OpIndex + 2);
+ if (Signed) {
+
+ CodeLabel* L;
+
+ /* Add sign extension - N is unused now */
+ N = CS_GetNextEntry (D->Code, D->OpIndex + 2);
+ CHECK (N != 0);
+ L = CS_GenLabel (D->Code, N);
+
+ X = NewCodeEntry (OP65_BPL, AM65_BRA, L->Name, L, X->LI);
+ InsertEntry (D, X, D->OpIndex + 3);
+
+ X = NewCodeEntry (OP65_DEX, AM65_IMP, 0, 0, X->LI);
+ InsertEntry (D, X, D->OpIndex + 4);
+ }
+
+ } else {
+
+ /* Store the value into the zeropage instead of pushing it */
+ ReplacePushByStore (D);
+
+ /* Inline the add */
+ D->IP = D->OpIndex+1;
+
+ /* clc */
+ X = NewCodeEntry (OP65_CLC, AM65_IMP, 0, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* Low byte */
+ AddOpLow (D, OP65_ADC, &D->Lhs);
+
+ /* High byte */
+ if (D->PushEntry->RI->In.RegX == 0) {
+
+ /* The high byte is the value in X plus the carry */
+ CodeLabel* L = CS_GenLabel (D->Code, D->NextEntry);
+
+ /* bcc L */
+ X = NewCodeEntry (OP65_BCC, AM65_BRA, L->Name, L, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* inx */
+ X = NewCodeEntry (OP65_INX, AM65_IMP, 0, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ } else if (D->OpEntry->RI->In.RegX == 0 &&
+ (RegValIsKnown (D->PushEntry->RI->In.RegX) ||
+ (D->Lhs.X.Flags & LI_RELOAD_Y) == 0)) {
+
+ /* The high byte is that of the first operand plus carry */
+ CodeLabel* L;
+ if (RegValIsKnown (D->PushEntry->RI->In.RegX)) {
+ /* Value of first op high byte is known */
+ const char* Arg = MakeHexArg (D->PushEntry->RI->In.RegX);
+ X = NewCodeEntry (OP65_LDX, AM65_IMM, Arg, 0, D->OpEntry->LI);
+ } else {
+ /* Value of first op high byte is unknown. Load from ZP or
+ ** original storage.
+ */
+ if (D->Lhs.X.Flags & LI_DIRECT) {
+ CodeEntry* LoadX = D->Lhs.X.LoadEntry;
+ X = NewCodeEntry (OP65_LDX, LoadX->AM, LoadX->Arg, 0, D->OpEntry->LI);
+ } else {
+ X = NewCodeEntry (OP65_LDX, AM65_ZP, D->ZPHi, 0, D->OpEntry->LI);
+ }
+ }
+ InsertEntry (D, X, D->IP++);
+
+ /* bcc label */
+ L = CS_GenLabel (D->Code, D->NextEntry);
+ X = NewCodeEntry (OP65_BCC, AM65_BRA, L->Name, L, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* inx */
+ X = NewCodeEntry (OP65_INX, AM65_IMP, 0, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+ } else {
+ /* High byte is unknown */
+ AddOpHigh (D, OP65_ADC, &D->Lhs, 1);
+ }
+ }
+
+ /* Remove the push and the call to the tosaddax function */
+ RemoveRemainders (D);
+
+ /* We changed the sequence */
+ return 1;
+}
+
+
+
+static unsigned Opt_tosandax (StackOpData* D)
+/* Optimize the tosandax sequence */
+{
+ /* Store the value into the zeropage instead of pushing it */
+ ReplacePushByStore (D);
+
+ /* Inline the and, low byte */
+ D->IP = D->OpIndex + 1;
+ AddOpLow (D, OP65_AND, &D->Lhs);
+
+ /* High byte */
+ AddOpHigh (D, OP65_AND, &D->Lhs, 1);
+
+ /* Remove the push and the call to the tosandax function */
+ RemoveRemainders (D);
+
+ /* We changed the sequence */
+ return 1;
+}
-/*****************************************************************************/
-/* Helpers */
-/*****************************************************************************/
+static unsigned Opt_tosaslax (StackOpData* D)
+/* Optimize the tosaslax sequence */
+{
+ return Opt_tosshift (D, "aslaxy");
+}
-static unsigned AdjustStackOffset (CodeSeg* S, unsigned Start, unsigned Stop,
- unsigned Offs)
-/* Adjust the offset for all stack accesses in the range Start to Stop, both
- * inclusive. The function returns the number of instructions that have been
- * inserted.
- */
+static unsigned Opt_tosasrax (StackOpData* D)
+/* Optimize the tosasrax sequence */
{
- /* Number of inserted instructions */
- unsigned Inserted = 0;
-
- /* Walk over all entries */
- unsigned I = Start;
- while (I <= Stop) {
-
- CodeEntry* E = CS_GetEntry (S, I);
+ return Opt_tosshift (D, "asraxy");
+}
- int NeedCorrection = 0;
- if ((E->Use & REG_SP) != 0) {
- /* Check for some things that should not happen */
- CHECK (E->AM == AM65_ZP_INDY || E->RI->In.RegY >= (short) Offs);
- CHECK (strcmp (E->Arg, "sp") == 0);
- /* We need to correct this one */
- NeedCorrection = 1;
+static unsigned Opt_toseqax (StackOpData* D)
+/* Optimize the toseqax sequence */
+{
+ return Opt_toseqax_tosneax (D, "booleq");
+}
- } else if (CE_IsCallTo (E, "ldaxysp")) {
- /* We need to correct this one */
- NeedCorrection = 1;
- }
+static unsigned Opt_tosgeax (StackOpData* D)
+/* Optimize the tosgeax sequence */
+{
+ CodeEntry* X;
+ CodeLabel* L;
- if (NeedCorrection) {
+ /* Inline the sbc */
+ D->IP = D->OpIndex+1;
- CodeEntry* P;
+ /* Must be true because of OP_RHS_LOAD */
+ CHECK ((D->Rhs.A.Flags & D->Rhs.X.Flags & LI_DIRECT) != 0);
- /* Get the code entry before this one. If it's a LDY, adjust the
- * value.
