mirror of
https://github.com/cc65/cc65.git
synced 2025-01-11 11:30:13 +00:00
Added optimizations for commutative arithmetic ops
git-svn-id: svn://svn.cc65.org/cc65/trunk@469 b7a2c559-68d2-44c3-8de9-860c34a00d81
This commit is contained in:
cuz
parent
901a8088e6
commit
cefb4c067d
@ -177,6 +177,8 @@ static const struct {
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{ "\tstz\t", 0, REG_NONE, REG_NONE },
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{ "\ttax", 1, REG_A, REG_X },
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{ "\ttay", 1, REG_A, REG_Y },
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{ "\ttrb\t", 0, REG_A, REG_NONE },
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{ "\ttsb\t", 0, REG_A, REG_NONE },
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{ "\ttsx", 1, REG_NONE, REG_X },
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{ "\ttxa", 1, REG_X, REG_A },
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{ "\ttya", 1, REG_Y, REG_A },
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@ -1754,20 +1756,20 @@ static void OptRegLoads (void)
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/* Search for a load of X and check if the value is used later */
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if (LineMatch (L, "\tldx\t") &&
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!RegXUsed (L) &&
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!IsCondJump (NextInstruction (L))) {
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!RegXUsed (L) &&
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!IsCondJump (NextInstruction (L))) {
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/* Remember to delete this line */
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Delete = 1;
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/* Remember to delete this line */
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Delete = 1;
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}
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/* Search for a load of A and check if the value is used later */
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else if (LineMatch (L, "\tlda\t") &&
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!RegAUsed (L) &&
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!IsCondJump (NextInstruction (L))) {
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!RegAUsed (L) &&
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!IsCondJump (NextInstruction (L))) {
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/* Remember to delete this line */
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Delete = 1;
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/* Remember to delete this line */
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Delete = 1;
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}
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/* Search for a load of Y and check if the value is used later */
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@ -1775,16 +1777,16 @@ static void OptRegLoads (void)
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!RegYUsed (L) &&
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!IsCondJump (NextInstruction (L))) {
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/* Remember to delete this line */
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Delete = 1;
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/* Remember to delete this line */
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Delete = 1;
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}
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/* Go to the next line, delete the current if requested */
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Lx = L;
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L = NextCodeLine (L);
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if (Delete) {
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FreeLine (Lx);
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++Deletions;
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FreeLine (Lx);
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++Deletions;
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}
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}
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} while (Deletions > 0);
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@ -1932,7 +1934,7 @@ static int OptPtrOps1 (Line** Start)
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/* Store to pointer */
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L = ReplaceLine (L, L3[5]->Line);
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L = NewLineAfter (L, "\tldy\t#$00");
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L = NewLineAfter (L, "\tldy\t#$00");
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L = NewLineAfter (L, "\tsta\t(%s),y", Reg);
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L = NewLineAfter (L, "\tinc\t%s", Reg);
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L = NewLineAfter (L, "\tbne\t*+4");
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@ -2197,7 +2199,7 @@ static int OptPtrOps2 (Line** Start)
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L = NewLineAfter (L, "\tlda\t(ptr1,x)");
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NeedLoad = 0;
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++LinesToRemove;
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} else if (LineFullMatch (L3[1], "\tsta\tptr1") &&
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} else if (LineFullMatch (L3[1], "\tsta\tptr1") &&
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GetNextCodeLines (L3[1], &L3[2], 3) &&
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LineFullMatch (L3[2], "\tstx\tptr1+1") &&
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LineFullMatch (L3[3], "\tldx\t#$00") &&
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@ -2627,7 +2629,7 @@ static void OptPtrOps (void)
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else if (LineMatch (L, "\tldy\t#$") &&
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GetNextCodeLines (L, L2, 6) &&
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LineFullMatch (L2 [0], "\tlda\t(sp),y") &&
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LineFullMatch (L2 [1], "\ttax") &&
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LineFullMatch (L2 [1], "\ttax") &&
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LineFullMatch (L2 [2], "\tdey") &&
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LineFullMatch (L2 [3], "\tlda\t(sp),y") &&
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LineMatch (L2 [4], "\tldy\t#$") &&
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@ -2782,7 +2784,7 @@ static void OptRegVars (void)
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* lda regbank+n
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* ldx regbank+n+1
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* ldy #$..
