Merge pull request #2941 from avolkov76/anv-coptstop-refactor

[cc65] Refactor OptStackOps() subopt precondition evaluation framework, phase 1

src/cc65/codeoptutil.c

@@ -756,6 +756,10 @@ void ResetStackOpData (StackOpData* Data)
 
     Data->PushIndex     = -1;
     Data->OpIndex       = -1;
+
+    /* Clear to prevent silent optimizer bugs */
+    Data->ZPLo          = 0;
+    Data->ZPHi          = 0;
 }
 
 
@@ -946,10 +950,9 @@ void AdjustStackOffset (StackOpData* D, unsigned Offs)
 
 
 
-int IsRegVar (StackOpData* D)
+int IsRegVar (const StackOpData* D)
 /* If the value pushed is that of a zeropage variable that is unchanged until Op,
-** replace ZPLo and ZPHi in the given StackOpData struct by the variable and return true.
-** Otherwise leave D untouched and return false.
+** return true.
 */
 {
     CodeEntry*  LoadA = D->Lhs.A.LoadEntry;
@@ -979,9 +982,7 @@ int IsRegVar (StackOpData* D)
         return 0;
     }
 
-    /* Use the zero page location directly */
-    D->ZPLo = LoadA->Arg;
-    D->ZPHi = LoadX->Arg;
+    /* ZP location can be used directly */
     return 1;
 }
 
@@ -990,6 +991,8 @@ int IsRegVar (StackOpData* D)
 void AddStoreLhsA (StackOpData* D)
 /* Add a store to zero page after the push insn */
 {
+    CHECK (D->ZPLo != 0);
+
     CodeEntry* X = NewCodeEntry (OP65_STA, AM65_ZP, D->ZPLo, 0, D->PushEntry->LI);
     InsertEntry (D, X, D->PushIndex+1);
 }
@@ -999,6 +1002,8 @@ void AddStoreLhsA (StackOpData* D)
 void AddStoreLhsX (StackOpData* D)
 /* Add a store to zero page after the push insn */
 {
+    CHECK (D->ZPHi != 0);
+
     CodeEntry* X = NewCodeEntry (OP65_STX, AM65_ZP, D->ZPHi, 0, D->PushEntry->LI);
     InsertEntry (D, X, D->PushIndex+1);
 }
@@ -1071,6 +1076,8 @@ void AddOpLow (StackOpData* D, opc_t OPC, LoadInfo* LI)
 
     } else {
 
+        CHECK (D->ZPLo != 0);
+
         /* Op with temp storage */
         X = NewCodeEntry (OPC, AM65_ZP, D->ZPLo, 0, D->OpEntry->LI);
         InsertEntry (D, X, D->IP++);
@@ -1134,6 +1141,9 @@ void AddOpHigh (StackOpData* D, opc_t OPC, LoadInfo* LI, int KeepResult)
         }
 
     } else {
+
+        CHECK (D->ZPHi != 0);
+
         /* opc zphi */
         X = NewCodeEntry (OPC, AM65_ZP, D->ZPHi, 0, D->OpEntry->LI);
         InsertEntry (D, X, D->IP++);

src/cc65/codeoptutil.h

@@ -223,10 +223,9 @@ void AdjustStackOffset (StackOpData* D, unsigned Offs);
 ** OpIndex is adjusted according to the insertions.
 */
 
-int IsRegVar (StackOpData* D);
+int IsRegVar (const StackOpData* D);
 /* If the value pushed is that of a zeropage variable that is unchanged until Op,
-** replace ZPLo and ZPHi in the given StackOpData struct by the variable and return true.
-** Otherwise leave D untouched and return false.
+** return true.
 */
 
 void AddStoreLhsA (StackOpData* D);

test/val/bug2395.c

@@ -8,6 +8,7 @@
 unsigned char a, b;
 unsigned char c = 199;
 unsigned char d = 100;
+int i = 50;
 
