Merge branch 'add-union-initializer-c99-syntax' into 'master'

Implemented C99 compatible union initializer method, using .member= syntax...

See merge request camelot/kickc!40

src/main/antlr4/dk/camelot64/kickc/parser/KickCParser.g4

@@ -243,9 +243,10 @@ expr
     | expr ( '&&' )  expr #exprBinary
     | expr ( '||' )  expr #exprBinary
     | expr '?'   expr COLON expr #exprTernary
-    | <assoc=right> expr '=' expr  #exprAssignment
+    | <assoc=right> expr ASSIGN expr  #exprAssignment
     | <assoc=right> expr ASSIGN_COMPOUND expr  #exprAssignmentCompound
     | CURLY_BEGIN expr (COMMA expr )* COMMA? CURLY_END #initList
+    | CURLY_BEGIN DOT NAME ASSIGN expr CURLY_END #initUnion
     | NAME  #exprId
     | NUMBER #exprNumber
     | STRING+ #exprString

src/main/java/dk/camelot64/kickc/model/Initializers.java

@@ -89,6 +89,8 @@ public class Initializers {
                return new ConstantCastValue(toType, (ConstantValue) constantSub);
             }
          }
+      } else if(initValue instanceof UnionDesignator) {
+         initValue = constantifyUnion((UnionDesignator) initValue, (SymbolTypeStruct) typeSpec.getType(), program, source);
       } else if(initValue instanceof ValueList) {
          ValueList initList = (ValueList) initValue;
          if(typeSpec.getType() instanceof SymbolTypePointer && ((SymbolTypePointer) typeSpec.getType()).getArraySpec() != null) {
@@ -96,7 +98,7 @@ public class Initializers {
             initValue = constantifyArray(initList, (SymbolTypePointer) typeSpec.getType(), program, source);
          } else if(typeSpec.getType() instanceof SymbolTypeStruct) {
             // Type is a struct
-            initValue = constantifyStruct(initList, (SymbolTypeStruct) typeSpec.getType(), program, source);
+            initValue = constantifyStructOrUnion(initList, (SymbolTypeStruct) typeSpec.getType(), program, source);
          } else {
             throw new CompileError("Value list cannot initialize type " + typeSpec.getType(), source);
          }
@@ -127,6 +129,41 @@ public class Initializers {
       return initValue;
    }
 
+   /**
+    * Convert a union designator initializer to a constant.
+    *
+    * @param unionInit The union initializer
+    * @param structType The union type
+    * @param program The program
+    * @param source The source line
+    * @return The constantified value
+    */
+   private static RValue constantifyUnion(UnionDesignator unionInit, SymbolTypeStruct structType, Program program, StatementSource source) {
+      StructDefinition structDefinition = structType.getStructDefinition(program.getScope());
+      Collection<Variable> memberDefinitions = structDefinition.getAllVars(false);
+
+      final String memberName = unionInit.getMemberName();
+      final RValue initValue = unionInit.getMemberValue();
+
+      Variable memberDef = null;
+      for(Variable definition : memberDefinitions) {
+         if(definition.getLocalName().equals(memberName)) {
+            memberDef = definition;
+         }
+      }
+      if(memberDef==null)
+         throw new CompileError( "Union member not found", source);
+
+      RValue constantifiedMemberValue = constantify(initValue, new ValueTypeSpec(memberDef.getType()), program, source);
+      if(constantifiedMemberValue instanceof ConstantValue) {
+         LinkedHashMap<SymbolVariableRef, ConstantValue> constMemberMap = new LinkedHashMap<>();
+         constMemberMap.put(memberDef.getRef(), (ConstantValue) constantifiedMemberValue);
+         return new ConstantStructValue(structType, constMemberMap);
+      } else {
+         throw new CompileError( "Union initializer is not constant", source);
+      }
+   }
+
    /**
     * Convert as much as possible of a struct to constants.
     *
@@ -136,7 +173,7 @@ public class Initializers {
     * @param source The source line
     * @return The constantified value
     */
-   private static RValue constantifyStruct(ValueList valueList, SymbolTypeStruct structType, Program program, StatementSource source) {
+   private static RValue constantifyStructOrUnion(ValueList valueList, SymbolTypeStruct structType, Program program, StatementSource source) {
       // Recursively cast all sub-elements
       StructDefinition structDefinition = structType.getStructDefinition(program.getScope());
       Collection<Variable> memberDefinitions = structDefinition.getAllVars(false);
@@ -144,7 +181,7 @@ public class Initializers {
       if(structInitNeedSize != valueList.getList().size()) {
          if(structDefinition.isUnion()) {
             throw new CompileError(
-                  "Union initializer has too many values, since only one is allowed.\n" +
+                  "Union initializer has wrong size. One value is required.\n" +
                         " Union initializer: " + valueList.toString(program),
                   source);
          } else {

src/main/java/dk/camelot64/kickc/model/values/UnionDesignator.java

@@ -0,0 +1,40 @@
+package dk.camelot64.kickc.model.values;
+
+import dk.camelot64.kickc.model.Program;
+
+/**
+ * A union designator initializer.
+ */
+public class UnionDesignator implements RValue {
+
+   private final String memberName;
+
+   private final RValue rValue;
+
+   public UnionDesignator(String memberName, RValue rValue) {
+      this.memberName = memberName;
+      this.rValue = rValue;
+   }
+
+   public String getMemberName() { return memberName; }
+
+   public RValue getMemberValue() {
+      return rValue;
+   }
+
+   @Override
+   public String toString(Program program) {
+      StringBuilder out = new StringBuilder();
+      out.append("{ ");
+      out.append(memberName);
+      out.append("=");
+      out.append(rValue.toString(program));
+      out.append(" }");
+      return out.toString();
+   }
+
+   @Override
+   public String toString() {
+      return toString(null);
+   }
+}

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

@@ -1913,13 +1913,20 @@ public class Pass0GenerateStatementSequence extends KickCParserBaseVisitor<Objec
       return null;
    }
 
