Added a test with two levels of methods to test live ranges / call-paths and allocation of a minimal number of registers.

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

@@ -24,6 +24,10 @@ public class TestPrograms extends TestCase {
       helper = new ReferenceHelper("dk/camelot64/kickc/test/ref/");
    }
 
+   public void testOverlapAllocation2() throws IOException, URISyntaxException {
+      compileAndCompare("overlap-allocation-2");
+   }
+
    public void testOverlapAllocation() throws IOException, URISyntaxException {
       compileAndCompare("overlap-allocation");
    }

src/main/java/dk/camelot64/kickc/test/overlap-allocation-2.kc

@@ -0,0 +1,20 @@
+// Two levels of functions to test that register allocation handles live ranges and call-ranges optimally to allocate the fewest possible ZP-variables
+byte* SCREEN = $0400;
+
+void main() {
+    for(byte i : 0..8) {
+       line(i);
+    }
+   for(byte j : 10..18) {
+       line(j);
+    }
+}
+
+void line(byte l) {
+    plot(l);
+    plot(l+20);
+}
+
+void plot(byte x) {
+    SCREEN[x] = '*';
+}

src/main/java/dk/camelot64/kickc/test/ref/overlap-allocation-2.asm

@@ -0,0 +1,35 @@
+.pc = $801 "Basic"
+:BasicUpstart(main)
+.pc = $80d "Program"
+  .const SCREEN = $400
+  jsr main
+main: {
+    ldy #0
+  b1:
+    jsr line
+    iny
+    cpy #9
+    bne b1
+    ldy #$a
+  b2:
+    jsr line
+    iny
+    cpy #$13
+    bne b2
+    rts
+}
+line: {
+    tya
+    jsr plot
+    tya
+    clc
+    adc #$14
+    jsr plot
+    rts
+}
+plot: {
+    tax
+    lda #'*'
+    sta SCREEN,x
+    rts
+}