- */
- P = CS_GetPrevEntry (S, I);
- if (P && P->OPC == OP65_LDY && CE_KnownImm (P)) {
+ /* Add code for low operand */
+ AddOpLow (D, OP65_CMP, &D->Rhs);
- /* The Y load is just before the stack access, adjust it */
- CE_SetNumArg (P, P->Num - Offs);
+ /* Add code for high operand */
+ AddOpHigh (D, OP65_SBC, &D->Rhs, 0);
- } else {
+ /* eor #$80 */
+ X = NewCodeEntry (OP65_EOR, AM65_IMM, "$80", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
- /* Insert a new load instruction before the stack access */
- const char* Arg = MakeHexArg (E->RI->In.RegY - Offs);
- CodeEntry* X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, E->LI);
- CS_InsertEntry (S, X, I);
+ /* asl a */
+ X = NewCodeEntry (OP65_ASL, AM65_ACC, "a", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+ L = CS_GenLabel (D->Code, X);
- /* One more inserted entries */
- ++Inserted;
- ++Stop;
+ /* Insert a bvs L before the eor insn */
+ X = NewCodeEntry (OP65_BVS, AM65_BRA, L->Name, L, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP - 2);
+ ++D->IP;
- /* Be sure to skip the stack access for the next round */
- ++I;
+ /* lda #$00 */
+ X = NewCodeEntry (OP65_LDA, AM65_IMM, "$00", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
- }
+ /* ldx #$00 */
+ X = NewCodeEntry (OP65_LDX, AM65_IMM, "$00", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
- }
+ /* rol a */
+ X = NewCodeEntry (OP65_ROL, AM65_ACC, "a", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
- /* Next entry */
- ++I;
- }
+ /* Remove the push and the call to the tosgeax function */
+ RemoveRemainders (D);
- /* Return the number of inserted entries */
- return Inserted;
+ /* We changed the sequence */
+ return 1;
}
-static void InsertEntry (StackOpData* D, CodeEntry* E, unsigned Index)
-/* Insert a new entry. Depending on Index, D->PushIndex and D->OpIndex will
- * be adjusted by this function.
- */
+static unsigned Opt_tosltax (StackOpData* D)
+/* Optimize the tosltax sequence */
{
- /* Insert the entry into the code segment */
- CS_InsertEntry (D->Code, E, Index);
+ CodeEntry* X;
+ CodeLabel* L;
- /* Adjust the indices if necessary */
- if (D->PushEntry && Index <= D->PushIndex) {
- ++D->PushIndex;
- }
- if (D->OpEntry && Index <= D->OpIndex) {
- ++D->OpIndex;
- }
-}
+ /* Inline the compare */
+ D->IP = D->OpIndex+1;
+ /* Must be true because of OP_RHS_LOAD */
+ CHECK ((D->Rhs.A.Flags & D->Rhs.X.Flags & LI_DIRECT) != 0);
-static void DelEntry (StackOpData* D, unsigned Index)
-/* Delete an entry. Depending on Index, D->PushIndex and D->OpIndex will be
- * adjusted by this function, and PushEntry/OpEntry may get invalidated.
- */
-{
- /* Delete the entry from the code segment */
- CS_DelEntry (D->Code, Index);
+ /* Add code for low operand */
+ AddOpLow (D, OP65_CMP, &D->Rhs);
- /* Adjust the indices if necessary */
- if (Index < D->PushIndex) {
- --D->PushIndex;
- } else if (Index == D->PushIndex) {
- D->PushEntry = 0;
- }
- if (Index < D->OpIndex) {
- --D->OpIndex;
- } else if (Index == D->OpIndex) {
- D->OpEntry = 0;
- }
-}
+ /* Add code for high operand */
+ AddOpHigh (D, OP65_SBC, &D->Rhs, 0);
+ /* eor #$80 */
+ X = NewCodeEntry (OP65_EOR, AM65_IMM, "$80", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+ /* asl a */
+ X = NewCodeEntry (OP65_ASL, AM65_ACC, "a", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+ L = CS_GenLabel (D->Code, X);
-static void CheckDirectOp (StackOpData* D)
-/* Check if the given entry is a lda instruction with an addressing mode
- * that allows us to replace it by another operation (like ora). If so, we may
- * use this location for the or and must not save the value in the zero
- * page location.
- */
-{
- /* We need the entry before the push */
- CodeEntry* E;
- CHECK ((E = D->PrevEntry) != 0);
+ /* Insert a bvc L before the eor insn */
+ X = NewCodeEntry (OP65_BVC, AM65_BRA, L->Name, L, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP - 2);
+ ++D->IP;
- if (E->OPC == OP65_LDA) {
- if (E->AM == AM65_IMM || E->AM == AM65_ZP || E->AM == AM65_ABS) {
- /* These insns are all ok and replaceable */
- D->Flags |= OP_DIRECT;
- } else if (E->AM == AM65_ZP_INDY && RegValIsKnown (E->RI->In.RegY)) {
- /* Load indirect with known offset is also ok */
- D->Flags |= (OP_DIRECT | OP_RELOAD_Y);
- }
- }
-}
+ /* lda #$00 */
+ X = NewCodeEntry (OP65_LDA, AM65_IMM, "$00", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+ /* ldx #$00 */
+ X = NewCodeEntry (OP65_LDX, AM65_IMM, "$00", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+ /* rol a */
+ X = NewCodeEntry (OP65_ROL, AM65_ACC, "a", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
-static void ReplacePushByStore (StackOpData* D)
-/* Replace the call to the push subroutine by a store into the zero page
- * location (actually, the push is not replaced, because we need it for
- * later, but the name is still ok since the push will get removed at the
- * end of each routine).
- */
-{
- CodeEntry* X;
+ /* Remove the push and the call to the tosltax function */
+ RemoveRemainders (D);
- /* Store the value into the zeropage instead of pushing it */
- X = NewCodeEntry (OP65_STX, AM65_ZP, D->ZPHi, 0, D->PushEntry->LI);
- InsertEntry (D, X, D->PushIndex+1);
- if ((D->Flags & OP_DIRECT) == 0) {
- X = NewCodeEntry (OP65_STA, AM65_ZP, D->ZPLo, 0, D->PushEntry->LI);
- InsertEntry (D, X, D->PushIndex+1);
- }
+ /* We changed the sequence */
+ return 1;
}
-static void AddOpLow (StackOpData* D, opc_t OPC)
-/* Add an op for the low byte of an operator. This function honours the
- * OP_DIRECT and OP_RELOAD_Y flags and generates the necessary instructions.
- * All code is inserted at the current insertion point.
- */
+static unsigned Opt_tosneax (StackOpData* D)
+/* Optimize the tosneax sequence */
{
- CodeEntry* X;
-
- if ((D->Flags & OP_DIRECT) != 0) {
- /* Op with a variable location. If the location is on the stack, we
- * need to reload the Y register.
