#include "coptptrload.h"
#include "coptptrstore.h"
#include "coptpush.h"
+#include "coptshift.h"
#include "coptsize.h"
#include "coptstop.h"
#include "coptstore.h"
-/*****************************************************************************/
-/* Data */
-/*****************************************************************************/
-
-
-
-/* Shift types */
-enum {
- SHIFT_NONE,
- SHIFT_ASR_1,
- SHIFT_ASL_1,
- SHIFT_LSR_1,
- SHIFT_LSL_1
-};
-
-
-
-/*****************************************************************************/
-/* Optimize shifts */
-/*****************************************************************************/
-
-
-
-static unsigned OptShift1 (CodeSeg* S)
-/* A call to the shlaxN routine may get replaced by one or more asl insns
- * if the value of X is not used later. If X is used later, but it is zero
- * on entry and it's a shift by one, it may get replaced by:
- *
- * asl a
- * bcc L1
- * inx
- * L1:
- *
- */
-{
- unsigned Changes = 0;
- unsigned I;
-
- /* Walk over the entries */
- I = 0;
- while (I < CS_GetEntryCount (S)) {
-
- CodeEntry* N;
- CodeEntry* X;
- CodeLabel* L;
-
- /* Get next entry */
- CodeEntry* E = CS_GetEntry (S, I);
-
- /* Check for the sequence */
- if (E->OPC == OP65_JSR &&
- (strncmp (E->Arg, "shlax", 5) == 0 ||
- strncmp (E->Arg, "aslax", 5) == 0) &&
- strlen (E->Arg) == 6 &&
- IsDigit (E->Arg[5])) {
-
- if (!RegXUsed (S, I+1)) {
-
- /* Insert shift insns */
- unsigned Count = E->Arg[5] - '0';
- while (Count--) {
- X = NewCodeEntry (OP65_ASL, AM65_ACC, "a", 0, E->LI);
- CS_InsertEntry (S, X, I+1);
- }
-
- /* Delete the call to shlax */
- CS_DelEntry (S, I);
-
- /* Remember, we had changes */
- ++Changes;
-
- } else if (E->RI->In.RegX == 0 &&
- E->Arg[5] == '1' &&
- (N = CS_GetNextEntry (S, I)) != 0) {
-
- /* asl a */
- X = NewCodeEntry (OP65_ASL, AM65_ACC, "a", 0, E->LI);
- CS_InsertEntry (S, X, I+1);
-
- /* bcc L1 */
- L = CS_GenLabel (S, N);
- X = NewCodeEntry (OP65_BCC, AM65_BRA, L->Name, L, E->LI);
- CS_InsertEntry (S, X, I+2);
-
- /* inx */
- X = NewCodeEntry (OP65_INX, AM65_IMP, 0, 0, E->LI);
- CS_InsertEntry (S, X, I+3);
-
- /* Delete the call to shlax */
- CS_DelEntry (S, I);
-
- /* Remember, we had changes */
- ++Changes;
- }
-
- }
-
- /* Next entry */
- ++I;
-
- }
-
- /* Return the number of changes made */
- return Changes;
-}
-
-
-
-static unsigned OptShift2(CodeSeg* S)
-/* A call to the asrax1 routines may get replaced by something simpler, if
- * X is not used later:
- *
- * cmp #$80
- * ror a
- *
- */
-{
- unsigned Changes = 0;
- unsigned I;
-
- /* Walk over the entries */
- I = 0;
- while (I < CS_GetEntryCount (S)) {
-
- unsigned Count;
-
- /* Get next entry */
- CodeEntry* E = CS_GetEntry (S, I);
-
- /* Check for the sequence */
- if (E->OPC == OP65_JSR &&
- strncmp (E->Arg, "asrax", 5) == 0 &&
- strlen (E->Arg) == 6 &&
- IsDigit (E->Arg[5]) &&
- (Count = (E->Arg[5] - '0')) >= 1 &&
- Count * 100 <= S->CodeSizeFactor &&
- !RegXUsed (S, I+1)) {
-
- CodeEntry* X;
- unsigned J = I+1;
-
- /* Generate the replacement sequence */
- while (Count--) {
- /* cmp #$80 */
- X = NewCodeEntry (OP65_CMP, AM65_IMM, "$80", 0, E->LI);
- CS_InsertEntry (S, X, J++);
-
- /* ror a */
- X = NewCodeEntry (OP65_ROR, AM65_ACC, "a", 0, E->LI);
- CS_InsertEntry (S, X, J++);
- }
-
- /* Delete the call to asrax */
- CS_DelEntry (S, I);
-
- /* Remember, we had changes */
- ++Changes;
- }
-
- /* Next entry */
- ++I;
-
- }
-
- /* Return the number of changes made */
- return Changes;
-}
-
-
-
-static unsigned OptShift3 (CodeSeg* S)
-/* The sequence
- *
- * bcc L
- * inx
- * L: jsr shrax1
- *
- * may get replaced by
- *
- * ror a
- *
- * if X is zero on entry and unused later. For shift counts > 1, more
- *
- * shr a
- *
- * must be added.