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* jsr ldauidx
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* jsr ldauidx
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*
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* and replace it by:
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*
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@ -2868,7 +2870,7 @@ static void OptRegVars (void)
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*
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* ldy #$mm
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* lda (sp),y
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* ldy #$ll
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* ldy #$ll
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* sta (regbank+n),y
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*
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* The source form is not generated by the parser but by the optimizer.
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@ -2954,7 +2956,7 @@ static void OptDoubleJumps (void)
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if ((D = GetJumpDistance (L, FinalTarget)) >= 123) {
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break;
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}
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}
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}
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/* Make sure the jump does indeed point to another label.
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* It may happen that this is not the case for some endless
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@ -3186,7 +3188,7 @@ static void OptCompares2 (void)
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* jne/jeq ...
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*/
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else if (LineMatch (L, "\tldy\t#$") &&
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GetNextCodeLines (L, L2, 8) &&
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GetNextCodeLines (L, L2, 8) &&
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LineFullMatch (L2[0], "\tlda\t(sp),y") &&
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LineFullMatch (L2[1], "\ttax") &&
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LineFullMatch (L2[2], "\tdey") &&
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@ -3304,7 +3306,7 @@ static void OptTests (void)
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{
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Line* L2 [2];
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const char* BitOps [] = {
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static const char* BitOps [] = {
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"\tand\t",
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"\tora\t",
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"\teor\t",
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@ -3323,7 +3325,7 @@ static void OptTests (void)
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/* Search for lda/tay/jne or lda/tay/jeq, remove the tay.
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* Search for
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* lda/and/ora/eor
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* lda/and/ora/eor
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* cmp #$00
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* jne/jeq ...
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* Remove the cmp.
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@ -3401,6 +3403,127 @@ static void OptTests (void)
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static void OptBitOps (void)
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/* Optimize bit oeprations */
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{
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Line* L2 [2];
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/* Walk over the code */
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Line* L = FirstCode;
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while (L) {
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/* Search for
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*
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* lda xxx
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* and #$yy ; adc/eor/ora
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* sta xxx
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*
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* and replace it by
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*
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* lda #$yy
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* and xxx
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* sta xxx
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*
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* While this saves nothing here, it transforms the code to contain an
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* explicit register load that may be removed by the basic block
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* optimization later. As a special optimization for the 65C02, the
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* "ora" and "and" ops may be replaced by "trb" and "tsb" resp. if the
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* value in A is not used later.
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*/
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if (LineMatch (L, "\tlda\t") &&
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L->Line[5] != '#' &&
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GetNextCodeLines (L, L2, 2) &&
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LineMatch (L2[1], "\tsta\t") &&
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strcmp (L->Line+5, L2[1]->Line+5) == 0) {
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if (LineMatch (L2[0], "\tand\t#$")) {
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unsigned Val = GetHexNum (L2[0]->Line+7);
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if (Val == 0x00) {
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/* AND with 0x00, remove the mem access */
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FreeLine (L);
