Identified constant variable (byte*) main::screen Culled Empty Block (label) main::@2 CONTROL FLOW GRAPH SSA @begin: scope:[] from to:@1 main: scope:[main] from @1 (byte*) main::screen#0 ← ((byte*)) (number) $400 (byte) main::b#0 ← (byte) 0 to:main::@1 main::@1: scope:[main] from main main::@1 (byte) main::b#2 ← phi( main/(byte) main::b#0 main::@1/(byte) main::b#1 ) (number~) main::$0 ← (number) $55 << (byte) main::b#2 *((byte*) main::screen#0 + (byte) main::b#2) ← (number~) main::$0 (byte) main::b#1 ← (byte) main::b#2 + rangenext(0,7) (bool~) main::$1 ← (byte) main::b#1 != rangelast(0,7) 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::b (byte) main::b#0 (byte) main::b#1 (byte) main::b#2 (byte*) main::screen (byte*) main::screen#0 Adding number conversion cast (unumber) $55 in (number~) main::$0 ← (number) $55 << (byte) main::b#2 Adding number conversion cast (unumber) main::$0 in (number~) main::$0 ← (unumber)(number) $55 << (byte) main::b#2 Successful SSA optimization PassNAddNumberTypeConversions Inlining cast (byte*) main::screen#0 ← (byte*)(number) $400 Successful SSA optimization Pass2InlineCast Simplifying constant pointer cast (byte*) 1024 Simplifying constant integer cast $55 Successful SSA optimization PassNCastSimplification Finalized unsigned number type (byte) $55 Successful SSA optimization PassNFinalizeNumberTypeConversions Inferred type updated to byte in (unumber~) main::$0 ← (byte) $55 << (byte) main::b#2 Simple Condition (bool~) main::$1 [7] if((byte) main::b#1!=rangelast(0,7)) goto main::@1 Successful SSA optimization Pass2ConditionalJumpSimplification Constant (const byte*) main::screen#0 = (byte*) 1024 Constant (const byte) main::b#0 = 0 Successful SSA optimization Pass2ConstantIdentification Resolved ranged next value [5] main::b#1 ← ++ main::b#2 to ++ Resolved ranged comparison value [7] if(main::b#1!=rangelast(0,7)) goto main::@1 to (number) 8 Adding number conversion cast (unumber) 8 in if((byte) main::b#1!=(number) 8) goto main::@1 Successful SSA optimization PassNAddNumberTypeConversions Simplifying constant integer cast 8 Successful SSA optimization PassNCastSimplification Finalized unsigned number type (byte) 8 Successful SSA optimization PassNFinalizeNumberTypeConversions Inlining constant with var siblings (const byte) main::b#0 Constant inlined main::b#0 = (byte) 0 Successful SSA optimization Pass2ConstantInlining 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 [12] main::b#3 ← main::b#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() main: scope:[main] from @1 [4] phi() to:main::@1 main::@1: scope:[main] from main main::@1 [5] (byte) main::b#2 ← phi( main/(byte) 0 main::@1/(byte) main::b#1 ) [6] (byte~) main::$0 ← (byte) $55 << (byte) main::b#2 [7] *((const byte*) main::screen#0 + (byte) main::b#2) ← (byte~) main::$0 [8] (byte) main::b#1 ← ++ (byte) main::b#2 [9] if((byte) main::b#1!=(byte) 8) goto main::@1 to:main::@return main::@return: scope:[main] from main::@1 [10] return to:@return VARIABLE REGISTER WEIGHTS (void()) main() (byte~) main::$0 22.0 (byte) main::b (byte) main::b#1 16.5 (byte) main::b#2 14.666666666666666 (byte*) main::screen Initial phi equivalence classes [ main::b#2 main::b#1 ] Added variable main::$0 to zero page equivalence class [ main::$0 ] Complete equivalence classes [ main::b#2 main::b#1 ] [ main::$0 ] Allocated zp ZP_BYTE:2 [ main::b#2 main::b#1 ] Allocated zp ZP_BYTE:3 [ main::$0 ] INITIAL ASM Target platform is c64basic // File Comments // Rolling constants by a variable amount // 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 _0 = 3 .label b = 2 // [5] phi from main to main::@1 [phi:main->main::@1] b1_from_main: // [5] phi (byte) main::b#2 = (byte) 0 [phi:main->main::@1#0] -- vbuz1=vbuc1 lda #0 sta b jmp b1 // [5] phi from main::@1 to main::@1 [phi:main::@1->main::@1] b1_from_b1: // [5] phi (byte) main::b#2 = (byte) main::b#1 [phi:main::@1->main::@1#0] -- register_copy jmp b1 // main::@1 b1: // [6] (byte~) main::$0 ← (byte) $55 << (byte) main::b#2 -- vbuz1=vbuc1_rol_vbuz2 lda #$55 ldy b cpy #0 beq !e+ !: asl dey bne !