Setting inferred volatile on symbol affected by address-of (byte**~) main::$0 ← & (byte*) main::screen
Culled Empty Block (label) @1

CONTROL FLOW GRAPH SSA
@begin: scope:[]  from
  to:@2
main: scope:[main]  from @2
  (byte*) main::screen#0 ← ((byte*)) (number) $400
  (byte**~) main::$0 ← & (byte*) main::screen#0
  (byte**) main::pscreen#0 ← (byte**~) main::$0
  (byte) sub::ch#0 ← (byte) 'a'
  (byte**) sub::dst#0 ← (byte**) main::pscreen#0
  call sub 
  to:main::@1
main::@1: scope:[main]  from main
  (byte**) main::pscreen#1 ← phi( main/(byte**) main::pscreen#0 )
  (byte) sub::ch#1 ← (byte) 'b'
  (byte**) sub::dst#1 ← (byte**) main::pscreen#1
  call sub 
  to:main::@2
main::@2: scope:[main]  from main::@1
  to:main::@return
main::@return: scope:[main]  from main::@2
  return 
  to:@return
sub: scope:[sub]  from main main::@1
  (byte**) sub::dst#2 ← phi( main/(byte**) sub::dst#0 main::@1/(byte**) sub::dst#1 )
  (byte) sub::ch#2 ← phi( main/(byte) sub::ch#0 main::@1/(byte) sub::ch#1 )
  *(*((byte**) sub::dst#2)) ← (byte) sub::ch#2
  *((byte**) sub::dst#2) ← ++ *((byte**) sub::dst#2)
  to:sub::@return
sub::@return: scope:[sub]  from sub
  return 
  to:@return
@2: scope:[]  from @begin
  call main 
  to:@3
@3: scope:[]  from @2
  to:@end
@end: scope:[]  from @3

SYMBOL TABLE SSA
(label) @2
(label) @3
(label) @begin
(label) @end
(void()) main()
(byte**~) main::$0
(label) main::@1
(label) main::@2
(label) main::@return
(byte**) main::pscreen
(byte**) main::pscreen#0
(byte**) main::pscreen#1
(byte*) main::screen
(byte*) main::screen#0
(void()) sub((byte) sub::ch , (byte**) sub::dst)
(label) sub::@return
(byte) sub::ch
(byte) sub::ch#0
(byte) sub::ch#1
(byte) sub::ch#2
(byte**) sub::dst
(byte**) sub::dst#0
(byte**) sub::dst#1
(byte**) sub::dst#2

Inlining cast (byte*) main::screen#0 ← (byte*)(number) $400
Successful SSA optimization Pass2InlineCast
Simplifying constant pointer cast (byte*) 1024
Successful SSA optimization PassNCastSimplification
Alias (byte**) main::pscreen#0 = (byte**~) main::$0 (byte**) main::pscreen#1 
Successful SSA optimization Pass2AliasElimination
Constant right-side identified [1] (byte**) main::pscreen#0 ← & (byte*) main::screen#0
Successful SSA optimization Pass2ConstantRValueConsolidation
Constant (const byte**) main::pscreen#0 = &main::screen#0
Constant (const byte) sub::ch#0 = 'a'
Constant (const byte) sub::ch#1 = 'b'
Successful SSA optimization Pass2ConstantIdentification
Constant (const byte**) sub::dst#0 = main::pscreen#0
Constant (const byte**) sub::dst#1 = main::pscreen#0
Successful SSA optimization Pass2ConstantIdentification
Inlining constant with var siblings (const byte) sub::ch#0
Inlining constant with var siblings (const byte) sub::ch#1
Inlining constant with var siblings (const byte**) sub::dst#0
Inlining constant with var siblings (const byte**) sub::dst#1
Constant inlined sub::ch#1 = (byte) 'b'
Constant inlined sub::ch#0 = (byte) 'a'
Constant inlined sub::dst#1 = (const byte**) main::pscreen#0
Constant inlined sub::dst#0 = (const byte**) main::pscreen#0
Successful SSA optimization Pass2ConstantInlining
Identical Phi Values (byte**) sub::dst#2 (const byte**) main::pscreen#0
Successful SSA optimization Pass2IdenticalPhiElimination
Adding NOP phi() at start of @begin
Adding NOP phi() at start of @2
Adding NOP phi() at start of @3
Adding NOP phi() at start of @end
Adding NOP phi() at start of main::@1
Adding NOP phi() at start of main::@2
CALL GRAPH
Calls in [] to main:2 
Calls in [main] to sub:6 sub:8 

Created 1 initial phi equivalence classes
Coalesced down to 1 phi equivalence classes
Culled Empty Block (label) @3
Culled Empty Block (label) main::@2
Renumbering block @2 to @1
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::@1