+   @Override
+   public RValue visitInitUnion(KickCParser.InitUnionContext ctx) {
+      final String memberName = ctx.NAME().getText();
+      final RValue rValue = (RValue) visit(ctx.expr());
+      return new UnionDesignator(memberName, rValue);
+   }
+
    @Override
    public RValue visitInitList(KickCParser.InitListContext ctx) {
       List<RValue> initValues = new ArrayList<>();
       for(KickCParser.ExprContext initializer : ctx.expr()) {
          RValue rValue = (RValue) visit(initializer);
-         initValues.add(rValue);
+            initValues.add(rValue);
-      }
+         }
       return new ValueList(initValues);
    }
 

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

@@ -2541,6 +2541,31 @@ public class TestProgramsFast extends TestPrograms {
       compileAndCompare("weeip-bbslist.c");
    }
 
+   @Test
+   public void testUnion13() throws IOException {
+      compileAndCompare("union-13.c");
+   }
+
+   @Test
+   public void testUnion12() throws IOException {
+      compileAndCompare("union-12.c");
+   }
+
+   @Test
+   public void testUnion11() throws IOException {
+      compileAndCompare("union-11.c");
+   }
+
+   @Test
+   public void testUnion10() throws IOException {
+      compileAndCompare("union-10.c");
+   }
+
+   @Test
+   public void testUnion9() throws IOException {
+      compileAndCompare("union-9.c");
+   }
+
    @Test
    public void testUnion8() throws IOException {
       compileAndCompare("union-8.c");

src/test/kc/union-10.c

@@ -0,0 +1,27 @@
+// More extensive union with C99 style designator initialization behaviour of the second element.
+
+struct Move {
+    char f;
+    char t;
+    char s;
+};
+
+struct Turn {
+    char t;
+    char s;
+    char r;
+    char d;
+};
+
+union Data {
+    struct Move m;
+    struct Turn t;
+};
+
+union Data data = { .t={1,2,3,4} };
+
+char* const SCREEN = (char*)0x0400;
+
+void main() {
+    SCREEN[0] = data.m.f;
+}

src/test/kc/union-11.c

@@ -0,0 +1,27 @@
+// More extensive union with C99 style designator initialization behaviour of the first element.
+
+struct Move {
+    char f;
+    char t;
+    char s;
+};
+
+struct Turn {
+    char t;
+    char s;
+    char r;
+    char d;
+};
+
+union Data {
+    struct Move m;
+    struct Turn t;
+};
+
+union Data data = { .m={1,2,3} };
+
+char* const SCREEN = (char*)0x0400;
+
+void main() {
+    SCREEN[0] = data.m.f;
+}

src/test/kc/union-12.c

@@ -0,0 +1,29 @@
+// More extensive union with C99 style designator initialization behaviour using const expressions.
+
+struct Move {
+    char f;
+    char t;
+    char s;
+};
+
+struct Turn {
+    char t;
+    char s;
+    char r;
+    char d;
+};
+
+union Data {
+    struct Move m;
+    struct Turn t;
+};
+
+const struct Move move = {1,2,3};
+
+union Data data = { .m=move };
+
+char* const SCREEN = (char*)0x0400;
+
+void main() {
+    SCREEN[0] = data.m.f;
+}

src/test/kc/union-13.c

@@ -0,0 +1,20 @@
+// More extensive union with C99 style designator initialization behaviour using const expressions.
+
+union A {
+    unsigned char b;
+    unsigned int w;
+};
+
+union B {
+    union A a;
+    char b[4];
+};
+
+union B b1 = { .a={ .b=1 } };
+
+
+char* const SCREEN = (char*)0x0400;
+
+void main() {
+    SCREEN[0] = b1.b[0];
+}

src/test/kc/union-9.c

@@ -0,0 +1,14 @@
+// Minimal union with C99 style designator initialization behaviour.
+
+union Data {
+    char b;
+    unsigned w;
+};
+
+union Data data = { .w=1234 };
+
+char* const SCREEN = (char*)0x0400;
+
+void main() {
+    SCREEN[0] = data.b;
+}

src/test/ref/union-10.asm

@@ -0,0 +1,20 @@
+// More extensive union with C99 style designator initialization behaviour of the second element.
+  // Commodore 64 PRG executable file
+.file [name="union-10.prg", type="prg", segments="Program"]
+.segmentdef Program [segments="Basic, Code, Data"]
+.segmentdef Basic [start=$0801]
+.segmentdef Code [start=$80d]
+.segmentdef Data [startAfter="Code"]
+.segment Basic
+:BasicUpstart(main)
+  .label SCREEN = $400
+.segment Code
+main: {
+    // SCREEN[0] = data.m.f
+    lda data
+    sta SCREEN
+    // }
+    rts
+}
+.segment Data
+  data: .byte 1, 2, 3, 4

src/test/ref/union-10.cfg

@@ -0,0 +1,8 @@
+
+void main()
+main: scope:[main]  from
+  [0] *SCREEN = *((char *)(struct Move *)&data)
+  to:main::@return
+main::@return: scope:[main]  from main
+  [1] return 
+  to:@return

