Fixed problem where uninitialized variables resultes in compile errors. Closes #131

src/main/java/dk/camelot64/kickc/passes/Pass2AliasElimination.java

@@ -212,12 +212,13 @@ public class Pass2AliasElimination extends Pass2SsaOptimization {
                   }
                }
             } else if(statement instanceof StatementPhiBlock) {
+               boolean modified = false;
                StatementPhiBlock phiBlock = (StatementPhiBlock) statement;
                Iterator<StatementPhiBlock.PhiVariable> variableIterator = phiBlock.getPhiVariables().iterator();
                while(variableIterator.hasNext()) {
                   StatementPhiBlock.PhiVariable phiVariable = variableIterator.next();
                   AliasSet aliasSet = aliases.findAliasSet(phiVariable.getVariable());
-                  if(aliasSet != null) {
+                  if(aliasSet != null && phiVariable.getValues().size()>0) {
                      boolean remove = true;
                      for(StatementPhiBlock.PhiRValue phiRValue : phiVariable.getValues()) {
                         if(!aliasSet.contains(phiRValue.getrValue())) {
@@ -227,10 +228,11 @@ public class Pass2AliasElimination extends Pass2SsaOptimization {
                      }
                      if(remove) {
                         variableIterator.remove();
+                        modified = true;
                      }
                   }
                }
-               if(phiBlock.getPhiVariables().size() == 0) {
+               if(modified && phiBlock.getPhiVariables().size() == 0) {
                   iterator.remove();
                }
             }

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

@@ -84,30 +84,30 @@ public class TestPrograms {
       compileAndCompare("examples/tetris/tetris");
    }
 
+   @Test
+   public void testVarInitProblem() throws IOException, URISyntaxException {
+      compileAndCompare("var-init-problem");
+   }
+
    /*
-      @Test
-      public void testVarInitProblem() throws IOException, URISyntaxException {
-         compileAndCompare("var-init-problem");
-      }
+   @Test
+   public void testConstIfProblem() throws IOException, URISyntaxException {
+      compileAndCompare("const-if-problem");
+   }
 
-      @Test
-      public void testConstIfProblem() throws IOException, URISyntaxException {
-         compileAndCompare("const-if-problem");
-      }
+   @Test
+   public void testTetrisNullPointer() throws IOException, URISyntaxException {
+      compileAndCompare("tetris-npe");
+   }
 
-      @Test
-      public void testTetrisNullPointer() throws IOException, URISyntaxException {
-         compileAndCompare("tetris-npe");
-      }
-
-      //@Test
-      //public void testUnrollCall() throws IOException, URISyntaxException {
-      //   compileAndCompare("unroll-call");
-      //}
+   //@Test
+   //public void testUnrollCall() throws IOException, URISyntaxException {
+   //   compileAndCompare("unroll-call");
+   //}
 
 
 
-   */
+*/
    @Test
    public void testFastMultiply8() throws IOException, URISyntaxException {
       compileAndCompare("examples/fastmultiply/fastmultiply8.kc");
@@ -1182,6 +1182,7 @@ public class TestPrograms {
 
    /**
     * Ensures that the path to the passed file is created.
+    *
     * @param file The file to create a path for
     */
    private void mkPath(File file) {
@@ -1203,5 +1204,4 @@ public class TestPrograms {
    }
 
 
-
 }

src/test/ref/var-init-problem.asm

@@ -0,0 +1,9 @@
+.pc = $801 "Basic"
+:BasicUpstart(main)
+.pc = $80d "Program"
+  .label screen = $400
+main: {
+    lda #'a'
+    sta screen
+    rts
+}

src/test/ref/var-init-problem.cfg

@@ -0,0 +1,15 @@
+@begin: scope:[]  from
+  [0] phi()
+  to:@1
+@1: scope:[]  from @begin
+  [1] phi()
+  [2] call main 
+  to:@end
+@end: scope:[]  from @1
+  [3] phi()
+main: scope:[main]  from @1
+  [4] *((const byte*) screen#0) ← (byte) 'a'
+  to:main::@return
+main::@return: scope:[main]  from main
+  [5] return 
+  to:@return

