Implemented memory variable data output. Initialization can still be optimized. #328

src/main/java/dk/camelot64/kickc/Compiler.java

@@ -114,6 +114,7 @@ public class Compiler {
          fileName = fileName.substring(0, fileName.length() - 3);
       }
       program.setFileName(fileName);
+
       initAsmFragmentSynthesizer();
       try {
          Path currentPath = new File(".").toPath();

src/main/java/dk/camelot64/kickc/model/symbols/SymbolVariable.java

@@ -55,12 +55,12 @@ public abstract class SymbolVariable implements Symbol {
 
    /** Strategy being used for storing and accessing the variable. The value depends on the directives memory/register/volatile/const - and on the compilers optimization decisions.
     * <ul>
-    * <li>REGISTER-variables are turned into versions and PHI-nodes are used for them throughout the entire program. They cannot be "volatile" and the "address-of" operator cannot be used on them.</li>
+    * <li>PHI_REGISTER-variables are turned into versions and PHI-nodes are used for them throughout the entire program. They cannot be "volatile" and the "address-of" operator cannot be used on them.</li>
     * <li>MEMORY-variables are stored in memory and accessed through load/store operators. They cannot be declared as "register".</li>
     * <li>CONSTANT-variables are constant.
     * </ul>
     **/
-   public enum StorageStrategy { REGISTER, MEMORY, CONSTANT }
+   public enum StorageStrategy {PHI_REGISTER, MEMORY, CONSTANT }
 
    /** The storage strategy for the variable. */
    private StorageStrategy storageStrategy;
@@ -82,7 +82,7 @@ public abstract class SymbolVariable implements Symbol {
       this.inferredType = false;
       this.comments = new ArrayList<>();
       this.dataSegment = dataSegment;
-      this.storageStrategy = StorageStrategy.REGISTER;
+      this.storageStrategy = StorageStrategy.PHI_REGISTER;
       setFullName();
    }
 

src/main/java/dk/camelot64/kickc/passes/Pass0GenerateStatementSequence.java

@@ -262,7 +262,7 @@ public class Pass0GenerateStatementSequence extends KickCParserBaseVisitor<Objec
       List<Directive> directives = declVarDirectives;
       VariableUnversioned param = new VariableUnversioned(ctx.NAME().getText(), getCurrentScope(), type, currentDataSegment);
       // Set initial storage strategy
-      param.setStorageStrategy(SymbolVariable.StorageStrategy.REGISTER);
+      param.setStorageStrategy(SymbolVariable.StorageStrategy.PHI_REGISTER);
       // Add directives
       addDirectives(param, type, directives, new StatementSource(ctx));
       exitDeclTypes();
@@ -620,7 +620,7 @@ public class Pass0GenerateStatementSequence extends KickCParserBaseVisitor<Objec
          throw new CompileError(e.getMessage(), new StatementSource(ctx));
       }
       // Set initial storage strategy
-      lValue.setStorageStrategy(SymbolVariable.StorageStrategy.REGISTER);
+      lValue.setStorageStrategy(SymbolVariable.StorageStrategy.PHI_REGISTER);
       // Add directives
       addDirectives(lValue, type, directives, new StatementSource(ctx));
       // Array / String variables are implicitly constant
@@ -704,7 +704,7 @@ public class Pass0GenerateStatementSequence extends KickCParserBaseVisitor<Objec
          } else if(directive instanceof DirectiveRegister) {
             DirectiveRegister directiveRegister = (DirectiveRegister) directive;
             lValue.setDeclaredAsRegister(true);
-            lValue.setStorageStrategy(SymbolVariable.StorageStrategy.REGISTER);
+            lValue.setStorageStrategy(SymbolVariable.StorageStrategy.PHI_REGISTER);
             if(directiveRegister.name != null) {
                // Ignore register directive without parameter (all variables are placed on ZP and attempted register uplift anyways)
                Registers.Register register = Registers.getRegister(directiveRegister.name);
@@ -1207,7 +1207,7 @@ public class Pass0GenerateStatementSequence extends KickCParserBaseVisitor<Objec
             throw new CompileError(e.getMessage(), statementSource);
          }
          // Set initial storage strategy
-         lValue.setStorageStrategy(SymbolVariable.StorageStrategy.REGISTER);
+         lValue.setStorageStrategy(SymbolVariable.StorageStrategy.PHI_REGISTER);
          // Add directives
          addDirectives(lValue, varType, varDirectives, statementSource);
       } else {

