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Moved some reusable code from cc65/coptstop.c into new files.

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acqn 2020-04-16 17:17:08 +08:00 committed by Oliver Schmidt
parent 28c7aa2bc8
commit d379affc4b
4 changed files with 1253 additions and 1026 deletions
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2
src/cc65.vcxproj
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@ -87,6 +87,7 @@
<ClInclude Include="cc65\codeinfo.h" />
<ClInclude Include="cc65\codelab.h" />
<ClInclude Include="cc65\codeopt.h" />
<ClInclude Include="cc65\codeoptutil.h" />
<ClInclude Include="cc65\codeseg.h" />
<ClInclude Include="cc65\compile.h" />
<ClInclude Include="cc65\coptadd.h" />
@ -163,6 +164,7 @@
<ClCompile Include="cc65\codeinfo.c" />
<ClCompile Include="cc65\codelab.c" />
<ClCompile Include="cc65\codeopt.c" />
<ClCompile Include="cc65\codeoptutil.c" />
<ClCompile Include="cc65\codeseg.c" />
<ClCompile Include="cc65\compile.c" />
<ClCompile Include="cc65\coptadd.c" />

993
src/cc65/codeoptutil.c Normal file
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@ -0,0 +1,993 @@
/*****************************************************************************/
/* */
/* codeoptutil.c */
/* */
/* Optimize operations that take operands via the stack */
/* */
/* */
/* */
/* (C) 2001 Ullrich von Bassewitz */
/* Wacholderweg 14 */
/* D-70597 Stuttgart */
/* EMail: uz@cc65.org */
/* */
/* */
/* This software is provided 'as-is', without any expressed or implied */
/* warranty. In no event will the authors be held liable for any damages */
/* arising from the use of this software. */
/* */
/* Permission is granted to anyone to use this software for any purpose, */
/* including commercial applications, and to alter it and redistribute it */
/* freely, subject to the following restrictions: */
/* */
/* 1. The origin of this software must not be misrepresented; you must not */
/* claim that you wrote the original software. If you use this software */
/* in a product, an acknowledgment in the product documentation would be */
/* appreciated but is not required. */
/* 2. Altered source versions must be plainly marked as such, and must not */
/* be misrepresented as being the original software. */
/* 3. This notice may not be removed or altered from any source */
/* distribution. */
/* */
/*****************************************************************************/
#include <stdlib.h>
/* common */
#include "chartype.h"
#include "xmalloc.h"
/* cc65 */
#include "codeinfo.h"
#include "codeoptutil.h"
#include "error.h"
/*****************************************************************************/
/* Load tracking code */
/*****************************************************************************/
void ClearLoadRegInfo (LoadRegInfo* RI)
/* Clear a LoadRegInfo struct */
{
RI->Flags = LI_NONE;
RI->LoadIndex = -1;
RI->LoadEntry = 0;
RI->LoadYIndex = -1;
RI->LoadYEntry = 0;
RI->XferIndex = -1;
RI->XferEntry = 0;
RI->Offs = 0;
}
void CopyLoadRegInfo (LoadRegInfo* To, LoadRegInfo* From)
/* Copy a LoadRegInfo struct */
{
To->Flags = From->Flags;
To->LoadIndex = From->LoadIndex;
To->LoadEntry = From->LoadEntry;
To->LoadYIndex = From->LoadYIndex;
To->LoadYEntry = From->LoadYEntry;
To->XferIndex = From->XferIndex;
To->XferEntry = From->XferEntry;
To->Offs = From->Offs;
}
