Culled Empty Block (label) main::@2

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

(void()) main()
main: scope:[main]  from @1
  (byte*) main::screen ← ((byte*)) (number) $400
  (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 )
  (number~) main::$0 ← (number) $28*(number) $a + (byte) main::i#2
  *((byte*) main::screen + (number~) main::$0) ← (byte) 'a'
  (byte) main::i#1 ← (byte) main::i#2 + rangenext(0,$27)
  (bool~) main::$1 ← (byte) main::i#1 != rangelast(0,$27)
  if((bool~) main::$1) goto main::@1
  to:main::@return
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
(void()) main()
(number~) main::$0
(bool~) main::$1
(label) main::@1
(label) main::@return
(byte) main::i
(byte) main::i#0
(byte) main::i#1
(byte) main::i#2
(byte*) main::screen

Adding number conversion cast (unumber) $28*$a in (number~) main::$0 ← (number) $28*(number) $a + (byte) main::i#2
Adding number conversion cast (unumber) main::$0 in (number~) main::$0 ← (unumber)(number) $28*(number) $a + (byte) main::i#2
Successful SSA optimization PassNAddNumberTypeConversions
Inlining cast (byte*) main::screen ← (byte*)(number) $400
Successful SSA optimization Pass2InlineCast
Simplifying constant pointer cast (byte*) 1024
Successful SSA optimization PassNCastSimplification
Inferred type updated to word in (unumber~) main::$0 ← (word)(number) $28*(number) $a + (byte) main::i#2
Simple Condition (bool~) main::$1 [7] if((byte) main::i#1!=rangelast(0,$27)) goto main::@1
Successful SSA optimization Pass2ConditionalJumpSimplification
Constant (const byte*) main::screen = (byte*) 1024
Constant (const byte) main::i#0 = 0
Successful SSA optimization Pass2ConstantIdentification
Resolved ranged next value [5] main::i#1 ← ++ main::i#2 to ++
Resolved ranged comparison value [7] if(main::i#1!=rangelast(0,$27)) goto main::@1 to (number) $28
De-inlining pointer[w] to *(pointer+w)   [4] *((const byte*) main::screen + (word~) main::$0) ← (byte) 'a'
Successful SSA optimization Pass2DeInlineWordDerefIdx
Adding number conversion cast (unumber) $28 in if((byte) main::i#1!=(number) $28) goto main::@1
Successful SSA optimization PassNAddNumberTypeConversions
Simplifying constant integer cast $28
Successful SSA optimization PassNCastSimplification
Finalized unsigned number type (byte) $28
Successful SSA optimization PassNFinalizeNumberTypeConversions
Inlining constant with var siblings (const byte) main::i#0
Constant inlined main::i#0 = (byte) 0
Successful SSA optimization Pass2ConstantInlining
Consolidated constant in assignment main::$2
Successful SSA optimization Pass2ConstantAdditionElimination
Alias (byte) main::i#2 = (word~) main::$0 
Successful SSA optimization Pass2AliasElimination
Converting *(pointer+n) to pointer[n] [3] *((byte*~) main::$2) ← (byte) 'a'  -- *(main::screen+(word)$28*$a + main::i#2)
Successful SSA optimization Pass2InlineDerefIdx
Eliminating unused variable (byte*~) main::$2 and assignment [1] (byte*~) main::$2 ← (const byte*) main::screen+(word)(number) $28*(number) $a + (byte) main::i#2
Successful SSA optimization PassNEliminateUnusedVars
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 1 initial phi equivalence classes
Coalesced [11] main::i#3 ← main::i#1
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()
  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::@1
  [5] (byte) main::i#2 ← phi( main/(byte) 0 main::@1/(byte) main::i#1 )
  [6] *((const byte*) main::screen+(word)(number) $28*(number) $a + (byte) main::i#2) ← (byte) 'a'
  [7] (byte) main::i#1 ← ++ (byte) main::i#2
  [8] if((byte) main::i#1!=(byte) $28) goto main::@1
  to:main::@return
main::@return: scope:[main]  from main::@1
  [9] return 
  to:@return


VARIABLE REGISTER WEIGHTS
(void()) main()
(byte) main::i
(byte) main::i#1 16.5
(byte) main::i#2 16.5

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

INITIAL ASM
Target platform is c64basic / MOS6502X
  // File Comments
// Tests that array-indexing by a word variable that is a sum of a constant word and a byte is turned back into derefidx
  // Upstart
.pc = $801 "Basic"
:BasicUpstart(__bbegin)
.pc = $80d "Program"
  // Global Constants & labels
  // @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 screen = $400
    .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
    // [5] 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 
    jmp __b1
    // main::@1
  __b1:
    // [6] *((const byte*) main::screen+(word)(number) $28*(number) $a + (byte) main::i#2) ← (byte) 'a' -- pbuc1_derefidx_vbuz1=vbuc2 
    lda #'a'
    ldy.z i
    sta screen+$28*$a,y
    // [7] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuz1=_inc_vbuz1 
    inc.z i
    // [8] if((byte) main::i#1!=(byte) $28) goto main::@1 -- vbuz1_neq_vbuc1_then_la1 
    lda #$28
    cmp.z i
    bne __b1_from___b1
    jmp __breturn
    // main::@return
  __breturn:
    // [9] return 
    rts
}
  // File Data