src/main/java/dk/camelot64/kickc/test/ref/overlap-allocation-2.cfg

@@ -0,0 +1,50 @@
+@begin: scope:[]  from
+  to:@3
+@3: scope:[]  from @begin
+  [0] call main param-assignment [ ] ( )
+  to:@end
+@end: scope:[]  from @3
+main: scope:[main]  from @3
+  [1] phi() [ ] ( main:0 [ ] )
+  to:main::@1
+main::@1: scope:[main]  from main main::@5
+  [2] (byte) main::i#2 ← phi( main/(byte) 0 main::@5/(byte) main::i#1 ) [ main::i#2 ] ( main:0 [ main::i#2 ] )
+  [3] (byte) line::l#0 ← (byte) main::i#2 [ main::i#2 line::l#0 ] ( main:0 [ main::i#2 line::l#0 ] )
+  [4] call line param-assignment [ main::i#2 ] ( main:0 [ main::i#2 ] )
+  to:main::@5
+main::@5: scope:[main]  from main::@1
+  [5] (byte) main::i#1 ← ++ (byte) main::i#2 [ main::i#1 ] ( main:0 [ main::i#1 ] )
+  [6] if((byte) main::i#1!=(byte) 9) goto main::@1 [ main::i#1 ] ( main:0 [ main::i#1 ] )
+  to:main::@2
+main::@2: scope:[main]  from main::@5 main::@6
+  [7] (byte) main::j#2 ← phi( main::@5/(byte) 10 main::@6/(byte) main::j#1 ) [ main::j#2 ] ( main:0 [ main::j#2 ] )
+  [8] (byte) line::l#1 ← (byte) main::j#2 [ main::j#2 line::l#1 ] ( main:0 [ main::j#2 line::l#1 ] )
+  [9] call line param-assignment [ main::j#2 ] ( main:0 [ main::j#2 ] )
+  to:main::@6
+main::@6: scope:[main]  from main::@2
+  [10] (byte) main::j#1 ← ++ (byte) main::j#2 [ main::j#1 ] ( main:0 [ main::j#1 ] )
+  [11] if((byte) main::j#1!=(byte) 19) goto main::@2 [ main::j#1 ] ( main:0 [ main::j#1 ] )
+  to:main::@return
+main::@return: scope:[main]  from main::@6
+  [12] return  [ ] ( main:0 [ ] )
+  to:@return
+line: scope:[line]  from main::@1 main::@2
+  [13] (byte) line::l#2 ← phi( main::@1/(byte) line::l#0 main::@2/(byte) line::l#1 ) [ line::l#2 ] ( main:0::line:4 [ main::i#2 line::l#2 ] main:0::line:9 [ main::j#2 line::l#2 ] )
+  [14] (byte) plot::x#0 ← (byte) line::l#2 [ line::l#2 plot::x#0 ] ( main:0::line:4 [ main::i#2 line::l#2 plot::x#0 ] main:0::line:9 [ main::j#2 line::l#2 plot::x#0 ] )
+  [15] call plot param-assignment [ line::l#2 ] ( main:0::line:4 [ main::i#2 line::l#2 ] main:0::line:9 [ main::j#2 line::l#2 ] )
+  to:line::@1
+line::@1: scope:[line]  from line
+  [16] (byte~) line::$1 ← (byte) line::l#2 + (byte) 20 [ line::$1 ] ( main:0::line:4 [ main::i#2 line::$1 ] main:0::line:9 [ main::j#2 line::$1 ] )
+  [17] (byte) plot::x#1 ← (byte~) line::$1 [ plot::x#1 ] ( main:0::line:4 [ main::i#2 plot::x#1 ] main:0::line:9 [ main::j#2 plot::x#1 ] )
+  [18] call plot param-assignment [ ] ( main:0::line:4 [ main::i#2 ] main:0::line:9 [ main::j#2 ] )
+  to:line::@return
+line::@return: scope:[line]  from line::@1
+  [19] return  [ ] ( main:0::line:4 [ main::i#2 ] main:0::line:9 [ main::j#2 ] )
+  to:@return
+plot: scope:[plot]  from line line::@1
+  [20] (byte) plot::x#2 ← phi( line/(byte) plot::x#0 line::@1/(byte) plot::x#1 ) [ plot::x#2 ] ( main:0::line:4::plot:15 [ main::i#2 line::l#2 plot::x#2 ] main:0::line:9::plot:15 [ main::j#2 line::l#2 plot::x#2 ] main:0::line:4::plot:18 [ main::i#2 plot::x#2 ] main:0::line:9::plot:18 [ main::j#2 plot::x#2 ] )
+  [21] *((const byte*) SCREEN#0 + (byte) plot::x#2) ← (byte) '*' [ ] ( main:0::line:4::plot:15 [ main::i#2 line::l#2 ] main:0::line:9::plot:15 [ main::j#2 line::l#2 ] main:0::line:4::plot:18 [ main::i#2 ] main:0::line:9::plot:18 [ main::j#2 ] )
+  to:plot::@return
+plot::@return: scope:[plot]  from plot
+  [22] return  [ ] ( main:0::line:4::plot:15 [ main::i#2 line::l#2 ] main:0::line:9::plot:15 [ main::j#2 line::l#2 ] main:0::line:4::plot:18 [ main::i#2 ] main:0::line:9::plot:18 [ main::j#2 ] )
+  to:@return

src/main/java/dk/camelot64/kickc/test/ref/overlap-allocation-2.sym

@@ -0,0 +1,37 @@
+(label) @3
+(label) @begin
+(label) @end
+(byte*) SCREEN
+(const byte*) SCREEN#0 SCREEN = (word) 1024
+(void()) line((byte) line::l)
+(byte~) line::$1 reg byte a 4.0
+(label) line::@1
+(label) line::@return
+(byte) line::l
+(byte) line::l#0 reg byte y 22.0
+(byte) line::l#1 reg byte y 22.0
+(byte) line::l#2 reg byte y 8.666666666666666
+(void()) main()
+(label) main::@1
+(label) main::@2
+(label) main::@5
+(label) main::@6
+(label) main::@return
+(byte) main::i
+(byte) main::i#1 reg byte y 16.5
+(byte) main::i#2 reg byte y 11.0
+(byte) main::j
+(byte) main::j#1 reg byte y 16.5
+(byte) main::j#2 reg byte y 11.0
+(void()) plot((byte) plot::x)
+(label) plot::@return
+(byte) plot::x
+(byte) plot::x#0 reg byte a 4.0
+(byte) plot::x#1 reg byte a 4.0
+(byte) plot::x#2 reg byte a 6.0
+
+reg byte y [ main::i#2 main::i#1 ]
+reg byte y [ main::j#2 main::j#1 ]
+reg byte y [ line::l#2 line::l#0 line::l#1 ]
+reg byte a [ plot::x#2 plot::x#0 plot::x#1 ]
+reg byte a [ line::$1 ]