src/test/ref/var-init-problem.log

@@ -0,0 +1,218 @@
+
+CONTROL FLOW GRAPH SSA
+@begin: scope:[]  from
+  (byte*) screen#6 ← phi( )
+  to:@1
+main: scope:[main]  from @1
+  (byte*) screen#0 ← ((byte*)) (word/signed word/dword/signed dword) 1024
+  *((byte*) screen#0) ← (byte) 'a'
+  to:main::@return
+main::@return: scope:[main]  from main
+  (byte*) screen#3 ← phi( main/(byte*) screen#0 )
+  (byte*) screen#1 ← (byte*) screen#3
+  return 
+  to:@return
+@1: scope:[]  from @begin
+  (byte*) screen#5 ← phi( @begin/(byte*) screen#6 )
+  call main 
+  to:@2
+@2: scope:[]  from @1
+  (byte*) screen#4 ← phi( @1/(byte*) screen#1 )
+  (byte*) screen#2 ← (byte*) screen#4
+  to:@end
+@end: scope:[]  from @2
+
+SYMBOL TABLE SSA
+(label) @1
+(label) @2
+(label) @begin
+(label) @end
+(void()) main()
+(label) main::@return
+(byte*) screen
+(byte*) screen#0
+(byte*) screen#1
+(byte*) screen#2
+(byte*) screen#3
+(byte*) screen#4
+(byte*) screen#5
+(byte*) screen#6
+
+Alias (byte*) screen#0 = (byte*) screen#3 (byte*) screen#1 
+Alias (byte*) screen#5 = (byte*) screen#6 
+Alias (byte*) screen#2 = (byte*) screen#4 
+Successful SSA optimization Pass2AliasElimination
+Redundant Phi (byte*) screen#5 VOID
+Redundant Phi (byte*) screen#2 (byte*) screen#0
+Successful SSA optimization Pass2RedundantPhiElimination
+Constant (const byte*) screen#0 = ((byte*))1024
+Successful SSA optimization Pass2ConstantIdentification
+Culled Empty Block (label) @2
+Successful SSA optimization Pass2CullEmptyBlocks
+Adding NOP phi() at start of @begin
+Adding NOP phi() at start of @1
+Adding NOP phi() at start of @end
+CALL GRAPH
+Calls in [] to main:2 
+
+Created 0 initial phi equivalence classes
+Coalesced down to 0 phi equivalence classes
+Adding NOP phi() at start of @begin
+Adding NOP phi() at start of @1
+Adding NOP phi() at start of @end
+
+FINAL CONTROL FLOW GRAPH
+@begin: scope:[]  from
+  [0] phi()
+  to:@1
+@1: scope:[]  from @begin
+  [1] phi()
+  [2] call main 
+  to:@end
+@end: scope:[]  from @1
+  [3] phi()
+main: scope:[main]  from @1
+  [4] *((const byte*) screen#0) ← (byte) 'a'
+  to:main::@return
+main::@return: scope:[main]  from main
+  [5] return 
+  to:@return
+
+
+VARIABLE REGISTER WEIGHTS
+(void()) main()
+(byte*) screen
+
+Initial phi equivalence classes
+Complete equivalence classes
+
+INITIAL ASM
+//SEG0 Basic Upstart
+.pc = $801 "Basic"
+:BasicUpstart(bbegin)
+.pc = $80d "Program"
+//SEG1 Global Constants & labels
+  .label screen = $400
+//SEG2 @begin
+bbegin:
+//SEG3 [1] phi from @begin to @1 [phi:@begin->@1]
+b1_from_bbegin:
+  jmp b1
+//SEG4 @1
+b1:
+//SEG5 [2] call main 
+  jsr main
+//SEG6 [3] phi from @1 to @end [phi:@1->@end]
+bend_from_b1:
+  jmp bend
+//SEG7 @end
+bend:
+//SEG8 main
+main: {
