CONTROL FLOW GRAPH SSA
@begin: scope:[]  from
  to:@1

(void()) main()
main: scope:[main]  from @1
  (byte) main::i#0 ← (byte) 0
  to:main::@1
main::@1: scope:[main]  from main main::@2
  (byte) main::i#2 ← phi( main/(byte) main::i#0 main::@2/(byte) main::i#1 )
  (bool~) main::$0 ← (byte) main::i#2 < (number) $fa
  if((bool~) main::$0) goto main::@2
  to:main::@return
main::@2: scope:[main]  from main::@1
  (byte) main::i#3 ← phi( main::@1/(byte) main::i#2 )
  *((const byte*) SCREEN + (byte) main::i#3) ← (byte) ' '
  (byte*~) main::$1 ← (const byte*) SCREEN + (number) $fa
  *((byte*~) main::$1 + (byte) main::i#3) ← (byte) ' '
  (byte*~) main::$2 ← (const byte*) SCREEN + (number) $1f4
  *((byte*~) main::$2 + (byte) main::i#3) ← (byte) ' '
  (byte*~) main::$3 ← (const byte*) SCREEN + (number) $2ee
  *((byte*~) main::$3 + (byte) main::i#3) ← (byte) ' '
  (byte) main::i#1 ← ++ (byte) main::i#3
  to:main::@1
main::@return: scope:[main]  from main::@1
  return 
  to:@return
@1: scope:[]  from @begin
  call main 
  to:@2
@2: scope:[]  from @1
  to:@end
@end: scope:[]  from @2

SYMBOL TABLE SSA
(label) @1
(label) @2
(label) @begin
(label) @end
(const byte*) SCREEN = (byte*)(number) $400
(void()) main()
(bool~) main::$0
(byte*~) main::$1
(byte*~) main::$2
(byte*~) main::$3
(label) main::@1
(label) main::@2
(label) main::@return
(byte) main::i
(byte) main::i#0
(byte) main::i#1
(byte) main::i#2
(byte) main::i#3

Adding number conversion cast (unumber) $fa in (bool~) main::$0 ← (byte) main::i#2 < (number) $fa
Adding number conversion cast (unumber) $fa in (byte*~) main::$1 ← (const byte*) SCREEN + (number) $fa
Adding number conversion cast (unumber) $1f4 in (byte*~) main::$2 ← (const byte*) SCREEN + (number) $1f4
Adding number conversion cast (unumber) $2ee in (byte*~) main::$3 ← (const byte*) SCREEN + (number) $2ee
Successful SSA optimization PassNAddNumberTypeConversions
Simplifying constant pointer cast (byte*) 1024
Simplifying constant integer cast $fa
Simplifying constant integer cast $fa
Simplifying constant integer cast $1f4
Simplifying constant integer cast $2ee
Successful SSA optimization PassNCastSimplification
Finalized unsigned number type (byte) $fa
Finalized unsigned number type (byte) $fa
Finalized unsigned number type (word) $1f4
Finalized unsigned number type (word) $2ee
Successful SSA optimization PassNFinalizeNumberTypeConversions
Alias main::i#2 = main::i#3 
Successful SSA optimization Pass2AliasElimination
Simple Condition (bool~) main::$0 [3] if((byte) main::i#2<(byte) $fa) goto main::@2
Successful SSA optimization Pass2ConditionalJumpSimplification
Constant right-side identified [5] (byte*~) main::$1 ← (const byte*) SCREEN + (byte) $fa
Constant right-side identified [7] (byte*~) main::$2 ← (const byte*) SCREEN + (word) $1f4
Constant right-side identified [9] (byte*~) main::$3 ← (const byte*) SCREEN + (word) $2ee
Successful SSA optimization Pass2ConstantRValueConsolidation
Constant (const byte) main::i#0 = 0
Constant (const byte*) main::$1 = SCREEN+$fa
Constant (const byte*) main::$2 = SCREEN+$1f4
Constant (const byte*) main::$3 = SCREEN+$2ee
Successful SSA optimization Pass2ConstantIdentification
Inlining constant with var siblings (const byte) main::i#0
Constant inlined main::i#0 = (byte) 0
Constant inlined main::$3 = (const byte*) SCREEN+(word) $2ee
Constant inlined main::$1 = (const byte*) SCREEN+(byte) $fa
Constant inlined main::$2 = (const byte*) SCREEN+(word) $1f4
Successful SSA optimization Pass2ConstantInlining
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 1 initial phi equivalence classes
Coalesced [14] main::i#4 ← main::i#1
Coalesced down to 1 phi equivalence classes
Culled Empty Block (label) @2
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()
  to:@1
@1: scope:[]  from @begin
  [1] phi()
  [2] call main 
  to:@end
@end: scope:[]  from @1
  [3] phi()

