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Added optimization for g_inc and g_dec (remove handling of high byte if

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not used).


git-svn-id: svn://svn.cc65.org/cc65/trunk@680 b7a2c559-68d2-44c3-8de9-860c34a00d81
This commit is contained in:
cuz 2001-03-27 22:52:16 +00:00
parent e07945e9fc
commit 8e5d8b9e4f
2 changed files with 103 additions and 29 deletions
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47
src/cc65/codegen.c
View File

@ -3367,14 +3367,47 @@ void g_dec (unsigned flags, unsigned long val)
/* FALLTHROUGH */
case CF_INT:
if (val <= 8) {
AddCodeLine ("\tjsr\tdecax%d", (int) val);
} else if (val <= 255) {
ldyconst (val);
AddCodeLine ("\tjsr\tdecaxy");
if (CodeSizeFactor < 200) {
/* Use subroutines */
if (val <= 8) {
AddCodeLine ("\tjsr\tdecax%d", (int) val);
} else if (val <= 255) {
ldyconst (val);
AddCodeLine ("\tjsr\tdecaxy");
} else {
g_sub (flags | CF_CONST, val);
}
} else {
g_sub (flags | CF_CONST, val);
}
/* Inline the code */
if (val < 0x300) {
if ((val & 0xFF) != 0) {
AddCodeLine ("\tsec");
AddCodeLine ("\tsbc\t#$%02X", (unsigned char) val);
AddCodeLine ("\tbcs\t*+3");
AddCodeLine ("\tdex");
/* Tell the optimizer that the X register may be invalid */
AddCodeHint ("x:!");
}
if (val >= 0x100) {
AddCodeLine ("\tdex");
}
if (val >= 0x200) {
AddCodeLine ("\tdex");
}
} else {
AddCodeLine ("\tsec");
if ((val & 0xFF) != 0) {
AddCodeLine ("\tsbc\t#$%02X", (unsigned char) val);
/* Tell the optimizer that the X register may be invalid */
AddCodeHint ("x:!");
}
AddCodeLine ("\tpha");
AddCodeLine ("\ttxa");
AddCodeLine ("\tsbc\t#$%02X", (unsigned char) (val >> 8));
AddCodeLine ("\ttax");
AddCodeLine ("\tpla");
}
}
break;
case CF_LONG:

85
src/cc65/optimize.c
View File

@ -1737,10 +1737,10 @@ static void OptLoads (void)
* and replace it by:
*
* lda xx
* ldy #$01
* ldy #$01
* sta (sp),y
* dey
* lda yy
* lda yy
* sta (sp),y
*
* provided that that the X register is not used later. This code
@ -1762,22 +1762,63 @@ static void OptLoads (void)
/* Remove the remaining line */
FreeLine (L2[1]);
}
/* Search for
*
* adc #xx
* bcc *+3
* inx
*
* Remove the handling of the high byte if the X register
* is not used any more
*/
} else if (LineMatch (L, "\tadc\t#") &&
GetNextCodeLines (L, L2, 3) &&
LineFullMatch (L2[0], "\tbcc\t*+3") &&
LineFullMatch (L2[1], "\tinx") &&
L2[1]->Next &&
IsHint (L2[1]->Next, "x:!") &&
!RegXUsed (L2[1])) {
/* Delete the lines */
FreeLines (L2[0], L2[1]->Next);
/* Search for
*
* sbc #xx
* bcs *+3
* dex
*
* Remove the handling of the high byte if the X register
* is not used any more
*/
} else if (LineMatch (L, "\tsbc\t#") &&
GetNextCodeLines (L, L2, 3) &&
LineFullMatch (L2[0], "\tbcs\t*+3") &&
LineFullMatch (L2[1], "\tdex") &&
L2[1]->Next &&
IsHint (L2[1]->Next, "x:!") &&
!RegXUsed (L2[1])) {
/* Delete the lines */
FreeLines (L2[0], L2[1]->Next);
}
/* All other patterns start with this one: */
if (!LineFullMatch (L, "\tldx\t#$00")) {
/* Next line */
goto NextLine;
}
}
/* Search for:
*
* ldx #$00
* jsr pushax
* ldx #$00
* jsr pushax
*
* and replace it by:
*
* jsr pusha0
* jsr pusha0
*
*/
if (GetNextCodeLines (L, L2, 1) &&
@ -1792,13 +1833,13 @@ static void OptLoads (void)
/* Search for:
*
* ldx #$00
* lda ...
* jsr pushax
* ldx #$00
* lda ...
* jsr pushax
*
* and replace it by:
*
* lda ...
* lda ...
* jsr pusha0
*
*/
@ -1812,7 +1853,7 @@ static void OptLoads (void)
/* Replace the subroutine call */
L2 [1] = ReplaceLine (L2 [1], "\tjsr\tpusha0");
/* Remove the unnecessary load */
/* Remove the unnecessary load */
FreeLine (L);
/* L must be valid */
@ -1898,20 +1939,20 @@ static void OptRegLoads (void)
/* Search for a load of X and check if the value is used later */
if (LineMatch (L, "\tldx\t") &&
!RegXUsed (L) &&
!IsCondJump (NextInstruction (L))) {
!RegXUsed (L) &&
!IsCondJump (NextInstruction (L))) {
/* Remember to delete this line */
Delete = 1;
/* Remember to delete this line */
Delete = 1;
}
/* Search for a load of A and check if the value is used later */
else if (LineMatch (L, "\tlda\t") &&
!RegAUsed (L) &&
!IsCondJump (NextInstruction (L))) {
!RegAUsed (L) &&
!IsCondJump (NextInstruction (L))) {
/* Remember to delete this line */
Delete = 1;
/* Remember to delete this line */
Delete = 1;
}
/* Search for a load of Y and check if the value is used later */
@ -1919,8 +1960,8 @@ static void OptRegLoads (void)
!RegYUsed (L) &&
!IsCondJump (NextInstruction (L))) {
/* Remember to delete this line */
Delete = 1;
/* Remember to delete this line */
Delete = 1;
}
/* Go to the next line, delete the current if requested */