- */
-{
- unsigned Changes = 0;
- unsigned I;
-
- /* Walk over the entries */
- I = 0;
- while (I < CS_GetEntryCount (S)) {
-
- CodeEntry* L[3];
-
- /* Get next entry */
- L[0] = CS_GetEntry (S, I);
-
- /* Check for the sequence */
- if ((L[0]->OPC == OP65_BCC || L[0]->OPC == OP65_JCC) &&
- L[0]->JumpTo != 0 &&
- L[0]->RI->In.RegX == 0 &&
- CS_GetEntries (S, L+1, I+1, 2) &&
- L[1]->OPC == OP65_INX &&
- L[0]->JumpTo->Owner == L[2] &&
- !CS_RangeHasLabel (S, I, 2) &&
- L[2]->OPC == OP65_JSR &&
- strlen (L[2]->Arg) == 6 &&
- memcmp (L[2]->Arg, "shrax", 5) == 0 &&
- IsDigit (L[2]->Arg[5]) &&
- !RegXUsed (S, I+3)) {
-
- unsigned ShiftCount = (L[2]->Arg[5] - '0');
-
- /* Add the replacement insn instead */
- CodeEntry* X = NewCodeEntry (OP65_ROR, AM65_ACC, "a", 0, L[2]->LI);
- CS_InsertEntry (S, X, I+3);
- while (--ShiftCount) {
- X = NewCodeEntry (OP65_LSR, AM65_ACC, "a", 0, L[2]->LI);
- CS_InsertEntry (S, X, I+4);
- }
-
- /* Remove the bcs/dex/jsr */
- CS_DelEntries (S, I, 3);
-
- /* Remember, we had changes */
- ++Changes;
-
- }
-
- /* Next entry */
- ++I;
-
- }
-
- /* Return the number of changes made */
- return Changes;
-}
-
-
-
-static unsigned OptShift4 (CodeSeg* S)
-/* Calls to the asraxN or shraxN routines may get replaced by one or more lsr
- * insns if the value of X is zero.
- */
-{
- unsigned Changes = 0;
- unsigned I;
-
- /* Walk over the entries */
- I = 0;
- while (I < CS_GetEntryCount (S)) {
-
- /* Get next entry */
- CodeEntry* E = CS_GetEntry (S, I);
-
- /* Check for the sequence */
- if (E->OPC == OP65_JSR &&
- (strncmp (E->Arg, "shrax", 5) == 0 ||
- strncmp (E->Arg, "asrax", 5) == 0) &&
- strlen (E->Arg) == 6 &&
- IsDigit (E->Arg[5]) &&
- E->RI->In.RegX == 0) {
-
- /* Insert shift insns */
- unsigned Count = E->Arg[5] - '0';
- while (Count--) {
- CodeEntry* X = NewCodeEntry (OP65_LSR, AM65_ACC, "a", 0, E->LI);
- CS_InsertEntry (S, X, I+1);
- }
-
- /* Delete the call to shrax */
- CS_DelEntry (S, I);
-
- /* Remember, we had changes */
- ++Changes;
-
- }
-
- /* Next entry */
- ++I;
-
- }
-
- /* Return the number of changes made */
- return Changes;
-}
-
-
-
-static unsigned GetShiftType (const char* Sub)
-/* Helper function for OptShift5 */
-{
- if (*Sub == 'a') {
- if (strcmp (Sub+1, "slax1") == 0) {
- return SHIFT_ASL_1;
- } else if (strcmp (Sub+1, "srax1") == 0) {
- return SHIFT_ASR_1;
- }
- } else if (*Sub == 's') {
- if (strcmp (Sub+1, "hlax1") == 0) {
- return SHIFT_LSL_1;
- } else if (strcmp (Sub+1, "hrax1") == 0) {
- return SHIFT_LSR_1;
- }
- }
- return SHIFT_NONE;
-}
-
-
-
-static unsigned OptShift5 (CodeSeg* S)
-/* Search for the sequence
- *
- * lda xxx
- * ldx yyy
- * jsr aslax1/asrax1/shlax1/shrax1
- * sta aaa
- * stx bbb
- *
- * and replace it by
- *
- * lda xxx
- * asl a
- * sta aaa
- * lda yyy
- * rol a
- * sta bbb
- *
- * or similar, provided that a/x is not used later
- */
-{
- unsigned Changes = 0;
-
- /* Walk over the entries */
- unsigned I = 0;
- while (I < CS_GetEntryCount (S)) {
-