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FreeLine (L2[1]);
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/* Replace the AND by a load */
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L = ReplaceLine (L2[0], "\tlda\t#$%02X", Val);
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} else if (Val == 0xFF) {
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/* AND with 0xFF, just load the value from memory */
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FreeLines (L2[0], L2[1]);
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} else if (CPU == CPU_65C02 &&
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!IsXAddrMode (L) &&
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!IsYAddrMode (L) &&
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!RegAUsed (L2[1])) {
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/* Replace by trb */
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ReplaceLine (L, "\tlda\t#$%02X", (~Val) & 0xFF);
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ReplaceLine (L2[0], "\ttrb\t%s", L2[1]->Line+5);
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FreeLine (L2[1]);
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L = L2[0];
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} else {
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/* Just reorder */
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L = ReplaceLine (L, "\tlda\t#$%02X", Val);
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ReplaceLine (L2[0], "\tand\t%s", L2[1]->Line+5);
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L = L2[1];
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}
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} else if (LineMatch (L2[0], "\tora\t#$")) {
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unsigned Val = GetHexNum (L2[0]->Line+7);
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if (Val == 0x00) {
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/* ORA with 0x00, just load the value from memory */
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FreeLines (L2[0], L2[1]);
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} else if (Val == 0xFF) {
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/* ORA with 0xFF, replace by a store of $FF */
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FreeLine (L);
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ReplaceLine (L2[0], "\tlda\t#$FF");
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} else if (CPU == CPU_65C02 &&
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!IsXAddrMode (L) &&
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!IsYAddrMode (L) &&
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!RegAUsed (L2[1])) {
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/* Replace by trb */
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ReplaceLine (L, "\tlda\t#$%02X", Val);
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ReplaceLine (L2[0], "\ttsb\t%s", L2[1]->Line+5);
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FreeLine (L2[1]);
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L = L2[0];
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} else {
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/* Just reorder */
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L = ReplaceLine (L, "\tlda\t#$%02X", Val);
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ReplaceLine (L2[0], "\tora\t%s", L2[1]->Line+5);
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L = L2[1];
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}
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} else if (LineMatch (L2[0], "\teor\t#$") ||
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LineMatch (L2[0], "\tadc\t#$")) {
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/* Just reorder */
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L = ReplaceLine (L, "\tlda\t%s", L2[0]->Line+5);
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ReplaceLine (L2[0], "\t%.3s\t%s", L2[0]->Line+1, L2[1]->Line+5);
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}
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}
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/* Next line */
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L = NextCodeLine (L);
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}
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}
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static void OptNeg (void)
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/* Optimize the "bnegax/jeq" and "bnegax/jne" sequences */
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{
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@ -3642,7 +3765,7 @@ static Line* OptOneBlock (Line* L)
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}
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} else if (LineMatch (L, "\tadc\t")) {
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if (CPU == CPU_65C02 && Y == 0 && L->Line[5] == '(' && IsYAddrMode(L)) {
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L->Line[strlen(L->Line)-2] = '\0';
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L->Line[strlen(L->Line)-2] = '\0';
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}
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A = -1;
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} else if (LineMatch (L, "\tand\t")) {
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@ -3873,7 +3996,7 @@ static Line* OptOneBlock (Line* L)
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* cycles.
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*/
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if (X == 0) {
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L = ReplaceLine (L, "\tjsr\tpushax");
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L = ReplaceLine (L, "\tjsr\tpushax");
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}
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X = 0;
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Y = 1;
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@ -3986,7 +4109,7 @@ static Line* OptOneBlock (Line* L)
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/* lda (zp,x) - if Y and X are both zero, replace by
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* load indirect y and save one cycle in some cases.