- */
- if ((D->Flags & OP_RELOAD_Y) != 0) {
- const char* Arg = MakeHexArg (D->PrevEntry->RI->In.RegY);
- X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, D->OpEntry->LI);
- InsertEntry (D, X, D->IP++);
- }
- X = NewCodeEntry (OPC, D->PrevEntry->AM, D->PrevEntry->Arg, 0, D->OpEntry->LI);
- } else {
- /* Op with temp storage */
- X = NewCodeEntry (OPC, AM65_ZP, D->ZPLo, 0, D->OpEntry->LI);
- }
- InsertEntry (D, X, D->IP++);
+ return Opt_toseqax_tosneax (D, "boolne");
}
-static void AddOpHigh (StackOpData* D, opc_t OPC)
-/* Add an op for the high byte of an operator. Special cases (constant values
- * or similar have to be checked separately, the function covers only the
- * generic case. Code is inserted at the insertion point.
- */
+static unsigned Opt_tosorax (StackOpData* D)
+/* Optimize the tosorax sequence */
{
- CodeEntry* X;
+ /* Store the value into the zeropage instead of pushing it */
+ ReplacePushByStore (D);
- /* High byte is unknown */
- X = NewCodeEntry (OP65_STA, AM65_ZP, D->ZPLo, 0, D->OpEntry->LI);
- InsertEntry (D, X, D->IP++);
- X = NewCodeEntry (OP65_TXA, AM65_IMP, 0, 0, D->OpEntry->LI);
- InsertEntry (D, X, D->IP++);
- X = NewCodeEntry (OPC, AM65_ZP, D->ZPHi, 0, D->OpEntry->LI);
- InsertEntry (D, X, D->IP++);
- X = NewCodeEntry (OP65_TAX, AM65_IMP, 0, 0, D->OpEntry->LI);
- InsertEntry (D, X, D->IP++);
- X = NewCodeEntry (OP65_LDA, AM65_ZP, D->ZPLo, 0, D->OpEntry->LI);
- InsertEntry (D, X, D->IP++);
-}
+ /* Inline the or, low byte */
+ D->IP = D->OpIndex + 1;
+ AddOpLow (D, OP65_ORA, &D->Lhs);
+ /* High byte */
+ AddOpHigh (D, OP65_ORA, &D->Lhs, 1);
+ /* Remove the push and the call to the tosorax function */
+ RemoveRemainders (D);
-static void RemovePushAndOp (StackOpData* D)
-/* Remove the call to pushax and the call to the operator subroutine */
-{
- DelEntry (D, D->OpIndex);
- DelEntry (D, D->PushIndex);
+ /* We changed the sequence */
+ return 1;
}
-static const char* IsRegVar (const StackOpData* D)
-/* If the value pushed is that of a register variable, return the name of the
- * entry in the register bank. Otherwise return NULL.
- */
+static unsigned Opt_tosshlax (StackOpData* D)
+/* Optimize the tosshlax sequence */
{
- CodeEntry* P;
-
- if (D->PushIndex >= 2 &&
- (P = D->PrevEntry) != 0 &&
- P->OPC == OP65_LDX &&
- P->AM == AM65_ZP &&
- strncmp (P->Arg, "regbank+", 7) == 0 &&
- isdigit (P->Arg[8]) &&
- (P = CS_GetEntry (D->Code, D->PushIndex-2)) != 0 &&
- P->OPC == OP65_LDA &&
- P->AM == AM65_ZP &&
- strncmp (P->Arg, "regbank+", 7) == 0 &&
- isdigit (P->Arg[8])) {
- /* Ok, it loads the register variable */
- return P->Arg;
- } else {
- return 0;
- }
+ return Opt_tosshift (D, "shlaxy");
}
-/*****************************************************************************/
-/* Actual optimization functions */
-/*****************************************************************************/
+static unsigned Opt_tosshrax (StackOpData* D)
+/* Optimize the tosshrax sequence */
+{
+ return Opt_tosshift (D, "shraxy");
+}
-static unsigned Opt_staspidx (StackOpData* D)
-/* Optimize the staspidx sequence if possible */
+static unsigned Opt_tossubax (StackOpData* D)
+/* Optimize the tossubax sequence. Note: subtraction is not commutative! */
{
- CodeEntry* X;
- const char* ZPLo;
+ CodeEntry* X;
- /* Check if we're using a register variable */
- if ((ZPLo = IsRegVar (D)) == 0) {
- /* Store the value into the zeropage instead of pushing it */
- ReplacePushByStore (D);
+ /* Inline the sbc */
+ D->IP = D->OpIndex+1;
- /* Use the given zero page loc */
- ZPLo = D->ZPLo;
- }
+ /* sec */
+ X = NewCodeEntry (OP65_SEC, AM65_IMP, 0, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
- /* Replace the store subroutine call by a direct op */
- X = NewCodeEntry (OP65_STA, AM65_ZP_INDY, ZPLo, 0, D->OpEntry->LI);
- InsertEntry (D, X, D->OpIndex+1);
+ /* Must be true because of OP_RHS_LOAD */
+ CHECK ((D->Rhs.A.Flags & D->Rhs.X.Flags & LI_DIRECT) != 0);
- /* Remove the push and the call to the staspidx function */
- RemovePushAndOp (D);
+ /* Add code for low operand */
+ AddOpLow (D, OP65_SBC, &D->Rhs);
+
+ /* Add code for high operand */
+ AddOpHigh (D, OP65_SBC, &D->Rhs, 1);
+
+ /* Remove the push and the call to the tossubax function */
+ RemoveRemainders (D);
/* We changed the sequence */
return 1;
-static unsigned Opt_staxspidx (StackOpData* D)
-/* Optimize the staxspidx sequence if possible */
+static unsigned Opt_tosugeax (StackOpData* D)
+/* Optimize the tosugeax sequence */
{
- CodeEntry* X;
- const char* ZPLo;
+ CodeEntry* X;
- /* Check if we're using a register variable */
- if ((ZPLo = IsRegVar (D)) == 0) {
- /* Store the value into the zeropage instead of pushing it */
- ReplacePushByStore (D);
+ /* Inline the sbc */
+ D->IP = D->OpIndex+1;
- /* Use the given zero page loc */
- ZPLo = D->ZPLo;
- }
