CONTROL FLOW GRAPH SSA @begin: scope:[] from to:@1 main: scope:[main] from @1 (byte*) main::screen#0 ← ((byte*)) (word/signed word/dword/signed dword) $400 (byte) main::b#0 ← (byte/signed byte/word/signed word/dword/signed dword) 0 to:main::@1 main::@1: scope:[main] from main main::@1 (byte*) main::screen#1 ← phi( main/(byte*) main::screen#0 main::@1/(byte*) main::screen#1 ) (byte) main::b#2 ← phi( main/(byte) main::b#0 main::@1/(byte) main::b#1 ) (byte/signed byte/word/signed word/dword/signed dword~) main::$0 ← (byte/signed byte/word/signed word/dword/signed dword) $55 << (byte) main::b#2 *((byte*) main::screen#1 + (byte) main::b#2) ← (byte/signed byte/word/signed word/dword/signed dword~) 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() (byte/signed byte/word/signed word/dword/signed dword~) 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 (byte*) main::screen#1 Culled Empty Block (label) @2 Successful SSA optimization Pass2CullEmptyBlocks Self Phi Eliminated (byte*) main::screen#1 Successful SSA optimization Pass2SelfPhiElimination Redundant Phi (byte*) main::screen#1 (byte*) main::screen#0 Successful SSA optimization Pass2RedundantPhiElimination 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*))$400 Constant (const byte) main::b#0 = 0 Successful SSA optimization Pass2ConstantIdentification Resolved ranged next value main::b#1 ← ++ main::b#2 to ++ Resolved ranged comparison value if(main::b#1!=rangelast(0,7)) goto main::@1 to (byte/signed byte/word/signed word/dword/signed dword) 8 Inlining constant with var siblings (const byte) main::b#0 Constant inlined main::b#0 = (byte/signed byte/word/signed word/dword/signed dword) 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 @end Adding NOP phi() at start of main CALL GRAPH Calls in [] to main:2 Created 1 initial phi equivalence classes Coalesced [11] main::b#3 ← main::b#1 Coalesced down to 1 phi equivalence classes 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/signed byte/word/signed word/dword/signed dword) 0 main::@1/(byte) main::b#1 ) [6] (byte/signed byte/word/signed word/dword/signed dword~) main::$0 ← (byte/signed byte/word/signed word/dword/signed dword) $55 << (byte) main::b#2 [7] *((const byte*) main::screen#0 + (byte) main::b#2) ← (byte/signed byte/word/signed word/dword/signed dword~) main::$0 [8] (byte) main::b#1 ← ++ (byte) main::b#2 [9] if((byte) main::b#1!=(byte/signed byte/word/signed word/dword/signed dword) 8) goto main::@1 to:main::@return main::@return: scope:[main] from main::@1 [10] return to:@return VARIABLE REGISTER WEIGHTS (void()) main() (byte/signed byte/word/signed word/dword/signed dword~) 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 //SEG0 File Comments // Rolling constants by a variable amount //SEG1 Basic Upstart .pc = $801 "Basic" :BasicUpstart(bbegin) .pc = $80d "Program" //SEG2 Global Constants & labels //SEG3 @begin bbegin: //SEG4 [1] phi from @begin to @1 [phi:@begin->@1] b1_from_bbegin: jmp b1 //SEG5 @1 b1: //SEG6 [2] call main //SEG7 [4] phi from @1 to main [phi:@1->main] main_from_b1: jsr main //SEG8 [3] phi from @1 to @end [phi:@1->@end] bend_from_b1: jmp bend //SEG9 @end bend: //SEG10 main main: { .label screen = $400 .label _0 = 3 .label b = 2 //SEG11 [5] phi from main to main::@1 [phi:main->main::@1] b1_from_main: //SEG12 [5] phi (byte) main::b#2 = (byte/signed byte/word/signed word/dword/signed dword) 0 [phi:main->main::@1#0] -- vbuz1=vbuc1 lda #0 sta b jmp b1 //SEG13 [5] phi from main::@1 to main::@1 [phi:main::@1->main::@1] b1_from_b1: //SEG14 [5] phi (byte) main::b#2 = (byte) main::b#1 [phi:main::@1->main::@1#0] -- register_copy jmp b1 //SEG15 main::@1 b1: //SEG16 [6] (byte/signed byte/word/signed word/dword/signed dword~) main::$0 ← (byte/signed byte/word/signed word/dword/signed dword) $55 << (byte) main::b#2 -- vbuz1=vbuc1_rol_vbuz2 lda #$55 ldy b cpy #0 beq !e+ !: asl dey bne !- !e: sta _0 //SEG17 [7] *((const byte*) main::screen#0 + (byte) main::b#2) ← (byte/signed byte/word/signed word/dword/signed dword~) main::$0 -- pbuc1_derefidx_vbuz1=vbuz2 lda _0 ldy b sta screen,y //SEG18 [8] (byte) main::b#1 ← ++ (byte) main::b#2 -- vbuz1=_inc_vbuz1 inc b //SEG19 [9] if((byte) main::b#1!