src/main/java/dk/camelot64/kickc/passes/Pass4CodeGeneration.java

@@ -433,6 +433,7 @@ public class Pass4CodeGeneration {
       Scope scope = program.getScope().getScope(scopeRef);
       Collection<ConstantVar> scopeConstants = scope.getAllConstants(false);
       Set<String> added = new LinkedHashSet<>();
+      // Add all constants arrays incl. strings with data
       for(ConstantVar constantVar : scopeConstants) {
          if(hasData(constantVar)) {
             // Skip if already added
@@ -461,6 +462,31 @@ public class Pass4CodeGeneration {
             added.add(asmName);
          }
       }
+      // Add all memory variables
+      Collection<Variable> scopeVariables = scope.getAllVariables(false);
+      for(Variable variable : scopeVariables) {
+         if(variable.getStorageStrategy().equals(SymbolVariable.StorageStrategy.MEMORY)) {
+            // Skip if already added
+            String asmName = variable.getAsmName() == null ? variable.getLocalName() : variable.getAsmName();
+            if(added.contains(asmName)) {
+               continue;
+            }
+            // Set segment
+            setCurrentSegment(variable.getDataSegment(), asm);
+            // Add any comments
+            generateComments(asm, variable.getComments());
+            // Add any alignment
+            Integer declaredAlignment = variable.getDeclaredAlignment();
+            if(declaredAlignment != null) {
+               String alignment = AsmFormat.getAsmNumber(declaredAlignment);
+               asm.addDataAlignment(alignment);
+            }
+            AsmDataChunk asmDataChunk = new AsmDataChunk();
+            addChunkData(asmDataChunk, ZeroConstantValues.zeroValue(variable.getType(), getScope()), variable.getType(), scopeRef);
+            asmDataChunk.addToAsm(AsmFormat.asmFix(asmName), asm);
+            added.add(asmName);
+         }
+      }
    }
 
    /**

src/test/java/dk/camelot64/kickc/test/TestPrograms.java

@@ -35,12 +35,10 @@ public class TestPrograms {
    public TestPrograms() {
    }
 
-   /*
    @Test
-   public void testDelcaredMemoryVar0() throws IOException, URISyntaxException {
+   public void testDeclaredMemoryVar0() throws IOException, URISyntaxException {
-      compileAndCompare("declared-memory-var-0", log().verboseParse().verboseCreateSsa());
+      compileAndCompare("declared-memory-var-0", log());
    }
-   */
 
    /*
    @Test

src/test/kc/declared-memory-var-0.kc

@@ -1,6 +1,6 @@
 // Test declaring a variable as "memory", meaning it will be stored in memory and accessed through an implicit pointer (using load/store)
 
-memory char idx=0;
+memory char idx;
 
 const char* SCREEN = 0x0400;
 

src/test/ref/declared-memory-var-0.asm

@@ -1,18 +1,27 @@
 // Test declaring a variable as "memory", meaning it will be stored in memory and accessed through an implicit pointer (using load/store)
 .pc = $801 "Basic"
-:BasicUpstart(main)
+:BasicUpstart(bbegin)
 .pc = $80d "Program"
+  .label idx_ptr = idx
   .label SCREEN = $400
+bbegin:
+  lda #0
+  sta idx_ptr
+  jsr main
+  rts
 main: {
     ldx #0
-    txa
   b1:
+    lda idx_ptr
     sta SCREEN,x
-    stx.z $ff
+    txa
     clc
-    adc.z $ff
+    adc idx_ptr
+    sta idx_ptr
     inx
     cpx #6
     bne b1
+    sta idx_ptr
     rts
 }
+  idx: .byte 0

src/test/ref/declared-memory-var-0.cfg

@@ -1,25 +1,28 @@
 @begin: scope:[]  from
-  [0] phi()
+  [0] *((const byte*) idx_ptr) ← (byte) 0
   to:@1
 @1: scope:[]  from @begin
   [1] phi()
   [2] call main 
+  to:@2
+@2: scope:[]  from @1
+  [3] *((const byte*) idx_ptr) ← *((const byte*) idx_ptr)
   to:@end
-@end: scope:[]  from @1
+@end: scope:[]  from @2
-  [3] phi()
+  [4] phi()
 
 (void()) main()
 main: scope:[main]  from @1
-  [4] phi()
+  [5] phi()
   to:main::@1
 main::@1: scope:[main]  from main main::@1
-  [5] (byte) main::i#2 ← phi( main/(byte) 0 main::@1/(byte) main::i#1 )
+  [6] (byte) main::i#2 ← phi( main/(byte) 0 main::@1/(byte) main::i#1 )
-  [5] (byte) idx#5 ← phi( main/(byte) 0 main::@1/(byte) idx#2 )
+  [7] *((const byte*) SCREEN#0 + (byte) main::i#2) ← *((const byte*) idx_ptr)
-  [6] *((const byte*) SCREEN#0 + (byte) main::i#2) ← (byte) idx#5
+  [8] *((const byte*) idx_ptr) ← *((const byte*) idx_ptr) + (byte) main::i#2
-  [7] (byte) idx#2 ← (byte) idx#5 + (byte) main::i#2
+  [9] (byte) main::i#1 ← ++ (byte) main::i#2
-  [8] (byte) main::i#1 ← ++ (byte) main::i#2
+  [10] if((byte) main::i#1!=(byte) 6) goto main::@1
-  [9] if((byte) main::i#1!=(byte) 6) goto main::@1
   to:main::@return
 main::@return: scope:[main]  from main::@1
-  [10] return 
+  [11] *((const byte*) idx_ptr) ← *((const byte*) idx_ptr)
+  [12] return 
   to:@return