+ /* Must be true because of OP_RHS_LOAD */
+ CHECK ((D->Rhs.A.Flags & D->Rhs.X.Flags & LI_DIRECT) != 0);
- /* Inline the store */
- X = NewCodeEntry (OP65_STA, AM65_ZP_INDY, ZPLo, 0, D->OpEntry->LI);
- InsertEntry (D, X, D->OpIndex+1);
- X = NewCodeEntry (OP65_INY, AM65_IMP, 0, 0, D->OpEntry->LI);
- InsertEntry (D, X, D->OpIndex+2);
- if (RegValIsKnown (D->OpEntry->RI->In.RegX)) {
- /* Value of X is known */
- const char* Arg = MakeHexArg (D->OpEntry->RI->In.RegX);
- X = NewCodeEntry (OP65_LDA, AM65_IMM, Arg, 0, D->OpEntry->LI);
- } else {
- /* Value unknown */
- X = NewCodeEntry (OP65_TXA, AM65_IMP, 0, 0, D->OpEntry->LI);
- }
- InsertEntry (D, X, D->OpIndex+3);
- X = NewCodeEntry (OP65_STA, AM65_ZP_INDY, ZPLo, 0, D->OpEntry->LI);
- InsertEntry (D, X, D->OpIndex+4);
+ /* Add code for low operand */
+ AddOpLow (D, OP65_CMP, &D->Rhs);
- /* Remove the push and the call to the staspidx function */
- RemovePushAndOp (D);
+ /* Add code for high operand */
+ AddOpHigh (D, OP65_SBC, &D->Rhs, 0);
+
+ /* lda #$00 */
+ X = NewCodeEntry (OP65_LDA, AM65_IMM, "$00", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* ldx #$00 */
+ X = NewCodeEntry (OP65_LDX, AM65_IMM, "$00", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* rol a */
+ X = NewCodeEntry (OP65_ROL, AM65_ACC, "a", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* Remove the push and the call to the tosugeax function */
+ RemoveRemainders (D);
/* We changed the sequence */
return 1;
-static unsigned Opt_tosaddax (StackOpData* D)
-/* Optimize the tosaddax sequence if possible */
+static unsigned Opt_tosugtax (StackOpData* D)
+/* Optimize the tosugtax sequence */
{
CodeEntry* X;
- /* We need the entry behind the add */
- CHECK (D->NextEntry != 0);
+ /* Inline the sbc */
+ D->IP = D->OpIndex+1;
- /* Check the entry before the push. If it's a lda instruction with an
- * addressing mode that allows us to replace it, we may use this
- * location for the op and must not save the value in the zero page
- * location.
- */
- CheckDirectOp (D);
+ /* Must be true because of OP_RHS_LOAD */
+ CHECK ((D->Rhs.A.Flags & D->Rhs.X.Flags & LI_DIRECT) != 0);
- /* Store the value into the zeropage instead of pushing it */
- ReplacePushByStore (D);
+ /* sec */
+ X = NewCodeEntry (OP65_SEC, AM65_IMP, 0, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
- /* Inline the add */
- D->IP = D->OpIndex+1;
- X = NewCodeEntry (OP65_CLC, AM65_IMP, 0, 0, D->OpEntry->LI);
+ /* Add code for low operand */
+ AddOpLow (D, OP65_SBC, &D->Rhs);
+
+ /* We need the zero flag, so remember the immediate result */
+ X = NewCodeEntry (OP65_STA, AM65_ZP, "tmp1", 0, D->OpEntry->LI);
InsertEntry (D, X, D->IP++);
- /* Low byte */
- AddOpLow (D, OP65_ADC);
+ /* Add code for high operand */
+ AddOpHigh (D, OP65_SBC, &D->Rhs, 0);
- /* High byte */
- if (D->PushEntry->RI->In.RegX == 0) {
- /* The high byte is the value in X plus the carry */
- CodeLabel* L = CS_GenLabel (D->Code, D->NextEntry);
- X = NewCodeEntry (OP65_BCC, AM65_BRA, L->Name, L, D->OpEntry->LI);
- InsertEntry (D, X, D->IP++);
- X = NewCodeEntry (OP65_INX, AM65_IMP, 0, 0, D->OpEntry->LI);
- InsertEntry (D, X, D->IP++);
- } else if (D->OpEntry->RI->In.RegX == 0) {
- /* The high byte is that of the first operand plus carry */
- CodeLabel* L;
- if (RegValIsKnown (D->PushEntry->RI->In.RegX)) {
- /* Value of first op high byte is known */
- const char* Arg = MakeHexArg (D->PushEntry->RI->In.RegX);
- X = NewCodeEntry (OP65_LDX, AM65_IMM, Arg, 0, D->OpEntry->LI);
- } else {
- /* Value of first op high byte is unknown */
- X = NewCodeEntry (OP65_LDX, AM65_ZP, D->ZPHi, 0, D->OpEntry->LI);
- }
- InsertEntry (D, X, D->IP++);
- L = CS_GenLabel (D->Code, D->NextEntry);
- X = NewCodeEntry (OP65_BCC, AM65_BRA, L->Name, L, D->OpEntry->LI);
- InsertEntry (D, X, D->IP++);
- X = NewCodeEntry (OP65_INX, AM65_IMP, 0, 0, D->OpEntry->LI);
- InsertEntry (D, X, D->IP++);
- } else {
- /* High byte is unknown */
- AddOpHigh (D, OP65_ADC);
- }
+ /* Set Z flag */
+ X = NewCodeEntry (OP65_ORA, AM65_ZP, "tmp1", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
- /* Remove the push and the call to the tosaddax function */
- RemovePushAndOp (D);
+ /* Transform to boolean */
+ X = NewCodeEntry (OP65_JSR, AM65_ABS, "boolugt", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* Remove the push and the call to the operator function */
+ RemoveRemainders (D);
/* We changed the sequence */
return 1;
-static unsigned Opt_tosandax (StackOpData* D)
-/* Optimize the tosandax sequence if possible */
+static unsigned Opt_tosuleax (StackOpData* D)
+/* Optimize the tosuleax sequence */
{
CodeEntry* X;
- /* Check the entry before the push. If it's a lda instruction with an
- * addressing mode that allows us to replace it, we may use this
- * location for the op and must not save the value in the zero page
- * location.