- unsigned ShiftType;
- CodeEntry* L[5];
-
- /* Get next entry */
- L[0] = CS_GetEntry (S, I);
-
- /* Check for the sequence */
- if (L[0]->OPC == OP65_LDA &&
- (L[0]->AM == AM65_ABS || L[0]->AM == AM65_ZP) &&
- CS_GetEntries (S, L+1, I+1, 4) &&
- !CS_RangeHasLabel (S, I+1, 4) &&
- L[1]->OPC == OP65_LDX &&
- (L[1]->AM == AM65_ABS || L[1]->AM == AM65_ZP) &&
- L[2]->OPC == OP65_JSR &&
- (ShiftType = GetShiftType (L[2]->Arg)) != SHIFT_NONE&&
- L[3]->OPC == OP65_STA &&
- (L[3]->AM == AM65_ABS || L[3]->AM == AM65_ZP) &&
- L[4]->OPC == OP65_STX &&
- (L[4]->AM == AM65_ABS || L[4]->AM == AM65_ZP) &&
- !RegAXUsed (S, I+5)) {
-
- CodeEntry* X;
-
- /* Handle the four shift types differently */
- switch (ShiftType) {
-
- case SHIFT_ASR_1:
- X = NewCodeEntry (OP65_LDA, L[1]->AM, L[1]->Arg, 0, L[1]->LI);
- CS_InsertEntry (S, X, I+5);
- X = NewCodeEntry (OP65_CMP, AM65_IMM, "$80", 0, L[2]->LI);
- CS_InsertEntry (S, X, I+6);
- X = NewCodeEntry (OP65_ROR, AM65_ACC, "a", 0, L[2]->LI);
- CS_InsertEntry (S, X, I+7);
- X = NewCodeEntry (OP65_STA, L[4]->AM, L[4]->Arg, 0, L[4]->LI);
- CS_InsertEntry (S, X, I+8);
- X = NewCodeEntry (OP65_LDA, L[0]->AM, L[0]->Arg, 0, L[0]->LI);
- CS_InsertEntry (S, X, I+9);
- X = NewCodeEntry (OP65_ROR, AM65_ACC, "a", 0, L[2]->LI);
- CS_InsertEntry (S, X, I+10);
- X = NewCodeEntry (OP65_STA, L[3]->AM, L[3]->Arg, 0, L[3]->LI);
- CS_InsertEntry (S, X, I+11);
- CS_DelEntries (S, I, 5);
- break;
-
- case SHIFT_LSR_1:
- X = NewCodeEntry (OP65_LDA, L[1]->AM, L[1]->Arg, 0, L[1]->LI);
- CS_InsertEntry (S, X, I+5);
- X = NewCodeEntry (OP65_LSR, AM65_ACC, "a", 0, L[2]->LI);
- CS_InsertEntry (S, X, I+6);
- X = NewCodeEntry (OP65_STA, L[4]->AM, L[4]->Arg, 0, L[4]->LI);
- CS_InsertEntry (S, X, I+7);
- X = NewCodeEntry (OP65_LDA, L[0]->AM, L[0]->Arg, 0, L[0]->LI);
- CS_InsertEntry (S, X, I+8);
- X = NewCodeEntry (OP65_ROR, AM65_ACC, "a", 0, L[2]->LI);
- CS_InsertEntry (S, X, I+9);
- X = NewCodeEntry (OP65_STA, L[3]->AM, L[3]->Arg, 0, L[3]->LI);
- CS_InsertEntry (S, X, I+10);
- CS_DelEntries (S, I, 5);
- break;
-
- case SHIFT_LSL_1:
- case SHIFT_ASL_1:
- /* These two are identical */
- X = NewCodeEntry (OP65_ASL, AM65_ACC, "a", 0, L[2]->LI);
- CS_InsertEntry (S, X, I+1);
- X = NewCodeEntry (OP65_STA, L[3]->AM, L[3]->Arg, 0, L[3]->LI);
- CS_InsertEntry (S, X, I+2);
- X = NewCodeEntry (OP65_LDA, L[1]->AM, L[1]->Arg, 0, L[1]->LI);
- CS_InsertEntry (S, X, I+3);
- X = NewCodeEntry (OP65_ROL, AM65_ACC, "a", 0, L[2]->LI);
- CS_InsertEntry (S, X, I+4);
- X = NewCodeEntry (OP65_STA, L[4]->AM, L[4]->Arg, 0, L[4]->LI);
- CS_InsertEntry (S, X, I+5);
- CS_DelEntries (S, I+6, 4);
- break;
-
- }
-
- /* Remember, we had changes */
- ++Changes;
-
- }
-
- /* Next entry */
- ++I;
-
- }
-
- /* Return the number of changes made */
- return Changes;
-}
-
-
-
-static unsigned OptShift6 (CodeSeg* S)
-/* Inline the shift subroutines. */
-{
- unsigned Changes = 0;
-
- /* Walk over the entries */
- unsigned I = 0;
- while (I < CS_GetEntryCount (S)) {
-
- CodeEntry* X;
