Changd all Find*Last*InOpenRange() to return the beginning of the open range.

Fixed FindArgLastUsageInOpenRange().

src/cc65/codeoptutil.c

@@ -3038,13 +3038,13 @@ int FindArgLastUsageInOpenRange (CodeSeg* S, int First, int Last, CodeEntry* E,
 /* Find the last index where the arg of E might be used or changed in the range (First, Last).
 ** ReloadY indicates whether Y is supposed to be reloaded.
 ** The code block in the range must be basic without any jump backwards.
-** Return the index of the found entry, or -1 if not found.
+** Return the index of the found entry, or First if not found.
 */
 {
     LoadRegInfo LRI;
     CodeEntry* X;
     unsigned CheckedFlags = LI_SRC_USE | LI_SRC_CHG;
-    int Found = -1;
+    int Found = First;
 
     CHECK (Last <= (int)CollCount (&S->Entries));
 
@@ -3066,8 +3066,8 @@ int FindArgLastUsageInOpenRange (CodeSeg* S, int First, int Last, CodeEntry* E,
 
     /* TODO: We don't currently check for all cases */
     if ((LRI.Flags & (LI_DIRECT | LI_CHECK_ARG | LI_CHECK_Y | LI_RELOAD_Y)) == 0) {
-        /* Just bail out as if the src would change right away */
+        /* Just bail out as if the src would change everywhere */
-        return 0;
+        return First < Last ? Last - 1 : First;
     }
 
     if ((LRI.Flags & LI_CHECK_Y) != 0) {
@@ -3145,11 +3145,11 @@ int FindRegLastChangeInOpenRange (CodeSeg* S, int First, int Last, unsigned what
 /* Find the last possible spot where the queried ZPs, registers and/or processor
 ** states might be changed in the range (First, Last). The code block in the
 ** range must be basic without any jump backwards.
-** Return the index of the found entry, or -1 if not found.
+** Return the index of the found entry, or First if not found.
 */
 {
     CodeEntry* X;
-    int Found = -1;
+    int Found = First;
 
     CHECK (Last <= (int)CollCount (&S->Entries));
 
@@ -3169,11 +3169,11 @@ int FindRegLastUseInOpenRange (CodeSeg* S, int First, int Last, unsigned what)
 /* Find the last possible spot where the queried ZPs, registers and/or processor
 ** states might be used in the range (First, Last). The code block in the range
 ** must be basic without any jump backwards.
-** Return the index of the found entry, or -1 if not found.
+** Return the index of the found entry, or First if not found.
 */
 {
     CodeEntry* X;
-    int Found = -1;
+    int Found = First;
 
     CHECK (Last <= (int)CollCount (&S->Entries));
 

src/cc65/codeoptutil.h

@@ -433,7 +433,7 @@ int FindArgLastUsageInOpenRange (CodeSeg* S, int First, int Last, CodeEntry* E,
 /* Find the last index where the arg of E might be used or changed in the range (First, Last).
 ** ReloadY indicates whether Y is supposed to be reloaded.
 ** The code block in the range must be basic without any jump backwards.
-** Return the index of the found entry, or -1 if not found.
+** Return the index of the found entry, or First if not found.
 */
 
 int FindRegFirstChangeInOpenRange (CodeSeg* S, int First, int Last, unsigned what);
@@ -454,14 +454,14 @@ int FindRegLastChangeInOpenRange (CodeSeg* S, int First, int Last, unsigned what
 /* Find the last possible spot where the queried ZPs, registers and/or processor
 ** states might be changed in the range (First, Last). The code block in the
 ** range must be basic without any jump backwards.
-** Return the index of the found entry, or -1 if not found.
+** Return the index of the found entry, or First if not found.
 */
 
 int FindRegLastUseInOpenRange (CodeSeg* S, int First, int Last, unsigned what);
 /* Find the last possible spot where the queried ZPs, registers and/or processor
 ** states might be used in the range (First, Last). The code block in the range
 ** must be basic without any jump backwards.
-** Return the index of the found entry, or -1 if not found.
+** Return the index of the found entry, or First if not found.
 */
 
 /* End of codeoptutil.h */