- */
- CheckDirectOp (D);
- /* Store the value into the zeropage instead of pushing it */
- ReplacePushByStore (D);
+ /* Inline the sbc */
+ D->IP = D->OpIndex+1;
- /* Inline the and, low byte */
- D->IP = D->OpIndex + 1;
- AddOpLow (D, OP65_AND);
+ /* Must be true because of OP_RHS_LOAD */
+ CHECK ((D->Rhs.A.Flags & D->Rhs.X.Flags & LI_DIRECT) != 0);
- /* High byte */
- if (D->PushEntry->RI->In.RegX == 0 || D->OpEntry->RI->In.RegX == 0) {
- /* The high byte is zero */
- X = NewCodeEntry (OP65_LDX, AM65_IMM, "$00", 0, D->OpEntry->LI);
- InsertEntry (D, X, D->IP++);
- } else {
- /* High byte is unknown */
- AddOpHigh (D, OP65_AND);
- }
+ /* sec */
+ X = NewCodeEntry (OP65_SEC, AM65_IMP, 0, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
- /* Remove the push and the call to the tosandax function */
- RemovePushAndOp (D);
+ /* Add code for low operand */
+ AddOpLow (D, OP65_SBC, &D->Rhs);
+
+ /* We need the zero flag, so remember the immediate result */
+ X = NewCodeEntry (OP65_STA, AM65_ZP, "tmp1", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* Add code for high operand */
+ AddOpHigh (D, OP65_SBC, &D->Rhs, 0);
+
+ /* Set Z flag */
+ X = NewCodeEntry (OP65_ORA, AM65_ZP, "tmp1", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* Transform to boolean */
+ X = NewCodeEntry (OP65_JSR, AM65_ABS, "boolule", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* Remove the push and the call to the operator function */
+ RemoveRemainders (D);
/* We changed the sequence */
return 1;
-static unsigned Opt_tosorax (StackOpData* D)
-/* Optimize the tosorax sequence if possible */
+static unsigned Opt_tosultax (StackOpData* D)
+/* Optimize the tosultax sequence */
{
CodeEntry* X;
- /* Check the entry before the push. If it's a lda instruction with an
- * addressing mode that allows us to replace it, we may use this
- * location for the op and must not save the value in the zero page
- * location.
- */
- CheckDirectOp (D);
- /* Store the value into the zeropage instead of pushing it */
- ReplacePushByStore (D);
+ /* Inline the sbc */
+ D->IP = D->OpIndex+1;
- /* Inline the or, low byte */
- D->IP = D->OpIndex + 1;
- AddOpLow (D, OP65_ORA);
+ /* Must be true because of OP_RHS_LOAD */
+ CHECK ((D->Rhs.A.Flags & D->Rhs.X.Flags & LI_DIRECT) != 0);
- /* High byte */
- if (RegValIsKnown (D->PushEntry->RI->In.RegX) &&
- RegValIsKnown (D->OpEntry->RI->In.RegX)) {
- /* Both values known, precalculate the result */
- const char* Arg = MakeHexArg (D->PushEntry->RI->In.RegX | D->OpEntry->RI->In.RegX);
- X = NewCodeEntry (OP65_LDX, AM65_IMM, Arg, 0, D->OpEntry->LI);
- InsertEntry (D, X, D->IP++);
- } else if (D->PushEntry->RI->In.RegX != 0) {
- /* High byte is unknown */
- AddOpHigh (D, OP65_ORA);
- }
+ /* Add code for low operand */
+ AddOpLow (D, OP65_CMP, &D->Rhs);
- /* Remove the push and the call to the tosorax function */
- RemovePushAndOp (D);
+ /* Add code for high operand */
+ AddOpHigh (D, OP65_SBC, &D->Rhs, 0);
+
+ /* Transform to boolean */
+ X = NewCodeEntry (OP65_JSR, AM65_ABS, "boolult", 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
+
+ /* Remove the push and the call to the operator function */
+ RemoveRemainders (D);
/* We changed the sequence */
return 1;
static unsigned Opt_tosxorax (StackOpData* D)
-/* Optimize the tosxorax sequence if possible */
+/* Optimize the tosxorax sequence */
{
CodeEntry* X;
- /* Check the entry before the push. If it's a lda instruction with an
- * addressing mode that allows us to replace it, we may use this
- * location for the op and must not save the value in the zero page
- * location.
- */
- CheckDirectOp (D);
/* Store the value into the zeropage instead of pushing it */
ReplacePushByStore (D);
/* Inline the xor, low byte */
D->IP = D->OpIndex + 1;
- AddOpLow (D, OP65_EOR);
+ AddOpLow (D, OP65_EOR, &D->Lhs);
/* High byte */
if (RegValIsKnown (D->PushEntry->RI->In.RegX) &&
RegValIsKnown (D->OpEntry->RI->In.RegX)) {
- /* Both values known, precalculate the result */
- const char* Arg = MakeHexArg (D->PushEntry->RI->In.RegX ^ D->OpEntry->RI->In.RegX);
- X = NewCodeEntry (OP65_LDX, AM65_IMM, Arg, 0, D->OpEntry->LI);
- InsertEntry (D, X, D->IP++);
+ /* Both values known, precalculate the result */
+ const char* Arg = MakeHexArg (D->PushEntry->RI->In.RegX ^ D->OpEntry->RI->In.RegX);
+ X = NewCodeEntry (OP65_LDX, AM65_IMM, Arg, 0, D->OpEntry->LI);
+ InsertEntry (D, X, D->IP++);
} else if (D->PushEntry->RI->In.RegX != 0) {
- /* High byte is unknown */
- AddOpHigh (D, OP65_EOR);
+ /* High byte is unknown */
+ AddOpHigh (D, OP65_EOR, &D->Lhs, 1);
}
/* Remove the push and the call to the tosandax function */
- RemovePushAndOp (D);
+ RemoveRemainders (D);
/* We changed the sequence */
return 1;
/*****************************************************************************/
-/* Code */
+/* Code */
/*****************************************************************************/
-/* Flags for the functions */
-typedef enum {