 int main(void) {
     int fails = 0;
@@ -38,6 +39,117 @@ int main(void) {
       printf("AND error: a %d instead of %d\n", a, b);
       fails++;
     }
+
+    a = c + (d != 0);
+    b = c + 1;
+
+    printf("%u ^ (%u != 0) => %u\n", c, d, a);
+    if (a != b) {
+      printf("ADD error: a %d instead of %d\n", a, b);
+      fails++;
+    }
+
+    a = c - (d != 0);
+    b = c - 1;
+
+    printf("%u ^ (%u != 0) => %u\n", c, d, a);
+    if (a != b) {
+      printf("SUB error: a %d instead of %d\n", a, b);
+      fails++;
+    }
+
+    a = c ^ (d >= 0);
+    b = c ^ 1;
+
+    printf("%u ^ (%u >= 0) => %u\n", c, d, a);
+    if (a != b) {
+      printf("XOR error: a %d instead of %d\n", a, b);
+      fails++;
+    }
+
+    a = c | (d >= 0);
+    b = c | 1;
+
+    printf("%u | (%u >= 0) => %u\n", c, d, a);
+    if (a != b) {
+      printf("OR error: a %d instead of %d\n", a, b);
+      fails++;
+    }
+
+    a = c & (d >= 0);
+    b = c & 1;
+
+    printf("%u & (%u >= 0) => %u\n", c, d, a);
+    if (a != b) {
+      printf("AND error: a %d instead of %d\n", a, b);
+      fails++;
+    }
+
+    a = c + (d >= 0);
+    b = c + 1;
+
+    printf("%u ^ (%u >= 0) => %u\n", c, d, a);
+    if (a != b) {
+      printf("ADD error: a %d instead of %d\n", a, b);
+      fails++;
+    }
+
+    a = c - (d >= 0);
+    b = c - 1;
+
+    printf("%u ^ (%u >= 0) => %u\n", c, d, a);
+    if (a != b) {
+      printf("SUB error: a %d instead of %d\n", a, b);
+      fails++;
+    }
+
+    printf("%d errors\n", fails);
+
+    a = c ^ (i >= 0);
+    b = c ^ 1;
+
+    printf("%u ^ (%d >= 0) => %u\n", c, d, a);
+    if (a != b) {
+      printf("XOR int cmp error: a %d instead of %d\n", a, b);
+      fails++;
+    }
+
+    a = c | (i >= 0);
+    b = c | 1;
+
+    printf("%u | (%d >= 0) => %u\n", c, i, a);
+    if (a != b) {
+      printf("OR int cmp error: a %d instead of %d\n", a, b);
+      fails++;
+    }
+
+    a = c & (i >= 0);
+    b = c & 1;
+
+    printf("%u & (%d >= 0) => %u\n", c, i, a);
+    if (a != b) {
+      printf("AND int cmp error: a %d instead of %d\n", a, b);
+      fails++;
+    }
+
+    a = c + (i >= 0);
+    b = c + 1;
+
+    printf("%u ^ (%d >= 0) => %u\n", c, i, a);
+    if (a != b) {
+      printf("ADD int cmp error: a %d instead of %d\n", a, b);
+      fails++;
+    }
+
+    a = c - (i >= 0);
+    b = c - 1;
+
+    printf("%u ^ (%d >= 0) => %u\n", c, i, a);
+    if (a != b) {
+      printf("SUB int cmp error: a %d instead of %d\n", a, b);
+      fails++;
+    }
+
     printf("%d errors\n", fails);
 
     return fails;

test/val/bug2946.c

@@ -0,0 +1,22 @@
+
+/* bug #2946: Incomplete, non-removable Rhs asserts in OptStackOps */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+unsigned char a, b = 0;
+unsigned char c = 10;
+unsigned char d = 1;
+
+int main(void) {
+    /* 'if' needed to produce a label below, moved by OptJumpTarget3  */
+    if (b != 0) {
+        /* Operation not important; it only affects the removal of one LDX #$00 */
+        b = 0;
+    }
+
+    /* d >= 0 is const, A/X=1 (Warning: Result of comparison is always true) */
+    a = c - (d >= 0);
+
+    return !(a == 9);
+}

test/val/bug2947.c

@@ -0,0 +1,22 @@
+
+/* bug #2947: Opt_a_tosbitwise() attempts to remove non-removable Rhs X */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+unsigned char a, b = 0;
+unsigned char c = 10;
+unsigned char d = 1;
+
+int main(void) {
+    /* 'if' needed to produce a label below, moved by OptJumpTarget3  */
+    if (b != 0) {
+        /* Operation not important; it only affects the removal of one LDX #$00 */
+        b = 0;
+    }
+
+    /* d >= 0 is const, A/X=1 (Warning: Result of comparison is always true) */
+    a = c ^ (d >= 0);
+
+    return !(a == 11);
+}