src/test/ref/declared-memory-var-0.log

@@ -1,37 +1,41 @@
 Culled Empty Block (label) main::@2
+Adding memory variable constant pointer (const byte*) idx_ptr
+Updating memory variable reference *((const byte*) idx_ptr)
+Updating memory variable reference *((const byte*) idx_ptr)
+Updating memory variable reference *((const byte*) idx_ptr)
+Updating memory variable reference *((const byte*) idx_ptr)
+Updating memory variable reference *((const byte*) idx_ptr)
+Updating memory variable reference *((const byte*) idx_ptr)
+Updating memory variable reference *((const byte*) idx_ptr)
+Updating memory variable reference *((const byte*) idx_ptr)
 
 CONTROL FLOW GRAPH SSA
 @begin: scope:[]  from
-  (byte) idx#0 ← (byte) 0
+  *((const byte*) idx_ptr) ← (number) 0
   (byte*) SCREEN#0 ← ((byte*)) (number) $400
   to:@1
 
 (void()) main()
 main: scope:[main]  from @1
-  (byte) idx#1 ← (number) 0
   (byte) main::i#0 ← (byte) 0
   to:main::@1
 main::@1: scope:[main]  from main main::@1
   (byte) main::i#2 ← phi( main/(byte) main::i#0 main::@1/(byte) main::i#1 )
-  (byte) idx#5 ← phi( main/(byte) idx#1 main::@1/(byte) idx#2 )
+  *((byte*) SCREEN#0 + (byte) main::i#2) ← *((const byte*) idx_ptr)
-  *((byte*) SCREEN#0 + (byte) main::i#2) ← (byte) idx#5
+  *((const byte*) idx_ptr) ← *((const byte*) idx_ptr) + (byte) main::i#2
-  (byte) idx#2 ← (byte) idx#5 + (byte) main::i#2
   (byte) main::i#1 ← (byte) main::i#2 + rangenext(0,5)
   (bool~) main::$0 ← (byte) main::i#1 != rangelast(0,5)
   if((bool~) main::$0) goto main::@1
   to:main::@return
 main::@return: scope:[main]  from main::@1
-  (byte) idx#6 ← phi( main::@1/(byte) idx#2 )
+  *((const byte*) idx_ptr) ← *((const byte*) idx_ptr)
-  (byte) idx#3 ← (byte) idx#6
   return 
   to:@return
 @1: scope:[]  from @begin
-  (byte) idx#8 ← phi( @begin/(byte) idx#0 )
   call main 
   to:@2
 @2: scope:[]  from @1
-  (byte) idx#7 ← phi( @1/(byte) idx#3 )
+  *((const byte*) idx_ptr) ← *((const byte*) idx_ptr)
-  (byte) idx#4 ← (byte) idx#7
   to:@end
 @end: scope:[]  from @2
 
@@ -43,15 +47,7 @@ SYMBOL TABLE SSA
 (byte*) SCREEN
 (byte*) SCREEN#0
 (byte) idx memory
-(byte) idx#0 memory
+(const byte*) idx_ptr = &(byte) idx
-(byte) idx#1 memory
-(byte) idx#2 memory
-(byte) idx#3 memory
-(byte) idx#4 memory
-(byte) idx#5 memory
-(byte) idx#6 memory
-(byte) idx#7 memory
-(byte) idx#8 memory
 (void()) main()
 (bool~) main::$0
 (label) main::@1
@@ -61,33 +57,23 @@ SYMBOL TABLE SSA
 (byte) main::i#1
 (byte) main::i#2
 