- STOP_NONE, /* Nothing special */
- STOP_A_UNUSED /* Call only if a unused later */
-} STOP_FLAGS;
-
-
-typedef unsigned (*OptFunc) (StackOpData* D);
-typedef struct OptFuncDesc OptFuncDesc;
-struct OptFuncDesc {
- const char* Name; /* Name of the replaced runtime function */
- OptFunc Func; /* Function pointer */
- STOP_FLAGS Flags; /* Flags */
-};
-
static const OptFuncDesc FuncTable[] = {
- { "staspidx", Opt_staspidx, STOP_NONE },
- { "staxspidx", Opt_staxspidx, STOP_A_UNUSED },
- { "tosaddax", Opt_tosaddax, STOP_NONE },
- { "tosandax", Opt_tosandax, STOP_NONE },
- { "tosorax", Opt_tosorax, STOP_NONE },
- { "tosxorax", Opt_tosxorax, STOP_NONE },
+ { "__bzero", Opt___bzero, REG_NONE, OP_X_ZERO | OP_A_KNOWN },
+ { "staspidx", Opt_staspidx, REG_NONE, OP_NONE },
+ { "staxspidx", Opt_staxspidx, REG_AX, OP_NONE },
+ { "tosaddax", Opt_tosaddax, REG_NONE, OP_NONE },
+ { "tosandax", Opt_tosandax, REG_NONE, OP_NONE },
+ { "tosaslax", Opt_tosaslax, REG_NONE, OP_NONE },
+ { "tosasrax", Opt_tosasrax, REG_NONE, OP_NONE },
+ { "toseqax", Opt_toseqax, REG_NONE, OP_NONE },
+ { "tosgeax", Opt_tosgeax, REG_NONE, OP_RHS_LOAD_DIRECT },
+ { "tosltax", Opt_tosltax, REG_NONE, OP_RHS_LOAD_DIRECT },
+ { "tosneax", Opt_tosneax, REG_NONE, OP_NONE },
+ { "tosorax", Opt_tosorax, REG_NONE, OP_NONE },
+ { "tosshlax", Opt_tosshlax, REG_NONE, OP_NONE },
+ { "tosshrax", Opt_tosshrax, REG_NONE, OP_NONE },
+ { "tossubax", Opt_tossubax, REG_NONE, OP_RHS_LOAD_DIRECT },
+ { "tosugeax", Opt_tosugeax, REG_NONE, OP_RHS_LOAD_DIRECT },
+ { "tosugtax", Opt_tosugtax, REG_NONE, OP_RHS_LOAD_DIRECT },
+ { "tosuleax", Opt_tosuleax, REG_NONE, OP_RHS_LOAD_DIRECT },
+ { "tosultax", Opt_tosultax, REG_NONE, OP_RHS_LOAD_DIRECT },
+ { "tosxorax", Opt_tosxorax, REG_NONE, OP_NONE },
};
#define FUNC_COUNT (sizeof(FuncTable) / sizeof(FuncTable[0]))
static int CmpFunc (const void* Key, const void* Func)
/* Compare function for bsearch */
{
- return strcmp (Key, ((const OptFuncDesc*) Func)->Name);
+ return strcmp (Key, ((const OptFuncDesc*) Func)->Name);
}
static const OptFuncDesc* FindFunc (const char* Name)
/* Find the function with the given name. Return a pointer to the table entry
- * or NULL if the function was not found.
- */
+** or NULL if the function was not found.
+*/
{
return bsearch (Name, FuncTable, FUNC_COUNT, sizeof(OptFuncDesc), CmpFunc);
}
static int HarmlessCall (const char* Name)
/* Check if this is a call to a harmless subroutine that will not interrupt
- * the pushax/op sequence when encountered.
- */
+** the pushax/op sequence when encountered.
+*/
{
- static const char* Tab[] = {
+ static const char* const Tab[] = {
+ "aslax1",
+ "aslax2",
+ "aslax3",
+ "aslax4",
+ "aslaxy",
+ "asrax1",
+ "asrax2",
+ "asrax3",
+ "asrax4",
+ "asraxy",
+ "bnegax",
+ "complax",
+ "decax1",
+ "decax2",
+ "decax3",
+ "decax4",
+ "decax5",
+ "decax6",
+ "decax7",
+ "decax8",
+ "decaxy",
+ "incax1",
+ "incax2",
+ "incax3",
+ "incax4",
+ "incax5",
+ "incax6",
+ "incax7",
+ "incax8",
+ "incaxy",
"ldaxidx",
"ldaxysp",
+ "negax",
+ "shlax1",
+ "shlax2",
+ "shlax3",
+ "shlax4",
+ "shlaxy",
+ "shrax1",
+ "shrax2",
+ "shrax3",
+ "shrax4",
+ "shraxy",
};
void* R = bsearch (Name,
+static void ResetStackOpData (StackOpData* Data)
+/* Reset the given data structure */
+{
+ Data->OptFunc = 0;
+ Data->ZPUsage = REG_NONE;
+
+ ClearLoadInfo (&Data->Lhs);
+ ClearLoadInfo (&Data->Rhs);
+
+ Data->PushIndex = -1;
+ Data->OpIndex = -1;
+}
+
+
+
+static int PreCondOk (StackOpData* D)
+/* Check if the preconditions for a call to the optimizer subfunction are
+** satisfied. As a side effect, this function will also choose the zero page
+** register to use.
+*/
+{
+ /* Check the flags */
+ unsigned UnusedRegs = D->OptFunc->UnusedRegs;
+ if (UnusedRegs != REG_NONE &&
+ (GetRegInfo (D->Code, D->OpIndex+1, UnusedRegs) & UnusedRegs) != 0) {
+ /* Cannot optimize */
+ return 0;
+ }
+ if ((D->OptFunc->Flags & OP_A_KNOWN) != 0 &&
+ RegValIsUnknown (D->OpEntry->RI->In.RegA)) {
+ /* Cannot optimize */
+ return 0;
+ }
+ if ((D->OptFunc->Flags & OP_X_ZERO) != 0 &&
+ D->OpEntry->RI->In.RegX != 0) {
+ /* Cannot optimize */
+ return 0;
+ }
+ if ((D->OptFunc->Flags & OP_LHS_LOAD) != 0) {
+ if (D->Lhs.A.LoadIndex < 0 || D->Lhs.X.LoadIndex < 0) {
+ /* Cannot optimize */
+ return 0;
+ } else if ((D->OptFunc->Flags & OP_LHS_LOAD_DIRECT) != 0) {
+ if ((D->Lhs.A.Flags & D->Lhs.X.Flags & LI_DIRECT) == 0) {
+ /* Cannot optimize */
+ return 0;
+ }
+ }
+ }
+ if ((D->OptFunc->Flags & OP_RHS_LOAD) != 0) {
+ if (D->Rhs.A.LoadIndex < 0 || D->Rhs.X.LoadIndex < 0) {
+ /* Cannot optimize */
+ return 0;
+ } else if ((D->OptFunc->Flags & OP_RHS_LOAD_DIRECT) != 0) {
+ if ((D->Rhs.A.Flags & D->Rhs.X.Flags & LI_DIRECT) == 0) {
+ /* Cannot optimize */
+ return 0;
+ }
+ }
+ }
+ if ((D->Rhs.A.Flags | D->Rhs.X.Flags) & LI_DUP_LOAD) {
+ /* Cannot optimize */
+ return 0;
+ }
+
+ /* Determine the zero page locations to use. We've tracked the used
+ ** ZP locations, so try to find some for us that are unused.
