70755921a9
Changed/added several optimizer steps to detect register variables correctly or to handle them in a special way. git-svn-id: svn://svn.cc65.org/cc65/trunk@1636 b7a2c559-68d2-44c3-8de9-860c34a00d81
822 lines
26 KiB
C
822 lines
26 KiB
C
/*****************************************************************************/
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/* */
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/* coptstop.c */
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/* */
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/* Optimize operations that take operands via the stack */
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/* */
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/* */
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/* */
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/* (C) 2001-2002 Ullrich von Bassewitz */
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/* Wacholderweg 14 */
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/* D-70597 Stuttgart */
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/* EMail: uz@cc65.org */
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/* */
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/* */
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/* This software is provided 'as-is', without any expressed or implied */
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/* warranty. In no event will the authors be held liable for any damages */
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/* arising from the use of this software. */
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/* */
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/* Permission is granted to anyone to use this software for any purpose, */
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/* including commercial applications, and to alter it and redistribute it */
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/* freely, subject to the following restrictions: */
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/* */
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/* 1. The origin of this software must not be misrepresented; you must not */
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/* claim that you wrote the original software. If you use this software */
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/* in a product, an acknowledgment in the product documentation would be */
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/* appreciated but is not required. */
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/* 2. Altered source versions must be plainly marked as such, and must not */
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/* be misrepresented as being the original software. */
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/* 3. This notice may not be removed or altered from any source */
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/* distribution. */
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/* */
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/*****************************************************************************/
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#include <stdlib.h>
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#include <ctype.h>
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/* cc65 */
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#include "codeent.h"
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#include "codeinfo.h"
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#include "coptstop.h"
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/*****************************************************************************/
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/* Data */
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/*****************************************************************************/
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/* Structure that holds the needed data */
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typedef struct StackOpData StackOpData;
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struct StackOpData {
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CodeSeg* Code; /* Pointer to code segment */
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unsigned Flags; /* Flags to remember things */
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unsigned PushIndex; /* Index of call to pushax in codeseg */
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unsigned OpIndex; /* Index of actual operation */
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CodeEntry* PrevEntry; /* Entry before the call to pushax */
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CodeEntry* PushEntry; /* Pointer to entry with call to pushax */
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CodeEntry* OpEntry; /* Pointer to entry with op */
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CodeEntry* NextEntry; /* Entry after the op */
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const char* ZPLo; /* Lo byte of zero page loc to use */
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const char* ZPHi; /* Hi byte of zero page loc to use */
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unsigned IP; /* Insertion point used by some routines */
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};
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/* Flags returned by DirectOp */
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#define OP_DIRECT 0x01 /* Direct op may be used */
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#define OP_RELOAD_Y 0x02 /* Must reload index register Y */
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/*****************************************************************************/
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/* Helpers */
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/*****************************************************************************/
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static unsigned AdjustStackOffset (CodeSeg* S, unsigned Start, unsigned Stop,
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unsigned Offs)
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/* Adjust the offset for all stack accesses in the range Start to Stop, both
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* inclusive. The function returns the number of instructions that have been
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* inserted.
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*/
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{
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/* Number of inserted instructions */
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unsigned Inserted = 0;
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/* Walk over all entries */
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unsigned I = Start;
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while (I <= Stop) {
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CodeEntry* E = CS_GetEntry (S, I);
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int NeedCorrection = 0;
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if ((E->Use & REG_SP) != 0) {
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/* Check for some things that should not happen */
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CHECK (E->AM == AM65_ZP_INDY || E->RI->In.RegY >= (short) Offs);
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CHECK (strcmp (E->Arg, "sp") == 0);
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/* We need to correct this one */
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NeedCorrection = 1;
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} else if (CE_IsCallTo (E, "ldaxysp")) {
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/* We need to correct this one */
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NeedCorrection = 1;
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}
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if (NeedCorrection) {
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CodeEntry* P;
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/* Get the code entry before this one. If it's a LDY, adjust the
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* value.