=(byte/signed byte/word/signed word/dword/signed dword) 8) goto main::@1 -- vbuz1_neq_vbuc1_then_la1 lda b cmp #8 bne b1_from_b1 jmp breturn //SEG20 main::@return breturn: //SEG21 [10] return rts } REGISTER UPLIFT POTENTIAL REGISTERS Statement [6] (byte/signed byte/word/signed word/dword/signed dword~) main::$0 ← (byte/signed byte/word/signed word/dword/signed dword) $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/signed byte/word/signed word/dword/signed dword~) main::$0 ← (byte/signed byte/word/signed word/dword/signed dword) $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 //SEG0 File Comments // Rolling constants by a variable amount //SEG1 Basic Upstart .pc = $801 "Basic" :BasicUpstart(bbegin) .pc = $80d "Program" //SEG2 Global Constants & labels //SEG3 @begin bbegin: //SEG4 [1] phi from @begin to @1 [phi:@begin->@1] b1_from_bbegin: jmp b1 //SEG5 @1 b1: //SEG6 [2] call main //SEG7 [4] phi from @1 to main [phi:@1->main] main_from_b1: jsr main //SEG8 [3] phi from @1 to @end [phi:@1->@end] bend_from_b1: jmp bend //SEG9 @end bend: //SEG10 main main: { .label screen = $400 .label b = 2 //SEG11 [5] phi from main to main::@1 [phi:main->main::@1] b1_from_main: //SEG12 [5] phi (byte) main::b#2 = (byte/signed byte/word/signed word/dword/signed dword) 0 [phi:main->main::@1#0] -- vbuz1=vbuc1 lda #0 sta b jmp b1 //SEG13 [5] phi from main::@1 to main::@1 [phi:main::@1->main::@1] b1_from_b1: //SEG14 [5] phi (byte) main::b#2 = (byte) main::b#1 [phi:main::@1->main::@1#0] -- register_copy jmp b1 //SEG15 main::@1 b1: //SEG16 [6] (byte/signed byte/word/signed word/dword/signed dword~) main::$0 ← (byte/signed byte/word/signed word/dword/signed dword) $55 << (byte) main::b#2 -- vbuaa=vbuc1_rol_vbuz1 lda #$55 ldy b cpy #0 beq !e+ !: asl dey bne !- !e: //SEG17 [7] *((const byte*) main::screen#0 + (byte) main::b#2) ← (byte/signed byte/word/signed word/dword/signed dword~) main::$0 -- pbuc1_derefidx_vbuz1=vbuaa ldy b sta screen,y //SEG18 [8] (byte) main::b#1 ← ++ (byte) main::b#2 -- vbuz1=_inc_vbuz1 inc b //SEG19 [9] if((byte) main::b#1!=(byte/signed byte/word/signed word/dword/signed dword) 8) goto main::@1 -- vbuz1_neq_vbuc1_then_la1 lda b cmp #8 bne b1_from_b1 jmp breturn //SEG20 main::@return breturn: //SEG21 [10] return rts } 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/signed byte/word/signed word/dword/signed dword~) 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*))(word/signed word/dword/signed dword) $400 zp ZP_BYTE:2 [ main::b#2 main::b#1 ] reg byte a [ main::$0 ] FINAL ASSEMBLER Score: 421 //SEG0 File Comments // Rolling constants by a variable amount //SEG1 Basic Upstart .pc = $801 "Basic" :BasicUpstart(main) .pc = $80d "Program" //SEG2 Global Constants & labels //SEG3 @begin //SEG4 [1] phi from @begin to @1 [phi:@begin->@1] //SEG5 @1 //SEG6 [2] call main //SEG7 [4] phi from @1 to main [phi:@1->main] //SEG8 [3] phi from @1 to @end [phi:@1->@end] //SEG9 @end //SEG10 main main: { .label screen = $400 .label b = 2 //SEG11 [5] phi from main to main::@1 [phi:main->main::@1] //SEG12 [5] phi (byte) main::b#2 = (byte/signed byte/word/signed word/dword/signed dword) 0 [phi:main->main::@1#0] -- vbuz1=vbuc1 lda #0 sta b //SEG13 [5] phi from main::@1 to main::@1 [phi:main::@1->main::@1] //SEG14 [5] phi (byte) main::b#2 = (byte) main::b#1 [phi:main::@1->main::@1#0] -- register_copy //SEG15 main::@1 b1: //SEG16 [6] (byte/signed byte/word/signed word/dword/signed dword~) main::$0 ← (byte/signed byte/word/signed word/dword/signed dword) $55 << (byte) main::b#2 -- vbuaa=vbuc1_rol_vbuz1 lda #$55 ldy b cpy #0 beq !e+ !: asl dey bne !- !e: //SEG17 [7] *((const byte*) main::screen#0 + (byte) main::b#2) ← (byte/signed byte/word/signed word/dword/signed dword~) main::$0 -- pbuc1_derefidx_vbuz1=vbuaa ldy b sta screen,y //SEG18 [8] (byte) main::b#1 ← ++ (byte) main::b#2 -- vbuz1=_inc_vbuz1 inc b //SEG19 [9] if((byte) main::b#1!=(byte/signed byte/word/signed word/dword/signed dword) 8) goto main::@1 -- vbuz1_neq_vbuc1_then_la1 lda b cmp #8 bne b1 //SEG20 main::@return //SEG21 [10] return rts }