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Added load/store transformation

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git-svn-id: svn://svn.cc65.org/cc65/trunk@554 b7a2c559-68d2-44c3-8de9-860c34a00d81
This commit is contained in:
cuz 2000-12-04 22:47:21 +00:00
parent c8171988a2
commit a4fd5c7648
1 changed files with 32 additions and 4 deletions
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36
src/cc65/optimize.c
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@ -1589,7 +1589,6 @@ static void OptLoads (void)
/* Delete the remaining lines */
FreeLines (L2 [0], L2 [3]);
}
/* Check for
*
@ -1616,7 +1615,7 @@ static void OptLoads (void)
* possible to rewrite the library routine to get rid of the additional
* overhead.
*/
if (LineMatch (L, "\tldy\t#$") &&
} else if (LineMatch (L, "\tldy\t#$") &&
GetNextCodeLines (L, L2, 6) &&
LineFullMatch (L2 [0], "\tlda\t(sp),y") &&
LineFullMatch (L2 [1], "\ttax") &&
@ -1637,7 +1636,6 @@ static void OptLoads (void)
/* Delete the remaining lines */
FreeLines (L2 [0], L2 [3]);
}
/* Search for:
*
@ -1648,15 +1646,45 @@ static void OptLoads (void)
*
* jsr pushaysp
*/
if (LineFullMatch (L, "\tlda\t(sp),y") &&
} else if (LineFullMatch (L, "\tlda\t(sp),y") &&
GetNextCodeLines (L, L2, 1) &&
LineFullMatch (L2 [0], "\tjsr\tpusha")) {
/* Found, replace it */
L = ReplaceLine (L, "\tjsr\tpushaysp");
FreeLine (L2 [0]);
/* Search for:
*
* ldx xx
* lda yy
* sta zzz
* stx zzz+1
*
* and replace it by:
*
* lda xx
* sta zzz
* lda yy
* sta zzz+1
*
* provided that that the X register is not used later. While this is
* no direct optimization, it helps with other optimizations.
*/
} else if (LineMatch (L, "\tldx\t") &&
GetNextCodeLines (L, L2, 3) &&
LineMatch (L2 [0], "\tlda\t") &&
Is16BitStore (L2[1], L2[2]) &&
!RegXUsed (L2[2])) {
/* Found - replace it */
NewLineAfter (L2[1], "\tlda\t%s", L->Line+5);
L2[2]->Line[3] = 'a';
FreeLine (L);
L = L2[2];
}
/* All other patterns start with this one: */
if (!LineFullMatch (L, "\tldx\t#$00")) {
/* Next line */