+ */
+ if ((D->ZPUsage & REG_PTR1) == REG_NONE) {
+ D->ZPLo = "ptr1";
+ D->ZPHi = "ptr1+1";
+ } else if ((D->ZPUsage & REG_SREG) == REG_NONE) {
+ D->ZPLo = "sreg";
+ D->ZPHi = "sreg+1";
+ } else if ((D->ZPUsage & REG_PTR2) == REG_NONE) {
+ D->ZPLo = "ptr2";
+ D->ZPHi = "ptr2+1";
+ } else {
+ /* No registers available */
+ return 0;
+ }
+
+ /* Determine if we have a basic block */
+ return CS_IsBasicBlock (D->Code, D->PushIndex, D->OpIndex);
+}
+
+
+
/*****************************************************************************/
-/* Code */
+/* Code */
/*****************************************************************************/
unsigned OptStackOps (CodeSeg* S)
/* Optimize operations that take operands via the stack */
{
- unsigned Changes = 0; /* Number of changes in one run */
- int InSeq = 0; /* Inside a sequence */
- unsigned Push = 0; /* Index of pushax */
- unsigned UsedRegs = 0; /* Zeropage registers used in sequence */
- unsigned I;
+ unsigned Changes = 0; /* Number of changes in one run */
+ StackOpData Data;
+ int I;
+ int OldEntryCount; /* Old number of entries */
+ unsigned UsedRegs = 0; /* Registers used */
+ unsigned ChangedRegs = 0;/* Registers changed */
+
+
+ enum {
+ Initialize,
+ Search,
+ FoundPush,
+ FoundOp
+ } State = Initialize;
- /* Generate register info */
- CS_GenRegInfo (S);
+ /* Remember the code segment in the info struct */
+ Data.Code = S;
/* Look for a call to pushax followed by a call to some other function
- * that takes it's first argument on the stack, and the second argument
- * in the primary register.
- * It depends on the code between the two if we can handle/transform the
- * sequence, so check this code for the following list of things:
- *
- * - the range must be a basic block (one entry, one exit)
- * - there may not be accesses to local variables with unknown
- * offsets (because we have to adjust these offsets).
- * - no subroutine calls
- * - no jump labels
- *
- * Since we need a zero page register later, do also check the
- * intermediate code for zero page use.
- */
+ ** that takes it's first argument on the stack, and the second argument
+ ** in the primary register.
+ ** It depends on the code between the two if we can handle/transform the
+ ** sequence, so check this code for the following list of things:
+ **
+ ** - the range must be a basic block (one entry, one exit)
+ ** - there may not be accesses to local variables with unknown
+ ** offsets (because we have to adjust these offsets).
+ ** - no subroutine calls
+ ** - no jump labels
+ **
+ ** Since we need a zero page register later, do also check the
+ ** intermediate code for zero page use.
+ */
I = 0;
- while (I < CS_GetEntryCount (S)) {
-
- /* Get the next entry */
- CodeEntry* E = CS_GetEntry (S, I);
-
- /* Handling depends if we're inside a sequence or not */
- if (InSeq) {
-
- if (((E->Use & REG_SP) != 0 &&
- (E->AM != AM65_ZP_INDY || RegValIsUnknown (E->RI->In.RegY)))) {
-
- /* All this stuff is not allowed in a sequence */
- InSeq = 0;
-
- } else if (E->OPC == OP65_JSR) {
-
- /* Subroutine call: Check if this is one of our functions */
- const OptFuncDesc* F = FindFunc (E->Arg);
- if (F) {
-
- StackOpData Data;
- int PreCondOk = 1;
-
- /* Check the flags */
- if (F->Flags & STOP_A_UNUSED) {
- /* a must be unused later */
- if (RegAUsed (S, I+1)) {
- /* Cannot optimize */
- PreCondOk = 0;
- }
- }
-
- /* Determine the zero page locations to use */
- if (PreCondOk) {
- UsedRegs |= GetRegInfo (S, I+1, REG_SREG | REG_PTR1 | REG_PTR2);
- if ((UsedRegs & REG_SREG) == REG_NONE) {
- /* SREG is available */
- Data.ZPLo = "sreg";
- Data.ZPHi = "sreg+1";
- } else if ((UsedRegs & REG_PTR1) == REG_NONE) {
- Data.ZPLo = "ptr1";
- Data.ZPHi = "ptr1+1";
- } else if ((UsedRegs & REG_PTR2) == REG_NONE) {
- Data.ZPLo = "ptr2";
- Data.ZPHi = "ptr2+1";
- } else {
- /* No registers available */
- PreCondOk = 0;
- }
- }
-
- /* Determine if we have a basic block */
- if (PreCondOk) {
- PreCondOk = CS_IsBasicBlock (S, Push, I);
- }
-
- /* If preconditions are ok, call the optimizer function */
- if (PreCondOk) {
-
- /* Adjust stack offsets */
- Data.OpIndex = I + AdjustStackOffset (S, Push, I, 2);
-
- /* Prepare the remainder of the data structure */
- Data.Code = S;
- Data.Flags = 0;
- Data.PushIndex = Push;
- Data.PrevEntry = CS_GetPrevEntry (S, Data.PushIndex);
- Data.PushEntry = CS_GetEntry (S, Data.PushIndex);
- Data.OpEntry = E;
- Data.NextEntry = CS_GetNextEntry (S, Data.OpIndex);
-
- /* Call the optimizer function */
- Changes += F->Func (&Data);
-
- /* Regenerate register info */
- CS_GenRegInfo (S);
- }
-
- /* End of sequence */
- InSeq = 0;
-
- } else if (strcmp (E->Arg, "pushax") == 0) {
- /* Restart the sequence */
- Push = I;
- UsedRegs = REG_NONE;
- } else if (HarmlessCall (E->Arg)) {
- /* Track zeropage register usage */
- UsedRegs |= (E->Use | E->Chg);
+ while (I < (int)CS_GetEntryCount (S)) {
+
+ /* Get the next entry */
+ CodeEntry* E = CS_GetEntry (S, I);
+
+ /* Actions depend on state */
+ switch (State) {
+
+ case Initialize:
+ ResetStackOpData (&Data);
+ UsedRegs = ChangedRegs = REG_NONE;
+ State = Search;
+ /* FALLTHROUGH */
+
+ case Search:
+ /* While searching, track register load insns, so we can tell
+ ** what is in a register once pushax is encountered.
+ */
+ if (CE_HasLabel (E)) {
+ /* Currently we don't track across branches */
+ ClearLoadInfo (&Data.Lhs);
+ }
+ if (CE_IsCallTo (E, "pushax")) {
+ Data.PushIndex = I;
+ State = FoundPush;
} else {
- /* A call to an unkown subroutine ends the sequence */
- InSeq = 0;
- }
-
- } else {
- /* Other stuff: Track zeropage register usage */
- UsedRegs |= (E->Use | E->Chg);
- }
+ /* Track load insns */
+ TrackLoads (&Data.Lhs, E, I);
+ }
+ break;
+
+ case FoundPush:
+ /* We' found a pushax before. Search for a stack op that may
+ ** follow and in the meantime, track zeropage usage and check
+ ** for code that will disable us from translating the sequence.