- !e: sta _0 // [7] *((const byte*) main::screen#0 + (byte) main::b#2) ← (byte~) main::$0 -- pbuc1_derefidx_vbuz1=vbuz2 lda _0 ldy b sta screen,y // [8] (byte) main::b#1 ← ++ (byte) main::b#2 -- vbuz1=_inc_vbuz1 inc b // [9] if((byte) main::b#1!=(byte) 8) goto main::@1 -- vbuz1_neq_vbuc1_then_la1 lda #8 cmp b bne b1_from_b1 jmp breturn // main::@return breturn: // [10] return rts } // File Data REGISTER UPLIFT POTENTIAL REGISTERS Statement [6] (byte~) main::$0 ← (byte) $55 << (byte) main::b#2 [ main::b#2 main::$0 ] ( main:2 [ main::b#2 main::$0 ] ) always clobbers reg byte a Removing always clobbered register reg byte a as potential for zp ZP_BYTE:2 [ main::b#2 main::b#1 ] Statement [6] (byte~) main::$0 ← (byte) $55 << (byte) main::b#2 [ main::b#2 main::$0 ] ( main:2 [ main::b#2 main::$0 ] ) always clobbers reg byte a Potential registers zp ZP_BYTE:2 [ main::b#2 main::b#1 ] : zp ZP_BYTE:2 , reg byte x , reg byte y , Potential registers zp ZP_BYTE:3 [ main::$0 ] : zp ZP_BYTE:3 , reg byte a , reg byte x , reg byte y , REGISTER UPLIFT SCOPES Uplift Scope [main] 31.17: zp ZP_BYTE:2 [ main::b#2 main::b#1 ] 22: zp ZP_BYTE:3 [ main::$0 ] Uplift Scope [] Uplifting [main] best 523 combination zp ZP_BYTE:2 [ main::b#2 main::b#1 ] reg byte a [ main::$0 ] Uplifting [] best 523 combination Attempting to uplift remaining variables inzp ZP_BYTE:2 [ main::b#2 main::b#1 ] Uplifting [main] best 523 combination zp ZP_BYTE:2 [ main::b#2 main::b#1 ] ASSEMBLER BEFORE OPTIMIZATION // File Comments // Rolling constants by a variable amount // 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 b = 2 // [5] phi from main to main::@1 [phi:main->main::@1] b1_from_main: // [5] phi (byte) main::b#2 = (byte) 0 [phi:main->main::@1#0] -- vbuz1=vbuc1 lda #0 sta b jmp b1 // [5] phi from main::@1 to main::@1 [phi:main::@1->main::@1] b1_from_b1: // [5] phi (byte) main::b#2 = (byte) main::b#1 [phi:main::@1->main::@1#0] -- register_copy jmp b1 // main::@1 b1: // [6] (byte~) main::$0 ← (byte) $55 << (byte) main::b#2 -- vbuaa=vbuc1_rol_vbuz1 lda #$55 ldy b cpy #0 beq !e+ !: asl dey bne !- !e: // [7] *((const byte*) main::screen#0 + (byte) main::b#2) ← (byte~) main::$0 -- pbuc1_derefidx_vbuz1=vbuaa ldy b sta screen,y // [8] (byte) main::b#1 ← ++ (byte) main::b#2 -- vbuz1=_inc_vbuz1 inc b // [9] if((byte) main::b#1!=(byte) 8) goto main::@1 -- vbuz1_neq_vbuc1_then_la1 lda #8 cmp b bne b1_from_b1 jmp breturn // main::@return breturn: // [10] 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 b1_from_b1 with b1 Removing instruction b1_from_bbegin: Removing instruction b1: 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 bbegin: Succesful ASM optimization Pass5UnusedLabelElimination FINAL SYMBOL TABLE (label) @1 (label) @begin (label) @end (void()) main() (byte~) main::$0 reg byte a 22.0 (label) main::@1 (label) main::@return (byte) main::b (byte) main::b#1 b zp ZP_BYTE:2 16.5 (byte) main::b#2 b zp ZP_BYTE:2 14.666666666666666 (byte*) main::screen (const byte*) main::screen#0 screen = (byte*) 1024 zp ZP_BYTE:2 [ main::b#2 main::b#1 ] reg byte a [ main::$0 ] FINAL ASSEMBLER Score: 421 // File Comments // Rolling constants by a variable amount // 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 .label b = 2 // [5] phi from main to main::@1 [phi:main->main::@1] // [5] phi (byte) main::b#2 = (byte) 0 [phi:main->main::@1#0] -- vbuz1=vbuc1 lda #0 sta b // [5] phi from main::@1 to main::@1 [phi:main::@1->main::@1] // [5] phi (byte) main::b#2 = (byte) main::b#1 [phi:main::@1->main::@1#0] -- register_copy // main::@1 b1: // $55 << b // [6] (byte~) main::$0 ← (byte) $55 << (byte) main::b#2 -- vbuaa=vbuc1_rol_vbuz1 lda #$55 ldy b cpy #0 beq !e+ !: asl dey bne !- !e: // screen[b] = $55 << b // [7] *((const byte*) main::screen#0 + (byte) main::b#2) ← (byte~) main::$0 -- pbuc1_derefidx_vbuz1=vbuaa ldy b sta screen,y // for( byte b: 0..7) // [8] (byte) main::b#1 ← ++ (byte) main::b#2 -- vbuz1=_inc_vbuz1 inc b // [9] if((byte) main::b#1!=(byte) 8) goto main::@1 -- vbuz1_neq_vbuc1_then_la1 lda #8 cmp b bne b1 // main::@return // } // [10] return rts } // File Data