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] (byte*) main::screen#0 ← (byte*) 1024
  [5] call sub 
  to:main::@1
main::@1: scope:[main]  from main
  [6] phi()
  [7] call sub 
  to:main::@return
main::@return: scope:[main]  from main::@1
  [8] return 
  to:@return
sub: scope:[sub]  from main main::@1
  [9] (byte) sub::ch#2 ← phi( main/(byte) 'a' main::@1/(byte) 'b' )
  [10] *(*((const byte**) main::pscreen#0)) ← (byte) sub::ch#2
  [11] *((const byte**) main::pscreen#0) ← ++ *((const byte**) main::pscreen#0)
  to:sub::@return
sub::@return: scope:[sub]  from sub
  [12] return 
  to:@return


VARIABLE REGISTER WEIGHTS
(void()) main()
(byte**) main::pscreen
(byte*) main::screen
(byte*) main::screen#0 20.0
(void()) sub((byte) sub::ch , (byte**) sub::dst)
(byte) sub::ch
(byte) sub::ch#2 2.0
(byte**) sub::dst

Initial phi equivalence classes
[ sub::ch#2 ]
Complete equivalence classes
[ sub::ch#2 ]
[ main::screen#0 ]
Allocated zp ZP_BYTE:2 [ sub::ch#2 ]
Allocated zp ZP_WORD:3 [ main::screen#0 ]

INITIAL ASM
  // File Comments
// Tests optimization of constant pointers to pointers
  // Basic 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 
  jsr main
  // [3] phi from @1 to @end [phi:@1->@end]
bend_from_b1:
  jmp bend
  // @end
bend:
  // main
main: {
    .label pscreen = screen
    .label screen = 3
    // [4] (byte*) main::screen#0 ← (byte*) 1024 -- pbuz1=pbuc1 
    lda #<$400
    sta screen
    lda #>$400
    sta screen+1
    // [5] call sub 
    // [9] phi from main to sub [phi:main->sub]
  sub_from_main:
    // [9] phi (byte) sub::ch#2 = (byte) 'a' [phi:main->sub#0] -- vbuz1=vbuc1 
    lda #'a'
    sta sub.ch
    jsr sub
    // [6] phi from main to main::@1 [phi:main->main::@1]
  b1_from_main:
    jmp b1
    // main::@1
  b1:
    // [7] call sub 
    // [9] phi from main::@1 to sub [phi:main::@1->sub]
  sub_from_b1:
    // [9] phi (byte) sub::ch#2 = (byte) 'b' [phi:main::@1->sub#0] -- vbuz1=vbuc1 
    lda #'b'
    sta sub.ch
    jsr sub
    jmp breturn
    // main::@return
  breturn:
    // [8] return 
    rts
}
  // sub
// sub(byte zeropage(2) ch)
sub: {
    .label ch = 2
    // [10] *(*((const byte**) main::pscreen#0)) ← (byte) sub::ch#2 -- _deref__deref_pptc1=vbuz1 
    lda ch
    ldy #0
    sta (main.pscreen),y
    // [11] *((const byte**) main::pscreen#0) ← ++ *((const byte**) main::pscreen#0) -- _deref_pptc1=_inc__deref_pptc1 
    inc main.pscreen
    bne !+
    inc main.pscreen+1
  !:
    jmp breturn
    // sub::@return
  breturn:
    // [12] return 
    rts
}
  // File Data

REGISTER UPLIFT POTENTIAL REGISTERS
Statement [4] (byte*) main::screen#0 ← (byte*) 1024 [ ] ( main:2 [ ] ) always clobbers reg byte a 
Statement [10] *(*((const byte**) main::pscreen#0)) ← (byte) sub::ch#2 [ ] ( main:2::sub:5 [ ] main:2::sub:7 [ ] ) always clobbers reg byte y 
Potential registers zp ZP_BYTE:2 [ sub::ch#2 ] : zp ZP_BYTE:2 , reg byte a , reg byte x , reg byte y , 
Potential registers zp ZP_WORD:3 [ main::screen#0 ] : zp ZP_WORD:3 , 

REGISTER UPLIFT SCOPES
Uplift Scope [main] 20: zp ZP_WORD:3 [ main::screen#0 ] 
Uplift Scope [sub] 2: zp ZP_BYTE:2 [ sub::ch#2 ] 
Uplift Scope [] 

Uplifting [main] best 90 combination zp ZP_WORD:3 [ main::screen#0 ] 
Uplifting [sub] best 81 combination reg byte a [ sub::ch#2 ] 
Uplifting [] best 81 combination 
Allocated (was zp ZP_WORD:3) zp ZP_WORD:2 [ main::screen#0 ]