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*/
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P = CS_GetPrevEntry (S, I);
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if (P && P->OPC == OP65_LDY && CE_KnownImm (P)) {
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/* The Y load is just before the stack access, adjust it */
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CE_SetNumArg (P, P->Num - Offs);
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} else {
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/* Insert a new load instruction before the stack access */
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const char* Arg = MakeHexArg (E->RI->In.RegY - Offs);
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CodeEntry* X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, E->LI);
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CS_InsertEntry (S, X, I);
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/* One more inserted entries */
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++Inserted;
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++Stop;
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/* Be sure to skip the stack access for the next round */
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++I;
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}
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}
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/* Next entry */
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++I;
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}
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/* Return the number of inserted entries */
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return Inserted;
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}
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static void InsertEntry (StackOpData* D, CodeEntry* E, unsigned Index)
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/* Insert a new entry. Depending on Index, D->PushIndex and D->OpIndex will
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* be adjusted by this function.
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*/
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{
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/* Insert the entry into the code segment */
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CS_InsertEntry (D->Code, E, Index);
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/* Adjust the indices if necessary */
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if (D->PushEntry && Index <= D->PushIndex) {
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++D->PushIndex;
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}
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if (D->OpEntry && Index <= D->OpIndex) {
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++D->OpIndex;
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}
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}
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static void DelEntry (StackOpData* D, unsigned Index)
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/* Delete an entry. Depending on Index, D->PushIndex and D->OpIndex will be
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* adjusted by this function, and PushEntry/OpEntry may get invalidated.
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*/
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{
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/* Delete the entry from the code segment */
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CS_DelEntry (D->Code, Index);
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/* Adjust the indices if necessary */
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if (Index < D->PushIndex) {
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--D->PushIndex;
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} else if (Index == D->PushIndex) {
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D->PushEntry = 0;
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}
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if (Index < D->OpIndex) {
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--D->OpIndex;
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} else if (Index == D->OpIndex) {
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D->OpEntry = 0;
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}
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}
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static void CheckDirectOp (StackOpData* D)
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/* Check if the given entry is a lda instruction with an addressing mode
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* that allows us to replace it by another operation (like ora). If so, we may
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* use this location for the or and must not save the value in the zero
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* page location.
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*/
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{
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/* We need the entry before the push */
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CodeEntry* E;
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CHECK ((E = D->PrevEntry) != 0);
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if (E->OPC == OP65_LDA) {
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if (E->AM == AM65_IMM || E->AM == AM65_ZP || E->AM == AM65_ABS) {
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/* These insns are all ok and replaceable */
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D->Flags |= OP_DIRECT;
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} else if (E->AM == AM65_ZP_INDY && RegValIsKnown (E->RI->In.RegY)) {
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/* Load indirect with known offset is also ok */
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D->Flags |= (OP_DIRECT | OP_RELOAD_Y);
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}
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}
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}
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static void ReplacePushByStore (StackOpData* D)
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/* Replace the call to the push subroutine by a store into the zero page
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* location (actually, the push is not replaced, because we need it for
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* later, but the name is still ok since the push will get removed at the
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* end of each routine).
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*/
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{
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CodeEntry* X;
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/* Store the value into the zeropage instead of pushing it */
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X = NewCodeEntry (OP65_STX, AM65_ZP, D->ZPHi, 0, D->PushEntry->LI);
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InsertEntry (D, X, D->PushIndex+1);
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if ((D->Flags & OP_DIRECT) == 0) {
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X = NewCodeEntry (OP65_STA, AM65_ZP, D->ZPLo, 0, D->PushEntry->LI);
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InsertEntry (D, X, D->PushIndex+1);
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}
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}
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static void AddOpLow (StackOpData* D, opc_t OPC)
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/* Add an op for the low byte of an operator. This function honours the
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* OP_DIRECT and OP_RELOAD_Y flags and generates the necessary instructions.
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* All code is inserted at the current insertion point.
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*/
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{
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CodeEntry* X;
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if ((D->Flags & OP_DIRECT) != 0) {
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/* Op with a variable location. If the location is on the stack, we
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* need to reload the Y register.
