Track usage of the sreg and several other zero page registers and remove

[cc65] / src / cc65 / codeinfo.c

diff --git a/src/cc65/codeinfo.c b/src/cc65/codeinfo.c
index 3eeb48506bc5b6ae03a9f0d781e0ac9b8237b012..abf8a3bf5bac00aa2c69cd7946e9bc533654fc47 100644 (file)
--- a/src/cc65/codeinfo.c
+++ b/src/cc65/codeinfo.c
@@ -172,7 +172,8 @@ static const ZPInfo ZPInfoTable[] = {
     {   7,      "regbank",      REG_BANK        },
     {   7,      "regsave",      REG_SAVE        },
     {   2,      "sp",           REG_SP          },
-    {   4,      "sreg",         REG_SREG        },
+    {   0,      "sreg",         REG_SREG_LO     },
+    {  0,      "sreg+1",       REG_SREG_HI     },
     {   4,      "tmp1",         REG_TMP1        },
     {   4,      "tmp2",         REG_TMP2        },
     {   4,      "tmp3",         REG_TMP3        },
@@ -245,7 +246,7 @@ void GetFuncInfo (const char* Name, unsigned short* Use, unsigned short* Chg)
 
     } else {
 
-       /* Search for the function in the list of builtin functions */
+       /* Search for the function in the list of builtin functions */
        const FuncInfo* Info = bsearch (Name, FuncInfoTable, FuncInfoCount,
                                        sizeof(FuncInfo), CompareFuncInfo);
 
@@ -277,12 +278,18 @@ static int CompareZPInfo (const void* Name, const void* Info)
     /* Do the compare. Be careful because of the length (Info may contain
      * more than just the zeropage name).
      */
-    int Res = strncmp (N, E->Name, E->Len);
-    if (Res == 0 && (N[E->Len] != '\0' && N[E->Len] != '+')) {
-       /* Name is actually longer than Info->Name */
-       Res = -1;
+    if (E->Len == 0) {
+       /* Do a full compare */
+       return strcmp (N, E->Name);
+    } else {
+       /* Only compare the first part */
+       int Res = strncmp (N, E->Name, E->Len);
+       if (Res == 0 && (N[E->Len] != '\0' && N[E->Len] != '+')) {
+           /* Name is actually longer than Info->Name */
+           Res = -1;
+       }
+       return Res;
     }
-    return Res;
 }
 
 
@@ -312,22 +319,13 @@ int IsZPName (const char* Name, unsigned short* RegInfo)
 
 
 
-static unsigned GetRegInfo1 (CodeSeg* S,
-                                    CodeEntry* E,
-                                    int Index,
-                                    Collection* Visited,
-                                    unsigned Used,
-                                    unsigned Unused);
-/* Recursively called subfunction for GetRegInfo. */
-
-
-
 static unsigned GetRegInfo2 (CodeSeg* S,
                             CodeEntry* E,
                             int Index,
                             Collection* Visited,
                             unsigned Used,
-                            unsigned Unused)
+                            unsigned Unused,
+                            unsigned Wanted)
 /* Recursively called subfunction for GetRegInfo. */
 {
     /* Follow the instruction flow recording register usage. */
@@ -373,7 +371,7 @@ static unsigned GetRegInfo2 (CodeSeg* S,
        }
 
                /* If we know about all registers now, bail out */
-               if ((Used | Unused) == REG_AXY) {
+               if (((Used | Unused) & Wanted) == Wanted) {
            break;
        }
 
@@ -392,7 +390,7 @@ static unsigned GetRegInfo2 (CodeSeg* S,
 
                /* Unconditional jump */
                E     = E->JumpTo->Owner;
-               Index = -1;             /* Invalidate */
+               Index = -1;             /* Invalidate */
 
            } else {
                /* Jump outside means we're done */
@@ -411,7 +409,7 @@ static unsigned GetRegInfo2 (CodeSeg* S,
                unsigned U1;
                unsigned U2;
 
-               U1 = GetRegInfo1 (S, E->JumpTo->Owner, -1, Visited, Used, Unused);
+               U1 = GetRegInfo2 (S, E->JumpTo->Owner, -1, Visited, Used, Unused, Wanted);
                if (U1 == REG_AXY) {
                    /* All registers used, no need for second call */
                    return REG_AXY;
@@ -422,7 +420,7 @@ static unsigned GetRegInfo2 (CodeSeg* S,
                        if ((E = CS_GetEntry (S, ++Index)) == 0) {
                    Internal ("GetRegInfo2: No next entry!");
                }
-               U2 = GetRegInfo1 (S, E, Index, Visited, Used, Unused);
+                       U2 = GetRegInfo2 (S, E, Index, Visited, Used, Unused, Wanted);
                return U1 | U2;         /* Used in any of the branches */
 
            } else {
@@ -457,14 +455,15 @@ static unsigned GetRegInfo1 (CodeSeg* S,
                             int Index,
                             Collection* Visited,
                             unsigned Used,
-                            unsigned Unused)
+                            unsigned Unused,
+                            unsigned Wanted)
 /* Recursively called subfunction for GetRegInfo. */
 {
     /* Remember the current count of the line collection */
     unsigned Count = CollCount (Visited);
 
     /* Call the worker routine */
-    unsigned R = GetRegInfo2 (S, E, Index, Visited, Used, Unused);
+    unsigned R = GetRegInfo2 (S, E, Index, Visited, Used, Unused, Wanted);
 
     /* Restore the old count, unmarking all new entries */
     unsigned NewCount = CollCount (Visited);
@@ -480,7 +479,7 @@ static unsigned GetRegInfo1 (CodeSeg* S,
 
 
 
-unsigned GetRegInfo (struct CodeSeg* S, unsigned Index)
+unsigned GetRegInfo (struct CodeSeg* S, unsigned Index, unsigned Wanted)
 /* Determine register usage information for the instructions starting at the
  * given index.
  */
@@ -500,7 +499,7 @@ unsigned GetRegInfo (struct CodeSeg* S, unsigned Index)
     InitCollection (&Visited);
 
     /* Call the recursive subfunction */
-    R = GetRegInfo1 (S, E, Index, &Visited, REG_NONE, REG_NONE);
+    R = GetRegInfo1 (S, E, Index, &Visited, REG_NONE, REG_NONE, Wanted);
 
     /* Delete the line collection */
     DoneCollection (&Visited);
@@ -514,7 +513,7 @@ unsigned GetRegInfo (struct CodeSeg* S, unsigned Index)
 int RegAUsed (struct CodeSeg* S, unsigned Index)
 /* Check if the value in A is used. */
 {
-    return (GetRegInfo (S, Index) & REG_A) != 0;
+    return (GetRegInfo (S, Index, REG_A) & REG_A) != 0;
 }
 
 
@@ -522,7 +521,7 @@ int RegAUsed (struct CodeSeg* S, unsigned Index)
 int RegXUsed (struct CodeSeg* S, unsigned Index)
 /* Check if the value in X is used. */
 {
-    return (GetRegInfo (S, Index) & REG_X) != 0;
+    return (GetRegInfo (S, Index, REG_X) & REG_X) != 0;
 }
 
 
@@ -530,7 +529,7 @@ int RegXUsed (struct CodeSeg* S, unsigned Index)
 int RegYUsed (struct CodeSeg* S, unsigned Index)
 /* Check if the value in Y is used. */
 {
-    return (GetRegInfo (S, Index) & REG_Y) != 0;
+    return (GetRegInfo (S, Index, REG_Y) & REG_Y) != 0;
 }