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Added optimizer fix originating from Ullrich von Bassewitz prepared by Greg King.

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This commit is contained in:
Oliver Schmidt 2013-10-09 21:55:44 +02:00
parent c22c6f28ff
commit f3d74cd166
1 changed files with 24 additions and 17 deletions
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41
src/cc65/coptstop.c
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@ -6,10 +6,10 @@
/* */
/* */
/* */
/* (C) 2001-2009 Ullrich von Bassewitz */
/* Roemerstrasse 52 */
/* D-70794 Filderstadt */
/* EMail: uz@cc65.org */
/* (C) 2001-2013, Ullrich von Bassewitz */
/* Roemerstrasse 52 */
/* D-70794 Filderstadt */
/* EMail: uz@cc65.org */
/* */
/* */
/* This software is provided 'as-is', without any expressed or implied */
@ -58,7 +58,8 @@ typedef enum {
LI_DIRECT = 0x01, /* Direct op may be used */
LI_RELOAD_Y = 0x02, /* Reload index register Y */
LI_REMOVE = 0x04, /* Load may be removed */
LI_DUP_LOAD = 0x08, /* Duplicate load */
LI_DONT_REMOVE = 0x08, /* Load may not be removed */
LI_DUP_LOAD = 0x10, /* Duplicate load */
} LI_FLAGS;
/* Structure that tells us how to load the lhs values */
@ -245,6 +246,18 @@ static void AdjustLoadInfo (LoadInfo* LI, int Index, int Change)
static void HonourUseAndChg (LoadRegInfo* RI, unsigned Reg, const CodeEntry* E)
/* Honour use and change flags for an instruction */
{
if (E->Chg & Reg) {
ClearLoadRegInfo (RI);
} else if ((E->Use & Reg) && RI->LoadIndex >= 0) {
RI->Flags |= LI_DONT_REMOVE;
}
}
static void TrackLoads (LoadInfo* LI, CodeEntry* E, int I)
/* Track loads for a code entry */
{
@ -349,15 +362,9 @@ static void TrackLoads (LoadInfo* LI, CodeEntry* E, int I)
ClearLoadRegInfo (&LI->Y);
} else {
if (E->Chg & REG_A) {
ClearLoadRegInfo (&LI->A);
}
if (E->Chg & REG_X) {
ClearLoadRegInfo (&LI->X);
}
if (E->Chg & REG_Y) {
ClearLoadRegInfo (&LI->Y);
}
HonourUseAndChg (&LI->A, REG_A, E);
HonourUseAndChg (&LI->X, REG_X, E);
HonourUseAndChg (&LI->Y, REG_Y, E);
}
}
@ -646,7 +653,7 @@ static void RemoveRegLoads (StackOpData* D, LoadInfo* LI)
/* Both registers may be loaded with one insn, but DelEntry will in this
* case clear the other one.
*/
if (LI->A.Flags & LI_REMOVE) {
if ((LI->A.Flags & (LI_REMOVE | LI_DONT_REMOVE)) == LI_REMOVE) {
if (LI->A.LoadIndex >= 0) {
DelEntry (D, LI->A.LoadIndex);
}
@ -654,7 +661,7 @@ static void RemoveRegLoads (StackOpData* D, LoadInfo* LI)
DelEntry (D, LI->A.XferIndex);
}
}
if (LI->X.Flags & LI_REMOVE) {
if ((LI->X.Flags & (LI_REMOVE | LI_DONT_REMOVE)) == LI_REMOVE) {
if (LI->X.LoadIndex >= 0) {
DelEntry (D, LI->X.LoadIndex);
}
@ -875,7 +882,7 @@ static unsigned Opt_tosshift (StackOpData* D, const char* Name)
AddStoreA (D);
/* Be sure to setup IP after adding the stores, otherwise it will get
* messed up.
* messed up.
*/
D->IP = D->OpIndex+1;