(void()) main()
main: scope:[main]  from @1
  [4] phi()
  to:main::@1
main::@1: scope:[main]  from main main::@2
  [5] (byte) main::i#2 ← phi( main/(byte) 0 main::@2/(byte) main::i#1 )
  [6] if((byte) main::i#2<(byte) $fa) goto main::@2
  to:main::@return
main::@return: scope:[main]  from main::@1
  [7] return 
  to:@return
main::@2: scope:[main]  from main::@1
  [8] *((const byte*) SCREEN + (byte) main::i#2) ← (byte) ' '
  [9] *((const byte*) SCREEN+(byte) $fa + (byte) main::i#2) ← (byte) ' '
  [10] *((const byte*) SCREEN+(word) $1f4 + (byte) main::i#2) ← (byte) ' '
  [11] *((const byte*) SCREEN+(word) $2ee + (byte) main::i#2) ← (byte) ' '
  [12] (byte) main::i#1 ← ++ (byte) main::i#2
  to:main::@1


VARIABLE REGISTER WEIGHTS
(void()) main()
(byte) main::i
(byte) main::i#1 202.0
(byte) main::i#2 117.83333333333331

Initial phi equivalence classes
[ main::i#2 main::i#1 ]
Complete equivalence classes
[ main::i#2 main::i#1 ]
Allocated zp[1]:2 [ main::i#2 main::i#1 ]

INITIAL ASM
Target platform is c64basic / MOS6502X
  // File Comments
// Fill screen using an efficient char-based index
  // Upstart
.pc = $801 "Basic"
:BasicUpstart(main)
.pc = $80d "Program"
  // Global Constants & labels
  .label SCREEN = $400
  // @begin
__bbegin:
  // [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]
main_from___b1:
  jsr main
  // [3] phi from @1 to @end [phi:@1->@end]
__bend_from___b1:
  jmp __bend
  // @end
__bend:
  // main
main: {
    .label i = 2
    // [5] 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 
    lda #0
    sta.z i
    jmp __b1
    // main::@1
  __b1:
    // [6] if((byte) main::i#2<(byte) $fa) goto main::@2 -- vbuz1_lt_vbuc1_then_la1 
    lda.z i
    cmp #$fa
    bcc __b2
    jmp __breturn
    // main::@return
  __breturn:
    // [7] return 
    rts
    // main::@2
  __b2:
    // [8] *((const byte*) SCREEN + (byte) main::i#2) ← (byte) ' ' -- pbuc1_derefidx_vbuz1=vbuc2 
    lda #' '
    ldy.z i
    sta SCREEN,y
    // [9] *((const byte*) SCREEN+(byte) $fa + (byte) main::i#2) ← (byte) ' ' -- pbuc1_derefidx_vbuz1=vbuc2 
    lda #' '
    ldy.z i
    sta SCREEN+$fa,y
    // [10] *((const byte*) SCREEN+(word) $1f4 + (byte) main::i#2) ← (byte) ' ' -- pbuc1_derefidx_vbuz1=vbuc2 
    lda #' '
    ldy.z i
    sta SCREEN+$1f4,y
    // [11] *((const byte*) SCREEN+(word) $2ee + (byte) main::i#2) ← (byte) ' ' -- pbuc1_derefidx_vbuz1=vbuc2 
    lda #' '
    ldy.z i
    sta SCREEN+$2ee,y
    // [12] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuz1=_inc_vbuz1 
    inc.z i
    // [5] phi from main::@2 to main::@1 [phi:main::@2->main::@1]
  __b1_from___b2:
    // [5] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@2->main::@1#0] -- register_copy 
    jmp __b1
}
  // File Data