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;
}
/* Load from src not modified before op can be treated as direct */
if ((RI->Flags & LI_SRC_CHG) == 0 &&
(RI->Flags & (LI_CHECK_ARG | LI_CHECK_Y)) != 0) {
RI->Flags |= LI_DIRECT;
if ((RI->Flags & LI_CHECK_Y) != 0) {
RI->Flags |= LI_RELOAD_Y;
}
}
/* We cannot ldy src,y */
if ((RI->Flags & LI_RELOAD_Y) != 0 &&
RI->LoadYEntry != 0 &&
(RI->LoadYEntry->Use & REG_Y) == REG_Y) {
RI->Flags &= ~LI_DIRECT;
}
}
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;
}
}
}
void ClearLoadInfo (LoadInfo* LI)
/* Clear a LoadInfo struct */
{
ClearLoadRegInfo (&LI->A);
ClearLoadRegInfo (&LI->X);
ClearLoadRegInfo (&LI->Y);
}
void CopyLoadInfo (LoadInfo* To, LoadInfo* From)
/* Copy a LoadInfo struct */
{
CopyLoadRegInfo (&To->A, &From->A);
CopyLoadRegInfo (&To->X, &From->X);
CopyLoadRegInfo (&To->Y, &From->Y);
}
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);
}
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);
}
RegInfo* GetLastChangedRegInfo (StackOpData* D, LoadRegInfo* Reg)
/* Get RegInfo of the last load insn entry */
{
CodeEntry* E;
if (Reg->LoadIndex >= 0 && (E = CS_GetEntry (D->Code, Reg->LoadIndex)) != 0) {
return E->RI;
}
return 0;
}
static int Affected (LoadRegInfo* RI, const CodeEntry* E)
/* Check if the load src may be modified between the pushax and op */
{
fncls_t fncls;
unsigned int Use;
unsigned int Chg;
unsigned int UseToCheck = 0;
if ((RI->Flags & (LI_CHECK_ARG | LI_CHECK_Y)) != 0) {
if (E->AM == AM65_IMM || E->AM == AM65_ACC || E->AM == AM65_IMP || E->AM == AM65_BRA) {
return 0;
}
CHECK ((RI->Flags & LI_CHECK_ARG) == 0 || RI->LoadEntry != 0);
CHECK ((RI->Flags & LI_CHECK_Y) == 0 || RI->LoadYEntry != 0);
if ((RI->Flags & LI_CHECK_ARG) != 0) {
UseToCheck |= RI->LoadEntry->Use;
}
if ((RI->Flags & LI_CHECK_Y) != 0) {
UseToCheck |= RI->LoadYEntry->Use;
}
if (E->OPC == OP65_JSR) {
/* Try to know about the function */
fncls = GetFuncInfo (E->Arg, &Use, &Chg);
if ((UseToCheck & Chg & REG_ALL) == 0 &&
fncls == FNCLS_BUILTIN) {
/* Builtin functions are known to be harmless */
return 0;
}
/* Otherwise play it safe */
return 1;
} else if (E->OPC == OP65_DEC || E->OPC == OP65_INC ||
E->OPC == OP65_ASL || E->OPC == OP65_LSR ||
E->OPC == OP65_ROL || E->OPC == OP65_ROR ||
E->OPC == OP65_TRB || E->OPC == OP65_TSB ||
E->OPC == OP65_STA || E->OPC == OP65_STX || E->OPC == OP65_STY) {
if ((E->AM == AM65_ABS || E->AM == AM65_ZP)) {
if ((RI->Flags & LI_CHECK_ARG) != 0 &&
strcmp (RI->LoadEntry->Arg, E->Arg) == 0) {
return 1;
}
if ((RI->Flags & LI_CHECK_Y) != 0 &&
strcmp (RI->LoadYEntry->Arg, E->Arg) == 0) {
return 1;
}
return 0;
}
/* We could've check further for more cases where the load target isn't modified,
** But for now let's save the trouble and just play it safe. */
return 1;
}
}
return 0;
}
static void HonourUseAndChg (LoadRegInfo* RI, unsigned Reg, const CodeEntry* E, int I)
/* Honour use and change flags for an instruction */
{
if ((E->Chg & Reg) != 0) {
/* Remember this as an indirect load */
ClearLoadRegInfo (RI);
RI->LoadIndex = I;
RI->XferIndex = -1;
RI->Flags = 0;
} else if (Affected (RI, E)) {
RI->Flags |= LI_SRC_CHG;
}
}
unsigned int TrackLoads (LoadInfo* LI, LoadInfo* LLI, CodeSeg* S, int I)
/* Track loads for a code entry.
** Return used registers.
*/
{
unsigned Used;
CodeEntry* E = CS_GetEntry (S, I);
CHECK (E != 0);
/* By default */
Used = E->Use;