-Adding number conversion cast (unumber) 0 in (byte) idx#1 ← (number) 0
+Adding number conversion cast (unumber) 0 in *((const byte*) idx_ptr) ← (number) 0
 Successful SSA optimization PassNAddNumberTypeConversions
+Inlining cast *((const byte*) idx_ptr) ← (unumber)(number) 0
 Inlining cast (byte*) SCREEN#0 ← (byte*)(number) $400
-Inlining cast (byte) idx#1 ← (unumber)(number) 0
 Successful SSA optimization Pass2InlineCast
-Simplifying constant pointer cast (byte*) 1024
 Simplifying constant integer cast 0
+Simplifying constant pointer cast (byte*) 1024
 Successful SSA optimization PassNCastSimplification
 Finalized unsigned number type (byte) 0
 Successful SSA optimization PassNFinalizeNumberTypeConversions
-Alias (byte) idx#2 = (byte) idx#6 (byte) idx#3 
+Simple Condition (bool~) main::$0 [8] if((byte) main::i#1!=rangelast(0,5)) goto main::@1
-Alias (byte) idx#0 = (byte) idx#8 
-Alias (byte) idx#4 = (byte) idx#7 
-Successful SSA optimization Pass2AliasElimination
-Identical Phi Values (byte) idx#4 (byte) idx#2
-Successful SSA optimization Pass2IdenticalPhiElimination
-Simple Condition (bool~) main::$0 [9] if((byte) main::i#1!=rangelast(0,5)) goto main::@1
 Successful SSA optimization Pass2ConditionalJumpSimplification
-Constant (const byte) idx#0 = 0
 Constant (const byte*) SCREEN#0 = (byte*) 1024
-Constant (const byte) idx#1 = 0
 Constant (const byte) main::i#0 = 0
 Successful SSA optimization Pass2ConstantIdentification
-Resolved ranged next value [7] main::i#1 ← ++ main::i#2 to ++
+Resolved ranged next value [6] main::i#1 ← ++ main::i#2 to ++
-Resolved ranged comparison value [9] if(main::i#1!=rangelast(0,5)) goto main::@1 to (number) 6
+Resolved ranged comparison value [8] if(main::i#1!=rangelast(0,5)) goto main::@1 to (number) 6
-Eliminating unused constant (const byte) idx#0
-Successful SSA optimization PassNEliminateUnusedVars
 Adding number conversion cast (unumber) 6 in if((byte) main::i#1!=(number) 6) goto main::@1
 Successful SSA optimization PassNAddNumberTypeConversions
 Simplifying constant integer cast 6
@@ -95,76 +81,67 @@ Successful SSA optimization PassNCastSimplification
 Finalized unsigned number type (byte) 6
 Successful SSA optimization PassNFinalizeNumberTypeConversions
 Inlining constant with var siblings (const byte) main::i#0
-Inlining constant with var siblings (const byte) idx#1
 Constant inlined main::i#0 = (byte) 0
-Constant inlined idx#1 = (byte) 0
 Successful SSA optimization Pass2ConstantInlining
 Added new block during phi lifting main::@3(between main::@1 and main::@1)
-Adding NOP phi() at start of @begin
 Adding NOP phi() at start of @1
-Adding NOP phi() at start of @2
 Adding NOP phi() at start of @end
 Adding NOP phi() at start of main
 CALL GRAPH
 Calls in [] to main:2 
 
-Created 2 initial phi equivalence classes
+Created 1 initial phi equivalence classes
-Coalesced [12] idx#9 ← idx#2
 Coalesced [13] main::i#3 ← main::i#1
-Coalesced down to 2 phi equivalence classes
+Coalesced down to 1 phi equivalence classes
-Culled Empty Block (label) @2
 Culled Empty Block (label) main::@3
-Adding NOP phi() at start of @begin
 Adding NOP phi() at start of @1
 Adding NOP phi() at start of @end
 Adding NOP phi() at start of main
 
 FINAL CONTROL FLOW GRAPH
 @begin: scope:[]  from
-  [0] phi()
+  [0] *((const byte*) idx_ptr) ← (byte) 0
   to:@1
 @1: scope:[]  from @begin
   [1] phi()
   [2] call main 
+  to:@2
+@2: scope:[]  from @1
+  [3] *((const byte*) idx_ptr) ← *((const byte*) idx_ptr)
   to:@end
-@end: scope:[]  from @1
+@end: scope:[]  from @2
-  [3] phi()
+  [4] phi()
 
 (void()) main()
 main: scope:[main]  from @1
-  [4] phi()
+  [5] phi()
   to:main::@1
 main::@1: scope:[main]  from main main::@1
-  [5] (byte) main::i#2 ← phi( main/(byte) 0 main::@1/(byte) main::i#1 )
+  [6] (byte) main::i#2 ← phi( main/(byte) 0 main::@1/(byte) main::i#1 )
-  [5] (byte) idx#5 ← phi( main/(byte) 0 main::@1/(byte) idx#2 )
+  [7] *((const byte*) SCREEN#0 + (byte) main::i#2) ← *((const byte*) idx_ptr)
-  [6] *((const byte*) SCREEN#0 + (byte) main::i#2) ← (byte) idx#5
+  [8] *((const byte*) idx_ptr) ← *((const byte*) idx_ptr) + (byte) main::i#2
-  [7] (byte) idx#2 ← (byte) idx#5 + (byte) main::i#2
+  [9] (byte) main::i#1 ← ++ (byte) main::i#2
-  [8] (byte) main::i#1 ← ++ (byte) main::i#2
+  [10] if((byte) main::i#1!=(byte) 6) goto main::@1
-  [9] if((byte) main::i#1!=(byte) 6) goto main::@1
   to:main::@return
 main::@return: scope:[main]  from main::@1
-  [10] return 
+  [11] *((const byte*) idx_ptr) ← *((const byte*) idx_ptr)
+  [12] return 
   to:@return
 
 
 VARIABLE REGISTER WEIGHTS
 (byte*) SCREEN
 (byte) idx memory
-(byte) idx#2 memory 7.333333333333333
-(byte) idx#5 memory 16.5
 (void()) main()
 (byte) main::i
 (byte) main::i#1 16.5
 (byte) main::i#2 14.666666666666666
 