REGISTER UPLIFT POTENTIAL REGISTERS
Statement [8] *((const byte*) SCREEN + (byte) main::i#2) ← (byte) ' ' [ main::i#2 ] ( main:2 [ main::i#2 ] { }  ) always clobbers reg byte a 
Removing always clobbered register reg byte a as potential for zp[1]:2 [ main::i#2 main::i#1 ]
Statement [9] *((const byte*) SCREEN+(byte) $fa + (byte) main::i#2) ← (byte) ' ' [ main::i#2 ] ( main:2 [ main::i#2 ] { }  ) always clobbers reg byte a 
Statement [10] *((const byte*) SCREEN+(word) $1f4 + (byte) main::i#2) ← (byte) ' ' [ main::i#2 ] ( main:2 [ main::i#2 ] { }  ) always clobbers reg byte a 
Statement [11] *((const byte*) SCREEN+(word) $2ee + (byte) main::i#2) ← (byte) ' ' [ main::i#2 ] ( main:2 [ main::i#2 ] { }  ) always clobbers reg byte a 
Statement [8] *((const byte*) SCREEN + (byte) main::i#2) ← (byte) ' ' [ main::i#2 ] ( main:2 [ main::i#2 ] { }  ) always clobbers reg byte a 
Statement [9] *((const byte*) SCREEN+(byte) $fa + (byte) main::i#2) ← (byte) ' ' [ main::i#2 ] ( main:2 [ main::i#2 ] { }  ) always clobbers reg byte a 
Statement [10] *((const byte*) SCREEN+(word) $1f4 + (byte) main::i#2) ← (byte) ' ' [ main::i#2 ] ( main:2 [ main::i#2 ] { }  ) always clobbers reg byte a 
Statement [11] *((const byte*) SCREEN+(word) $2ee + (byte) main::i#2) ← (byte) ' ' [ main::i#2 ] ( main:2 [ main::i#2 ] { }  ) always clobbers reg byte a 
Potential registers zp[1]:2 [ main::i#2 main::i#1 ] : zp[1]:2 , reg byte x , reg byte y , 

REGISTER UPLIFT SCOPES
Uplift Scope [main] 319.83: zp[1]:2 [ main::i#2 main::i#1 ] 
Uplift Scope [] 

Uplifting [main] best 473 combination reg byte x [ main::i#2 main::i#1 ] 
Uplifting [] best 473 combination 

ASSEMBLER BEFORE OPTIMIZATION
  // File Comments
// Fill screen using an efficient char-based index
  // Upstart
.pc = $801 "Basic"
:BasicUpstart(main)
.pc = $80d "Program"
  // Global Constants & labels
  .label SCREEN = $400
  // @begin
__bbegin:
  // [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]
main_from___b1:
  jsr main
  // [3] phi from @1 to @end [phi:@1->@end]
__bend_from___b1:
  jmp __bend
  // @end
__bend:
  // main
main: {
    // [5] 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 
    ldx #0
    jmp __b1
    // main::@1
  __b1:
    // [6] if((byte) main::i#2<(byte) $fa) goto main::@2 -- vbuxx_lt_vbuc1_then_la1 
    cpx #$fa
    bcc __b2
    jmp __breturn
    // main::@return
  __breturn:
    // [7] return 
    rts
    // main::@2
  __b2:
    // [8] *((const byte*) SCREEN + (byte) main::i#2) ← (byte) ' ' -- pbuc1_derefidx_vbuxx=vbuc2 
    lda #' '
    sta SCREEN,x
    // [9] *((const byte*) SCREEN+(byte) $fa + (byte) main::i#2) ← (byte) ' ' -- pbuc1_derefidx_vbuxx=vbuc2 
    lda #' '
    sta SCREEN+$fa,x
    // [10] *((const byte*) SCREEN+(word) $1f4 + (byte) main::i#2) ← (byte) ' ' -- pbuc1_derefidx_vbuxx=vbuc2 
    lda #' '
    sta SCREEN+$1f4,x
    // [11] *((const byte*) SCREEN+(word) $2ee + (byte) main::i#2) ← (byte) ' ' -- pbuc1_derefidx_vbuxx=vbuc2 
    lda #' '
    sta SCREEN+$2ee,x
    // [12] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuxx=_inc_vbuxx 
    inx
    // [5] phi from main::@2 to main::@1 [phi:main::@2->main::@1]
  __b1_from___b2:
    // [5] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@2->main::@1#0] -- register_copy 
    jmp __b1
}
  // File Data