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*/
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if ((D->Flags & OP_RELOAD_Y) != 0) {
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const char* Arg = MakeHexArg (D->PrevEntry->RI->In.RegY);
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X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, D->OpEntry->LI);
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InsertEntry (D, X, D->IP++);
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}
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X = NewCodeEntry (OPC, D->PrevEntry->AM, D->PrevEntry->Arg, 0, D->OpEntry->LI);
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} else {
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/* Op with temp storage */
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X = NewCodeEntry (OPC, AM65_ZP, D->ZPLo, 0, D->OpEntry->LI);
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}
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InsertEntry (D, X, D->IP++);
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}
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static void AddOpHigh (StackOpData* D, opc_t OPC)
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/* Add an op for the high byte of an operator. Special cases (constant values
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* or similar have to be checked separately, the function covers only the
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* generic case. Code is inserted at the insertion point.
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*/
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{
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CodeEntry* X;
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/* High byte is unknown */
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X = NewCodeEntry (OP65_STA, AM65_ZP, D->ZPLo, 0, D->OpEntry->LI);
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InsertEntry (D, X, D->IP++);
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X = NewCodeEntry (OP65_TXA, AM65_IMP, 0, 0, D->OpEntry->LI);
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InsertEntry (D, X, D->IP++);
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X = NewCodeEntry (OPC, AM65_ZP, D->ZPHi, 0, D->OpEntry->LI);
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InsertEntry (D, X, D->IP++);
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X = NewCodeEntry (OP65_TAX, AM65_IMP, 0, 0, D->OpEntry->LI);
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InsertEntry (D, X, D->IP++);
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X = NewCodeEntry (OP65_LDA, AM65_ZP, D->ZPLo, 0, D->OpEntry->LI);
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InsertEntry (D, X, D->IP++);
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}
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static void RemovePushAndOp (StackOpData* D)
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/* Remove the call to pushax and the call to the operator subroutine */
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{
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DelEntry (D, D->OpIndex);
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DelEntry (D, D->PushIndex);
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}
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static const char* IsRegVar (const StackOpData* D)
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/* If the value pushed is that of a register variable, return the name of the
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* entry in the register bank. Otherwise return NULL.
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*/
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{
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CodeEntry* P;
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if (D->PushIndex >= 2 &&
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(P = D->PrevEntry) != 0 &&
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P->OPC == OP65_LDX &&
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P->AM == AM65_ZP &&
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strncmp (P->Arg, "regbank+", 7) == 0 &&
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isdigit (P->Arg[8]) &&
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(P = CS_GetEntry (D->Code, D->PushIndex-2)) != 0 &&
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P->OPC == OP65_LDA &&
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P->AM == AM65_ZP &&
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strncmp (P->Arg, "regbank+", 7) == 0 &&
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isdigit (P->Arg[8])) {
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/* Ok, it loads the register variable */
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return P->Arg;
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} else {
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return 0;
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}
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}
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/*****************************************************************************/
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/* Actual optimization functions */
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/*****************************************************************************/
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static unsigned Opt_staspidx (StackOpData* D)
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/* Optimize the staspidx sequence if possible */
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{
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CodeEntry* X;
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const char* ZPLo;
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/* Check if we're using a register variable */
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if ((ZPLo = IsRegVar (D)) == 0) {
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/* Store the value into the zeropage instead of pushing it */
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ReplacePushByStore (D);
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/* Use the given zero page loc */
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ZPLo = D->ZPLo;
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}
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/* Replace the store subroutine call by a direct op */
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X = NewCodeEntry (OP65_STA, AM65_ZP_INDY, ZPLo, 0, D->OpEntry->LI);
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InsertEntry (D, X, D->OpIndex+1);
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/* Remove the push and the call to the staspidx function */
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RemovePushAndOp (D);
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/* We changed the sequence */
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return 1;
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}
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static unsigned Opt_staxspidx (StackOpData* D)
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/* Optimize the staxspidx sequence if possible */
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{
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CodeEntry* X;
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const char* ZPLo;
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/* Check if we're using a register variable */
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if ((ZPLo = IsRegVar (D)) == 0) {