src/test/ref/union-10.log

@@ -0,0 +1,166 @@
+
+CONTROL FLOW GRAPH SSA
+
+void main()
+main: scope:[main]  from __start
+  SCREEN[0] = *((char *)(struct Move *)&data+OFFSET_UNION_DATA_M+OFFSET_STRUCT_MOVE_F)
+  to:main::@return
+main::@return: scope:[main]  from main
+  return 
+  to:@return
+
+void __start()
+__start: scope:[__start]  from
+  call main
+  to:__start::@1
+__start::@1: scope:[__start]  from __start
+  to:__start::@return
+__start::@return: scope:[__start]  from __start::@1
+  return 
+  to:@return
+
+SYMBOL TABLE SSA
+__constant char OFFSET_STRUCT_MOVE_F = 0
+__constant char OFFSET_UNION_DATA_M = 0
+__constant char * const SCREEN = (char *)$400
+void __start()
+__loadstore union Data data = { t: { t: 1, s: 2, r: 3, d: 4 } }
+void main()
+
+Adding number conversion cast (unumber) 0 in SCREEN[0] = *((char *)(struct Move *)&data+OFFSET_UNION_DATA_M+OFFSET_STRUCT_MOVE_F)
+Successful SSA optimization PassNAddNumberTypeConversions
+Simplifying constant pointer cast (char *) 1024
+Simplifying constant integer cast 0
+Successful SSA optimization PassNCastSimplification
+Finalized unsigned number type (char) 0
+Successful SSA optimization PassNFinalizeNumberTypeConversions
+Simplifying expression containing zero (char *)(struct Move *)&data+OFFSET_UNION_DATA_M in [0] SCREEN[0] = *((char *)(struct Move *)&data+OFFSET_UNION_DATA_M+OFFSET_STRUCT_MOVE_F)
+Simplifying expression containing zero (struct Move *)&data in [0] SCREEN[0] = *((char *)(struct Move *)&data+OFFSET_UNION_DATA_M)
+Simplifying expression containing zero SCREEN in [0] SCREEN[0] = *((char *)(struct Move *)&data)
+Successful SSA optimization PassNSimplifyExpressionWithZero
+Eliminating unused constant OFFSET_UNION_DATA_M
+Eliminating unused constant OFFSET_STRUCT_MOVE_F
+Successful SSA optimization PassNEliminateUnusedVars
+Removing unused procedure __start
+Removing unused procedure block __start
+Removing unused procedure block __start::@1
+Removing unused procedure block __start::@return
+Successful SSA optimization PassNEliminateEmptyStart
+CALL GRAPH
+
+Created 0 initial phi equivalence classes
+Coalesced down to 0 phi equivalence classes
+
+FINAL CONTROL FLOW GRAPH
+
+void main()
+main: scope:[main]  from
+  [0] *SCREEN = *((char *)(struct Move *)&data)
+  to:main::@return
+main::@return: scope:[main]  from main
+  [1] return 
+  to:@return
+
+
+VARIABLE REGISTER WEIGHTS
+__loadstore union Data data = { t: { t: 1, s: 2, r: 3, d: 4 } }
+void main()
+
+Initial phi equivalence classes
+Added variable data to live range equivalence class [ data ]
+Complete equivalence classes
+[ data ]
+Allocated mem[4] [ data ]
+REGISTER UPLIFT POTENTIAL REGISTERS
+Statement [0] *SCREEN = *((char *)(struct Move *)&data) [ ] (  [ ] { }  ) always clobbers reg byte a 
+Potential registers mem[4] [ data ] : mem[4] , 
+
+REGISTER UPLIFT SCOPES
+Uplift Scope [Move] 
+Uplift Scope [Turn] 
+Uplift Scope [Data] 
+Uplift Scope [main] 
+Uplift Scope [] 0: mem[4] [ data ] 
+
+Uplifting [Move] best 17 combination 
+Uplifting [Turn] best 17 combination 
+Uplifting [Data] best 17 combination 
+Uplifting [main] best 17 combination 
+Uplifting [] best 17 combination mem[4] [ data ] 
+
+ASSEMBLER BEFORE OPTIMIZATION
+  // File Comments
+// More extensive union with C99 style designator initialization behaviour of the second element.
+  // Upstart
+  // Commodore 64 PRG executable file
+.file [name="union-10.prg", type="prg", segments="Program"]
+.segmentdef Program [segments="Basic, Code, Data"]
+.segmentdef Basic [start=$0801]
+.segmentdef Code [start=$80d]
+.segmentdef Data [startAfter="Code"]
+.segment Basic
+:BasicUpstart(main)
+  // Global Constants & labels
+  .label SCREEN = $400
+.segment Code
+  // main
+main: {
+    // [0] *SCREEN = *((char *)(struct Move *)&data) -- _deref_pbuc1=_deref_pbuc2 
+    lda data
+    sta SCREEN
+    jmp __breturn
+    // main::@return
+  __breturn:
+    // [1] return 
+    rts
+}
+  // File Data
+.segment Data
+  data: .byte 1, 2, 3, 4
+
+ASSEMBLER OPTIMIZATIONS
+Removing instruction jmp __breturn
+Succesful ASM optimization Pass5NextJumpElimination
+Removing instruction __breturn:
+Succesful ASM optimization Pass5UnusedLabelElimination
+
+FINAL SYMBOL TABLE
+__constant char * const SCREEN = (char *) 1024
+__loadstore union Data data = { t: { t: 1, s: 2, r: 3, d: 4 } } // mem[4]
+void main()
+
+mem[4] [ data ]
+
+
+FINAL ASSEMBLER
+Score: 14
+
+  // File Comments
+// More extensive union with C99 style designator initialization behaviour of the second element.
+  // Upstart
+  // Commodore 64 PRG executable file
+.file [name="union-10.prg", type="prg", segments="Program"]
+.segmentdef Program [segments="Basic, Code, Data"]
+.segmentdef Basic [start=$0801]
+.segmentdef Code [start=$80d]
+.segmentdef Data [startAfter="Code"]
+.segment Basic
+:BasicUpstart(main)
+  // Global Constants & labels
+  .label SCREEN = $400
+.segment Code
+  // main
+main: {
+    // SCREEN[0] = data.m.f
+    // [0] *SCREEN = *((char *)(struct Move *)&data) -- _deref_pbuc1=_deref_pbuc2 
+    lda data
+    sta SCREEN
+    // main::@return
+    // }
+    // [1] return 
+    rts
+}
+  // File Data
+.segment Data
+  data: .byte 1, 2, 3, 4
+

src/test/ref/union-10.sym

@@ -0,0 +1,5 @@
+__constant char * const SCREEN = (char *) 1024
+__loadstore union Data data = { t: { t: 1, s: 2, r: 3, d: 4 } } // mem[4]
+void main()
+
+mem[4] [ data ]