- unsigned IP;
-
- /* Get next entry */
- CodeEntry* E = CS_GetEntry (S, I);
-
- /* Check for a call to one of the shift routine */
- if (E->OPC == OP65_JSR &&
- (strncmp (E->Arg, "shlax", 5) == 0 ||
- strncmp (E->Arg, "aslax", 5) == 0) &&
- strlen (E->Arg) == 6 &&
- IsDigit (E->Arg[5])) {
-
- /* Get number of shifts */
- unsigned ShiftCount = (E->Arg[5] - '0');
-
- /* Code is:
- *
- * stx tmp1
- * asl a
- * rol tmp1
- * (repeat ShiftCount-1 times)
- * ldx tmp1
- *
- * which makes 4 + 3 * ShiftCount bytes, compared to the original
- * 3 bytes for the subroutine call. However, in most cases, the
- * final load of the X register gets merged with some other insn
- * and replaces a txa, so for a shift count of 1, we get a factor
- * of 200, which matches nicely the CodeSizeFactor enabled with -Oi
- */
- if (ShiftCount > 1 || S->CodeSizeFactor > 200) {
- unsigned Size = 4 + 3 * ShiftCount;
- if ((Size * 100 / 3) > S->CodeSizeFactor) {
- /* Not acceptable */
- goto NextEntry;
- }
- }
-
- /* Inline the code. Insertion point is behind the subroutine call */
- IP = (I + 1);
-
- /* stx tmp1 */
- X = NewCodeEntry (OP65_STX, AM65_ZP, "tmp1", 0, E->LI);
- CS_InsertEntry (S, X, IP++);
-
- while (ShiftCount--) {
- /* asl a */
- X = NewCodeEntry (OP65_ASL, AM65_ACC, "a", 0, E->LI);
- CS_InsertEntry (S, X, IP++);
-
- /* rol tmp1 */
- X = NewCodeEntry (OP65_ROL, AM65_ZP, "tmp1", 0, E->LI);
- CS_InsertEntry (S, X, IP++);
- }
-
- /* ldx tmp1 */
- X = NewCodeEntry (OP65_LDX, AM65_ZP, "tmp1", 0, E->LI);
- CS_InsertEntry (S, X, IP++);
-
- /* Remove the subroutine call */
- CS_DelEntry (S, I);
-
- /* Remember, we had changes */
- ++Changes;
- }
-
-NextEntry:
- /* Next entry */
- ++I;
-
- }
-
- /* Return the number of changes made */
- return Changes;
-}
-
-
-
/*****************************************************************************/
/* Optimize loads */
/*****************************************************************************/
--- /dev/null
+/*****************************************************************************/
+/* */
+/* coptshift.c */
+/* */
+/* Optimize shifts */
+/* */
+/* */
+/* */
+/* (C) 2001-2012, 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. */
+/* */
+/*****************************************************************************/
+
+
+
+/* common */
+#include "chartype.h"
+
+/* cc65 */
+#include "codeent.h"
+#include "codeinfo.h"
+#include "coptshift.h"
+
+
+
+/*****************************************************************************/
+/* Data */
+/*****************************************************************************/
+
+
+
+/* Shift types */
+enum {
+ SHIFT_NONE,
+ SHIFT_ASR_1,
+ SHIFT_ASL_1,
+ SHIFT_LSR_1,
+ SHIFT_LSL_1
+};
+
+
+
+/*****************************************************************************/
+/* Optimize shifts */
+/*****************************************************************************/
+
+
+
+unsigned OptShift1 (CodeSeg* S)
+/* A call to the shlaxN routine may get replaced by one or more asl insns
