CONTROL FLOW GRAPH SSA @begin: scope:[] from to:@1 (void()) main() main: scope:[main] from @1 (byte) main::i#0 ← (byte) 0 to:main::@1 main::@1: scope:[main] from main main::@2 (byte) main::i#2 ← phi( main/(byte) main::i#0 main::@2/(byte) main::i#1 ) (bool~) main::$0 ← (byte) main::i#2 < (number) $32 (bool~) main::$1 ← ! (bool~) main::$0 if((bool~) main::$1) goto main::@2 to:main::@3 main::@2: scope:[main] from main::@1 main::@3 (byte) main::i#3 ← phi( main::@1/(byte) main::i#2 main::@3/(byte) main::i#4 ) (byte) main::i#1 ← ++ (byte) main::i#3 (bool~) main::$2 ← (byte) main::i#1 < (number) $64 if((bool~) main::$2) goto main::@1 to:main::@return main::@3: scope:[main] from main::@1 (byte) main::i#4 ← phi( main::@1/(byte) main::i#2 ) *((const byte*) SCREEN) ← (byte) main::i#4 to:main::@2 main::@return: scope:[main] from main::@2 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 (const byte*) SCREEN = (byte*)(number) $400 (void()) main() (bool~) main::$0 (bool~) main::$1 (bool~) main::$2 (label) main::@1 (label) main::@2 (label) main::@3 (label) main::@return (byte) main::i (byte) main::i#0 (byte) main::i#1 (byte) main::i#2 (byte) main::i#3 (byte) main::i#4 Adding number conversion cast (unumber) $32 in (bool~) main::$0 ← (byte) main::i#2 < (number) $32 Adding number conversion cast (unumber) $64 in (bool~) main::$2 ← (byte) main::i#1 < (number) $64 Successful SSA optimization PassNAddNumberTypeConversions Simplifying constant pointer cast (byte*) 1024 Simplifying constant integer cast $32 Simplifying constant integer cast $64 Successful SSA optimization PassNCastSimplification Finalized unsigned number type (byte) $32 Finalized unsigned number type (byte) $64 Successful SSA optimization PassNFinalizeNumberTypeConversions Inversing boolean not [3] (bool~) main::$1 ← (byte) main::i#2 >= (byte) $32 from [2] (bool~) main::$0 ← (byte) main::i#2 < (byte) $32 Successful SSA optimization Pass2UnaryNotSimplification Alias main::i#2 = main::i#4 Successful SSA optimization Pass2AliasElimination Alias main::i#2 = main::i#3 Successful SSA optimization Pass2AliasElimination Simple Condition (bool~) main::$1 [3] if((byte) main::i#2>=(byte) $32) goto main::@2 Simple Condition (bool~) main::$2 [6] if((byte) main::i#1<(byte) $64) goto main::@1 Successful SSA optimization Pass2ConditionalJumpSimplification Constant (const byte) main::i#0 = 0 Successful SSA optimization Pass2ConstantIdentification 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::@4(between main::@2 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::i#5 ← main::i#1 Coalesced down to 1 phi equivalence classes Culled Empty Block (label) @2 Culled Empty Block (label) main::@4 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::@2 [5] (byte) main::i#2 ← phi( main/(byte) 0 main::@2/(byte) main::i#1 ) [6] if((byte) main::i#2>=(byte) $32) goto main::@2 to:main::@3 main::@3: scope:[main] from main::@1 [7] *((const byte*) SCREEN) ← (byte) main::i#2 to:main::@2 main::@2: scope:[main] from main::@1 main::@3 [8] (byte) main::i#1 ← ++ (byte) main::i#2 [9] if((byte) main::i#1<(byte) $64) goto main::@1 to:main::@return main::@return: scope:[main] from main::@2 [10] return to:@return VARIABLE REGISTER WEIGHTS (void()) main() (byte) main::i (byte) main::i#1 151.5 (byte) main::i#2 134.66666666666666 Initial phi equivalence classes [ main::i#2 main::i#1 ] Complete equivalence classes [ main::i#2 main::i#1 ] Allocated zp[1]:2 [ main::i#2 main::i#1 ] INITIAL ASM Target platform is c64basic / MOS6502X // File Comments // Minimal if() test // Upstart .pc = $801 "Basic" :BasicUpstart(main) .pc = $80d "Program" // Global Constants & labels .label SCREEN = $400 // @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 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::@2 to main::@1 [phi:main::@2->main::@1] __b1_from___b2: // [5] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@2->main::@1#0] -- register_copy