src/test/ref/union-11.asm

@@ -0,0 +1,21 @@
+// More extensive union with C99 style designator initialization behaviour of the first element.
+  // Commodore 64 PRG executable file
+.file [name="union-11.prg", type="prg", segments="Program"]
+.segmentdef Program [segments="Basic, Code, Data"]
+.segmentdef Basic [start=$0801]
+.segmentdef Code [start=$80d]
+.segmentdef Data [startAfter="Code"]
+.segment Basic
+:BasicUpstart(main)
+  .label SCREEN = $400
+.segment Code
+main: {
+    // SCREEN[0] = data.m.f
+    lda data
+    sta SCREEN
+    // }
+    rts
+}
+.segment Data
+  data: .byte 1, 2, 3
+  .fill 1, 0

src/test/ref/union-11.cfg

@@ -0,0 +1,8 @@
+
+void main()
+main: scope:[main]  from
+  [0] *SCREEN = *((char *)(struct Move *)&data)
+  to:main::@return
+main::@return: scope:[main]  from main
+  [1] return 
+  to:@return

src/test/ref/union-11.log

@@ -0,0 +1,168 @@
+
+CONTROL FLOW GRAPH SSA
+
+void main()
+main: scope:[main]  from __start
+  SCREEN[0] = *((char *)(struct Move *)&data+OFFSET_UNION_DATA_M+OFFSET_STRUCT_MOVE_F)
+  to:main::@return
+main::@return: scope:[main]  from main
+  return 
+  to:@return
+
+void __start()
+__start: scope:[__start]  from
+  call main
+  to:__start::@1
+__start::@1: scope:[__start]  from __start
+  to:__start::@return
+__start::@return: scope:[__start]  from __start::@1
+  return 
+  to:@return
+
+SYMBOL TABLE SSA
+__constant char OFFSET_STRUCT_MOVE_F = 0
+__constant char OFFSET_UNION_DATA_M = 0
+__constant char * const SCREEN = (char *)$400
+void __start()
+__loadstore union Data data = { m: { f: 1, t: 2, s: 3 } }
+void main()
+
+Adding number conversion cast (unumber) 0 in SCREEN[0] = *((char *)(struct Move *)&data+OFFSET_UNION_DATA_M+OFFSET_STRUCT_MOVE_F)
+Successful SSA optimization PassNAddNumberTypeConversions
+Simplifying constant pointer cast (char *) 1024
+Simplifying constant integer cast 0
+Successful SSA optimization PassNCastSimplification
+Finalized unsigned number type (char) 0
+Successful SSA optimization PassNFinalizeNumberTypeConversions
+Simplifying expression containing zero (char *)(struct Move *)&data+OFFSET_UNION_DATA_M in [0] SCREEN[0] = *((char *)(struct Move *)&data+OFFSET_UNION_DATA_M+OFFSET_STRUCT_MOVE_F)
+Simplifying expression containing zero (struct Move *)&data in [0] SCREEN[0] = *((char *)(struct Move *)&data+OFFSET_UNION_DATA_M)
+Simplifying expression containing zero SCREEN in [0] SCREEN[0] = *((char *)(struct Move *)&data)
+Successful SSA optimization PassNSimplifyExpressionWithZero
+Eliminating unused constant OFFSET_UNION_DATA_M
+Eliminating unused constant OFFSET_STRUCT_MOVE_F
+Successful SSA optimization PassNEliminateUnusedVars
+Removing unused procedure __start
+Removing unused procedure block __start
+Removing unused procedure block __start::@1
+Removing unused procedure block __start::@return
+Successful SSA optimization PassNEliminateEmptyStart
+CALL GRAPH
+
+Created 0 initial phi equivalence classes
+Coalesced down to 0 phi equivalence classes
+
+FINAL CONTROL FLOW GRAPH
+
+void main()
+main: scope:[main]  from
+  [0] *SCREEN = *((char *)(struct Move *)&data)
+  to:main::@return
+main::@return: scope:[main]  from main
+  [1] return 
+  to:@return
+
+
+VARIABLE REGISTER WEIGHTS
+__loadstore union Data data = { m: { f: 1, t: 2, s: 3 } }
+void main()
+
+Initial phi equivalence classes
+Added variable data to live range equivalence class [ data ]
+Complete equivalence classes
+[ data ]
+Allocated mem[4] [ data ]
+REGISTER UPLIFT POTENTIAL REGISTERS
+Statement [0] *SCREEN = *((char *)(struct Move *)&data) [ ] (  [ ] { }  ) always clobbers reg byte a 
+Potential registers mem[4] [ data ] : mem[4] , 
+
+REGISTER UPLIFT SCOPES
+Uplift Scope [Move] 
+Uplift Scope [Turn] 
+Uplift Scope [Data] 
+Uplift Scope [main] 
+Uplift Scope [] 0: mem[4] [ data ] 
+
+Uplifting [Move] best 17 combination 
+Uplifting [Turn] best 17 combination 
+Uplifting [Data] best 17 combination 
+Uplifting [main] best 17 combination 
+Uplifting [] best 17 combination mem[4] [ data ] 
+
+ASSEMBLER BEFORE OPTIMIZATION
+  // File Comments
+// More extensive union with C99 style designator initialization behaviour of the first element.
+  // Upstart
+  // Commodore 64 PRG executable file
+.file [name="union-11.prg", type="prg", segments="Program"]
+.segmentdef Program [segments="Basic, Code, Data"]
+.segmentdef Basic [start=$0801]
+.segmentdef Code [start=$80d]
+.segmentdef Data [startAfter="Code"]
+.segment Basic
+:BasicUpstart(main)
+  // Global Constants & labels
+  .label SCREEN = $400
+.segment Code
+  // main
+main: {
+    // [0] *SCREEN = *((char *)(struct Move *)&data) -- _deref_pbuc1=_deref_pbuc2 
+    lda data
+    sta SCREEN
+    jmp __breturn
+    // main::@return
+  __breturn:
+    // [1] return 
+    rts
+}
+  // File Data
+.segment Data
+  data: .byte 1, 2, 3
+  .fill 1, 0
+
+ASSEMBLER OPTIMIZATIONS
+Removing instruction jmp __breturn
+Succesful ASM optimization Pass5NextJumpElimination
+Removing instruction __breturn:
+Succesful ASM optimization Pass5UnusedLabelElimination
+
+FINAL SYMBOL TABLE
+__constant char * const SCREEN = (char *) 1024
+__loadstore union Data data = { m: { f: 1, t: 2, s: 3 } } // mem[4]
+void main()
+
+mem[4] [ data ]
+
+
+FINAL ASSEMBLER
+Score: 14
+
+  // File Comments
+// More extensive union with C99 style designator initialization behaviour of the first element.
+  // Upstart
+  // Commodore 64 PRG executable file
+.file [name="union-11.prg", type="prg", segments="Program"]
+.segmentdef Program [segments="Basic, Code, Data"]
+.segmentdef Basic [start=$0801]
+.segmentdef Code [start=$80d]
+.segmentdef Data [startAfter="Code"]
+.segment Basic
+:BasicUpstart(main)
+  // Global Constants & labels
+  .label SCREEN = $400
+.segment Code
+  // main
+main: {
+    // SCREEN[0] = data.m.f
+    // [0] *SCREEN = *((char *)(struct Move *)&data) -- _deref_pbuc1=_deref_pbuc2 
+    lda data
+    sta SCREEN
+    // main::@return
+    // }
+    // [1] return 
+    rts
+}
+  // File Data
+.segment Data
+  data: .byte 1, 2, 3
+  .fill 1, 0
+