/* Whether we had a load or xfer op before or not, the newly loaded value
** will be the real one used for the pushax/op unless it's overwritten,
** so we can just reset the flags about it in such cases.
*/
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);
/* Remember the load */
RI->LoadIndex = I;
RI->XferIndex = -1;
/* Set load flags */
RI->Flags = LI_LOAD_INSN;
if (E->AM == AM65_IMM) {
/* These insns are all ok and replaceable */
RI->Flags |= LI_DIRECT;
} else if (E->AM == AM65_ZP || E->AM == AM65_ABS) {
/* These insns are replaceable only if they are not modified later */
RI->Flags |= LI_CHECK_ARG;
} else if (E->AM == AM65_ZPY || E->AM == AM65_ABSY) {
/* These insns are replaceable only if they are not modified later */
RI->Flags |= LI_CHECK_ARG | LI_CHECK_Y;
} else if (E->AM == AM65_ZP_INDY &&
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->Flags |= LI_DIRECT | LI_CHECK_Y | LI_SP;
/* Reg Y can be regarded as unused if this load is removed */
Used &= ~REG_Y;
if (RI == &LI->A) {
LI->Y.Flags |= LI_USED_BY_A;
} else {
LI->Y.Flags |= LI_USED_BY_X;
}
}
/* If the load offset has a known value, we can just remember and reload
** it into the index register later.
*/
if ((RI->Flags & LI_CHECK_Y) != 0) {
if (RegValIsKnown (E->RI->In.RegY)) {
RI->Offs = (unsigned char)E->RI->In.RegY;
RI->Flags &= ~LI_CHECK_Y;
RI->Flags |= LI_RELOAD_Y;
} else {
/* We need to check if the src of Y is changed */
RI->LoadYIndex = LI->Y.LoadIndex;
RI->LoadYEntry = CS_GetEntry (S, RI->LoadYIndex);
}
}
/* Watch for any change of the load target */
if ((RI->Flags & LI_CHECK_ARG) != 0) {
RI->LoadEntry = CS_GetEntry (S, I);
}
} 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;
Used &= ~REG_A;
Src->Flags |= LI_USED_BY_X;
break;
case OP65_TAY:
Src = &LI->A;
Tgt = &LI->Y;
Used &= ~REG_A;
Src->Flags |= LI_USED_BY_Y;
break;
case OP65_TXA:
Src = &LI->X;
Tgt = &LI->A;
Used &= ~REG_X;
Src->Flags |= LI_USED_BY_A;
break;
case OP65_TYA:
Src = &LI->Y;
Tgt = &LI->A;
Used &= ~REG_Y;
Src->Flags |= LI_USED_BY_A;
break;
case OP65_TSX:
ClearLoadRegInfo (&LI->X);
return Used;
case OP65_TXS:
return Used;
default: Internal ("Unknown XFR insn in TrackLoads");
}
/* Transfer the data */
Tgt->LoadIndex = Src->LoadIndex;
Tgt->LoadEntry = Src->LoadEntry;
Tgt->LoadYIndex = Src->LoadYIndex;
Tgt->LoadYEntry = Src->LoadYEntry;
Tgt->XferIndex = I;
Tgt->Offs = Src->Offs;
Tgt->Flags = Src->Flags;
} else if (CE_IsCallTo (E, "ldaxysp") && RegValIsKnown (E->RI->In.RegY)) {
/* Both registers set, Y changed */
LI->A.LoadIndex = I;
LI->A.XferIndex = -1;
LI->A.Flags = (LI_LOAD_INSN | LI_DIRECT | LI_RELOAD_Y | LI_SP);
LI->A.Offs = (unsigned char) E->RI->In.RegY - 1;
LI->X.LoadIndex = I;
LI->X.XferIndex = -1;
LI->X.Flags = (LI_LOAD_INSN | LI_DIRECT | LI_RELOAD_Y | LI_SP);
LI->X.Offs = (unsigned char) E->RI->In.RegY;
/* Reg Y can be regarded as unused if this load is removed */
Used &= ~REG_Y;
LI->Y.Flags |= LI_USED_BY_A | LI_USED_BY_X;
} else {
HonourUseAndChg (&LI->A, REG_A, E, I);
HonourUseAndChg (&LI->X, REG_X, E, I);
HonourUseAndChg (&LI->Y, REG_Y, E, I);
/* The other operand may be affected too */
if (LLI != 0) {
if (Affected (&LLI->A, E)) {
LLI->A.Flags |= LI_SRC_CHG;
}
if (Affected (&LLI->X, E)) {
LLI->X.Flags |= LI_SRC_CHG;
}
if (Affected (&LLI->Y, E)) {
LLI->Y.Flags |= LI_SRC_CHG;
}