+ * if the value of X is not used later. If X is used later, but it is zero
+ * on entry and it's a shift by one, it may get replaced by:
+ *
+ * asl a
+ * bcc L1
+ * inx
+ * L1:
+ *
+ */
+{
+ unsigned Changes = 0;
+ unsigned I;
+
+ /* Walk over the entries */
+ I = 0;
+ while (I < CS_GetEntryCount (S)) {
+
+ CodeEntry* N;
+ CodeEntry* X;
+ CodeLabel* L;
+
+ /* Get next entry */
+ CodeEntry* E = CS_GetEntry (S, I);
+
+ /* Check for the sequence */
+ if (E->OPC == OP65_JSR &&
+ (strncmp (E->Arg, "shlax", 5) == 0 ||
+ strncmp (E->Arg, "aslax", 5) == 0) &&
+ strlen (E->Arg) == 6 &&
+ IsDigit (E->Arg[5])) {
+
+ if (!RegXUsed (S, I+1)) {
+
+ /* Insert shift insns */
+ unsigned Count = E->Arg[5] - '0';
+ while (Count--) {
+ X = NewCodeEntry (OP65_ASL, AM65_ACC, "a", 0, E->LI);
+ CS_InsertEntry (S, X, I+1);
+ }
+
+ /* Delete the call to shlax */
+ CS_DelEntry (S, I);
+
+ /* Remember, we had changes */
+ ++Changes;
+
+ } else if (E->RI->In.RegX == 0 &&
+ E->Arg[5] == '1' &&
+ (N = CS_GetNextEntry (S, I)) != 0) {
+
+ /* asl a */
+ X = NewCodeEntry (OP65_ASL, AM65_ACC, "a", 0, E->LI);
+ CS_InsertEntry (S, X, I+1);
+
+ /* bcc L1 */
+ L = CS_GenLabel (S, N);
+ X = NewCodeEntry (OP65_BCC, AM65_BRA, L->Name, L, E->LI);
+ CS_InsertEntry (S, X, I+2);
+
+ /* inx */
+ X = NewCodeEntry (OP65_INX, AM65_IMP, 0, 0, E->LI);
+ CS_InsertEntry (S, X, I+3);
+
+ /* Delete the call to shlax */
+ CS_DelEntry (S, I);
+
+ /* Remember, we had changes */
+ ++Changes;
+ }
+
+ }
+
+ /* Next entry */
+ ++I;
+
+ }
+
+ /* Return the number of changes made */
+ return Changes;
+}
+
+
+
+unsigned OptShift2(CodeSeg* S)
+/* A call to the asrax1 routines may get replaced by something simpler, if
+ * X is not used later:
+ *
+ * cmp #$80
+ * ror a
+ *
+ */
+{
+ unsigned Changes = 0;
+ unsigned I;
+
+ /* Walk over the entries */
+ I = 0;
+ while (I < CS_GetEntryCount (S)) {
+
+ unsigned Count;
+
+ /* Get next entry */
+ CodeEntry* E = CS_GetEntry (S, I);
+
+ /* Check for the sequence */
+ if (E->OPC == OP65_JSR &&
+ strncmp (E->Arg, "asrax", 5) == 0 &&
+ strlen (E->Arg) == 6 &&
+ IsDigit (E->Arg[5]) &&
+ (Count = (E->Arg[5] - '0')) >= 1 &&
+ Count * 100 <= S->CodeSizeFactor &&
+ !RegXUsed (S, I+1)) {
+
+ CodeEntry* X;
+ unsigned J = I+1;
+
+ /* Generate the replacement sequence */
+ while (Count--) {
+ /* cmp #$80 */
+ X = NewCodeEntry (OP65_CMP, AM65_IMM, "$80", 0, E->LI);
+ CS_InsertEntry (S, X, J++);
+
+ /* ror a */
+ X = NewCodeEntry (OP65_ROR, AM65_ACC, "a", 0, E->LI);
+ CS_InsertEntry (S, X, J++);
+ }
+
+ /* Delete the call to asrax */
+ CS_DelEntry (S, I);
+
+ /* Remember, we had changes */
+ ++Changes;
+ }
+
+ /* Next entry */
+ ++I;
+
+ }
+
+ /* Return the number of changes made */
+ return Changes;
+}
+
+
+
+unsigned OptShift3 (CodeSeg* S)
+/* The sequence
+ *
+ * bcc L
+ * inx
+ * L: jsr shrax1
+ *
+ * may get replaced by
+ *
+ * ror a
+ *
+ * if X is zero on entry and unused later. For shift counts > 1, more
+ *
+ * shr a
+ *
+ * must be added.
