Fixed a bug

git-svn-id: svn://svn.cc65.org/cc65/trunk@2523 b7a2c559-68d2-44c3-8de9-860c34a00d81

diff --git a/src/cc65/coptstop.c b/src/cc65/coptstop.c
index 4f83b8ef5b64de7d7965b165c56d494eb299d391..cd05efa1b79198797f928dce8784745596d4cbb9 100644 (file)
--- a/src/cc65/coptstop.c
+++ b/src/cc65/coptstop.c
@@ -6,9 +6,9 @@
 /*                                                                           */
 /*                                                                           */
 /*                                                                           */
-/* (C) 2001-2002 Ullrich von Bassewitz                                       */
-/*               Wacholderweg 14                                             */
-/*               D-70597 Stuttgart                                           */
+/* (C) 2001-2003 Ullrich von Bassewitz                                       */
+/*               Römerstrasse 52                                             */
+/*               D-70794 Filderstadt                                         */
 /* EMail:        uz@cc65.org                                                 */
 /*                                                                           */
 /*                                                                           */
@@ -72,13 +72,13 @@ struct StackOpData {
 
 
 /*****************************************************************************/
-/*                                         Helpers                                  */
+/*                                         Helpers                                  */
 /*****************************************************************************/
 
 
 
 static unsigned AdjustStackOffset (CodeSeg* S, unsigned Start, unsigned Stop,
-                                  unsigned Offs)
+                                  unsigned Offs)
 /* Adjust the offset for all stack accesses in the range Start to Stop, both
  * inclusive. The function returns the number of instructions that have been
  * inserted.
@@ -114,31 +114,50 @@ static unsigned AdjustStackOffset (CodeSeg* S, unsigned Start, unsigned Stop,
 
            CodeEntry* P;
 
+            /* If the Y register value is needed later, we have to reload the
+             * register after changing it.
+             */
+            int NeedY = RegYUsed (S, I+1);
+            unsigned YVal = E->RI->In.RegY;
+
            /* Get the code entry before this one. If it's a LDY, adjust the
             * value.
             */
            P = CS_GetPrevEntry (S, I);
            if (P && P->OPC == OP65_LDY && CE_KnownImm (P)) {
 
-               /* The Y load is just before the stack access, adjust it */
-               CE_SetNumArg (P, P->Num - Offs);
+               /* The Y load is just before the stack access, adjust it */
+               CE_SetNumArg (P, P->Num - Offs);
 
            } else {
 
-               /* Insert a new load instruction before the stack access */
-               const char* Arg = MakeHexArg (E->RI->In.RegY - Offs);
-               CodeEntry* X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, E->LI);
-               CS_InsertEntry (S, X, I);
+               /* Insert a new load instruction before the stack access */
+               const char* Arg = MakeHexArg (YVal - Offs);
+               CodeEntry* X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, E->LI);
+               CS_InsertEntry (S, X, I);
 
-               /* One more inserted entries */
-               ++Inserted;
-               ++Stop;
+               /* One more inserted entries */
+               ++Inserted;
+               ++Stop;
 
-               /* Be sure to skip the stack access for the next round */
-               ++I;
+               /* Be sure to skip the stack access for the next round */
+               ++I;
 
            }
 
+            /* If we need the value of Y later, be sure to reload it */
+            if (NeedY) {
+               const char* Arg = MakeHexArg (YVal);
+               CodeEntry* X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, E->LI);
+               CS_InsertEntry (S, X, I+1);
+
+               /* One more inserted entries */
+               ++Inserted;
+               ++Stop;
+
+               /* Skip this instruction int the next round */
+               ++I;
+            }
        }
 
        /* Next entry */