}
}
return Used;
}
void SetDontRemoveEntryFlag (LoadRegInfo* RI)
/* Flag the entry as non-removable according to register flags */
{
if (RI->Flags & LI_DONT_REMOVE) {
if (RI->LoadEntry != 0) {
RI->LoadEntry->Flags |= CEF_DONT_REMOVE;
}
}
}
void ResetDontRemoveEntryFlag (LoadRegInfo* RI)
/* Unflag the entry as non-removable according to register flags */
{
if (RI->Flags & LI_DONT_REMOVE) {
if (RI->LoadEntry != 0) {
RI->LoadEntry->Flags &= ~CEF_DONT_REMOVE;
}
}
}
void SetDontRemoveEntryFlags (StackOpData* D)
/* Flag the entries as non-removable according to register flags */
{
SetDontRemoveEntryFlag (&D->Lhs.A);
SetDontRemoveEntryFlag (&D->Lhs.X);
SetDontRemoveEntryFlag (&D->Rhs.A);
SetDontRemoveEntryFlag (&D->Rhs.X);
}
void ResetDontRemoveEntryFlags (StackOpData* D)
/* Unflag the entries as non-removable according to register flags */
{
ResetDontRemoveEntryFlag (&D->Lhs.A);
ResetDontRemoveEntryFlag (&D->Lhs.X);
ResetDontRemoveEntryFlag (&D->Rhs.A);
ResetDontRemoveEntryFlag (&D->Rhs.X);
}
void ResetStackOpData (StackOpData* Data)
/* Reset the given data structure */
{
Data->OptFunc = 0;
Data->ZPUsage = REG_NONE;
Data->ZPChanged = REG_NONE;
Data->UsedRegs = REG_NONE;
Data->RhsMultiChg = 0;
ClearLoadInfo (&Data->Lhs);
ClearLoadInfo (&Data->Rhs);
Data->PushIndex = -1;
Data->OpIndex = -1;
}
/*****************************************************************************/
/* Helpers */
/*****************************************************************************/
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;
}
}
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;
}
}
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);
/* Check if this entry does a stack access, and if so, if it's a plain
** load from stack, since this is needed later.
*/
int Correction = 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 */
Correction = (E->OPC == OP65_LDA)? 2 : 1;
} else if (CE_IsCallTo (E, "ldaxysp")) {
/* We need to correct this one */
Correction = 1;
}
if (Correction) {
/* 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)) {
CodeEntry* N;
const char* Arg = MakeHexArg (E->RI->In.RegY);
if (Correction == 2 && (N = CS_GetNextEntry(D->Code, I)) != 0 &&
((N->Info & OF_ZBRA) != 0) && N->JumpTo != 0) {
/* The Y register is used but the load instruction loads A
** and is followed by a branch that evaluates the zero flag.
** This means that we cannot just insert the load insn
** for the Y register at this place, because it would
** destroy the Z flag. Instead place load insns at the
** target of the branch and after it.
** Note: There is a chance that this code won't work. The
** jump may be a backwards jump (in which case the stack
** offset has already been adjusted) or there may be other
** instructions between the load and the conditional jump.
** Currently the compiler does not generate such code, but
** it is possible to force the optimizer into something
** invalid by use of inline assembler.
*/
/* Add load insn after the branch */
CodeEntry* X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, E->LI);
InsertEntry (D, X, I+2);
/* Add load insn before branch target */
CodeEntry* Y = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, E->LI);
int J = CS_GetEntryIndex (D->Code, N->JumpTo->Owner);
CHECK (J > I); /* Must not happen */