+ */
+{
+ unsigned Changes = 0;
+ unsigned I;
+
+ /* Walk over the entries */
+ I = 0;
+ while (I < CS_GetEntryCount (S)) {
+
+ CodeEntry* L[3];
+
+ /* Get next entry */
+ L[0] = CS_GetEntry (S, I);
+
+ /* Check for the sequence */
+ if ((L[0]->OPC == OP65_BCC || L[0]->OPC == OP65_JCC) &&
+ L[0]->JumpTo != 0 &&
+ L[0]->RI->In.RegX == 0 &&
+ CS_GetEntries (S, L+1, I+1, 2) &&
+ L[1]->OPC == OP65_INX &&
+ L[0]->JumpTo->Owner == L[2] &&
+ !CS_RangeHasLabel (S, I, 2) &&
+ L[2]->OPC == OP65_JSR &&
+ strlen (L[2]->Arg) == 6 &&
+ memcmp (L[2]->Arg, "shrax", 5) == 0 &&
+ IsDigit (L[2]->Arg[5]) &&
+ !RegXUsed (S, I+3)) {
+
+ unsigned ShiftCount = (L[2]->Arg[5] - '0');
+
+ /* Add the replacement insn instead */
+ CodeEntry* X = NewCodeEntry (OP65_ROR, AM65_ACC, "a", 0, L[2]->LI);
+ CS_InsertEntry (S, X, I+3);
+ while (--ShiftCount) {
+ X = NewCodeEntry (OP65_LSR, AM65_ACC, "a", 0, L[2]->LI);
+ CS_InsertEntry (S, X, I+4);
+ }
+
+ /* Remove the bcs/dex/jsr */
+ CS_DelEntries (S, I, 3);
+
+ /* Remember, we had changes */
+ ++Changes;
+
+ }
+
+ /* Next entry */
+ ++I;
+
+ }
+
+ /* Return the number of changes made */
+ return Changes;
+}
+
+
+
+unsigned OptShift4 (CodeSeg* S)
+/* Calls to the asraxN or shraxN routines may get replaced by one or more lsr
+ * insns if the value of X is zero.
+ */
+{
+ unsigned Changes = 0;
+ unsigned I;
+
+ /* Walk over the entries */
+ I = 0;
+ while (I < CS_GetEntryCount (S)) {
+
+ /* Get next entry */
+ CodeEntry* E = CS_GetEntry (S, I);
+
+ /* Check for the sequence */
+ if (E->OPC == OP65_JSR &&
+ (strncmp (E->Arg, "shrax", 5) == 0 ||
+ strncmp (E->Arg, "asrax", 5) == 0) &&
+ strlen (E->Arg) == 6 &&
+ IsDigit (E->Arg[5]) &&
+ E->RI->In.RegX == 0) {
+
+ /* Insert shift insns */
+ unsigned Count = E->Arg[5] - '0';
+ while (Count--) {
+ CodeEntry* X = NewCodeEntry (OP65_LSR, AM65_ACC, "a", 0, E->LI);
+ CS_InsertEntry (S, X, I+1);
+ }
+
+ /* Delete the call to shrax */
+ CS_DelEntry (S, I);
+
+ /* Remember, we had changes */
+ ++Changes;
+
+ }
+
+ /* Next entry */
+ ++I;
+
+ }
+
+ /* Return the number of changes made */
+ return Changes;
+}
+
+
+
+static unsigned GetShiftType (const char* Sub)
+/* Helper function for OptShift5 */
+{
+ if (*Sub == 'a') {
+ if (strcmp (Sub+1, "slax1") == 0) {
+ return SHIFT_ASL_1;
+ } else if (strcmp (Sub+1, "srax1") == 0) {
+ return SHIFT_ASR_1;
+ }
+ } else if (*Sub == 's') {
+ if (strcmp (Sub+1, "hlax1") == 0) {
+ return SHIFT_LSL_1;
+ } else if (strcmp (Sub+1, "hrax1") == 0) {
+ return SHIFT_LSR_1;
+ }
+ }
+ return SHIFT_NONE;
+}
+
+
+
+unsigned OptShift5 (CodeSeg* S)
+/* Search for the sequence
+ *
+ * lda xxx
+ * ldx yyy
+ * jsr aslax1/asrax1/shlax1/shrax1
+ * sta aaa
+ * stx bbb
+ *
+ * and replace it by
+ *
+ * lda xxx
+ * asl a
+ * sta aaa
+ * lda yyy
+ * rol a
+ * sta bbb
+ *
+ * or similar, provided that a/x is not used later
+ */
+{
+ unsigned Changes = 0;
+
+ /* Walk over the entries */
+ unsigned I = 0;
+ while (I < CS_GetEntryCount (S)) {
+
+ unsigned ShiftType;
+ CodeEntry* L[5];
+
+ /* Get next entry */
+ L[0] = CS_GetEntry (S, I);
+
+ /* Check for the sequence */
+ if (L[0]->OPC == OP65_LDA &&
+ (L[0]->AM == AM65_ABS || L[0]->AM == AM65_ZP) &&
+ CS_GetEntries (S, L+1, I+1, 4) &&
+ !CS_RangeHasLabel (S, I+1, 4) &&
+ L[1]->OPC == OP65_LDX &&
+ (L[1]->AM == AM65_ABS || L[1]->AM == AM65_ZP) &&