src/test/ref/union-11.sym

@@ -0,0 +1,5 @@
+__constant char * const SCREEN = (char *) 1024
+__loadstore union Data data = { m: { f: 1, t: 2, s: 3 } } // mem[4]
+void main()
+
+mem[4] [ data ]

src/test/ref/union-12.asm

@@ -0,0 +1,21 @@
+// More extensive union with C99 style designator initialization behaviour using const expressions.
+  // Commodore 64 PRG executable file
+.file [name="union-12.prg", type="prg", segments="Program"]
+.segmentdef Program [segments="Basic, Code, Data"]
+.segmentdef Basic [start=$0801]
+.segmentdef Code [start=$80d]
+.segmentdef Data [startAfter="Code"]
+.segment Basic
+:BasicUpstart(main)
+  .label SCREEN = $400
+.segment Code
+main: {
+    // SCREEN[0] = data.m.f
+    lda data
+    sta SCREEN
+    // }
+    rts
+}
+.segment Data
+  move: .byte 1, 2, 3
+  data: .fill 1, 0

src/test/ref/union-12.cfg

@@ -0,0 +1,8 @@
+
+void main()
+main: scope:[main]  from
+  [0] *SCREEN = *((char *)(struct Move *)&data)
+  to:main::@return
+main::@return: scope:[main]  from main
+  [1] return 
+  to:@return

src/test/ref/union-12.log

@@ -0,0 +1,170 @@
+
+CONTROL FLOW GRAPH SSA
+
+void main()
+main: scope:[main]  from __start
+  SCREEN[0] = *((char *)(struct Move *)&data+OFFSET_UNION_DATA_M+OFFSET_STRUCT_MOVE_F)
+  to:main::@return
+main::@return: scope:[main]  from main
+  return 
+  to:@return
+
+void __start()
+__start: scope:[__start]  from
+  call main
+  to:__start::@1
+__start::@1: scope:[__start]  from __start
+  to:__start::@return
+__start::@return: scope:[__start]  from __start::@1
+  return 
+  to:@return
+
+SYMBOL TABLE SSA
+__constant char OFFSET_STRUCT_MOVE_F = 0
+__constant char OFFSET_UNION_DATA_M = 0
+__constant char * const SCREEN = (char *)$400
+void __start()
+__loadstore union Data data = { m: move }
+void main()
+__constant const struct Move move = { f: 1, t: 2, s: 3 }
+
+Adding number conversion cast (unumber) 0 in SCREEN[0] = *((char *)(struct Move *)&data+OFFSET_UNION_DATA_M+OFFSET_STRUCT_MOVE_F)
+Successful SSA optimization PassNAddNumberTypeConversions
+Simplifying constant pointer cast (char *) 1024
+Simplifying constant integer cast 0
+Successful SSA optimization PassNCastSimplification
+Finalized unsigned number type (char) 0
+Successful SSA optimization PassNFinalizeNumberTypeConversions
+Simplifying expression containing zero (char *)(struct Move *)&data+OFFSET_UNION_DATA_M in [0] SCREEN[0] = *((char *)(struct Move *)&data+OFFSET_UNION_DATA_M+OFFSET_STRUCT_MOVE_F)
+Simplifying expression containing zero (struct Move *)&data in [0] SCREEN[0] = *((char *)(struct Move *)&data+OFFSET_UNION_DATA_M)
+Simplifying expression containing zero SCREEN in [0] SCREEN[0] = *((char *)(struct Move *)&data)
+Successful SSA optimization PassNSimplifyExpressionWithZero
+Eliminating unused constant OFFSET_UNION_DATA_M
+Eliminating unused constant OFFSET_STRUCT_MOVE_F
+Successful SSA optimization PassNEliminateUnusedVars
+Removing unused procedure __start
+Removing unused procedure block __start
+Removing unused procedure block __start::@1
+Removing unused procedure block __start::@return
+Successful SSA optimization PassNEliminateEmptyStart
+CALL GRAPH
+
+Created 0 initial phi equivalence classes
+Coalesced down to 0 phi equivalence classes
+
+FINAL CONTROL FLOW GRAPH
+
+void main()
+main: scope:[main]  from
+  [0] *SCREEN = *((char *)(struct Move *)&data)
+  to:main::@return
+main::@return: scope:[main]  from main
+  [1] return 
+  to:@return
+
+
+VARIABLE REGISTER WEIGHTS
+__loadstore union Data data = { m: move }
+void main()
+
+Initial phi equivalence classes
+Added variable data to live range equivalence class [ data ]
+Complete equivalence classes
+[ data ]
+Allocated mem[4] [ data ]
+REGISTER UPLIFT POTENTIAL REGISTERS
+Statement [0] *SCREEN = *((char *)(struct Move *)&data) [ ] (  [ ] { }  ) always clobbers reg byte a 
+Potential registers mem[4] [ data ] : mem[4] , 
+
+REGISTER UPLIFT SCOPES
+Uplift Scope [Move] 
+Uplift Scope [Turn] 
+Uplift Scope [Data] 
+Uplift Scope [main] 
+Uplift Scope [] 0: mem[4] [ data ] 
+
+Uplifting [Move] best 17 combination 
+Uplifting [Turn] best 17 combination 
+Uplifting [Data] best 17 combination 
+Uplifting [main] best 17 combination 
+Uplifting [] best 17 combination mem[4] [ data ] 
+
+ASSEMBLER BEFORE OPTIMIZATION
+  // File Comments
+// More extensive union with C99 style designator initialization behaviour using const expressions.
+  // Upstart
+  // Commodore 64 PRG executable file
+.file [name="union-12.prg", type="prg", segments="Program"]
+.segmentdef Program [segments="Basic, Code, Data"]
+.segmentdef Basic [start=$0801]
+.segmentdef Code [start=$80d]
+.segmentdef Data [startAfter="Code"]
+.segment Basic
+:BasicUpstart(main)
+  // Global Constants & labels
+  .label SCREEN = $400
+.segment Code
+  // main
+main: {
+    // [0] *SCREEN = *((char *)(struct Move *)&data) -- _deref_pbuc1=_deref_pbuc2 
+    lda data
+    sta SCREEN
+    jmp __breturn
+    // main::@return
+  __breturn:
+    // [1] return 
+    rts
+}
+  // File Data
+.segment Data
+  move: .byte 1, 2, 3
+  data: .fill 1, 0
+
+ASSEMBLER OPTIMIZATIONS
+Removing instruction jmp __breturn
+Succesful ASM optimization Pass5NextJumpElimination
+Removing instruction __breturn:
+Succesful ASM optimization Pass5UnusedLabelElimination
+
+FINAL SYMBOL TABLE
+__constant char * const SCREEN = (char *) 1024
+__loadstore union Data data = { m: move } // mem[4]
+void main()
+__constant const struct Move move = { f: 1, t: 2, s: 3 }
+
+mem[4] [ data ]
+
+
+FINAL ASSEMBLER
+Score: 14
+
+  // File Comments
+// More extensive union with C99 style designator initialization behaviour using const expressions.
+  // Upstart
+  // Commodore 64 PRG executable file
+.file [name="union-12.prg", type="prg", segments="Program"]
+.segmentdef Program [segments="Basic, Code, Data"]
+.segmentdef Basic [start=$0801]
+.segmentdef Code [start=$80d]
+.segmentdef Data [startAfter="Code"]
+.segment Basic
+:BasicUpstart(main)
+  // Global Constants & labels
+  .label SCREEN = $400
+.segment Code
+  // main
+main: {
+    // SCREEN[0] = data.m.f
+    // [0] *SCREEN = *((char *)(struct Move *)&data) -- _deref_pbuc1=_deref_pbuc2 
+    lda data
+    sta SCREEN
+    // main::@return
+    // }
+    // [1] return 
+    rts
+}
+  // File Data
+.segment Data
+  move: .byte 1, 2, 3
+  data: .fill 1, 0
+