 Initial phi equivalence classes
-[ idx#5 idx#2 ]
 [ main::i#2 main::i#1 ]
 Complete equivalence classes
-[ idx#5 idx#2 ]
 [ main::i#2 main::i#1 ]
-Allocated zp ZP_BYTE:2 [ idx#5 idx#2 ]
+Allocated zp ZP_BYTE:2 [ main::i#2 main::i#1 ]
-Allocated zp ZP_BYTE:3 [ main::i#2 main::i#1 ]
 
 INITIAL ASM
 Target platform is c64basic / MOS6502X
@@ -175,79 +152,95 @@ Target platform is c64basic / MOS6502X
 :BasicUpstart(bbegin)
 .pc = $80d "Program"
   // Global Constants & labels
+  .label idx_ptr = idx
   .label SCREEN = $400
-  .label idx = 2
   // @begin
 bbegin:
+  // [0] *((const byte*) idx_ptr) ← (byte) 0 -- _deref_pbuc1=vbuc2 
+  lda #0
+  sta idx_ptr
   // [1] phi from @begin to @1 [phi:@begin->@1]
 b1_from_bbegin:
   jmp b1
   // @1
 b1:
   // [2] call main 
-  // [4] phi from @1 to main [phi:@1->main]
+  // [5] phi from @1 to main [phi:@1->main]
 main_from_b1:
   jsr main
-  // [3] phi from @1 to @end [phi:@1->@end]
+  jmp b2
-bend_from_b1:
+  // @2
+b2:
+  // [3] *((const byte*) idx_ptr) ← *((const byte*) idx_ptr) -- _deref_pbuc1=_deref_pbuc1 
+  lda idx_ptr
+  sta idx_ptr
+  // [4] phi from @2 to @end [phi:@2->@end]
+bend_from_b2:
   jmp bend
   // @end
 bend:
   // main
 main: {
-    .label i = 3
+    .label i = 2
-    // [5] phi from main to main::@1 [phi:main->main::@1]
+    // [6] phi from main to main::@1 [phi:main->main::@1]
   b1_from_main:
-    // [5] phi (byte) main::i#2 = (byte) 0 [phi:main->main::@1#0] -- vbuz1=vbuc1 
+    // [6] phi (byte) main::i#2 = (byte) 0 [phi:main->main::@1#0] -- vbuz1=vbuc1 
     lda #0
     sta.z i
-    // [5] phi (byte) idx#5 = (byte) 0 [phi:main->main::@1#1] -- vbuz1=vbuc1 
-    lda #0
-    sta.z idx
     jmp b1
-    // [5] phi from main::@1 to main::@1 [phi:main::@1->main::@1]
+    // [6] phi from main::@1 to main::@1 [phi:main::@1->main::@1]
   b1_from_b1:
-    // [5] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@1->main::@1#0] -- register_copy 
+    // [6] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@1->main::@1#0] -- register_copy 
-    // [5] phi (byte) idx#5 = (byte) idx#2 [phi:main::@1->main::@1#1] -- register_copy 
     jmp b1
     // main::@1
   b1:
-    // [6] *((const byte*) SCREEN#0 + (byte) main::i#2) ← (byte) idx#5 -- pbuc1_derefidx_vbuz1=vbuz2 
+    // [7] *((const byte*) SCREEN#0 + (byte) main::i#2) ← *((const byte*) idx_ptr) -- pbuc1_derefidx_vbuz1=_deref_pbuc2 
-    lda.z idx
     ldy.z i
+    lda idx_ptr
     sta SCREEN,y
-    // [7] (byte) idx#2 ← (byte) idx#5 + (byte) main::i#2 -- vbuz1=vbuz1_plus_vbuz2 
+    // [8] *((const byte*) idx_ptr) ← *((const byte*) idx_ptr) + (byte) main::i#2 -- _deref_pbuc1=_deref_pbuc1_plus_vbuz1 
-    lda.z idx
+    lda idx_ptr
     clc
     adc.z i
-    sta.z idx
+    sta idx_ptr
-    // [8] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuz1=_inc_vbuz1 
+    // [9] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuz1=_inc_vbuz1 
     inc.z i
-    // [9] if((byte) main::i#1!=(byte) 6) goto main::@1 -- vbuz1_neq_vbuc1_then_la1 
+    // [10] if((byte) main::i#1!=(byte) 6) goto main::@1 -- vbuz1_neq_vbuc1_then_la1 
     lda #6
     cmp.z i
     bne b1_from_b1
     jmp breturn
     // main::@return
   breturn:
-    // [10] return 
+    // [11] *((const byte*) idx_ptr) ← *((const byte*) idx_ptr) -- _deref_pbuc1=_deref_pbuc1 
+    lda idx_ptr
+    sta idx_ptr
+    // [12] return 
     rts
 }
   // File Data
+  idx: .byte 0
 