ASSEMBLER OPTIMIZATIONS
Removing instruction jmp __b1
Removing instruction jmp __bend
Removing instruction jmp __b1
Removing instruction jmp __breturn
Succesful ASM optimization Pass5NextJumpElimination
Removing instruction lda #' '
Removing instruction lda #' '
Removing instruction lda #' '
Succesful ASM optimization Pass5UnnecesaryLoadElimination
Removing instruction __b1_from___bbegin:
Removing instruction __b1:
Removing instruction main_from___b1:
Removing instruction __bend_from___b1:
Succesful ASM optimization Pass5RedundantLabelElimination
Removing instruction __bbegin:
Removing instruction __bend:
Removing instruction __b1_from_main:
Removing instruction __breturn:
Removing instruction __b1_from___b2:
Succesful ASM optimization Pass5UnusedLabelElimination
Removing instruction jsr main
Succesful ASM optimization Pass5SkipBegin

FINAL SYMBOL TABLE
(label) @1
(label) @begin
(label) @end
(const byte*) SCREEN = (byte*) 1024
(void()) main()
(label) main::@1
(label) main::@2
(label) main::@return
(byte) main::i
(byte) main::i#1 reg byte x 202.0
(byte) main::i#2 reg byte x 117.83333333333331

reg byte x [ main::i#2 main::i#1 ]


FINAL ASSEMBLER
Score: 341

  // File Comments
// Fill screen using an efficient char-based index
  // Upstart
.pc = $801 "Basic"
:BasicUpstart(main)
.pc = $80d "Program"
  // Global Constants & labels
  .label SCREEN = $400
  // @begin
  // [1] phi from @begin to @1 [phi:@begin->@1]
  // @1
  // [2] call main 
  // [4] phi from @1 to main [phi:@1->main]
  // [3] phi from @1 to @end [phi:@1->@end]
  // @end
  // main
main: {
    // [5] 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 
    ldx #0
    // main::@1
  __b1:
    // for(char i=0;i<250;i++)
    // [6] if((byte) main::i#2<(byte) $fa) goto main::@2 -- vbuxx_lt_vbuc1_then_la1 
    cpx #$fa
    bcc __b2
    // main::@return
    // }
    // [7] return 
    rts
    // main::@2
  __b2:
    // SCREEN[i] = ' '
    // [8] *((const byte*) SCREEN + (byte) main::i#2) ← (byte) ' ' -- pbuc1_derefidx_vbuxx=vbuc2 
    lda #' '
    sta SCREEN,x
    // (SCREEN+250)[i] = ' '
    // [9] *((const byte*) SCREEN+(byte) $fa + (byte) main::i#2) ← (byte) ' ' -- pbuc1_derefidx_vbuxx=vbuc2 
    sta SCREEN+$fa,x
    // (SCREEN+500)[i] = ' '
    // [10] *((const byte*) SCREEN+(word) $1f4 + (byte) main::i#2) ← (byte) ' ' -- pbuc1_derefidx_vbuxx=vbuc2 
    sta SCREEN+$1f4,x
    // (SCREEN+750)[i] = ' '
    // [11] *((const byte*) SCREEN+(word) $2ee + (byte) main::i#2) ← (byte) ' ' -- pbuc1_derefidx_vbuxx=vbuc2 
    sta SCREEN+$2ee,x
    // for(char i=0;i<250;i++)
    // [12] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuxx=_inc_vbuxx 
    inx
    // [5] phi from main::@2 to main::@1 [phi:main::@2->main::@1]
    // [5] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@2->main::@1#0] -- register_copy 
    jmp __b1
}
  // File Data