src/test/ref/union-12.sym

@@ -0,0 +1,6 @@
+__constant char * const SCREEN = (char *) 1024
+__loadstore union Data data = { m: move } // mem[4]
+void main()
+__constant const struct Move move = { f: 1, t: 2, s: 3 }
+
+mem[4] [ data ]

src/test/ref/union-13.asm

@@ -0,0 +1,22 @@
+// More extensive union with C99 style designator initialization behaviour using const expressions.
+  // Commodore 64 PRG executable file
+.file [name="union-13.prg", type="prg", segments="Program"]
+.segmentdef Program [segments="Basic, Code, Data"]
+.segmentdef Basic [start=$0801]
+.segmentdef Code [start=$80d]
+.segmentdef Data [startAfter="Code"]
+.segment Basic
+:BasicUpstart(main)
+  .label SCREEN = $400
+.segment Code
+main: {
+    // SCREEN[0] = b1.b[0]
+    lda b1
+    sta SCREEN
+    // }
+    rts
+}
+.segment Data
+  b1: .byte 1
+  .fill 1, 0
+  .fill 2, 0

src/test/ref/union-13.cfg

@@ -0,0 +1,8 @@
+
+void main()
+main: scope:[main]  from
+  [0] *SCREEN = *((char *)&b1)
+  to:main::@return
+main::@return: scope:[main]  from main
+  [1] return 
+  to:@return