 REGISTER UPLIFT POTENTIAL REGISTERS
-Statement [7] (byte) idx#2 ← (byte) idx#5 + (byte) main::i#2 [ main::i#2 idx#2 ] ( main:2 [ main::i#2 idx#2 ] ) always clobbers reg byte a 
+Statement [0] *((const byte*) idx_ptr) ← (byte) 0 [ ] (  [ ] ) always clobbers reg byte a 
-Removing always clobbered register reg byte a as potential for zp ZP_BYTE:3 [ main::i#2 main::i#1 ]
+Statement [3] *((const byte*) idx_ptr) ← *((const byte*) idx_ptr) [ ] (  [ ] ) always clobbers reg byte a 
-Statement [7] (byte) idx#2 ← (byte) idx#5 + (byte) main::i#2 [ main::i#2 idx#2 ] ( main:2 [ main::i#2 idx#2 ] ) always clobbers reg byte a 
+Statement [7] *((const byte*) SCREEN#0 + (byte) main::i#2) ← *((const byte*) idx_ptr) [ main::i#2 ] ( main:2 [ main::i#2 ] ) always clobbers reg byte a 
-Potential registers zp ZP_BYTE:2 [ idx#5 idx#2 ] : zp ZP_BYTE:2 , reg byte a , reg byte x , reg byte y , 
+Removing always clobbered register reg byte a as potential for zp ZP_BYTE:2 [ main::i#2 main::i#1 ]
-Potential registers zp ZP_BYTE:3 [ main::i#2 main::i#1 ] : zp ZP_BYTE:3 , reg byte x , reg byte y , 
+Statement [8] *((const byte*) idx_ptr) ← *((const byte*) idx_ptr) + (byte) main::i#2 [ main::i#2 ] ( main:2 [ main::i#2 ] ) always clobbers reg byte a 
+Statement [11] *((const byte*) idx_ptr) ← *((const byte*) idx_ptr) [ ] ( main:2 [ ] ) always clobbers reg byte a 
+Statement [0] *((const byte*) idx_ptr) ← (byte) 0 [ ] (  [ ] ) always clobbers reg byte a 
+Statement [3] *((const byte*) idx_ptr) ← *((const byte*) idx_ptr) [ ] (  [ ] ) always clobbers reg byte a 
+Statement [7] *((const byte*) SCREEN#0 + (byte) main::i#2) ← *((const byte*) idx_ptr) [ main::i#2 ] ( main:2 [ main::i#2 ] ) always clobbers reg byte a 
+Statement [8] *((const byte*) idx_ptr) ← *((const byte*) idx_ptr) + (byte) main::i#2 [ main::i#2 ] ( main:2 [ main::i#2 ] ) always clobbers reg byte a 
+Statement [11] *((const byte*) idx_ptr) ← *((const byte*) idx_ptr) [ ] ( main:2 [ ] ) always clobbers reg byte a 
+Potential registers zp ZP_BYTE:2 [ main::i#2 main::i#1 ] : zp ZP_BYTE:2 , reg byte x , reg byte y , 
 
 REGISTER UPLIFT SCOPES
-Uplift Scope [main] 31.17: zp ZP_BYTE:3 [ main::i#2 main::i#1 ] 
+Uplift Scope [main] 31.17: zp ZP_BYTE:2 [ main::i#2 main::i#1 ] 
-Uplift Scope [] 23.83: zp ZP_BYTE:2 [ idx#5 idx#2 ] 
+Uplift Scope [] 
 
-Uplifting [main] best 423 combination reg byte x [ main::i#2 main::i#1 ] 
+Uplifting [main] best 428 combination reg byte x [ main::i#2 main::i#1 ] 
-Uplifting [] best 343 combination reg byte a [ idx#5 idx#2 ] 
+Uplifting [] best 428 combination 
 