InsertEntry (D, Y, J);
/* Move the label to the new insn */
CodeLabel* L = CS_GenLabel (D->Code, Y);
CS_MoveLabelRef (D->Code, N, L);
} else {
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 | LI_SP | LI_CHECK_Y)) == (LI_RELOAD_Y | LI_SP)) {
D->Rhs.A.Offs -= Offs;
}
if ((D->Rhs.X.Flags & (LI_RELOAD_Y | LI_SP | LI_CHECK_Y)) == (LI_RELOAD_Y | LI_SP)) {
D->Rhs.X.Offs -= Offs;
}
}
int IsRegVar (StackOpData* D)
/* If the value pushed is that of a zeropage variable that is unchanged until Op,
** 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 be unchanged till Op */
if ((D->Lhs.A.Flags & (LI_DIRECT | LI_RELOAD_Y)) != LI_DIRECT ||
(D->Lhs.X.Flags & (LI_DIRECT | LI_RELOAD_Y)) != LI_DIRECT) {
return 0;
}
/* 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;
}
void AddStoreLhsA (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);
}
void AddStoreLhsX (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);
}
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) {
AddStoreLhsX (D);
}
if ((D->Lhs.A.Flags & LI_DIRECT) == 0) {
AddStoreLhsA (D);
}
}
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 {
if ((LI->A.Flags & LI_CHECK_Y) == 0) {
/* ldy #offs */
X = NewCodeEntry (OP65_LDY, AM65_IMM, MakeHexArg (LI->A.Offs), 0, D->OpEntry->LI);
} else {
/* ldy src */
X = NewCodeEntry (OP65_LDY, LI->A.LoadYEntry->AM, LI->A.LoadYEntry->Arg, 0, D->OpEntry->LI);
}
InsertEntry (D, X, D->IP++);
if (LI->A.LoadEntry->OPC == OP65_JSR) {
/* opc (sp),y */
X = NewCodeEntry (OPC, AM65_ZP_INDY, "sp", 0, D->OpEntry->LI);
} else {
/* opc src,y */
X = NewCodeEntry (OPC, LI->A.LoadEntry->AM, LI->A.LoadEntry->Arg, 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++);
}
}
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 {
if ((LI->A.Flags & LI_CHECK_Y) == 0) {
/* ldy #const */
X = NewCodeEntry (OP65_LDY, AM65_IMM, MakeHexArg (LI->X.Offs), 0, D->OpEntry->LI);
} else {
/* ldy src */
X = NewCodeEntry (OP65_LDY, LI->X.LoadYEntry->AM, LI->X.LoadYEntry->Arg, 0, D->OpEntry->LI);
}
InsertEntry (D, X, D->IP++);
if (LI->X.LoadEntry->OPC == OP65_JSR) {
/* opc (sp),y */
X = NewCodeEntry (OPC, AM65_ZP_INDY, "sp", 0, D->OpEntry->LI);
} else {
/* opc src,y */
X = NewCodeEntry (OPC, LI->A.LoadEntry->AM, LI->A.LoadEntry->Arg, 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++);
}
}
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_REMOVE) {
if (LI->A.LoadIndex >= 0 &&
(LI->A.LoadEntry->Flags & CEF_DONT_REMOVE) == 0) {
DelEntry (D, LI->A.LoadIndex);
}
if (LI->A.XferIndex >= 0 &&
(LI->A.XferEntry->Flags & CEF_DONT_REMOVE) == 0) {
DelEntry (D, LI->A.XferIndex);
}
}
if ((LI->X.Flags & LI_REMOVE) == LI_REMOVE) {
if (LI->X.LoadIndex >= 0 &&
(LI->X.LoadEntry->Flags & CEF_DONT_REMOVE) == 0) {
DelEntry (D, LI->X.LoadIndex);
}
if (LI->X.XferIndex >= 0 &&
(LI->X.XferEntry->Flags & CEF_DONT_REMOVE) == 0) {
DelEntry (D, LI->X.XferIndex);
}
}
}
void RemoveRemainders (StackOpData* D)
/* Remove the code that is unnecessary after translation of the sequence */
{
/* Remove the register loads for lhs and rhs if nothing prevents that */
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 CmpHarmless (const void* Key, const void* Entry)
/* Compare function for bsearch */
{
return strcmp (Key, *(const char**)Entry);
}
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.