+ L[2]->OPC == OP65_JSR &&
+ (ShiftType = GetShiftType (L[2]->Arg)) != SHIFT_NONE&&
+ L[3]->OPC == OP65_STA &&
+ (L[3]->AM == AM65_ABS || L[3]->AM == AM65_ZP) &&
+ L[4]->OPC == OP65_STX &&
+ (L[4]->AM == AM65_ABS || L[4]->AM == AM65_ZP) &&
+ !RegAXUsed (S, I+5)) {
+
+ CodeEntry* X;
+
+ /* Handle the four shift types differently */
+ switch (ShiftType) {
+
+ case SHIFT_ASR_1:
+ X = NewCodeEntry (OP65_LDA, L[1]->AM, L[1]->Arg, 0, L[1]->LI);
+ CS_InsertEntry (S, X, I+5);
+ X = NewCodeEntry (OP65_CMP, AM65_IMM, "$80", 0, L[2]->LI);
+ CS_InsertEntry (S, X, I+6);
+ X = NewCodeEntry (OP65_ROR, AM65_ACC, "a", 0, L[2]->LI);
+ CS_InsertEntry (S, X, I+7);
+ X = NewCodeEntry (OP65_STA, L[4]->AM, L[4]->Arg, 0, L[4]->LI);
+ CS_InsertEntry (S, X, I+8);
+ X = NewCodeEntry (OP65_LDA, L[0]->AM, L[0]->Arg, 0, L[0]->LI);
+ CS_InsertEntry (S, X, I+9);
+ X = NewCodeEntry (OP65_ROR, AM65_ACC, "a", 0, L[2]->LI);
+ CS_InsertEntry (S, X, I+10);
+ X = NewCodeEntry (OP65_STA, L[3]->AM, L[3]->Arg, 0, L[3]->LI);
+ CS_InsertEntry (S, X, I+11);
+ CS_DelEntries (S, I, 5);
+ break;
+
+ case SHIFT_LSR_1:
+ X = NewCodeEntry (OP65_LDA, L[1]->AM, L[1]->Arg, 0, L[1]->LI);
+ CS_InsertEntry (S, X, I+5);
+ X = NewCodeEntry (OP65_LSR, AM65_ACC, "a", 0, L[2]->LI);
+ CS_InsertEntry (S, X, I+6);
+ X = NewCodeEntry (OP65_STA, L[4]->AM, L[4]->Arg, 0, L[4]->LI);
+ CS_InsertEntry (S, X, I+7);
+ X = NewCodeEntry (OP65_LDA, L[0]->AM, L[0]->Arg, 0, L[0]->LI);
+ CS_InsertEntry (S, X, I+8);
+ X = NewCodeEntry (OP65_ROR, AM65_ACC, "a", 0, L[2]->LI);
+ CS_InsertEntry (S, X, I+9);
+ X = NewCodeEntry (OP65_STA, L[3]->AM, L[3]->Arg, 0, L[3]->LI);
+ CS_InsertEntry (S, X, I+10);
+ CS_DelEntries (S, I, 5);
+ break;
+
+ case SHIFT_LSL_1:
+ case SHIFT_ASL_1:
+ /* These two are identical */
+ X = NewCodeEntry (OP65_ASL, AM65_ACC, "a", 0, L[2]->LI);
+ CS_InsertEntry (S, X, I+1);
+ X = NewCodeEntry (OP65_STA, L[3]->AM, L[3]->Arg, 0, L[3]->LI);
+ CS_InsertEntry (S, X, I+2);
+ X = NewCodeEntry (OP65_LDA, L[1]->AM, L[1]->Arg, 0, L[1]->LI);
+ CS_InsertEntry (S, X, I+3);
+ X = NewCodeEntry (OP65_ROL, AM65_ACC, "a", 0, L[2]->LI);
+ CS_InsertEntry (S, X, I+4);
+ X = NewCodeEntry (OP65_STA, L[4]->AM, L[4]->Arg, 0, L[4]->LI);
+ CS_InsertEntry (S, X, I+5);
+ CS_DelEntries (S, I+6, 4);
+ break;
+
+ }
+
+ /* Remember, we had changes */
+ ++Changes;
+
+ }
+
+ /* Next entry */
+ ++I;
+
+ }
+
+ /* Return the number of changes made */
+ return Changes;
+}
+
+
+
+unsigned OptShift6 (CodeSeg* S)
+/* Inline the shift subroutines. */
+{
+ unsigned Changes = 0;
+
+ /* Walk over the entries */
+ unsigned I = 0;
+ while (I < CS_GetEntryCount (S)) {
+
+ CodeEntry* X;
+ unsigned IP;
+
+ /* Get next entry */
+ CodeEntry* E = CS_GetEntry (S, I);
+
+ /* Check for a call to one of the shift routine */
+ if (E->OPC == OP65_JSR &&
+ (strncmp (E->Arg, "shlax", 5) == 0 ||
+ strncmp (E->Arg, "aslax", 5) == 0) &&
+ strlen (E->Arg) == 6 &&
+ IsDigit (E->Arg[5])) {
+
+ /* Get number of shifts */
+ unsigned ShiftCount = (E->Arg[5] - '0');
+
+ /* Code is:
+ *
+ * stx tmp1
+ * asl a
+ * rol tmp1
+ * (repeat ShiftCount-1 times)
+ * ldx tmp1
+ *
+ * which makes 4 + 3 * ShiftCount bytes, compared to the original
+ * 3 bytes for the subroutine call. However, in most cases, the
+ * final load of the X register gets merged with some other insn