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/* Store the value into the zeropage instead of pushing it */
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ReplacePushByStore (D);
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/* Use the given zero page loc */
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ZPLo = D->ZPLo;
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}
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/* Inline the store */
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X = NewCodeEntry (OP65_STA, AM65_ZP_INDY, ZPLo, 0, D->OpEntry->LI);
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InsertEntry (D, X, D->OpIndex+1);
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X = NewCodeEntry (OP65_INY, AM65_IMP, 0, 0, D->OpEntry->LI);
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InsertEntry (D, X, D->OpIndex+2);
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if (RegValIsKnown (D->OpEntry->RI->In.RegX)) {
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/* Value of X is known */
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const char* Arg = MakeHexArg (D->OpEntry->RI->In.RegX);
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X = NewCodeEntry (OP65_LDA, AM65_IMM, Arg, 0, D->OpEntry->LI);
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} else {
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/* Value unknown */
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X = NewCodeEntry (OP65_TXA, AM65_IMP, 0, 0, D->OpEntry->LI);
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}
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InsertEntry (D, X, D->OpIndex+3);
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X = NewCodeEntry (OP65_STA, AM65_ZP_INDY, ZPLo, 0, D->OpEntry->LI);
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InsertEntry (D, X, D->OpIndex+4);
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/* Remove the push and the call to the staspidx function */
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RemovePushAndOp (D);
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/* We changed the sequence */
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return 1;
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}
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static unsigned Opt_tosaddax (StackOpData* D)
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/* Optimize the tosaddax sequence if possible */
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{
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CodeEntry* X;
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/* We need the entry behind the add */
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CHECK (D->NextEntry != 0);
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/* Check the entry before the push. If it's a lda instruction with an
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* addressing mode that allows us to replace it, we may use this
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* location for the op and must not save the value in the zero page
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* location.
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*/
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CheckDirectOp (D);
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/* Store the value into the zeropage instead of pushing it */
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ReplacePushByStore (D);
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/* Inline the add */
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D->IP = D->OpIndex+1;
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X = NewCodeEntry (OP65_CLC, AM65_IMP, 0, 0, D->OpEntry->LI);
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InsertEntry (D, X, D->IP++);
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/* Low byte */
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AddOpLow (D, OP65_ADC);
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/* High byte */
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if (D->PushEntry->RI->In.RegX == 0) {
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/* The high byte is the value in X plus the carry */
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CodeLabel* L = CS_GenLabel (D->Code, D->NextEntry);
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X = NewCodeEntry (OP65_BCC, AM65_BRA, L->Name, L, D->OpEntry->LI);
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InsertEntry (D, X, D->IP++);
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X = NewCodeEntry (OP65_INX, AM65_IMP, 0, 0, D->OpEntry->LI);
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InsertEntry (D, X, D->IP++);
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} else if (D->OpEntry->RI->In.RegX == 0) {
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/* The high byte is that of the first operand plus carry */
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CodeLabel* L;
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if (RegValIsKnown (D->PushEntry->RI->In.RegX)) {
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/* Value of first op high byte is known */
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const char* Arg = MakeHexArg (D->PushEntry->RI->In.RegX);
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X = NewCodeEntry (OP65_LDX, AM65_IMM, Arg, 0, D->OpEntry->LI);
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} else {
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/* Value of first op high byte is unknown */
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X = NewCodeEntry (OP65_LDX, AM65_ZP, D->ZPHi, 0, D->OpEntry->LI);
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}
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InsertEntry (D, X, D->IP++);
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L = CS_GenLabel (D->Code, D->NextEntry);
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X = NewCodeEntry (OP65_BCC, AM65_BRA, L->Name, L, D->OpEntry->LI);
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InsertEntry (D, X, D->IP++);
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X = NewCodeEntry (OP65_INX, AM65_IMP, 0, 0, D->OpEntry->LI);
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InsertEntry (D, X, D->IP++);
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} else {
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/* High byte is unknown */
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AddOpHigh (D, OP65_ADC);
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}
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/* Remove the push and the call to the tosaddax function */
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RemovePushAndOp (D);
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/* We changed the sequence */
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return 1;
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}
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static unsigned Opt_tosandax (StackOpData* D)
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/* Optimize the tosandax sequence if possible */
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{
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CodeEntry* X;
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/* Check the entry before the push. If it's a lda instruction with an
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* addressing mode that allows us to replace it, we may use this
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* location for the op and must not save the value in the zero page
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* location.