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*/
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if (X == 0 && Y == 0) {
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if (X == 0 && Y == 0) {
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char Buf [256];
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const char* S = L->Line + 6;
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char* T = Buf + 6;
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@ -4002,10 +4125,10 @@ static Line* OptOneBlock (Line* L)
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}
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}
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/* In any case invalidate A */
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A = -1;
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A = -1;
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} else if (LineMatch (L, "\tlda\t#$")) {
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/* Immidiate load into A */
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NewVal = GetHexNum (L->Line + 7);
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NewVal = GetHexNum (L->Line + 7);
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if (NewVal == A) {
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/* Load has no effect */
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Delete = 1;
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@ -4045,10 +4168,10 @@ static Line* OptOneBlock (Line* L)
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} else if (NewVal == A) {
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/* Requested value is already in A */
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L = ReplaceLine (L, "\ttax");
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} else if (X != -1 && NewVal == ((X + 1) & 0xFF)) {
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} else if (X != -1 && NewVal == ((X + 1) & 0xFF)) {
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/* Requested value is one more than current contents */
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L = ReplaceLine (L, "\tinx");
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} else if (X != -1 && NewVal == ((X - 1) & 0xFF)) {
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} else if (X != -1 && NewVal == ((X - 1) & 0xFF)) {
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/* Requested value is one less than current contents */
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L = ReplaceLine (L, "\tdex");
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}
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@ -4072,7 +4195,7 @@ static Line* OptOneBlock (Line* L)
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/* Requested value is already in A */
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L = ReplaceLine (L, "\ttay");
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} else if (Y != -1 && NewVal == ((Y + 1) & 0xFF)) {
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/* Requested value is one more than current contents */
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/* Requested value is one more than current contents */
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L = ReplaceLine (L, "\tiny");
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} else if (Y != -1 && NewVal == ((Y - 1) & 0xFF)) {
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/* Requested value is one less than current contents */
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@ -4106,36 +4229,36 @@ static Line* OptOneBlock (Line* L)
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A = X = Y = -1;
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} else if (LineMatch (L, "\tsbc\t")) {
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if (CPU == CPU_65C02 && Y == 0 && L->Line[5] == '(' && IsYAddrMode(L)) {
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L->Line[strlen(L->Line)-2] = '\0';
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L->Line[strlen(L->Line)-2] = '\0';
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}
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A = -1;
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} else if (CPU == CPU_65C02 && LineMatch (L, "\tst")) {
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/* Try to replace by stz if possible */
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if (A == 0 && LineMatch (L, "\tsta\t")) {
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/* Not indirect and not Y allowed */
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if (L->Line[5] != '(' && !IsYAddrMode (L)) {
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L->Line[3] = 'z';
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}
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/* Not indirect and not Y allowed */
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if (L->Line[5] != '(' && !IsYAddrMode (L)) {
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L->Line[3] = 'z';
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}
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} else if (X == 0 && LineMatch (L, "\tstx\t")) {
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/* absolute,y not allowed */
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if (!IsYAddrMode (L)) {
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L->Line[3] = 'z';
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}
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/* absolute,y not allowed */
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if (!IsYAddrMode (L)) {
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L->Line[3] = 'z';
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}
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} else if (Y == 0 && LineMatch (L, "\tsty\t")) {
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/* sty and stz share all addressing modes */
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L->Line[3] = 'z';
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/* sty and stz share all addressing modes */
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L->Line[3] = 'z';
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}
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} else if (LineFullMatch (L, "\ttax")) {
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if (A != -1 && X == A) {
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/* Load has no effect */
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Delete = 1;
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/* Load has no effect */
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Delete = 1;
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} else {
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X = A;
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}
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} else if (LineFullMatch (L, "\ttay")) {
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if (A != -1 && Y == A) {
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/* Load has no effect */