src/test/ref/union-13.log

@@ -0,0 +1,176 @@
+Fixing struct type size union B to 4
+Fixing struct type size union B to 4
+Fixing struct type SIZE_OF union B to 4
+Fixing struct type SIZE_OF union B to 4
+
+CONTROL FLOW GRAPH SSA
+
+void main()
+main: scope:[main]  from __start
+  SCREEN[0] = ((char *)&b1+OFFSET_UNION_B_B)[0]
+  to:main::@return
+main::@return: scope:[main]  from main
+  return 
+  to:@return
+
+void __start()
+__start: scope:[__start]  from
+  call main
+  to:__start::@1
+__start::@1: scope:[__start]  from __start
+  to:__start::@return
+__start::@return: scope:[__start]  from __start::@1
+  return 
+  to:@return
+
+SYMBOL TABLE SSA
+__constant char OFFSET_UNION_B_B = 0
+__constant char * const SCREEN = (char *)$400
+void __start()
+__loadstore union B b1 = { a: { b: 1 } }
+void main()
+
+Adding number conversion cast (unumber) 0 in SCREEN[0] = ((char *)&b1+OFFSET_UNION_B_B)[0]
+Adding number conversion cast (unumber) 0 in SCREEN[0] = ((char *)&b1+OFFSET_UNION_B_B)[(unumber)0]
+Successful SSA optimization PassNAddNumberTypeConversions
+Simplifying constant pointer cast (char *) 1024
+Simplifying constant integer cast 0
+Simplifying constant integer cast 0
+Successful SSA optimization PassNCastSimplification
+Finalized unsigned number type (char) 0
+Finalized unsigned number type (char) 0
+Successful SSA optimization PassNFinalizeNumberTypeConversions
+Simplifying expression containing zero (char *)&b1+OFFSET_UNION_B_B in [0] SCREEN[0] = ((char *)&b1+OFFSET_UNION_B_B)[0]
+Simplifying expression containing zero (char *)&b1 in [0] SCREEN[0] = *((char *)&b1+OFFSET_UNION_B_B)
+Simplifying expression containing zero SCREEN in [0] SCREEN[0] = *((char *)&b1)
+Successful SSA optimization PassNSimplifyExpressionWithZero
+Eliminating unused constant OFFSET_UNION_B_B
+Successful SSA optimization PassNEliminateUnusedVars
+Removing unused procedure __start
+Removing unused procedure block __start
+Removing unused procedure block __start::@1
+Removing unused procedure block __start::@return
+Successful SSA optimization PassNEliminateEmptyStart
+Finalized unsigned number type (char) 4
+Finalized unsigned number type (char) 4
+Successful SSA optimization PassNFinalizeNumberTypeConversions
+CALL GRAPH
+
+Created 0 initial phi equivalence classes
+Coalesced down to 0 phi equivalence classes
+
+FINAL CONTROL FLOW GRAPH
+
+void main()
+main: scope:[main]  from
+  [0] *SCREEN = *((char *)&b1)
+  to:main::@return
+main::@return: scope:[main]  from main
+  [1] return 
+  to:@return
+
+
+VARIABLE REGISTER WEIGHTS
+__loadstore union B b1 = { a: { b: 1 } }
+void main()
+
+Initial phi equivalence classes
+Added variable b1 to live range equivalence class [ b1 ]
+Complete equivalence classes
+[ b1 ]
+Allocated mem[4] [ b1 ]
+REGISTER UPLIFT POTENTIAL REGISTERS
+Statement [0] *SCREEN = *((char *)&b1) [ ] (  [ ] { }  ) always clobbers reg byte a 
+Potential registers mem[4] [ b1 ] : mem[4] , 
+
+REGISTER UPLIFT SCOPES
+Uplift Scope [A] 
+Uplift Scope [B] 
+Uplift Scope [main] 
+Uplift Scope [] 0: mem[4] [ b1 ] 
+
+Uplifting [A] best 17 combination 
+Uplifting [B] best 17 combination 
+Uplifting [main] best 17 combination 
+Uplifting [] best 17 combination mem[4] [ b1 ] 
+
+ASSEMBLER BEFORE OPTIMIZATION
+  // File Comments
+// More extensive union with C99 style designator initialization behaviour using const expressions.
+  // Upstart
+  // Commodore 64 PRG executable file
+.file [name="union-13.prg", type="prg", segments="Program"]
+.segmentdef Program [segments="Basic, Code, Data"]
+.segmentdef Basic [start=$0801]
+.segmentdef Code [start=$80d]
+.segmentdef Data [startAfter="Code"]
+.segment Basic
+:BasicUpstart(main)
+  // Global Constants & labels
+  .label SCREEN = $400
+.segment Code
+  // main
+main: {
+    // [0] *SCREEN = *((char *)&b1) -- _deref_pbuc1=_deref_pbuc2 
+    lda b1
+    sta SCREEN
+    jmp __breturn
+    // main::@return
+  __breturn:
+    // [1] return 
+    rts
+}
+  // File Data
+.segment Data
+  b1: .byte 1
+  .fill 1, 0
+  .fill 2, 0
+
+ASSEMBLER OPTIMIZATIONS
+Removing instruction jmp __breturn
+Succesful ASM optimization Pass5NextJumpElimination
+Removing instruction __breturn:
+Succesful ASM optimization Pass5UnusedLabelElimination
+
+FINAL SYMBOL TABLE
+__constant char * const SCREEN = (char *) 1024
+__loadstore union B b1 = { a: { b: 1 } } // mem[4]
+void main()
+
+mem[4] [ b1 ]
+
+
+FINAL ASSEMBLER
+Score: 14
+
+  // File Comments
+// More extensive union with C99 style designator initialization behaviour using const expressions.
+  // Upstart
+  // Commodore 64 PRG executable file
+.file [name="union-13.prg", type="prg", segments="Program"]
+.segmentdef Program [segments="Basic, Code, Data"]
+.segmentdef Basic [start=$0801]
+.segmentdef Code [start=$80d]
+.segmentdef Data [startAfter="Code"]
+.segment Basic
+:BasicUpstart(main)
+  // Global Constants & labels
+  .label SCREEN = $400
+.segment Code
+  // main
+main: {
+    // SCREEN[0] = b1.b[0]
+    // [0] *SCREEN = *((char *)&b1) -- _deref_pbuc1=_deref_pbuc2 
+    lda b1
+    sta SCREEN
+    // main::@return
+    // }
+    // [1] return 
+    rts
+}
+  // File Data
+.segment Data
+  b1: .byte 1
+  .fill 1, 0
+  .fill 2, 0
+

src/test/ref/union-13.sym

@@ -0,0 +1,5 @@
+__constant char * const SCREEN = (char *) 1024
+__loadstore union B b1 = { a: { b: 1 } } // mem[4]
+void main()
+
+mem[4] [ b1 ]

src/test/ref/union-9.asm

@@ -0,0 +1,20 @@
+// Minimal union with C99 style designator initialization behaviour.
+  // Commodore 64 PRG executable file
+.file [name="union-9.prg", type="prg", segments="Program"]
+.segmentdef Program [segments="Basic, Code, Data"]
+.segmentdef Basic [start=$0801]
+.segmentdef Code [start=$80d]
+.segmentdef Data [startAfter="Code"]
+.segment Basic
+:BasicUpstart(main)
+  .label SCREEN = $400
+.segment Code
+main: {
+    // SCREEN[0] = data.b
+    lda data
+    sta SCREEN
+    // }
+    rts
+}
+.segment Data
+  data: .word $4d2