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*/
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CheckDirectOp (D);
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/* Store the value into the zeropage instead of pushing it */
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ReplacePushByStore (D);
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/* Inline the and, low byte */
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D->IP = D->OpIndex + 1;
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AddOpLow (D, OP65_AND);
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/* High byte */
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if (D->PushEntry->RI->In.RegX == 0 || D->OpEntry->RI->In.RegX == 0) {
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/* The high byte is zero */
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X = NewCodeEntry (OP65_LDX, AM65_IMM, "$00", 0, D->OpEntry->LI);
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InsertEntry (D, X, D->IP++);
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} else {
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/* High byte is unknown */
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AddOpHigh (D, OP65_AND);
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}
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/* Remove the push and the call to the tosandax function */
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RemovePushAndOp (D);
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/* We changed the sequence */
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return 1;
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}
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static unsigned Opt_tosorax (StackOpData* D)
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/* Optimize the tosorax sequence if possible */
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{
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CodeEntry* X;
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/* Check the entry before the push. If it's a lda instruction with an
|
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* 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
|
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* location.
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*/
|
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CheckDirectOp (D);
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|
|
|
/* Store the value into the zeropage instead of pushing it */
|
|
ReplacePushByStore (D);
|
|
|
|
/* Inline the or, low byte */
|
|
D->IP = D->OpIndex + 1;
|
|
AddOpLow (D, OP65_ORA);
|
|
|
|
/* 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);
|
|
}
|
|
|
|
/* Remove the push and the call to the tosorax function */
|
|
RemovePushAndOp (D);
|
|
|
|
/* We changed the sequence */
|
|
return 1;
|
|
}
|
|
|
|
|
|
|
|
static unsigned Opt_tosxorax (StackOpData* D)
|
|
/* Optimize the tosxorax sequence if possible */
|
|
{
|
|
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);
|
|
|
|
/* 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_EOR);
|
|
}
|
|
|
|
/* Remove the push and the call to the tosandax function */
|
|
RemovePushAndOp (D);
|
|
|
|
/* We changed the sequence */
|
|
return 1;
|
|
}
|
|
|
|
|
|
|
|
/*****************************************************************************/
|
|
/* 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 },
|
|
};
|
|
#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);
|
|
}
|
|
|
|
|
|
|
|
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.
|
|
*/
|
|
{
|
|
return bsearch (Name, FuncTable, FUNC_COUNT, sizeof(OptFuncDesc), CmpFunc);
|
|
}
|
|
|
|
|
|
|
|
static int CmpHarmless (const void* Key, const void* Entry)
|
|
/* Compare function for bsearch */
|
|
{
|
|
return strcmp (Key, *(const char**)Entry);
|
|
}
|
|
|
|
|
|
|
|
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.
|
|
*/
|
|
{
|
|
static const char* Tab[] = {
|
|
"ldaxidx",
|
|
"ldaxysp",
|
|
};
|
|
|
|
void* R = bsearch (Name,
|
|
Tab,
|
|
sizeof (Tab) / sizeof (Tab[0]),
|
|
sizeof (Tab[0]),
|
|
CmpHarmless);
|
|
return (R != 0);
|
|
}
|
|
|
|
|
|
|
|
/*****************************************************************************/
|
|
/* 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;
|
|
|
|
|
|
/* Generate register info */
|
|
CS_GenRegInfo (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.
|
|
*/
|
|
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);
|
|
} else {
|
|
/* A call to an unkown subroutine ends the sequence */
|
|
InSeq = 0;
|
|
}
|
|
|
|
} else {
|
|
/* Other stuff: Track zeropage register usage */
|
|
UsedRegs |= (E->Use | E->Chg);
|
|
}
|
|
|
|
} else if (CE_IsCallTo (E, "pushax")) {
|
|
|
|
/* This starts a sequence */
|
|
Push = I;
|
|
UsedRegs = REG_NONE;
|
|
InSeq = 1;
|
|
|
|
}
|
|
|
|
/* Next entry */
|
|
++I;
|
|
|
|
}
|
|
|
|
/* Free the register info */
|
|
CS_FreeRegInfo (S);
|
|
|
|
/* Return the number of changes made */
|
|
return Changes;
|
|
}
|
|
|
|
|
|
|