jmp __b1 // main::@1 __b1: // [6] if((byte) main::i#2>=(byte) $32) goto main::@2 -- vbuz1_ge_vbuc1_then_la1 lda.z i cmp #$32 bcs __b2 jmp __b3 // main::@3 __b3: // [7] *((const byte*) SCREEN) ← (byte) main::i#2 -- _deref_pbuc1=vbuz1 lda.z i sta SCREEN jmp __b2 // main::@2 __b2: // [8] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuz1=_inc_vbuz1 inc.z i // [9] if((byte) main::i#1<(byte) $64) goto main::@1 -- vbuz1_lt_vbuc1_then_la1 lda.z i cmp #$64 bcc __b1_from___b2 jmp __breturn // main::@return __breturn: // [10] return rts } // File Data REGISTER UPLIFT POTENTIAL REGISTERS Potential registers zp[1]:2 [ main::i#2 main::i#1 ] : zp[1]:2 , reg byte a , reg byte x , reg byte y , REGISTER UPLIFT SCOPES Uplift Scope [main] 286.17: zp[1]:2 [ main::i#2 main::i#1 ] Uplift Scope [] Uplifting [main] best 338 combination reg byte x [ main::i#2 main::i#1 ] Uplifting [] best 338 combination ASSEMBLER BEFORE OPTIMIZATION // File Comments // Minimal if() test // Upstart .pc = $801 "Basic" :BasicUpstart(main) .pc = $80d "Program" // Global Constants & labels .label SCREEN = $400 // @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: { // [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::@2 to main::@1 [phi:main::@2->main::@1] __b1_from___b2: // [5] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@2->main::@1#0] -- register_copy jmp __b1 // main::@1 __b1: // [6] if((byte) main::i#2>=(byte) $32) goto main::@2 -- vbuxx_ge_vbuc1_then_la1 cpx #$32 bcs __b2 jmp __b3 // main::@3 __b3: // [7] *((const byte*) SCREEN) ← (byte) main::i#2 -- _deref_pbuc1=vbuxx stx SCREEN jmp __b2 // main::@2 __b2: // [8] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuxx=_inc_vbuxx inx // [9] if((byte) main::i#1<(byte) $64) goto main::@1 -- vbuxx_lt_vbuc1_then_la1 cpx #$64 bcc __b1_from___b2 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 __b3 Removing instruction jmp __b2 Removing instruction jmp __breturn Succesful ASM optimization Pass5NextJumpElimination Replacing label __b1_from___b2 with __b1 Removing instruction __b1_from___bbegin: Removing instruction __b1: Removing instruction main_from___b1: Removing instruction __bend_from___b1: Removing instruction __b1_from___b2: Succesful ASM optimization Pass5RedundantLabelElimination Removing instruction __bbegin: Removing instruction __bend: Removing instruction __b1_from_main: Removing instruction __b3: Removing instruction __breturn: Succesful ASM optimization Pass5UnusedLabelElimination Removing instruction jsr main Succesful ASM optimization Pass5SkipBegin Removing instruction jmp __b1 Succesful ASM optimization Pass5NextJumpElimination FINAL SYMBOL TABLE (label) @1 (label) @begin (label) @end (const byte*) SCREEN = (byte*) 1024 (void()) main() (label) main::@1 (label) main::@2 (label) main::@3 (label) main::@return (byte) main::i (byte) main::i#1 reg byte x 151.5 (byte) main::i#2 reg byte x 134.66666666666666 reg byte x [ main::i#2 main::i#1 ] FINAL ASSEMBLER Score: 176 // File Comments // Minimal if() test // Upstart .pc = $801 "Basic" :BasicUpstart(main) .pc = $80d "Program" // Global Constants & labels .label SCREEN = $400 // @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: { // [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::@2 to main::@1 [phi:main::@2->main::@1] // [5] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@2->main::@1#0] -- register_copy // main::@1 __b1: // if(i<50) // [6] if((byte) main::i#2>=(byte) $32) goto main::@2 -- vbuxx_ge_vbuc1_then_la1 cpx #$32 bcs __b2 // main::@3 // *SCREEN = i // [7] *((const byte*) SCREEN) ← (byte) main::i#2 -- _deref_pbuc1=vbuxx stx SCREEN // main::@2 __b2: // while(++i<100) // [8] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuxx=_inc_vbuxx inx // [9] if((byte) main::i#1<(byte) $64) goto main::@1 -- vbuxx_lt_vbuc1_then_la1 cpx #$64 bcc __b1 // main::@return // } // [10] return rts } // File Data