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Delete = 1;
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/* Load has no effect */
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Delete = 1;
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} else {
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Y = A;
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}
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@ -4143,15 +4266,15 @@ static Line* OptOneBlock (Line* L)
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X = -1;
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} else if (LineFullMatch (L, "\ttxa")) {
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if (X != -1 && A == X) {
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/* Load has no effect */
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Delete = 1;
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/* Load has no effect */
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Delete = 1;
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} else {
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A = X;
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}
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} else if (LineFullMatch (L, "\ttya")) {
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if (Y != -1 && A == Y) {
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/* Load has no effect */
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Delete = 1;
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/* Load has no effect */
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Delete = 1;
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} else {
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A = Y;
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}
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@ -4268,21 +4391,37 @@ static void OptRTS (void)
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static void OptOnePass (unsigned long Flag, void (*F) (void))
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/* Call one optimizer pass if enabled */
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{
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if ((OptDisable & Flag) == 0) {
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F ();
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} else if (Verbose || Debug) {
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printf ("Optimizer pass %04lX skipped\n", Flag);
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}
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}
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void OptDoOpt (void)
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/* Run the optimizer over the collected stuff */
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{
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typedef void (*OptFunc)(void);
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/* Table with optimizer steps - are called in this order */
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static const OptFunc OptFuncs [] = {
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OptCompares1, /* Optimize compares - first step */
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OptDeadJumps, /* Remove dead jumps */
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OptLoads, /* Remove unnecessary loads */
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OptRegLoads, /* Remove unnecessary register loads */
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OptPtrOps, /* Optimize stores through pointers */
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OptRegVars, /* Optimize use of register variables */
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OptDoubleJumps, /* Remove jump cascades - must be used before OptNeg */
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OptNeg, /* Remove unnecessary boolean negates */
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OptJumpRTS, /* Replace jumps to an RTS by an RTS */
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OptBoolTransforms, /* Optimize boolean transforms */
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OptCompares2, /* Optimize compares */
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OptTests, /* Remove unnecessary tests */
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OptBitOps, /* Optimize bit operations */
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OptTriples, /* Optimize several triples */
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OptBlocks, /* Optimize basic blocks */
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OptRegLoads, /* Remove unnecessary register loads (another pass) */
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OptBlocks, /* Optimize basic blocks */
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OptJumps, /* Optimize jumps */
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OptRTS, /* Optimize jsr/rts sequences */
|
||||
};
|
||||
|
||||
unsigned long Flags;
|
||||
unsigned I;
|
||||
|
||||
/* Find and remember the first line of code */
|
||||
FindCodeStart ();
|
||||
|
||||
@ -4293,57 +4432,14 @@ void OptDoOpt (void)
|
||||
CreateLabelList ();
|
||||
|
||||
/* Ok, now start the real optimizations */
|
||||
|
||||
/* Optimize compares - first step */
|
||||
OptOnePass (0x0001, OptCompares1);
|
||||
|
||||
/* Remove dead jumps */
|
||||
OptOnePass (0x0002, OptDeadJumps);
|
||||
|
||||
/* Remove unnecessary loads */
|
||||
OptOnePass (0x0004, OptLoads);
|
||||
|
||||
/* Remove unnecessary register loads */
|
||||
OptOnePass (0x0008, OptRegLoads);
|
||||
|
||||
/* Optimize stores through pointers */
|
||||
OptOnePass (0x0010, OptPtrOps);
|
||||
|
||||
/* Optimize use of register variables */
|
||||
OptOnePass (0x0020, OptRegVars);
|
||||
|
||||
/* Remove jump cascades - must be used before OptNeg */
|
||||
OptOnePass (0x0040, OptDoubleJumps);
|
||||
|
||||
/* Remove unnecessary boolean negates */
|
||||
OptOnePass (0x0080, OptNeg);
|
||||
|
||||
/* Replace jumps to an RTS by an RTS */
|
||||
OptOnePass (0x0100, OptJumpRTS);
|
||||
|
||||
/* Optimize boolean transforms */
|
||||
OptOnePass (0x0200, OptBoolTransforms);
|
||||
|
||||
/* Optimize compares */
|
||||
OptOnePass (0x0400, OptCompares2);
|
||||
|
||||
/* Remove unnecessary tests */
|
||||
OptOnePass (0x0800, OptTests);
|
||||
|
||||
/* Optimize several triples */
|
||||
OptOnePass (0x1000, OptTriples);
|
||||
|
||||
/* Optimize basic blocks */
|
||||
OptOnePass (0x2000, OptBlocks);
|
||||
|
||||
/* Remove unnecessary register loads (another pass) */
|
||||
OptOnePass (0x0008, OptRegLoads);
|
||||
|
||||
/* Optimize jumps */
|
||||
OptOnePass (0x4000, OptJumps);
|
||||
|
||||
/* Optimize jsr/rts sequences */
|
||||
OptOnePass (0x8000, OptRTS);
|
||||
Flags = 1UL;
|
||||
for (I = 0; I < sizeof(OptFuncs)/sizeof(OptFuncs[0]); ++I) {
|
||||
if ((OptDisable & Flags) == 0) {
|
||||
OptFuncs[I] ();
|
||||
} else if (Verbose || Debug) {
|
||||
printf ("Optimizer pass %u skipped\n", I);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user