/*****************************************************************************/ /* */ /* coptptrstore.c */ /* */ /* Optimize stores through pointers */ /* */ /* */ /* */ /* (C) 2012, Ullrich von Bassewitz */ /* Roemerstrasse 52 */ /* D-70794 Filderstadt */ /* 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 /* common */ #include "chartype.h" #include "strbuf.h" #include "xmalloc.h" #include "xsprintf.h" /* cc65 */ #include "codeent.h" #include "codeinfo.h" #include "coptptrstore.h" /*****************************************************************************/ /* Helper functions */ /*****************************************************************************/ static unsigned OptPtrStore1Sub (CodeSeg* S, unsigned I, CodeEntry** const L) /* Check if this is one of the allowed suboperation for OptPtrStore1 */ { /* Check for a label attached to the entry */ if (CE_HasLabel (L[0])) { return 0; } /* Check for single insn sub ops */ if (L[0]->OPC == OP65_AND || L[0]->OPC == OP65_EOR || L[0]->OPC == OP65_ORA || (L[0]->OPC == OP65_JSR && (strncmp (L[0]->Arg, "shlax", 5) == 0 || strncmp (L[0]->Arg, "shrax", 5) == 0) && strlen (L[0]->Arg) == 6 && IsDigit (L[0]->Arg[5]))) { /* One insn */ return 1; } else if (L[0]->OPC == OP65_CLC && (L[1] = CS_GetNextEntry (S, I)) != 0 && L[1]->OPC == OP65_ADC && !CE_HasLabel (L[1])) { return 2; } else if (L[0]->OPC == OP65_SEC && (L[1] = CS_GetNextEntry (S, I)) != 0 && L[1]->OPC == OP65_SBC && !CE_HasLabel (L[1])) { return 2; } /* Not found */ return 0; } static const char* LoadAXZP (CodeSeg* S, unsigned I) /* If the two instructions preceeding S/I are a load of A/X from a two byte * zero byte location, return the name of the zero page location. Otherwise * return NULL. */ { CodeEntry* L[2]; unsigned Len; if (I >= 2 && CS_GetEntries (S, L, I-2, 2) && L[0]->OPC == OP65_LDA && L[0]->AM == AM65_ZP && L[1]->OPC == OP65_LDX && L[1]->AM == AM65_ZP && !CE_HasLabel (L[1]) && (Len = strlen (L[0]->Arg)) == strlen (L[1]->Arg) - 2 && memcmp (L[0]->Arg, L[1]->Arg, Len) == 0 && L[1]->Arg[Len] == '+' && L[1]->Arg[Len+1] == '1') { /* Return the label */ return L[0]->Arg; } else { /* Not found */ return 0; } } static const char* LoadAXImm (CodeSeg* S, unsigned I) /* If the instructions preceeding S/I are a load of A/X of a constant value * or a word sized address label, return the address of the location as a * string. * Beware: In case of a numeric value, the result is returned in static * storage which is overwritten with each call. */ { static StrBuf Buf = STATIC_STRBUF_INITIALIZER; CodeEntry* L[2]; CodeEntry* ALoad; CodeEntry* XLoad; unsigned Len; /* Fetch entry at I and check if A/X is known */ L[0] = CS_GetEntry (S, I); if (L[0] != 0 && RegValIsKnown (L[0]->RI->In.RegA) && RegValIsKnown (L[0]->RI->In.RegX)) { /* Numeric argument - get low and high byte */ unsigned Lo = (L[0]->RI->In.RegA & 0xFF); unsigned Hi = (L[0]->RI->In.RegX & 0xFF); /* Format into buffer */ SB_Printf (&Buf, "$%04X", Lo | (Hi << 8)); /* Return the address as a string */ return SB_GetConstBuf (&Buf); } /* Search back for the two instructions loading A and X. Abort * the search if the registers are changed in any other way or * if a label is reached while we don't have both loads. */ ALoad = 0; XLoad = 0; while (I-- > 0) { /* Get next entry */ CodeEntry* E = CS_GetEntry (S, I); /* Check for the loads of A and X */ if (ALoad == 0 && E->OPC == OP65_LDA && E->AM == AM65_IMM) { ALoad = E; } else if (E->Chg & REG_A) { /* A is changed before we get the load */ return 0; } else if (XLoad == 0 && E->OPC == OP65_LDX && E->AM == AM65_IMM) { XLoad = E; } else if (E->Chg & REG_X) { /* X is changed before we get the load */ return 0; } if (ALoad != 0 && XLoad != 0) { /* We have both */ break; } /* If we have a label, before both are found, bail out */ if (CE_HasLabel (E)) { return 0; } } /* Check for a load of a label address */ if ((Len = strlen (ALoad->Arg)) > 3 && ALoad->Arg[0] == '<' && ALoad->Arg[1] == '(' && strlen (XLoad->Arg) == Len && XLoad->Arg[0] == '>' && memcmp (ALoad->Arg+1, XLoad->Arg+1, Len-1) == 0) { /* Load of an address label */ SB_CopyBuf (&Buf, ALoad->Arg + 2, Len - 3); SB_Terminate (&Buf); return SB_GetConstBuf (&Buf); } /* Not found */ return 0; } /*****************************************************************************/ /* Code */ /*****************************************************************************/ unsigned OptPtrStore1 (CodeSeg* S) /* Search for the sequence: * * clc * adc xxx * bcc L * inx * L: jsr pushax * ldx #$00 * lda yyy * ldy #$00 * jsr staspidx * * and replace it by: * * sta ptr1 * stx ptr1+1 * ldy xxx * ldx #$00 * lda yyy * sta (ptr1),y * * or by * * ldy xxx * ldx #$00 * lda yyy * sta (zp),y * * or by * * ldy xxx * ldx #$00 * lda yyy * sta label,y * * or by * * ldy xxx * ldx #$00 * lda yyy * sta $xxxx,y * * depending on the code preceeding the sequence above. */ { unsigned Changes = 0; unsigned I; /* Walk over the entries */ I = 0; while (I < CS_GetEntryCount (S)) { CodeEntry* L[9]; /* Get next entry */ L[0] = CS_GetEntry (S, I); /* Check for the sequence */ if (L[0]->OPC == OP65_CLC && CS_GetEntries (S, L+1, I+1, 8) && L[1]->OPC == OP65_ADC && (L[1]->AM == AM65_ABS || L[1]->AM == AM65_ZP || L[1]->AM == AM65_IMM || (L[1]->AM == AM65_ZP_INDY && RegValIsKnown (L[1]->RI->In.RegY))) && (L[2]->OPC == OP65_BCC || L[2]->OPC == OP65_JCC) && L[2]->JumpTo != 0 && L[2]->JumpTo->Owner == L[4] && L[3]->OPC == OP65_INX && CE_IsCallTo (L[4], "pushax") && L[5]->OPC == OP65_LDX && L[6]->OPC == OP65_LDA && L[7]->OPC == OP65_LDY && CE_IsKnownImm (L[7], 0) && CE_IsCallTo (L[8], "staspidx") && !CS_RangeHasLabel (S, I+1, 3) && !CS_RangeHasLabel (S, I+5, 4)) { CodeEntry* X; const char* Loc; am_t AM; /* Track the insertion point */ unsigned IP = I + 9; if ((Loc = LoadAXZP (S, I)) != 0) { /* If the sequence is preceeded by a load of a ZP value, * we can use this ZP value as a pointer using ZP * indirect Y addressing. */ AM = AM65_ZP_INDY; } else if ((Loc = LoadAXImm (S, I)) != 0) { /* If the sequence is preceeded by a load of an immediate * value, we can use this absolute value as an address * using absolute indexed Y addressing. */ AM = AM65_ABSY; } /* If we don't have a store location, we use ptr1 with