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::i#0 ← (number) 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 ) *((byte*) main::SCREEN#0 + (byte) main::i#2) ← (byte) main::i#2 (byte) main::i#1 ← ++ (byte) main::i#2 (bool~) main::$0 ← (byte) main::i#1 < (number) $a if((bool~) main::$0) 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() (bool~) main::$0 (label) main::@1 (label) main::@return (byte*) main::SCREEN (byte*) main::SCREEN#0 (byte) main::i (byte) main::i#0 (byte) main::i#1 (byte) main::i#2 Adding number conversion cast (unumber) 0 in (byte) main::i#0 ← (number) 0 Adding number conversion cast (unumber) $a in (bool~) main::$0 ← (byte) main::i#1 < (number) $a Successful SSA optimization PassNAddNumberTypeConversions Inlining cast (byte*) main::SCREEN#0 ← (byte*)(number) $400 Inlining cast (byte) main::i#0 ← (unumber)(number) 0 Successful SSA optimization Pass2InlineCast Simplifying constant pointer cast (byte*) 1024 Simplifying constant integer cast 0 Simplifying constant integer cast $a Successful SSA optimization PassNCastSimplification Finalized unsigned number type (byte) 0 Finalized unsigned number type (byte) $a Successful SSA optimization PassNFinalizeNumberTypeConversions Simple Condition (bool~) main::$0 [6] if((byte) main::i#1<(byte) $a) goto main::@1 Successful SSA optimization Pass2ConditionalJumpSimplification Constant (const byte*) main::SCREEN#0 = (byte*) 1024 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::@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 [11] main::i#3 ← main::i#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::i#2 ← phi( main/(byte) 0 main::@1/(byte) main::i#1 ) [6] *((const byte*) main::SCREEN#0 + (byte) main::i#2) ← (byte) main::i#2 [7] (byte) main::i#1 ← ++ (byte) main::i#2 [8] if((byte) main::i#1<(byte) $a) goto main::@1 to:main::@return main::@return: scope:[main] from main::@1 [9] return to:@return VARIABLE REGISTER WEIGHTS (void()) main() (byte*) main::SCREEN (byte) main::i (byte) main::i#1 16.5 (byte) main::i#2 22.0 Initial phi equivalence classes [ main::i#2 main::i#1 ] Complete equivalence classes [ main::i#2 main::i#1 ] Allocated zp ZP_BYTE:2 [ main::i#2 main::i#1 ] INITIAL ASM Target platform is c64basic // File Comments // Tests that for()-loops can have empty increments // 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 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 i jmp b1 // [5] phi from main::@1 to main::@1 [phi:main::@1->main::@1] b1_from_b1: // [5] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@1->main::@1#0] -- register_copy jmp b1 // main::@1 b1: // [6] *((const byte*) main::SCREEN#0 + (byte) main::i#2) ← (byte) main::i#2 -- pbuc1_derefidx_vbuz1=vbuz1 ldy i tya sta SCREEN,y // [7] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuz1=_inc_vbuz1 inc i // [8] if((byte) main::i#1<(byte) $a) goto main::@1 -- vbuz1_lt_vbuc1_then_la1 lda i cmp #$a bcc b1_from_b1 jmp breturn // main::@return breturn: // [9] return rts } // File Data REGISTER UPLIFT POTENTIAL REGISTERS Potential registers zp ZP_BYTE:2 [ main::i#2 main::i#1 ] : zp ZP_BYTE:2 , reg byte a , reg byte x , reg byte y , REGISTER UPLIFT SCOPES Uplift Scope [main] 38.5: zp ZP_BYTE:2 [ main::i#2 main::i#1 ] Uplift Scope [] Uplifting [main] best 263 combination reg byte x [ main::i#2 main::i#1 ] Uplifting [] best 263 combination ASSEMBLER BEFORE OPTIMIZATION // File Comments // Tests that for()-loops can have empty increments // 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 // [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::@1 to main::@1 [phi:main::@1->main::@1] b1_from_b1: // [5] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@1->main::@1#0] -- register_copy jmp b1 // main::@1 b1: // [6] *((const byte*) main::SCREEN#0 + (byte) main::i#2) ← (byte) main::i#2 -- pbuc1_derefidx_vbuxx=vbuxx txa sta SCREEN,x // [7] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuxx=_inc_vbuxx inx // [8] if((byte) main::i#1<(byte) $a) goto main::@1 -- vbuxx_lt_vbuc1_then_la1 cpx #$a bcc b1_from_b1 jmp breturn // main::@return breturn: // [9] 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() (label) main::@1 (label) main::@return (byte*) main::SCREEN (const byte*) main::SCREEN#0 SCREEN = (byte*) 1024 (byte) main::i (byte) main::i#1 reg byte x 16.5 (byte) main::i#2 reg byte x 22.0 reg byte x [ main::i#2 main::i#1 ] FINAL ASSEMBLER Score: 161 // File Comments // Tests that for()-loops can have empty increments // 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 // [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::@1 to main::@1 [phi:main::@1->main::@1] // [5] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@1->main::@1#0] -- register_copy // main::@1 b1: // SCREEN[i] = i++ // [6] *((const byte*) main::SCREEN#0 + (byte) main::i#2) ← (byte) main::i#2 -- pbuc1_derefidx_vbuxx=vbuxx txa sta SCREEN,x // SCREEN[i] = i++; // [7] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuxx=_inc_vbuxx inx // for(unsigned char i=0;i<10;) // [8] if((byte) main::i#1<(byte) $a) goto main::@1 -- vbuxx_lt_vbuc1_then_la1 cpx #$a bcc b1 // main::@return // } // [9] return rts } // File Data