ASSEMBLER BEFORE OPTIMIZATION
  // File Comments
// Tests optimization of constant pointers to pointers
  // Basic 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 
  jsr main
  // [3] phi from @1 to @end [phi:@1->@end]
bend_from_b1:
  jmp bend
  // @end
bend:
  // main
main: {
    .label pscreen = screen
    .label screen = 2
    // [4] (byte*) main::screen#0 ← (byte*) 1024 -- pbuz1=pbuc1 
    lda #<$400
    sta screen
    lda #>$400
    sta screen+1
    // [5] call sub 
    // [9] phi from main to sub [phi:main->sub]
  sub_from_main:
    // [9] phi (byte) sub::ch#2 = (byte) 'a' [phi:main->sub#0] -- vbuaa=vbuc1 
    lda #'a'
    jsr sub
    // [6] phi from main to main::@1 [phi:main->main::@1]
  b1_from_main:
    jmp b1
    // main::@1
  b1:
    // [7] call sub 
    // [9] phi from main::@1 to sub [phi:main::@1->sub]
  sub_from_b1:
    // [9] phi (byte) sub::ch#2 = (byte) 'b' [phi:main::@1->sub#0] -- vbuaa=vbuc1 
    lda #'b'
    jsr sub
    jmp breturn
    // main::@return
  breturn:
    // [8] return 
    rts
}
  // sub
// sub(byte register(A) ch)
sub: {
    // [10] *(*((const byte**) main::pscreen#0)) ← (byte) sub::ch#2 -- _deref__deref_pptc1=vbuaa 
    ldy #0
    sta (main.pscreen),y
    // [11] *((const byte**) main::pscreen#0) ← ++ *((const byte**) main::pscreen#0) -- _deref_pptc1=_inc__deref_pptc1 
    inc main.pscreen
    bne !+
    inc main.pscreen+1
  !:
    jmp breturn
    // sub::@return
  breturn:
    // [12] return 
    rts
}
  // File Data

ASSEMBLER OPTIMIZATIONS
Removing instruction jmp b1
Removing instruction jmp bend
Removing instruction jmp b1
Removing instruction jmp breturn
Removing instruction jmp breturn
Succesful ASM optimization Pass5NextJumpElimination
Removing instruction b1_from_bbegin:
Removing instruction b1:
Removing instruction bend_from_b1:
Removing instruction b1_from_main:
Removing instruction sub_from_b1:
Succesful ASM optimization Pass5RedundantLabelElimination
Removing instruction bend:
Removing instruction sub_from_main:
Removing instruction b1:
Removing instruction breturn:
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::@1
(label) main::@return
(byte**) main::pscreen
(const byte**) main::pscreen#0 pscreen = &(byte*) main::screen#0
(byte*) main::screen
(byte*) main::screen#0 screen zp ZP_WORD:2 20.0
(void()) sub((byte) sub::ch , (byte**) sub::dst)
(label) sub::@return
(byte) sub::ch
(byte) sub::ch#2 reg byte a 2.0
(byte**) sub::dst

reg byte a [ sub::ch#2 ]
zp ZP_WORD:2 [ main::screen#0 ]


FINAL ASSEMBLER
Score: 60

  // File Comments
// Tests optimization of constant pointers to pointers
  // Basic 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 
  // [3] phi from @1 to @end [phi:@1->@end]
  // @end
  // main
main: {
    .label pscreen = screen
    .label screen = 2
    // screen = 0x400
    // [4] (byte*) main::screen#0 ← (byte*) 1024 -- pbuz1=pbuc1 
    lda #<$400
    sta screen
    lda #>$400
    sta screen+1
    // sub('a',pscreen)
    // [5] call sub 
    // [9] phi from main to sub [phi:main->sub]
    // [9] phi (byte) sub::ch#2 = (byte) 'a' [phi:main->sub#0] -- vbuaa=vbuc1 
    lda #'a'
    jsr sub
    // [6] phi from main to main::@1 [phi:main->main::@1]
    // main::@1
    // sub('b',pscreen)
    // [7] call sub 
    // [9] phi from main::@1 to sub [phi:main::@1->sub]
    // [9] phi (byte) sub::ch#2 = (byte) 'b' [phi:main::@1->sub#0] -- vbuaa=vbuc1 
    lda #'b'
    jsr sub
    // main::@return
    // }
    // [8] return 
    rts
}
  // sub
// sub(byte register(A) ch)
sub: {
    // *(*dst)++ = ch
    // [10] *(*((const byte**) main::pscreen#0)) ← (byte) sub::ch#2 -- _deref__deref_pptc1=vbuaa 
    ldy #0
    sta (main.pscreen),y
    // *(*dst)++ = ch;
    // [11] *((const byte**) main::pscreen#0) ← ++ *((const byte**) main::pscreen#0) -- _deref_pptc1=_inc__deref_pptc1 
    inc main.pscreen
    bne !+
    inc main.pscreen+1
  !:
    // sub::@return
    // }
    // [12] return 
    rts
}
  // File Data