*/
{
const char* const Tab[] = {
"aslax1",
"aslax2",
"aslax3",
"aslax4",
"aslaxy",
"asrax1",
"asrax2",
"asrax3",
"asrax4",
"asraxy",
"bcastax",
"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,
Tab,
sizeof (Tab) / sizeof (Tab[0]),
sizeof (Tab[0]),
CmpHarmless);
return (R != 0);
}

257
src/cc65/codeoptutil.h Normal file
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@ -0,0 +1,257 @@
/*****************************************************************************/
/* */
/* codeoptutil.h */
/* */
/* Optimize operations that take operands via the stack */
/* */
/* */
/* */
/* (C) 2001 Ullrich von Bassewitz */
/* Wacholderweg 14 */
/* D-70597 Stuttgart */
/* EMail: uz@cc65.org */
/* */
/* */
/* This software is provided 'as-is', without any expressed or implied */
/* warranty. In no event will the authors be held liable for any damages */
/* arising from the use of this software. */
/* */
/* Permission is granted to anyone to use this software for any purpose, */
/* including commercial applications, and to alter it and redistribute it */
/* freely, subject to the following restrictions: */
/* */
/* 1. The origin of this software must not be misrepresented; you must not */
/* claim that you wrote the original software. If you use this software */
/* in a product, an acknowledgment in the product documentation would be */
/* appreciated but is not required. */
/* 2. Altered source versions must be plainly marked as such, and must not */
/* be misrepresented as being the original software. */
/* 3. This notice may not be removed or altered from any source */
/* distribution. */
/* */
/*****************************************************************************/
#ifndef CODEOPTUTIL_H
#define CODEOPTUTIL_H
/* cc65 */
#include "codeent.h"
#include "codeseg.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_CHECK_ARG = 0x10, /* Load src might be modified later */
LI_SRC_CHG = 0x20, /* Load src is possibly modified */
LI_LOAD_INSN = 0x40, /* Has a load insn */
LI_CHECK_Y = 0x80, /* Indexed load src might be modified later */
LI_USED_BY_A = 0x100, /* Content used by RegA */
LI_USED_BY_X = 0x200, /* Content used by RegX */
LI_USED_BY_Y = 0x400, /* Content used by RegY */
LI_SP = 0x800, /* Content on stack */
} 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 LoadYIndex; /* Index of Y-load insn, -1 if invalid */
CodeEntry* LoadYEntry; /* The actual Y-load 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 forward decl */
typedef struct StackOpData StackOpData;
typedef struct OptFuncDesc OptFuncDesc;
/* Structure that holds the needed data */
struct StackOpData {
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;
unsigned ZPChanged;
/* Freedom of registers inside the sequence */
unsigned UsedRegs; /* Registers used */
/* Whether the rhs is changed multiple times */
int RhsMultiChg;
/* 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 */
};
/*****************************************************************************/
/* Load tracking code */
/*****************************************************************************/
void ClearLoadRegInfo (LoadRegInfo* LRI);
/* Clear a LoadRegInfo struct */
void CopyLoadRegInfo (LoadRegInfo* To, LoadRegInfo* From);
/* Copy a LoadRegInfo struct */
void FinalizeLoadRegInfo (LoadRegInfo* LRI, CodeSeg* S);
/* Prepare a LoadRegInfo struct for use */
void AdjustLoadRegInfo (LoadRegInfo* LRI, int Index, int Change);
/* Adjust a load register info struct after deleting or inserting an entry
** with a given index
*/
void ClearLoadInfo (LoadInfo* LI);
/* Clear a LoadInfo struct */
void CopyLoadInfo (LoadInfo* To, LoadInfo* From);
/* Copy a LoadInfo struct */
void FinalizeLoadInfo (LoadInfo* LI, CodeSeg* S);
/* Prepare a LoadInfo struct for use */
void AdjustLoadInfo (LoadInfo* LI, int Index, int Change);
/* Adjust a load info struct after deleting entry with a given index */
RegInfo* GetLastChangedRegInfo (StackOpData* D, LoadRegInfo* Reg);
/* Get RegInfo of the last insn entry that changed the reg */
unsigned int TrackLoads (LoadInfo* LI, LoadInfo* LLI, CodeSeg* S, int I);
/* Track loads for a code entry.
** Return used registers.
*/
void SetDontRemoveEntryFlag (LoadRegInfo* LRI);
/* Flag the entry as non-removable according to register flags */
void ResetDontRemoveEntryFlag (LoadRegInfo* LRI);
/* Unflag the entry as non-removable according to register flags */
void SetDontRemoveEntryFlags (StackOpData* D);
/* Flag the entries as non-removable according to register flags */
void ResetDontRemoveEntryFlags (StackOpData* D);
/* Unflag the entries as non-removable according to register flags */
void ResetStackOpData (StackOpData* Data);
/* Reset the given data structure */
/*****************************************************************************/
/* Helpers */
/*****************************************************************************/
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.
*/
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.
*/
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.
*/
int IsRegVar (StackOpData* D);
/* If the value pushed is that of a zeropage variable that is unchanged until Op,
** replace ZPLo and ZPHi in the given StackOpData struct by the variable and return true.
** Otherwise leave D untouched and return false.
*/
void AddStoreLhsA (StackOpData* D);
/* Add a store to zero page after the push insn */
void AddStoreLhsX (StackOpData* D);
/* Add a store to zero page after the push insn */
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).
*/
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.
*/
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.
*/
void RemoveRegLoads (StackOpData* D, LoadInfo* LI);
/* Remove register load insns */
void RemoveRemainders (StackOpData* D);
/* Remove the code that is unnecessary after translation of the sequence */
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.
*/
/* End of codeoptutil.h */
#endif

1027
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