Culled Empty Block (label) @1 Culled Empty Block (label) popup_selector::@4 Culled Empty Block (label) popup_selector::@3 Culled Empty Block (label) popup_selector::@5 Culled Empty Block (label) popup_selector::@6 CONTROL FLOW GRAPH SSA @begin: scope:[] from (byte*) screen ← ((byte*)) (number) $400 (byte) opcode#0 ← (byte) 'a' to:@2 (void()) main() main: scope:[main] from @2 (byte) opcode#6 ← phi( @2/(byte) opcode#11 ) *((byte*) screen + (number) $28) ← (byte) opcode#6 call popup_selector to:main::@1 main::@1: scope:[main] from main (byte) opcode#7 ← phi( main/(byte) opcode#4 ) (byte) opcode#1 ← (byte) opcode#7 *((byte*) screen + (number) $29) ← (byte) opcode#1 to:main::@return main::@return: scope:[main] from main::@1 (byte) opcode#8 ← phi( main::@1/(byte) opcode#1 ) (byte) opcode#2 ← (byte) opcode#8 return to:@return (void()) popup_selector() popup_selector: scope:[popup_selector] from main (byte) opcode#13 ← phi( main/(byte) opcode#6 ) (byte) popup_selector::k#0 ← (number) 0 to:popup_selector::@1 popup_selector::@1: scope:[popup_selector] from popup_selector popup_selector::@2 (byte) opcode#12 ← phi( popup_selector/(byte) opcode#13 popup_selector::@2/(byte) opcode#3 ) (byte) popup_selector::k#2 ← phi( popup_selector/(byte) popup_selector::k#0 popup_selector::@2/(byte) popup_selector::k#1 ) (bool~) popup_selector::$0 ← (byte) popup_selector::k#2 <= (number) 2 if((bool~) popup_selector::$0) goto popup_selector::@2 to:popup_selector::@return popup_selector::@2: scope:[popup_selector] from popup_selector::@1 (byte) popup_selector::k#3 ← phi( popup_selector::@1/(byte) popup_selector::k#2 ) (byte) opcode#3 ← (byte) 'b' *((byte*) screen + (byte) popup_selector::k#3) ← (byte) opcode#3 (byte) popup_selector::k#1 ← ++ (byte) popup_selector::k#3 to:popup_selector::@1 popup_selector::@return: scope:[popup_selector] from popup_selector::@1 (byte) opcode#9 ← phi( popup_selector::@1/(byte) opcode#12 ) (byte) opcode#4 ← (byte) opcode#9 return to:@return @2: scope:[] from @begin (byte) opcode#11 ← phi( @begin/(byte) opcode#0 ) call main to:@3 @3: scope:[] from @2 (byte) opcode#10 ← phi( @2/(byte) opcode#2 ) (byte) opcode#5 ← (byte) opcode#10 to:@end @end: scope:[] from @3 SYMBOL TABLE SSA (label) @2 (label) @3 (label) @begin (label) @end (void()) main() (label) main::@1 (label) main::@return (byte) opcode (byte) opcode#0 (byte) opcode#1 (byte) opcode#10 (byte) opcode#11 (byte) opcode#12 (byte) opcode#13 (byte) opcode#2 (byte) opcode#3 (byte) opcode#4 (byte) opcode#5 (byte) opcode#6 (byte) opcode#7 (byte) opcode#8 (byte) opcode#9 (void()) popup_selector() (bool~) popup_selector::$0 (label) popup_selector::@1 (label) popup_selector::@2 (label) popup_selector::@return (byte) popup_selector::k (byte) popup_selector::k#0 (byte) popup_selector::k#1 (byte) popup_selector::k#2 (byte) popup_selector::k#3 (byte*) screen Adding number conversion cast (unumber) $28 in *((byte*) screen + (number) $28) ← (byte) opcode#6 Adding number conversion cast (unumber) $29 in *((byte*) screen + (number) $29) ← (byte) opcode#1 Adding number conversion cast (unumber) 0 in (byte) popup_selector::k#0 ← (number) 0 Adding number conversion cast (unumber) 2 in (bool~) popup_selector::$0 ← (byte) popup_selector::k#2 <= (number) 2 Successful SSA optimization