+ */
+ if (CE_HasLabel (E)) {
+ /* Currently we don't track across branches */
+ ClearLoadInfo (&Data.Rhs);
+ }
+ if (E->OPC == OP65_JSR) {
+
+ /* Subroutine call: Check if this is one of the functions,
+ ** we're going to replace.
+ */
+ Data.OptFunc = FindFunc (E->Arg);
+ if (Data.OptFunc) {
+ /* Remember the op index and go on */
+ Data.OpIndex = I;
+ Data.OpEntry = E;
+ State = FoundOp;
+ break;
+ } else if (!HarmlessCall (E->Arg)) {
+ /* A call to an unkown subroutine: We need to start
+ ** over after the last pushax. Note: This will also
+ ** happen if we encounter a call to pushax!
+ */
+ I = Data.PushIndex;
+ State = Initialize;
+ break;
+ } else {
+ /* Track register usage */
+ Data.ZPUsage |= (E->Use | E->Chg);
+ TrackLoads (&Data.Rhs, E, I);
+ }
- } else if (CE_IsCallTo (E, "pushax")) {
+ } else if (E->Info & OF_STORE && (E->Chg & REG_ZP) == 0) {
+
+ /* Too dangerous - there may be a change of a variable
+ ** within the sequence.
+ */
+ I = Data.PushIndex;
+ State = Initialize;
+ break;
+
+ } else if ((E->Use & REG_SP) != 0 &&
+ (E->AM != AM65_ZP_INDY ||
+ RegValIsUnknown (E->RI->In.RegY) ||
+ E->RI->In.RegY < 2)) {
+
+ /* If we are using the stack, and we don't have "indirect Y"
+ ** addressing mode, or the value of Y is unknown, or less
+ ** than two, we cannot cope with this piece of code. Having
+ ** an unknown value of Y means that we cannot correct the
+ ** stack offset, while having an offset less than two means
+ ** that the code works with the value on stack which is to
+ ** be removed.
+ */
+ I = Data.PushIndex;
+ State = Initialize;
+ break;
- /* This starts a sequence */
- Push = I;
- UsedRegs = REG_NONE;
- InSeq = 1;
+ } else {
+ /* Other stuff: Track register usage */
+ Data.ZPUsage |= (E->Use | E->Chg);
+ TrackLoads (&Data.Rhs, E, I);
+ }
+ /* If the registers from the push (A/X) are used before they're
+ ** changed, we cannot change the sequence, because this would
+ ** with a high probability change the register contents.
+ */
+ UsedRegs |= E->Use;
+ if ((UsedRegs & ~ChangedRegs) & REG_AX) {
+ I = Data.PushIndex;
+ State = Initialize;
+ break;
+ }
+ ChangedRegs |= E->Chg;
+ break;
+
+ case FoundOp:
+ /* Track zero page location usage beyond this point */
+ Data.ZPUsage |= GetRegInfo (S, I, REG_SREG | REG_PTR1 | REG_PTR2);
+
+ /* Finalize the load info */
+ FinalizeLoadInfo (&Data.Lhs, S);
+ FinalizeLoadInfo (&Data.Rhs, S);
+
+ /* Check if the lhs loads from zeropage. If this is true, these
+ ** zero page locations have to be added to ZPUsage, because
+ ** they cannot be used for intermediate storage. In addition,
+ ** if one of these zero page locations is destroyed between
+ ** pushing the lhs and the actual operation, we cannot use the
+ ** original zero page locations for the final op, but must
+ ** use another ZP location to save them.
+ */
+ ChangedRegs &= REG_ZP;
+ if (Data.Lhs.A.LoadEntry && Data.Lhs.A.LoadEntry->AM == AM65_ZP) {
+ Data.ZPUsage |= Data.Lhs.A.LoadEntry->Use;
+ if ((Data.Lhs.A.LoadEntry->Use & ChangedRegs) != 0) {
+ Data.Lhs.A.Flags &= ~(LI_DIRECT | LI_RELOAD_Y);
+ }
+ }
+ if (Data.Lhs.X.LoadEntry && Data.Lhs.X.LoadEntry->AM == AM65_ZP) {
+ Data.ZPUsage |= Data.Lhs.X.LoadEntry->Use;
+ if ((Data.Lhs.X.LoadEntry->Use & ChangedRegs) != 0) {
+ Data.Lhs.X.Flags &= ~(LI_DIRECT | LI_RELOAD_Y);
+ }
+ }
+
+ /* Check the preconditions. If they aren't ok, reset the insn
+ ** pointer to the pushax and start over. We will loose part of
+ ** load tracking but at least a/x has probably lost between
+ ** pushax and here and will be tracked again when restarting.
+ */
+ if (!PreCondOk (&Data)) {
+ I = Data.PushIndex;
+ State = Initialize;
+ break;
+ }
+
+ /* Prepare the remainder of the data structure. */
+ Data.PrevEntry = CS_GetPrevEntry (S, Data.PushIndex);
+ Data.PushEntry = CS_GetEntry (S, Data.PushIndex);
+ Data.OpEntry = CS_GetEntry (S, Data.OpIndex);
+ Data.NextEntry = CS_GetNextEntry (S, Data.OpIndex);
+
+ /* Remember the current number of code lines */
+ OldEntryCount = CS_GetEntryCount (S);
+
+ /* Adjust stack offsets to account for the upcoming removal */
+ AdjustStackOffset (&Data, 2);
+
+ /* Regenerate register info, since AdjustStackOffset changed
+ ** the code
+ */
+ CS_GenRegInfo (S);
+
+ /* Call the optimizer function */
+ Changes += Data.OptFunc->Func (&Data);
+
+ /* Since the function may have added or deleted entries,
+ ** correct the index.
+ */
+ I += CS_GetEntryCount (S) - OldEntryCount;
+
+ /* Regenerate register info */
+ CS_GenRegInfo (S);
+
+ /* Done */
+ State = Initialize;
+ continue;
- }
+ }
- /* Next entry */
- ++I;
+ /* Next entry */
+ ++I;
}
- /* Free the register info */
- CS_FreeRegInfo (S);
-
/* Return the number of changes made */
return Changes;
}
-
-
-
projects / cc65 / blobdiff