 ASSEMBLER BEFORE OPTIMIZATION
   // File Comments
@@ -257,93 +250,109 @@ ASSEMBLER BEFORE OPTIMIZATION
 :BasicUpstart(bbegin)
 .pc = $80d "Program"
   // Global Constants & labels
+  .label idx_ptr = idx
   .label SCREEN = $400
   // @begin
 bbegin:
+  // [0] *((const byte*) idx_ptr) ← (byte) 0 -- _deref_pbuc1=vbuc2 
+  lda #0
+  sta idx_ptr
   // [1] phi from @begin to @1 [phi:@begin->@1]
 b1_from_bbegin:
   jmp b1
   // @1
 b1:
   // [2] call main 
-  // [4] phi from @1 to main [phi:@1->main]
+  // [5] phi from @1 to main [phi:@1->main]
 main_from_b1:
   jsr main
-  // [3] phi from @1 to @end [phi:@1->@end]
+  jmp b2
-bend_from_b1:
+  // @2
+b2:
+  // [3] *((const byte*) idx_ptr) ← *((const byte*) idx_ptr) -- _deref_pbuc1=_deref_pbuc1 
+  lda idx_ptr
+  sta idx_ptr
+  // [4] phi from @2 to @end [phi:@2->@end]
+bend_from_b2:
   jmp bend
   // @end
 bend:
   // main
 main: {
-    // [5] phi from main to main::@1 [phi:main->main::@1]
+    // [6] phi from main to main::@1 [phi:main->main::@1]
   b1_from_main:
-    // [5] phi (byte) main::i#2 = (byte) 0 [phi:main->main::@1#0] -- vbuxx=vbuc1 
+    // [6] phi (byte) main::i#2 = (byte) 0 [phi:main->main::@1#0] -- vbuxx=vbuc1 
     ldx #0
-    // [5] phi (byte) idx#5 = (byte) 0 [phi:main->main::@1#1] -- vbuaa=vbuc1 
-    lda #0
     jmp b1
-    // [5] phi from main::@1 to main::@1 [phi:main::@1->main::@1]
+    // [6] phi from main::@1 to main::@1 [phi:main::@1->main::@1]
   b1_from_b1:
-    // [5] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@1->main::@1#0] -- register_copy 
+    // [6] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@1->main::@1#0] -- register_copy 
-    // [5] phi (byte) idx#5 = (byte) idx#2 [phi:main::@1->main::@1#1] -- register_copy 
     jmp b1
     // main::@1
   b1:
-    // [6] *((const byte*) SCREEN#0 + (byte) main::i#2) ← (byte) idx#5 -- pbuc1_derefidx_vbuxx=vbuaa 
+    // [7] *((const byte*) SCREEN#0 + (byte) main::i#2) ← *((const byte*) idx_ptr) -- pbuc1_derefidx_vbuxx=_deref_pbuc2 
+    lda idx_ptr
     sta SCREEN,x
-    // [7] (byte) idx#2 ← (byte) idx#5 + (byte) main::i#2 -- vbuaa=vbuaa_plus_vbuxx 
+    // [8] *((const byte*) idx_ptr) ← *((const byte*) idx_ptr) + (byte) main::i#2 -- _deref_pbuc1=_deref_pbuc1_plus_vbuxx 
-    stx.z $ff
+    txa
     clc
-    adc.z $ff
+    adc idx_ptr
-    // [8] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuxx=_inc_vbuxx 
+    sta idx_ptr
+    // [9] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuxx=_inc_vbuxx 
     inx
-    // [9] if((byte) main::i#1!=(byte) 6) goto main::@1 -- vbuxx_neq_vbuc1_then_la1 
+    // [10] if((byte) main::i#1!=(byte) 6) goto main::@1 -- vbuxx_neq_vbuc1_then_la1 
     cpx #6
     bne b1_from_b1
     jmp breturn
     // main::@return
   breturn:
-    // [10] return 
+    // [11] *((const byte*) idx_ptr) ← *((const byte*) idx_ptr) -- _deref_pbuc1=_deref_pbuc1 
+    lda idx_ptr
+    sta idx_ptr
+    // [12] return 
     rts
 }
   // File Data
+  idx: .byte 0
 
 ASSEMBLER OPTIMIZATIONS
 Removing instruction jmp b1
+Removing instruction jmp b2
 Removing instruction jmp bend
 Removing instruction jmp b1
 Removing instruction jmp breturn
 Succesful ASM optimization Pass5NextJumpElimination
-Replacing instruction lda #0 with TXA
 Replacing label b1_from_b1 with b1
 Removing instruction b1_from_bbegin:
-Removing instruction b1:
 Removing instruction main_from_b1:
-Removing instruction bend_from_b1:
+Removing instruction bend_from_b2:
 Removing instruction b1_from_b1:
 Succesful ASM optimization Pass5RedundantLabelElimination
+Removing instruction b1:
+Removing instruction b2:
 Removing instruction bend:
 Removing instruction b1_from_main:
 Removing instruction breturn:
 Succesful ASM optimization Pass5UnusedLabelElimination
-Updating BasicUpstart to call main directly
+Adding RTS to root block 
-Removing instruction jsr main
+Succesful ASM optimization Pass5AddMainRts
-Succesful ASM optimization Pass5SkipBegin
 Removing instruction jmp b1
 Succesful ASM optimization Pass5NextJumpElimination
-Removing instruction bbegin:
+Removing instruction lda idx_ptr
-Succesful ASM optimization Pass5UnusedLabelElimination
+Succesful ASM optimization Pass5UnnecesaryLoadElimination
+Removing unreachable instruction lda idx_ptr
+Removing unreachable instruction sta idx_ptr
+Succesful ASM optimization Pass5UnreachableCodeElimination
 
 FINAL SYMBOL TABLE
 (label) @1
+(label) @2
 (label) @begin
 (label) @end
 (byte*) SCREEN
 (const byte*) SCREEN#0 SCREEN = (byte*) 1024
 (byte) idx memory
-(byte) idx#2 memory reg byte a 7.333333333333333
+(const byte*) idx_ptr idx_ptr = &(byte) idx
-(byte) idx#5 memory reg byte a 16.5
 (void()) main()
 (label) main::@1
 (label) main::@return
@@ -351,58 +360,69 @@ FINAL SYMBOL TABLE
 (byte) main::i#1 reg byte x 16.5
 (byte) main::i#2 reg byte x 14.666666666666666
 