PassNAddNumberTypeConversions Inlining cast (byte*) screen ← (byte*)(number) $400 Inlining cast (byte) popup_selector::k#0 ← (unumber)(number) 0 Successful SSA optimization Pass2InlineCast Simplifying constant pointer cast (byte*) 1024 Simplifying constant integer cast $28 Simplifying constant integer cast $29 Simplifying constant integer cast 0 Simplifying constant integer cast 2 Successful SSA optimization PassNCastSimplification Finalized unsigned number type (byte) $28 Finalized unsigned number type (byte) $29 Finalized unsigned number type (byte) 0 Finalized unsigned number type (byte) 2 Successful SSA optimization PassNFinalizeNumberTypeConversions Alias (byte) opcode#1 = (byte) opcode#7 (byte) opcode#8 (byte) opcode#2 Alias (byte) popup_selector::k#2 = (byte) popup_selector::k#3 Alias (byte) opcode#12 = (byte) opcode#9 (byte) opcode#4 Alias (byte) opcode#0 = (byte) opcode#11 Alias (byte) opcode#10 = (byte) opcode#5 Successful SSA optimization Pass2AliasElimination Identical Phi Values (byte) opcode#6 (byte) opcode#0 Identical Phi Values (byte) opcode#1 (byte) opcode#12 Identical Phi Values (byte) opcode#13 (byte) opcode#6 Identical Phi Values (byte) opcode#10 (byte) opcode#1 Successful SSA optimization Pass2IdenticalPhiElimination Simple Condition (bool~) popup_selector::$0 [15] if((byte) popup_selector::k#2<=(byte) 2) goto popup_selector::@2 Successful SSA optimization Pass2ConditionalJumpSimplification Constant (const byte*) screen = (byte*) 1024 Constant (const byte) opcode#0 = 'a' Constant (const byte) popup_selector::k#0 = 0 Constant (const byte) opcode#3 = 'b' Successful SSA optimization Pass2ConstantIdentification Rewriting conditional comparison [15] if((byte) popup_selector::k#2<=(byte) 2) goto popup_selector::@2 Adding number conversion cast (unumber) 2+1 in if((byte) popup_selector::k#2<(byte) 2+(number) 1) goto popup_selector::@2 Adding number conversion cast (unumber) 1 in if((byte) popup_selector::k#2<(unumber)(byte) 2+(number) 1) goto popup_selector::@2 Successful SSA optimization PassNAddNumberTypeConversions Simplifying constant integer cast (byte) 2+(unumber)(number) 1 Simplifying constant integer cast 1 Successful SSA optimization PassNCastSimplification Finalized unsigned number type (byte) 1 Successful SSA optimization PassNFinalizeNumberTypeConversions Inlining constant with var siblings (const byte) popup_selector::k#0 Inlining constant with var siblings (const byte) opcode#0 Inlining constant with var siblings (const byte) opcode#3 Constant inlined opcode#3 = (byte) 'b' Constant inlined opcode#0 = (byte) 'a' Constant inlined popup_selector::k#0 = (byte) 0 Successful SSA optimization Pass2ConstantInlining Consolidated array index constant in *(screen+$28) Consolidated array index constant in *(screen+$29) Successful SSA optimization Pass2ConstantAdditionElimination Adding NOP phi() at start of @begin Adding NOP phi() at start of @2 Adding NOP phi() at start of @3 Adding NOP phi() at start of @end Adding NOP phi() at start of popup_selector CALL GRAPH Calls in [] to main:2 Calls in [main] to popup_selector:6 Created 2 initial phi equivalence classes Coalesced [15] popup_selector::k#4 ← popup_selector::k#1 Coalesced down to 2 phi equivalence classes Culled Empty Block (label) @3 Renumbering block @2 to @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 popup_selector 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) $28) ← (byte) 'a' [5] call popup_selector to:main::@1 main::@1: scope:[main] from main [6] *((const byte*) screen+(byte) $29) ← (byte) opcode#12 to:main::@return main::@return: scope:[main] from main::@1 [7] return to:@return (void()) popup_selector() popup_selector: scope:[popup_selector] from main [8] phi() to:popup_selector::@1 popup_selector::@1: scope:[popup_selector] from popup_selector popup_selector::@2 [9] (byte) opcode#12 ← phi( popup_selector/(byte) 'a' popup_selector::@2/(byte) 'b' ) [9] (byte) popup_selector::k#2 ← phi( popup_selector/(byte) 0 popup_selector::@2/(byte) popup_selector::k#1 ) [10] if((byte) popup_selector::k#2<(byte) 2+(byte) 1) goto popup_selector::@2 to:popup_selector::@return popup_selector::@return: scope:[popup_selector] from popup_selector::@1 [11] return to:@return popup_selector::@2: scope:[popup_selector] from popup_selector::@1 [12] *((const byte*) screen + (byte) popup_selector::k#2) ← (byte) 'b' [13] (byte) popup_selector::k#1 ← ++ (byte) popup_selector::k#2 to:popup_selector::@1 VARIABLE REGISTER WEIGHTS (void()) main() (byte) opcode (byte) opcode#12 0.5 (void()) popup_selector() (byte) popup_selector::k (byte) popup_selector::k#1 22.0 (byte) popup_selector::k#2 14.666666666666666 Initial phi equivalence classes [ popup_selector::k#2 popup_selector::k#1 ] [ opcode#12 ] Complete equivalence classes [ popup_selector::k#2 popup_selector::k#1 ] [ opcode#12 ] Allocated zp ZP_BYTE:2 [ popup_selector::k#2 popup_selector::k#1 ] Allocated zp ZP_BYTE:3 [ opcode#12 ] INITIAL ASM Target platform is c64basic / MOS6502X // File Comments // Demonstrates a problem where constant loophead unrolling results in an error // The result is a NullPointerException // The cause is that the Unroller does not handle the variable opcode correctly. // The Unroller gets the verwions for opcode wrong because it misses the fact that it is modified inside call to popup_selector() // Upstart .pc = $801 "Basic" :BasicUpstart(bbegin) .pc = $80d "Program" // Global Constants & labels .label screen = $400 .label opcode = 3 // @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 // Offending unroll variable main: { // [4] *((const byte*) screen+(byte) $28) ← (byte) 'a' -- _deref_pbuc1=vbuc2 lda #'a' sta screen+$28 // [5] call popup_selector // [8] phi from main to popup_selector [phi:main->popup_selector] popup_selector_from_main: jsr popup_selector jmp b1 // main::@1 b1: // [6] *((const byte*) screen+(byte) $29) ← (byte) opcode#12 -- _deref_pbuc1=vbuz1 lda.z opcode sta screen+$29 jmp breturn // main::@return breturn: // [7] return rts } // popup_selector popup_selector: { .label k = 2 // [9] phi from popup_selector to popup_selector::@1 [phi:popup_selector->popup_selector::@1] b1_from_popup_selector: // [9] phi (byte) opcode#12 = (byte) 'a' [phi:popup_selector->popup_selector::@1#0] -- vbuz1=vbuc1 lda #'a' sta.z opcode // [9] phi (byte) popup_selector::k#2 = (byte) 0 [phi:popup_selector->popup_selector::@1#1] -- vbuz1=vbuc1 lda #0 sta.z k jmp b1 // popup_selector::@1 b1: // [10] if((byte) popup_selector::k#2<(byte) 2+(byte) 1) goto popup_selector::@2 -- vbuz1_lt_vbuc1_then_la1 lda.z k cmp #2+1 bcc b2 jmp