+ * and replaces a txa, so for a shift count of 1, we get a factor
+ * of 200, which matches nicely the CodeSizeFactor enabled with -Oi
+ */
+ if (ShiftCount > 1 || S->CodeSizeFactor > 200) {
+ unsigned Size = 4 + 3 * ShiftCount;
+ if ((Size * 100 / 3) > S->CodeSizeFactor) {
+ /* Not acceptable */
+ goto NextEntry;
+ }
+ }
+
+ /* Inline the code. Insertion point is behind the subroutine call */
+ IP = (I + 1);
+
+ /* stx tmp1 */
+ X = NewCodeEntry (OP65_STX, AM65_ZP, "tmp1", 0, E->LI);
+ CS_InsertEntry (S, X, IP++);
+
+ while (ShiftCount--) {
+ /* asl a */
+ X = NewCodeEntry (OP65_ASL, AM65_ACC, "a", 0, E->LI);
+ CS_InsertEntry (S, X, IP++);
+
+ /* rol tmp1 */
+ X = NewCodeEntry (OP65_ROL, AM65_ZP, "tmp1", 0, E->LI);
+ CS_InsertEntry (S, X, IP++);
+ }
+
+ /* ldx tmp1 */
+ X = NewCodeEntry (OP65_LDX, AM65_ZP, "tmp1", 0, E->LI);
+ CS_InsertEntry (S, X, IP++);
+
+ /* Remove the subroutine call */
+ CS_DelEntry (S, I);
+
+ /* Remember, we had changes */
+ ++Changes;
+ }
+
+NextEntry:
+ /* Next entry */
+ ++I;
+
+ }
+
+ /* Return the number of changes made */
+ return Changes;
+}
+
+
+
--- /dev/null
+/*****************************************************************************/
+/* */
+/* coptshift.h */
+/* */
+/* Optimize shifts */
+/* */
+/* */
+/* */
+/* (C) 2001-2012, 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. */
+/* */
+/*****************************************************************************/
+
+
+
+#ifndef COPTSHIFT_H
+#define COPTSHIFT_H
+
+
+
+/* cc65 */
+#include "codeseg.h"
+
+
+
+/*****************************************************************************/
+/* Optimize shifts */
+/*****************************************************************************/
+
+
+
+unsigned OptShift1 (CodeSeg* S);
+/* A call to the shlaxN routine may get replaced by one or more asl insns
+ * if the value of X is not used later. If X is used later, but it is zero
+ * on entry and it's a shift by one, it may get replaced by:
+ *
+ * asl a
+ * bcc L1
+ * inx
+ * L1:
+ *
+ */
+
+unsigned OptShift2(CodeSeg* S);
+/* A call to the asrax1 routines may get replaced by something simpler, if
+ * X is not used later:
+ *
+ * cmp #$80
+ * ror a
+ *
+ */
+
+unsigned OptShift3 (CodeSeg* S);
+/* The sequence
+ *
+ * bcc L
+ * inx
+ * L: jsr shrax1
+ *
+ * may get replaced by
+ *
+ * ror a
+ *
+ * if X is zero on entry and unused later. For shift counts > 1, more
+ *
+ * shr a
+ *
+ * must be added.
+ */
+
+unsigned OptShift4 (CodeSeg* S);
+/* Calls to the asraxN or shraxN routines may get replaced by one or more lsr
+ * insns if the value of X is zero.
+ */
+
+unsigned OptShift5 (CodeSeg* S);
+/* Search for the sequence
+ *
+ * lda xxx
+ * ldx yyy
+ * jsr aslax1/asrax1/shlax1/shrax1
+ * sta aaa
+ * stx bbb
+ *
+ * and replace it by
+ *
+ * lda xxx
+ * asl a
+ * sta aaa
+ * lda yyy
+ * rol a
+ * sta bbb
+ *
+ * or similar, provided that a/x is not used later
+ */
+
+unsigned OptShift6 (CodeSeg* S);
+/* Inline the shift subroutines. */
+
+
+
+/* End of coptshift.h */
+#endif
+
+
+
coptptrload.o \
coptptrstore.o \
coptpush.o \
+ coptshift.o \
coptsize.o \
coptstop.o \
coptstore.o \
coptptrload.obj \
coptptrstore.obj\
coptpush.obj \
+ coptshift.obj \
coptsize.obj \
coptstop.obj \
coptstore.obj \
projects / cc65 / commitdiff