Setting inferred volatile on symbol affected by address-of (byte*) idx_p ← &(byte) idx Inlined call call _init CONTROL FLOW GRAPH SSA (void()) main() main: scope:[main] from _start::@1 (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 ) *((const nomodify byte*) SCREEN + (byte) main::i#2) ← *((const byte*) idx_p) *((const byte*) idx_p) ← *((const byte*) idx_p) + (byte) main::i#2 (byte) main::i#1 ← (byte) main::i#2 + rangenext(0,5) (bool~) main::$0 ← (byte) main::i#1 != rangelast(0,5) if((bool~) main::$0) goto main::@1 to:main::@return main::@return: scope:[main] from main::@1 return to:@return (void()) _start() _start: scope:[_start] from to:_start::_init1 _start::_init1: scope:[_start] from _start to:_start::@1 _start::@1: scope:[_start] from _start::_init1 call main to:_start::@2 _start::@2: scope:[_start] from _start::@1 to:_start::@return _start::@return: scope:[_start] from _start::@2 return to:@return SYMBOL TABLE SSA (const nomodify byte*) SCREEN = (byte*)(number) $400 (void()) _start() (label) _start::@1 (label) _start::@2 (label) _start::@return (label) _start::_init1 (volatile byte) idx loadstore = (byte) 0 (const byte*) idx_p = &(volatile byte) idx (void()) main() (bool~) main::$0 (label) main::@1 (label) main::@return (byte) main::i (byte) main::i#0 (byte) main::i#1 (byte) main::i#2 Simplifying constant pointer cast (byte*) 1024 Successful SSA optimization PassNCastSimplification Simple Condition (bool~) main::$0 [6] if((byte) main::i#1!=rangelast(0,5)) goto main::@1 Successful SSA optimization Pass2ConditionalJumpSimplification Constant (const byte) main::i#0 = 0 Successful SSA optimization Pass2ConstantIdentification Resolved ranged next value [4] main::i#1 ← ++ main::i#2 to ++ Resolved ranged comparison value [6] if(main::i#1!=rangelast(0,5)) goto main::@1 to (number) 6 Removing unused procedure _start Removing unused procedure block _start Removing unused procedure block _start::_init1 Removing unused procedure block _start::@1 Removing unused procedure block _start::@2 Removing unused procedure block _start::@return Successful SSA optimization PassNEliminateEmptyStart Adding number conversion cast (unumber) 6 in [4] if((byte) main::i#1!=(number) 6) goto main::@1 Successful SSA optimization PassNAddNumberTypeConversions Simplifying constant integer cast 6 Successful SSA optimization PassNCastSimplification Finalized unsigned number type (byte) 6 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 Added new block during phi lifting main::@2(between main::@1 and main::@1) Adding NOP phi() at start of main CALL GRAPH Created 1 initial phi equivalence classes Coalesced [7] main::i#3 ← main::i#1 Coalesced down to 1 phi equivalence classes Culled Empty Block (label) main::@2 Adding NOP phi() at start of main FINAL CONTROL FLOW GRAPH (void()) main() main: scope:[main] from [0] phi() to:main::@1 main::@1: scope:[main] from main main::@1 [1] (byte) main::i#2 ← phi( main/(byte) 0 main::@1/(byte) main::i#1 ) [2] *((const nomodify byte*) SCREEN + (byte) main::i#2) ← *((const byte*) idx_p) [3] *((const byte*) idx_p) ← *((const byte*) idx_p) + (byte) main::i#2 [4] (byte) main::i#1 ← ++ (byte) main::i#2 [5] if((byte) main::i#1!=(byte) 6) goto main::@1 to:main::@return main::@return: scope:[main] from main::@1 [6] return to:@return VARIABLE REGISTER WEIGHTS (volatile byte) idx loadstore = (byte) 0 (void()) main() (byte) main::i (byte) main::i#1 16.5 (byte) main::i#2 14.666666666666666 Initial phi equivalence classes [ main::i#2 main::i#1 ] Added variable idx to live range equivalence class [ idx ] Complete equivalence classes [ main::i#2 main::i#1 ] [ idx ] Allocated zp[1]:2 [ main::i#2 main::i#1 ] Allocated mem[1] [ idx ] INITIAL ASM Target platform is c64basic / MOS6502X // File Comments // Test declaring a variable as "memory", meaning it will be stored in memory and accessed through an implicit pointer (using load/store) // Test a pointer to a memory variable // Upstart .pc = $801 "Basic" :BasicUpstart(main) .pc = $80d "Program" // Global Constants & labels .label SCREEN = $400 .label idx_p = idx // main main: { .label i = 2 // [1] phi from main to main::@1 [phi:main->main::@1] __b1_from_main: // [1] phi (byte) main::i#2 = (byte) 0 [phi:main->main::@1#0] -- vbuz1=vbuc1 lda #0 sta.z i jmp __b1 // [1] phi from main::@1 to main::@1 [phi:main::@1->main::@1] __b1_from___b1: // [1] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@1->main::@1#0] -- register_copy jmp __b1 // main::@1 __b1: // [2] *((const nomodify byte*) SCREEN + (byte) main::i#2) ← *((const byte*) idx_p) -- pbuc1_derefidx_vbuz1=_deref_pbuc2 lda idx_p ldy.z i sta SCREEN,y // [3] *((const byte*) idx_p) ← *((const byte*) idx_p) + (byte) main::i#2 -- _deref_pbuc1=_deref_pbuc1_plus_vbuz1 lda idx_p clc adc.z i sta idx_p // [4] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuz1=_inc_vbuz1 inc.z i // [5] if((byte) main::i#1!