src/test/ref/union-9.cfg

@@ -0,0 +1,8 @@
+
+void main()
+main: scope:[main]  from
+  [0] *SCREEN = *((char *)&data)
+  to:main::@return
+main::@return: scope:[main]  from main
+  [1] return 
+  to:@return

src/test/ref/union-9.log

@@ -0,0 +1,159 @@
+
+CONTROL FLOW GRAPH SSA
+
+void main()
+main: scope:[main]  from __start
+  SCREEN[0] = *((char *)&data+OFFSET_UNION_DATA_B)
+  to:main::@return
+main::@return: scope:[main]  from main
+  return 
+  to:@return
+
+void __start()
+__start: scope:[__start]  from
+  call main
+  to:__start::@1
+__start::@1: scope:[__start]  from __start
+  to:__start::@return
+__start::@return: scope:[__start]  from __start::@1
+  return 
+  to:@return
+
+SYMBOL TABLE SSA
+__constant char OFFSET_UNION_DATA_B = 0
+__constant char * const SCREEN = (char *)$400
+void __start()
+__loadstore union Data data = { w: $4d2 }
+void main()
+
+Adding number conversion cast (unumber) 0 in SCREEN[0] = *((char *)&data+OFFSET_UNION_DATA_B)
+Successful SSA optimization PassNAddNumberTypeConversions
+Simplifying constant pointer cast (char *) 1024
+Simplifying constant integer cast 0
+Successful SSA optimization PassNCastSimplification
+Finalized unsigned number type (char) 0
+Successful SSA optimization PassNFinalizeNumberTypeConversions
+Simplifying expression containing zero (char *)&data in [0] SCREEN[0] = *((char *)&data+OFFSET_UNION_DATA_B)
+Simplifying expression containing zero SCREEN in [0] SCREEN[0] = *((char *)&data)
+Successful SSA optimization PassNSimplifyExpressionWithZero
+Eliminating unused constant OFFSET_UNION_DATA_B
+Successful SSA optimization PassNEliminateUnusedVars
+Removing unused procedure __start
+Removing unused procedure block __start
+Removing unused procedure block __start::@1
+Removing unused procedure block __start::@return
+Successful SSA optimization PassNEliminateEmptyStart
+CALL GRAPH
+
+Created 0 initial phi equivalence classes
+Coalesced down to 0 phi equivalence classes
+
+FINAL CONTROL FLOW GRAPH
+
+void main()
+main: scope:[main]  from
+  [0] *SCREEN = *((char *)&data)
+  to:main::@return
+main::@return: scope:[main]  from main
+  [1] return 
+  to:@return
+
+
+VARIABLE REGISTER WEIGHTS
+__loadstore union Data data = { w: $4d2 }
+void main()
+
+Initial phi equivalence classes
+Added variable data to live range equivalence class [ data ]
+Complete equivalence classes
+[ data ]
+Allocated mem[2] [ data ]
+REGISTER UPLIFT POTENTIAL REGISTERS
+Statement [0] *SCREEN = *((char *)&data) [ ] (  [ ] { }  ) always clobbers reg byte a 
+Potential registers mem[2] [ data ] : mem[2] , 
+
+REGISTER UPLIFT SCOPES
+Uplift Scope [Data] 
+Uplift Scope [main] 
+Uplift Scope [] 0: mem[2] [ data ] 
+
+Uplifting [Data] best 17 combination 
+Uplifting [main] best 17 combination 
+Uplifting [] best 17 combination mem[2] [ data ] 
+
+ASSEMBLER BEFORE OPTIMIZATION
+  // File Comments
+// Minimal union with C99 style designator initialization behaviour.
+  // Upstart
+  // Commodore 64 PRG executable file
+.file [name="union-9.prg", type="prg", segments="Program"]
+.segmentdef Program [segments="Basic, Code, Data"]
+.segmentdef Basic [start=$0801]
+.segmentdef Code [start=$80d]
+.segmentdef Data [startAfter="Code"]
+.segment Basic
+:BasicUpstart(main)
+  // Global Constants & labels
+  .label SCREEN = $400
+.segment Code
+  // main
+main: {
+    // [0] *SCREEN = *((char *)&data) -- _deref_pbuc1=_deref_pbuc2 
+    lda data
+    sta SCREEN
+    jmp __breturn
+    // main::@return
+  __breturn:
+    // [1] return 
+    rts
+}
+  // File Data
+.segment Data
+  data: .word $4d2
+
+ASSEMBLER OPTIMIZATIONS
+Removing instruction jmp __breturn
+Succesful ASM optimization Pass5NextJumpElimination
+Removing instruction __breturn:
+Succesful ASM optimization Pass5UnusedLabelElimination
+
+FINAL SYMBOL TABLE
+__constant char * const SCREEN = (char *) 1024
+__loadstore union Data data = { w: $4d2 } // mem[2]
+void main()
+
+mem[2] [ data ]
+
+
+FINAL ASSEMBLER
+Score: 14
+
+  // File Comments
+// Minimal union with C99 style designator initialization behaviour.
+  // Upstart
+  // Commodore 64 PRG executable file
+.file [name="union-9.prg", type="prg", segments="Program"]
+.segmentdef Program [segments="Basic, Code, Data"]
+.segmentdef Basic [start=$0801]
+.segmentdef Code [start=$80d]
+.segmentdef Data [startAfter="Code"]
+.segment Basic
+:BasicUpstart(main)
+  // Global Constants & labels
+  .label SCREEN = $400
+.segment Code
+  // main
+main: {
+    // SCREEN[0] = data.b
+    // [0] *SCREEN = *((char *)&data) -- _deref_pbuc1=_deref_pbuc2 
+    lda data
+    sta SCREEN
+    // main::@return
+    // }
+    // [1] return 
+    rts
+}
+  // File Data
+.segment Data
+  data: .word $4d2
+

src/test/ref/union-9.sym

@@ -0,0 +1,5 @@
+__constant char * const SCREEN = (char *) 1024
+__loadstore union Data data = { w: $4d2 } // mem[2]
+void main()
+
+mem[2] [ data ]