REGISTER UPLIFT POTENTIAL REGISTERS
Statement [6] *((const byte*) main::screen+(word)(number) $28*(number) $a + (byte) main::i#2) ← (byte) 'a' [ main::i#2 ] ( main:2 [ main::i#2 ] ) always clobbers reg byte a 
Removing always clobbered register reg byte a as potential for zp ZP_BYTE:2 [ main::i#2 main::i#1 ]
Statement [6] *((const byte*) main::screen+(word)(number) $28*(number) $a + (byte) main::i#2) ← (byte) 'a' [ main::i#2 ] ( main:2 [ main::i#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] 33: zp ZP_BYTE:2 [ main::i#2 main::i#1 ] 
Uplift Scope [] 

Uplifting [main] best 263 combination reg byte x [ main::i#2 main::i#1 ] 
Uplifting [] best 263 combination 

ASSEMBLER BEFORE OPTIMIZATION
  // File Comments
// Tests that array-indexing by a word variable that is a sum of a constant word and a byte is turned back into derefidx
  // Upstart
.pc = $801 "Basic"
:BasicUpstart(__bbegin)
.pc = $80d "Program"
  // Global Constants & labels
  // @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 screen = $400
    // [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
    // [5] 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 
    jmp __b1
    // main::@1
  __b1:
    // [6] *((const byte*) main::screen+(word)(number) $28*(number) $a + (byte) main::i#2) ← (byte) 'a' -- pbuc1_derefidx_vbuxx=vbuc2 
    lda #'a'
    sta screen+$28*$a,x
    // [7] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuxx=_inc_vbuxx 
    inx
    // [8] if((byte) main::i#1!=(byte) $28) goto main::@1 -- vbuxx_neq_vbuc1_then_la1 
    cpx #$28
    bne __b1_from___b1
    jmp __breturn
    // main::@return
  __breturn:
    // [9] return 
    rts
}
  // File Data

ASSEMBLER OPTIMIZATIONS
Removing instruction jmp __b1
Removing instruction jmp __bend
Removing instruction jmp __b1
Removing instruction jmp __breturn
Succesful ASM optimization Pass5NextJumpElimination
Replacing label __bbegin with __b1
Replacing label __b1_from___b1 with __b1
Removing instruction __bbegin:
Removing instruction __b1_from___bbegin:
Removing instruction main_from___b1:
Removing instruction __bend_from___b1:
Removing instruction __b1_from___b1:
Succesful ASM optimization Pass5RedundantLabelElimination
Removing instruction __bend:
Removing instruction __b1_from_main:
Removing instruction __breturn:
Succesful ASM optimization Pass5UnusedLabelElimination
Updating BasicUpstart to call main directly
Removing instruction jsr main
Succesful ASM optimization Pass5SkipBegin
Removing instruction jmp __b1
Succesful ASM optimization Pass5NextJumpElimination
Removing instruction __b1:
Succesful ASM optimization Pass5UnusedLabelElimination

FINAL SYMBOL TABLE
(label) @1
(label) @begin
(label) @end
(void()) main()
(label) main::@1
(label) main::@return
(byte) main::i
(byte) main::i#1 reg byte x 16.5
(byte) main::i#2 reg byte x 16.5
(const byte*) main::screen screen = (byte*) 1024

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


FINAL ASSEMBLER
Score: 161

  // File Comments
// Tests that array-indexing by a word variable that is a sum of a constant word and a byte is turned back into derefidx
  // Upstart
.pc = $801 "Basic"
:BasicUpstart(main)
.pc = $80d "Program"
  // Global Constants & labels
  // @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: {
    .label screen = $400
    // [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
    // [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 
    // main::@1
  __b1:
    // screen[40*10+i] = 'a'
    // [6] *((const byte*) main::screen+(word)(number) $28*(number) $a + (byte) main::i#2) ← (byte) 'a' -- pbuc1_derefidx_vbuxx=vbuc2 
    lda #'a'
    sta screen+$28*$a,x
    // for( byte i : 0..39)
    // [7] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuxx=_inc_vbuxx 
    inx
    // [8] if((byte) main::i#1!=(byte) $28) goto main::@1 -- vbuxx_neq_vbuc1_then_la1 
    cpx #$28
    bne __b1
    // main::@return
    // }
    // [9] return 
    rts
}
  // File Data