=(byte) 6) goto main::@1 -- vbuz1_neq_vbuc1_then_la1 lda #6 cmp.z i bne __b1_from___b1 jmp __breturn // main::@return __breturn: // [6] return rts } // File Data idx: .byte 0 REGISTER UPLIFT POTENTIAL REGISTERS Statement [2] *((const nomodify byte*) SCREEN + (byte) main::i#2) ← *((const byte*) idx_p) [ main::i#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 [3] *((const byte*) idx_p) ← *((const byte*) idx_p) + (byte) main::i#2 [ main::i#2 ] ( [ main::i#2 ] { } ) always clobbers reg byte a Statement [2] *((const nomodify byte*) SCREEN + (byte) main::i#2) ← *((const byte*) idx_p) [ main::i#2 ] ( [ main::i#2 ] { } ) always clobbers reg byte a Statement [3] *((const byte*) idx_p) ← *((const byte*) idx_p) + (byte) main::i#2 [ main::i#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 , Potential registers mem[1] [ idx ] : mem[1] , REGISTER UPLIFT SCOPES Uplift Scope [main] 31.17: zp[1]:2 [ main::i#2 main::i#1 ] Uplift Scope [] 0: mem[1] [ idx ] Uplifting [main] best 391 combination reg byte x [ main::i#2 main::i#1 ] Uplifting [] best 391 combination mem[1] [ idx ] Attempting to uplift remaining variables inmem[1] [ idx ] Uplifting [] best 391 combination mem[1] [ idx ] ASSEMBLER BEFORE OPTIMIZATION // File Comments // Test declaring a variable as "memory", meaning it will be stored in memory and accessed through an implicit pointer (using load/store) // Test a pointer to a memory variable // Upstart .pc = $801 "Basic" :BasicUpstart(main) .pc = $80d "Program" // Global Constants & labels .label SCREEN = $400 .label idx_p = idx // main main: { // [1] phi from main to main::@1 [phi:main->main::@1] __b1_from_main: // [1] phi (byte) main::i#2 = (byte) 0 [phi:main->main::@1#0] -- vbuxx=vbuc1 ldx #0 jmp __b1 // [1] phi from main::@1 to main::@1 [phi:main::@1->main::@1] __b1_from___b1: // [1] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@1->main::@1#0] -- register_copy jmp __b1 // main::@1 __b1: // [2] *((const nomodify byte*) SCREEN + (byte) main::i#2) ← *((const byte*) idx_p) -- pbuc1_derefidx_vbuxx=_deref_pbuc2 lda idx_p sta SCREEN,x // [3] *((const byte*) idx_p) ← *((const byte*) idx_p) + (byte) main::i#2 -- _deref_pbuc1=_deref_pbuc1_plus_vbuxx txa clc adc idx_p sta idx_p // [4] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuxx=_inc_vbuxx inx // [5] if((byte) main::i#1!=(byte) 6) goto main::@1 -- vbuxx_neq_vbuc1_then_la1 cpx #6 bne __b1_from___b1 jmp __breturn // main::@return __breturn: // [6] return rts } // File Data idx: .byte 0 ASSEMBLER OPTIMIZATIONS Removing instruction jmp __b1 Removing instruction jmp __breturn Succesful ASM optimization Pass5NextJumpElimination Replacing label __b1_from___b1 with __b1 Removing instruction __b1_from___b1: Succesful ASM optimization Pass5RedundantLabelElimination Removing instruction __b1_from_main: Removing instruction __breturn: Succesful ASM optimization Pass5UnusedLabelElimination Removing instruction jmp __b1 Succesful ASM optimization Pass5NextJumpElimination FINAL SYMBOL TABLE (const nomodify byte*) SCREEN = (byte*) 1024 (volatile byte) idx loadstore mem[1] = (byte) 0 (const byte*) idx_p = &(volatile byte) idx (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 14.666666666666666 reg byte x [ main::i#2 main::i#1 ] mem[1] [ idx ] FINAL ASSEMBLER Score: 301 // File Comments // Test declaring a variable as "memory", meaning it will be stored in memory and accessed through an implicit pointer (using load/store) // Test a pointer to a memory variable // Upstart .pc = $801 "Basic" :BasicUpstart(main) .pc = $80d "Program" // Global Constants & labels .label SCREEN = $400 .label idx_p = idx // main main: { // [1] phi from main to main::@1 [phi:main->main::@1] // [1] phi (byte) main::i#2 = (byte) 0 [phi:main->main::@1#0] -- vbuxx=vbuc1 ldx #0 // [1] phi from main::@1 to main::@1 [phi:main::@1->main::@1] // [1] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@1->main::@1#0] -- register_copy // main::@1 __b1: // SCREEN[i] = *idx_p // [2] *((const nomodify byte*) SCREEN + (byte) main::i#2) ← *((const byte*) idx_p) -- pbuc1_derefidx_vbuxx=_deref_pbuc2 lda idx_p sta SCREEN,x // *idx_p +=i // [3] *((const byte*) idx_p) ← *((const byte*) idx_p) + (byte) main::i#2 -- _deref_pbuc1=_deref_pbuc1_plus_vbuxx txa clc adc idx_p sta idx_p // for( char i: 0..5 ) // [4] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuxx=_inc_vbuxx inx // [5] if((byte) main::i#1!=(byte) 6) goto main::@1 -- vbuxx_neq_vbuc1_then_la1 cpx #6 bne __b1 // main::@return // } // [6] return rts } // File Data idx: .byte 0