-reg byte a [ idx#5 idx#2 ]
 reg byte x [ main::i#2 main::i#1 ]
 
 
 FINAL ASSEMBLER
-Score: 241
+Score: 323
 
   // File Comments
 // Test declaring a variable as "memory", meaning it will be stored in memory and accessed through an implicit pointer (using load/store)
   // Upstart
 .pc = $801 "Basic"
-:BasicUpstart(main)
+:BasicUpstart(bbegin)
 .pc = $80d "Program"
   // Global Constants & labels
+  .label idx_ptr = idx
   .label SCREEN = $400
   // @begin
+bbegin:
+  // idx=0
+  // [0] *((const byte*) idx_ptr) ← (byte) 0 -- _deref_pbuc1=vbuc2 
+  lda #0
+  sta idx_ptr
   // [1] phi from @begin to @1 [phi:@begin->@1]
   // @1
   // [2] call main 
-  // [4] phi from @1 to main [phi:@1->main]
+  // [5] phi from @1 to main [phi:@1->main]
-  // [3] phi from @1 to @end [phi:@1->@end]
+  jsr main
+  rts
+  // @2
+  // [3] *((const byte*) idx_ptr) ← *((const byte*) idx_ptr) -- _deref_pbuc1=_deref_pbuc1 
+  // [4] phi from @2 to @end [phi:@2->@end]
   // @end
   // main
 main: {
-    // [5] phi from main to main::@1 [phi:main->main::@1]
+    // [6] phi from main to main::@1 [phi:main->main::@1]
-    // [5] phi (byte) main::i#2 = (byte) 0 [phi:main->main::@1#0] -- vbuxx=vbuc1 
+    // [6] phi (byte) main::i#2 = (byte) 0 [phi:main->main::@1#0] -- vbuxx=vbuc1 
     ldx #0
-    // [5] phi (byte) idx#5 = (byte) 0 [phi:main->main::@1#1] -- vbuaa=vbuc1 
+    // [6] phi from main::@1 to main::@1 [phi:main::@1->main::@1]
-    txa
+    // [6] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@1->main::@1#0] -- register_copy 
-    // [5] phi from main::@1 to main::@1 [phi:main::@1->main::@1]
-    // [5] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@1->main::@1#0] -- register_copy 
-    // [5] phi (byte) idx#5 = (byte) idx#2 [phi:main::@1->main::@1#1] -- register_copy 
     // main::@1
   b1:
     // SCREEN[i] = idx
-    // [6] *((const byte*) SCREEN#0 + (byte) main::i#2) ← (byte) idx#5 -- pbuc1_derefidx_vbuxx=vbuaa 
+    // [7] *((const byte*) SCREEN#0 + (byte) main::i#2) ← *((const byte*) idx_ptr) -- pbuc1_derefidx_vbuxx=_deref_pbuc2 
+    lda idx_ptr
     sta SCREEN,x
     // idx +=i
-    // [7] (byte) idx#2 ← (byte) idx#5 + (byte) main::i#2 -- vbuaa=vbuaa_plus_vbuxx 
+    // [8] *((const byte*) idx_ptr) ← *((const byte*) idx_ptr) + (byte) main::i#2 -- _deref_pbuc1=_deref_pbuc1_plus_vbuxx 
-    stx.z $ff
+    txa
     clc
-    adc.z $ff
+    adc idx_ptr
+    sta idx_ptr
     // for( char i: 0..5 )
-    // [8] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuxx=_inc_vbuxx 
+    // [9] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuxx=_inc_vbuxx 
     inx
-    // [9] if((byte) main::i#1!=(byte) 6) goto main::@1 -- vbuxx_neq_vbuc1_then_la1 
+    // [10] if((byte) main::i#1!=(byte) 6) goto main::@1 -- vbuxx_neq_vbuc1_then_la1 
     cpx #6
     bne b1
     // main::@return
     // }
-    // [10] return 
+    // [11] *((const byte*) idx_ptr) ← *((const byte*) idx_ptr) -- _deref_pbuc1=_deref_pbuc1 
+    sta idx_ptr
+    // [12] return 
     rts
 }
   // File Data
+  idx: .byte 0
 

src/test/ref/declared-memory-var-0.sym

@@ -1,11 +1,11 @@
 (label) @1
+(label) @2
 (label) @begin
 (label) @end
 (byte*) SCREEN
 (const byte*) SCREEN#0 SCREEN = (byte*) 1024
 (byte) idx memory
-(byte) idx#2 memory reg byte a 7.333333333333333
+(const byte*) idx_ptr idx_ptr = &(byte) idx
-(byte) idx#5 memory reg byte a 16.5
 (void()) main()
 (label) main::@1
 (label) main::@return
@@ -13,5 +13,4 @@
 (byte) main::i#1 reg byte x 16.5
 (byte) main::i#2 reg byte x 14.666666666666666
 
-reg byte a [ idx#5 idx#2 ]
 reg byte x [ main::i#2 main::i#1 ]