+  //SEG9 [4] *((const byte*) screen#0) ← (byte) 'a' -- _deref_pbuc1=vbuc2 
+    lda #'a'
+    sta screen
+    jmp breturn
+  //SEG10 main::@return
+  breturn:
+  //SEG11 [5] return 
+    rts
+}
+
+REGISTER UPLIFT POTENTIAL REGISTERS
+Statement [4] *((const byte*) screen#0) ← (byte) 'a' [ ] ( main:2 [ ] ) always clobbers reg byte a 
+
+REGISTER UPLIFT SCOPES
+Uplift Scope [main] 
+Uplift Scope [] 
+
+Uplifting [main] best 27 combination 
+Uplifting [] best 27 combination 
+
+ASSEMBLER BEFORE OPTIMIZATION
+//SEG0 Basic Upstart
+.pc = $801 "Basic"
+:BasicUpstart(bbegin)
+.pc = $80d "Program"
+//SEG1 Global Constants & labels
+  .label screen = $400
+//SEG2 @begin
+bbegin:
+//SEG3 [1] phi from @begin to @1 [phi:@begin->@1]
+b1_from_bbegin:
+  jmp b1
+//SEG4 @1
+b1:
+//SEG5 [2] call main 
+  jsr main
+//SEG6 [3] phi from @1 to @end [phi:@1->@end]
+bend_from_b1:
+  jmp bend
+//SEG7 @end
+bend:
+//SEG8 main
+main: {
+  //SEG9 [4] *((const byte*) screen#0) ← (byte) 'a' -- _deref_pbuc1=vbuc2 
+    lda #'a'
+    sta screen
+    jmp breturn
+  //SEG10 main::@return
+  breturn:
+  //SEG11 [5] return 
+    rts
+}
+
+ASSEMBLER OPTIMIZATIONS
+Removing instruction jmp b1
+Removing instruction jmp bend
+Removing instruction jmp breturn
+Succesful ASM optimization Pass5NextJumpElimination
+Removing instruction b1_from_bbegin:
+Removing instruction b1:
+Removing instruction bend_from_b1:
+Succesful ASM optimization Pass5RedundantLabelElimination
+Removing instruction bend:
+Removing instruction breturn:
+Succesful ASM optimization Pass5UnusedLabelElimination
+Updating BasicUpstart to call main directly
+Removing instruction jsr main
+Succesful ASM optimization Pass5SkipBegin
+Removing instruction bbegin:
+Succesful ASM optimization Pass5UnusedLabelElimination
+
+FINAL SYMBOL TABLE
+(label) @1
+(label) @begin
+(label) @end
+(void()) main()
+(label) main::@return
+(byte*) screen
+(const byte*) screen#0 screen = ((byte*))(word/signed word/dword/signed dword) 1024
+
+
+
+FINAL ASSEMBLER
+Score: 12
+
+//SEG0 Basic Upstart
+.pc = $801 "Basic"
+:BasicUpstart(main)
+.pc = $80d "Program"
+//SEG1 Global Constants & labels
+  .label screen = $400
+//SEG2 @begin
+//SEG3 [1] phi from @begin to @1 [phi:@begin->@1]
+//SEG4 @1
+//SEG5 [2] call main 
+//SEG6 [3] phi from @1 to @end [phi:@1->@end]
+//SEG7 @end
+//SEG8 main
+main: {
+  //SEG9 [4] *((const byte*) screen#0) ← (byte) 'a' -- _deref_pbuc1=vbuc2 
+    lda #'a'
+    sta screen
+  //SEG10 main::@return
+  //SEG11 [5] return 
+    rts
+}
+

src/test/ref/var-init-problem.sym

@@ -0,0 +1,8 @@
+(label) @1
+(label) @begin
+(label) @end
+(void()) main()
+(label) main::@return
+(byte*) screen
+(const byte*) screen#0 screen = ((byte*))(word/signed word/dword/signed dword) 1024
+