zp * indirect Y addressing. We must store the value in A/X into * ptr1 in this case. */ if (Loc == 0) { /* Must use ptr1 */ Loc = "ptr1"; AM = AM65_ZP_INDY; X = NewCodeEntry (OP65_STA, AM65_ZP, "ptr1", 0, L[8]->LI); CS_InsertEntry (S, X, IP++); X = NewCodeEntry (OP65_STX, AM65_ZP, "ptr1+1", 0, L[8]->LI); CS_InsertEntry (S, X, IP++); } /* If the index is loaded from (zp),y, we cannot do that directly. * Note: In this case, the Y register will contain the correct * value after removing the old code, so we don't need to load * it here. */ if (L[1]->AM == AM65_ZP_INDY) { X = NewCodeEntry (OP65_LDA, L[1]->AM, L[1]->Arg, 0, L[1]->LI); CS_InsertEntry (S, X, IP++); X = NewCodeEntry (OP65_TAY, AM65_IMP, 0, 0, L[1]->LI); CS_InsertEntry (S, X, IP++); } else { X = NewCodeEntry (OP65_LDY, L[1]->AM, L[1]->Arg, 0, L[1]->LI); CS_InsertEntry (S, X, IP++); } X = NewCodeEntry (OP65_LDX, L[5]->AM, L[5]->Arg, 0, L[5]->LI); CS_InsertEntry (S, X, IP++); X = NewCodeEntry (OP65_LDA, L[6]->AM, L[6]->Arg, 0, L[6]->LI); CS_InsertEntry (S, X, IP++); X = NewCodeEntry (OP65_STA, AM, Loc, 0, L[8]->LI); CS_InsertEntry (S, X, IP++); /* Remove the old code */ CS_DelEntries (S, I, 9); /* Skip most of the generated replacement code */ I += 3; /* Remember, we had changes */ ++Changes; } /* Next entry */ ++I; } /* Return the number of changes made */ return Changes; } unsigned OptPtrStore2 (CodeSeg* S) /* Search for the sequence: * * clc * adc xxx * bcc L * inx * L: jsr pushax * ldy yyy * ldx #$00 * lda (sp),y * ldy #$00 * jsr staspidx * * and replace it by: * * sta ptr1 * stx ptr1+1 * ldy yyy-2 * ldx #$00 * lda (sp),y * ldy xxx * sta (ptr1),y * * or by * * ldy yyy-2 * ldx #$00 * lda (sp),y * ldy xxx * sta (zp),y * * or by * * ldy yyy-2 * ldx #$00 * lda (sp),y * ldy xxx * sta label,y * * or by * * ldy yyy-2 * ldx #$00 * lda (sp),y * ldy xxx * sta $xxxx,y * * depending on the code preceeding the sequence above. */ { unsigned Changes = 0; unsigned I; /* Walk over the entries */ I = 0; while (I < CS_GetEntryCount (S)) { CodeEntry* L[10]; /* Get next entry */ L[0] = CS_GetEntry (S, I); /* Check for the sequence */ if (L[0]->OPC == OP65_CLC && CS_GetEntries (S, L+1, I+1, 9) && L[1]->OPC == OP65_ADC && (L[1]->AM == AM65_ABS || L[1]->AM == AM65_ZP || L[1]->AM == AM65_IMM || (L[1]->AM == AM65_ZP_INDY && RegValIsKnown (L[1]->RI->In.RegY))) && (L[2]->OPC == OP65_BCC || L[2]->OPC == OP65_JCC) && L[2]->JumpTo != 0 && L[2]->JumpTo->Owner == L[4] && L[3]->OPC == OP65_INX && CE_IsCallTo (L[4], "pushax") && L[5]->OPC == OP65_LDY && CE_IsConstImm (L[5]) && L[6]->OPC == OP65_LDX && L[7]->OPC == OP65_LDA && L[7]->AM == AM65_ZP_INDY && strcmp (L[7]->Arg, "sp") == 0 && L[8]->OPC == OP65_LDY && (L[8]->AM == AM65_ABS || L[8]->AM == AM65_ZP || L[8]->AM == AM65_IMM) && CE_IsCallTo (L[9], "staspidx") && !CS_RangeHasLabel (S, I+1, 3) && !CS_RangeHasLabel (S, I+5, 5)) { CodeEntry* X; const char* Arg; const char* Loc; am_t AM; /* Track the insertion point */ unsigned IP = I + 10; if ((Loc = LoadAXZP (S, I)) != 0) { /* If the sequence is preceeded by a load of a ZP value, * we can use this ZP value as a pointer using ZP * indirect Y addressing. */ AM = AM65_ZP_INDY; } else if ((Loc = LoadAXImm (S, I)) != 0) { /* If the sequence is preceeded by a load of an immediate * value, we can use this absolute value as an address * using absolute indexed Y addressing. */ AM = AM65_ABSY; } /* If we don't have a store location, we use ptr1 with zp * indirect Y addressing. We must store the value in A/X into * ptr1 in this case. */ if (Loc == 0) { /* Must use ptr1 */ Loc = "ptr1"; AM = AM65_ZP_INDY; X = NewCodeEntry (OP65_STA, AM65_ZP, "ptr1", 0, L[8]->LI); CS_InsertEntry (S, X, IP++); X = NewCodeEntry (OP65_STX, AM65_ZP, "ptr1+1", 0, L[8]->LI); CS_InsertEntry (S, X, IP++); } /* Generate four different replacements depending on the addressing * mode of the store and from where the index is loaded: * * 1. If the index is not loaded ZP indirect Y, we can use Y for * the store index. * * 2. If the index is loaded ZP indirect Y and we store absolute * indexed, we need Y to load the index and will therefore * use X as index for the store. The disadvantage is that we * need to reload X later. * * 3. If the index is loaded ZP indirect Y and we store ZP indirect * Y, we must use Y for load and store and must therefore save * the A register when loading Y the second time. */ if (L[1]->AM != AM65_ZP_INDY) { /* Case 1 */ Arg = MakeHexArg (L[5]->Num - 2); X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, L[5]->LI); CS_InsertEntry (S, X, IP++); X = NewCodeEntry (OP65_LDX, L[6]->AM, L[6]->Arg, 0, L[6]->LI); CS_InsertEntry (S, X, IP++); X = NewCodeEntry (OP65_LDA, L[7]->AM, L[7]->Arg, 0, L[7]->LI); CS_InsertEntry (S, X, IP++); X = NewCodeEntry (OP65_LDY, L[1]->AM, L[1]->Arg, 0, L[1]->LI); CS_InsertEntry (S, X, IP++); X = NewCodeEntry (OP65_STA, AM, Loc, 0, L[9]->LI); CS_InsertEntry (S, X, IP++); } else if (AM == AM65_ABSY) { /* Case 2 */ X = NewCodeEntry (OP65_LDA, L[1]->AM, L[1]->Arg, 0, L[1]->LI); CS_InsertEntry (S, X, IP++); X = NewCodeEntry (OP65_TAX, AM65_IMP, 0, 0, L[1]->LI); CS_InsertEntry (S, X, IP++); Arg = MakeHexArg (L[5]->Num - 2); X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, L[5]->LI); CS_InsertEntry (S, X, IP++); X = NewCodeEntry (OP65_LDA, L[7]->AM, L[7]->Arg, 0, L[7]->LI); CS_InsertEntry (S, X, IP++); X = NewCodeEntry (OP65_STA, AM65_ABSX, Loc, 0, L[9]->LI); CS_InsertEntry (S, X, IP++); X = NewCodeEntry (OP65_LDX, L[6]->AM, L[6]->Arg, 0, L[6]->LI); CS_InsertEntry (S, X, IP++); } else { /* Case 3 */ Arg = MakeHexArg (L[5]->Num - 2); X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, L[5]->LI); CS_InsertEntry (S, X, IP++); X = NewCodeEntry (OP65_LDX, L[6]->AM, L[6]->Arg, 0, L[6]->LI); CS_InsertEntry (S, X, IP++); X = NewCodeEntry (OP65_LDA, L[7]->AM, L[7]->Arg, 0, L[7]->LI); CS_InsertEntry (S, X, IP++); X = NewCodeEntry (OP65_PHA, AM65_IMP, 0, 0, L[6]->LI); CS_InsertEntry (S, X, IP++); Arg = MakeHexArg (L[1]->RI->In.RegY); X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, L[1]->LI); CS_InsertEntry (S, X, IP++); X = NewCodeEntry (OP65_LDA, L[1]->AM, L[1]->Arg, 0, L[1]->LI); CS_InsertEntry (S, X, IP++); X = NewCodeEntry (OP65_TAY, AM65_IMP, 0, 0, L[1]->LI); CS_InsertEntry (S, X, IP++); X = NewCodeEntry (OP65_PLA, AM65_IMP, 0, 0, L[6]->LI); CS_InsertEntry (S, X, IP++); X = NewCodeEntry (OP65_STA, AM, Loc, 0, L[9]->LI); CS_InsertEntry (S, X, IP++); } /* Remove the old code */ CS_DelEntries (S, I, 10); /* Skip most of the generated replacement code */ I += 4; /* Remember, we had changes */ ++Changes; } /* Next entry */ ++I; } /* Return the number of changes made */ return Changes; } unsigned OptPtrStore3 (CodeSeg* S) /* Search for the sequence: * * jsr pushax * ldy xxx * jsr ldauidx * subop * ldy yyy * jsr staspidx * * and replace it by: * * sta ptr1 * stx ptr1+1 * ldy xxx * ldx #$00 * lda (ptr1),y * subop * ldy yyy * sta (ptr1),y * * In case a/x is loaded from the register bank before the pushax, we can even * use the register bank instead of ptr1. * */ { unsigned Changes = 0; /* Walk over the entries */ unsigned I = 0; while (I < CS_GetEntryCount (S)) { unsigned K; CodeEntry* L[10]; /* Get next entry */ L[0] = CS_GetEntry (S, I); /* Check for the sequence */ if (CE_IsCallTo (L[0], "pushax") && CS_GetEntries (S, L+1, I+1, 3) && L[1]->OPC == OP65_LDY && CE_IsConstImm (L[1]) && !CE_HasLabel (L[1]) && CE_IsCallTo (L[2], "ldauidx") && !CE_HasLabel (L[2]) && (K = OptPtrStore1Sub (S, I+3, L+3)) > 0 && CS_GetEntries (S, L+3+K, I+3+K, 2) && L[3+K]->OPC == OP65_LDY && CE_IsConstImm (L[3+K]) && !CE_HasLabel (L[3+K]) && CE_IsCallTo (L[4+K], "staspidx") && !CE_HasLabel (L[4+K])) { const char* RegBank = 0; const char* ZPLoc = "ptr1"; CodeEntry* X; /* Get the preceeding two instructions and check them. We check * for: * lda regbank+n * ldx regbank+n+1 */ if (I > 1) { CodeEntry* P[2]; P[0] = CS_GetEntry (S, I-2); P[1] = CS_GetEntry (S, I-1); if (P[0]->OPC == OP65_LDA && P[0]->AM == AM65_ZP && P[1]->OPC == OP65_LDX && P[1]->AM == AM65_ZP && !CE_HasLabel (P[1]) && strncmp (P[0]->Arg, "regbank+", 8) == 0) { unsigned Len = strlen (P[0]->Arg); if (strncmp (P[0]->Arg, P[1]->Arg, Len) == 0 && P[1]->Arg[Len+0] == '+' && P[1]->Arg[Len+1] == '1' && P[1]->Arg[Len+2] == '\0') { /* Ok, found. Use the name of the register bank */ RegBank = ZPLoc = P[0]->Arg; } } } /* Insert the load via the zp pointer */ X = NewCodeEntry (OP65_LDX, AM65_IMM, "$00", 0, L[3]->LI); CS_InsertEntry (S, X, I+3); X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, ZPLoc, 0, L[2]->LI); CS_InsertEntry (S, X, I+4); /* Insert the store through the zp pointer */ X = NewCodeEntry (OP65_STA, AM65_ZP_INDY, ZPLoc, 0, L[3]->LI); CS_InsertEntry (S, X, I+6+K); /* Delete the old code */ CS_DelEntry (S, I+7+K); /* jsr spaspidx */ CS_DelEntry (S, I+2); /* jsr ldauidx */ /* Create and insert the stores into the zp pointer if needed */ if (RegBank == 0) { X = NewCodeEntry (OP65_STA, AM65_ZP, "ptr1", 0, L[0]->LI); CS_InsertEntry (S, X, I+1); X = NewCodeEntry (OP65_STX, AM65_ZP, "ptr1+1", 0, L[0]->LI); CS_InsertEntry (S, X, I+2); } /* Delete more old code. Do it here to keep a label attached to * entry I in place. */ CS_DelEntry (S, I); /* jsr pushax */ /* Remember, we had changes */ ++Changes; } /* Next entry */ ++I; } /* Return the number of changes made */ return Changes; }