CONTROL FLOW GRAPH SSA @begin: scope:[] from (byte*) SCREEN ← ((byte*)) (number) $400 to:@1 (void()) main() main: scope:[main] from @1 *((byte*) SCREEN) ← (byte) 'a' to:main::@return main::@return: scope:[main] from main 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 (byte*) SCREEN (void()) main() (label) main::@return Inlining cast (byte*) SCREEN ← (byte*)(number) $400 Successful SSA optimization Pass2InlineCast Simplifying constant pointer cast (byte*) 1024 Successful SSA optimization PassNCastSimplification Constant (const byte*) SCREEN = (byte*) 1024 Successful SSA optimization Pass2ConstantIdentification 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 CALL GRAPH Calls in [] to main:2 Created 0 initial phi equivalence classes Coalesced down to 0 phi equivalence classes Culled Empty Block (label) @2 Adding NOP phi() at start of @begin Adding NOP phi() at start of @1 Adding NOP phi() at start of @end 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] *((const byte*) SCREEN) ← (byte) 'a' to:main::@return main::@return: scope:[main] from main [5] return to:@return VARIABLE REGISTER WEIGHTS (void()) main() Initial phi equivalence classes Complete equivalence classes INITIAL ASM Target platform is c64basic / MOS6502X // File Comments // Tests that single-line comments are only included once in the output // Upstart .pc = $801 "Basic" :BasicUpstart(bbegin) .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 jsr main // [3] phi from @1 to @end [phi:@1->@end] bend_from_b1: jmp bend // @end bend: // main // The program entry point main: { // [4] *((const byte*) SCREEN) ← (byte) 'a' -- _deref_pbuc1=vbuc2 lda #'a' sta SCREEN jmp breturn // main::@return breturn: // [5] return rts } // File Data REGISTER UPLIFT POTENTIAL REGISTERS Statement [4] *((const byte*) SCREEN) ← (byte) 'a' [ ] ( main:2 [ ] ) always clobbers reg byte a REGISTER UPLIFT SCOPES Uplift Scope [main] Uplift Scope [] Uplifting [main] best 27 combination Uplifting [] best 27 combination ASSEMBLER BEFORE OPTIMIZATION // File Comments // Tests that single-line comments are only included once in the output // Upstart .pc = $801 "Basic" :BasicUpstart(bbegin) .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 jsr main // [3] phi from @1 to @end [phi:@1->@end] bend_from_b1: jmp bend // @end bend: // main // The program entry point main: { // [4] *((const byte*) SCREEN) ← (byte) 'a' -- _deref_pbuc1=vbuc2 lda #'a' sta SCREEN jmp breturn // main::@return breturn: // [5] return rts } // File Data ASSEMBLER OPTIMIZATIONS Removing instruction jmp b1 Removing instruction jmp bend Removing instruction jmp breturn Succesful ASM optimization Pass5NextJumpElimination Removing instruction b1_from_bbegin: Removing instruction b1: Removing instruction bend_from_b1: Succesful ASM optimization Pass5RedundantLabelElimination Removing instruction bend: Removing instruction breturn: Succesful ASM optimization Pass5UnusedLabelElimination Updating BasicUpstart to call main directly Removing instruction jsr main Succesful ASM optimization Pass5SkipBegin Removing instruction bbegin: Succesful ASM optimization Pass5UnusedLabelElimination FINAL SYMBOL TABLE (label) @1 (label) @begin (label) @end (const byte*) SCREEN SCREEN = (byte*) 1024 (void()) main() (label) main::@return FINAL ASSEMBLER Score: 12 // File Comments // Tests that single-line comments are only included once in the output // 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 // [3] phi from @1 to @end [phi:@1->@end] // @end // main // The program entry point main: { // *SCREEN = 'a' // [4] *((const byte*) SCREEN) ← (byte) 'a' -- _deref_pbuc1=vbuc2 lda #'a' sta SCREEN // main::@return // } // [5] return rts } // File Data