breturn // popup_selector::@return breturn: // [11] return rts // popup_selector::@2 b2: // [12] *((const byte*) screen + (byte) popup_selector::k#2) ← (byte) 'b' -- pbuc1_derefidx_vbuz1=vbuc2 lda #'b' ldy.z k sta screen,y // [13] (byte) popup_selector::k#1 ← ++ (byte) popup_selector::k#2 -- vbuz1=_inc_vbuz1 inc.z k // [9] phi from popup_selector::@2 to popup_selector::@1 [phi:popup_selector::@2->popup_selector::@1] b1_from_b2: // [9] phi (byte) opcode#12 = (byte) 'b' [phi:popup_selector::@2->popup_selector::@1#0] -- vbuz1=vbuc1 lda #'b' sta.z opcode // [9] phi (byte) popup_selector::k#2 = (byte) popup_selector::k#1 [phi:popup_selector::@2->popup_selector::@1#1] -- register_copy jmp b1 } // File Data REGISTER UPLIFT POTENTIAL REGISTERS Statement [4] *((const byte*) screen+(byte) $28) ← (byte) 'a' [ ] ( main:2 [ ] ) always clobbers reg byte a Statement [12] *((const byte*) screen + (byte) popup_selector::k#2) ← (byte) 'b' [ popup_selector::k#2 ] ( main:2::popup_selector:5 [ popup_selector::k#2 ] ) always clobbers reg byte a Removing always clobbered register reg byte a as potential for zp ZP_BYTE:2 [ popup_selector::k#2 popup_selector::k#1 ] Statement [4] *((const byte*) screen+(byte) $28) ← (byte) 'a' [ ] ( main:2 [ ] ) always clobbers reg byte a Statement [12] *((const byte*) screen + (byte) popup_selector::k#2) ← (byte) 'b' [ popup_selector::k#2 ] ( main:2::popup_selector:5 [ popup_selector::k#2 ] ) always clobbers reg byte a Potential registers zp ZP_BYTE:2 [ popup_selector::k#2 popup_selector::k#1 ] : zp ZP_BYTE:2 , reg byte x , reg byte y , Potential registers zp ZP_BYTE:3 [ opcode#12 ] : zp ZP_BYTE:3 , reg byte a , reg byte x , reg byte y , REGISTER UPLIFT SCOPES Uplift Scope [popup_selector] 36.67: zp ZP_BYTE:2 [ popup_selector::k#2 popup_selector::k#1 ] Uplift Scope [] 0.5: zp ZP_BYTE:3 [ opcode#12 ] Uplift Scope [main] Uplifting [popup_selector] best 394 combination reg byte x [ popup_selector::k#2 popup_selector::k#1 ] Uplifting [] best 331 combination reg byte a [ opcode#12 ] Uplifting [main] best 331 combination ASSEMBLER BEFORE OPTIMIZATION // File Comments // Demonstrates a problem where constant loophead unrolling results in an error // The result is a NullPointerException // The cause is that the Unroller does not handle the variable opcode correctly. // The Unroller gets the verwions for opcode wrong because it misses the fact that it is modified inside call to popup_selector() // 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 // Offending unroll variable main: { // [4] *((const byte*) screen+(byte) $28) ← (byte) 'a' -- _deref_pbuc1=vbuc2 lda #'a' sta screen+$28 // [5] call popup_selector // [8] phi from main to popup_selector [phi:main->popup_selector] popup_selector_from_main: jsr popup_selector jmp b1 // main::@1 b1: // [6] *((const byte*) screen+(byte) $29) ← (byte) opcode#12 -- _deref_pbuc1=vbuaa sta screen+$29 jmp breturn // main::@return breturn: // [7] return rts } // popup_selector popup_selector: { // [9] phi from popup_selector to popup_selector::@1 [phi:popup_selector->popup_selector::@1] b1_from_popup_selector: // [9] phi (byte) opcode#12 = (byte) 'a' [phi:popup_selector->popup_selector::@1#0] -- vbuaa=vbuc1 lda #'a' // [9] phi (byte) popup_selector::k#2 = (byte) 0 [phi:popup_selector->popup_selector::@1#1] -- vbuxx=vbuc1 ldx #0 jmp b1 // popup_selector::@1 b1: // [10] if((byte) popup_selector::k#2<(byte) 2+(byte) 1) goto popup_selector::@2 -- vbuxx_lt_vbuc1_then_la1 cpx #2+1 bcc b2 jmp breturn // popup_selector::@return breturn: // [11] return rts // popup_selector::@2 b2: // [12] *((const byte*) screen + (byte) popup_selector::k#2) ← (byte) 'b' -- pbuc1_derefidx_vbuxx=vbuc2 lda #'b' sta screen,x // [13] (byte) popup_selector::k#1 ← ++ (byte) popup_selector::k#2 -- vbuxx=_inc_vbuxx inx // [9] phi from popup_selector::@2 to popup_selector::@1 [phi:popup_selector::@2->popup_selector::@1] b1_from_b2: // [9] phi (byte) opcode#12 = (byte) 'b' [phi:popup_selector::@2->popup_selector::@1#0] -- vbuaa=vbuc1 lda #'b' // [9] phi (byte) popup_selector::k#2 = (byte) popup_selector::k#1 [phi:popup_selector::@2->popup_selector::@1#1] -- register_copy jmp b1 } // File Data ASSEMBLER OPTIMIZATIONS Removing instruction jmp b1 Removing instruction jmp bend Removing instruction jmp b1 Removing instruction jmp breturn Removing instruction jmp b1 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 popup_selector_from_main: Removing instruction b1: Removing instruction breturn: Removing instruction b1_from_popup_selector: Removing instruction breturn: Removing instruction b1_from_b2: Succesful ASM optimization Pass5UnusedLabelElimination Updating BasicUpstart to call main directly Removing instruction jsr main Succesful ASM optimization Pass5SkipBegin Removing instruction lda #'b' Succesful ASM optimization Pass5UnnecesaryLoadElimination 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) opcode (byte) opcode#12 reg byte a 0.5 (void()) popup_selector() (label) popup_selector::@1 (label) popup_selector::@2 (label) popup_selector::@return (byte) popup_selector::k (byte) popup_selector::k#1 reg byte x 22.0 (byte) popup_selector::k#2 reg byte x 14.666666666666666 (const byte*) screen screen = (byte*) 1024 reg byte x [ popup_selector::k#2 popup_selector::k#1 ] reg byte a [ opcode#12 ] FINAL ASSEMBLER Score: 233 // File Comments // Demonstrates a problem where constant loophead unrolling results in an error // The result is a NullPointerException // The cause is that the Unroller does not handle the variable opcode correctly. // The Unroller gets the verwions for opcode wrong because it misses the fact that it is modified inside call to popup_selector() // 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 // Offending unroll variable main: { // screen[40] = opcode // [4] *((const byte*) screen+(byte) $28) ← (byte) 'a' -- _deref_pbuc1=vbuc2 lda #'a' sta screen+$28 // popup_selector() // [5] call popup_selector // [8] phi from main to popup_selector [phi:main->popup_selector] jsr popup_selector // main::@1 // screen[41] = opcode // [6] *((const byte*) screen+(byte) $29) ← (byte) opcode#12 -- _deref_pbuc1=vbuaa sta screen+$29 // main::@return // } // [7] return rts } // popup_selector popup_selector: { // [9] phi from popup_selector to popup_selector::@1 [phi:popup_selector->popup_selector::@1] // [9] phi (byte) opcode#12 = (byte) 'a' [phi:popup_selector->popup_selector::@1#0] -- vbuaa=vbuc1 lda #'a' // [9] phi (byte) popup_selector::k#2 = (byte) 0 [phi:popup_selector->popup_selector::@1#1] -- vbuxx=vbuc1 ldx #0 // popup_selector::@1 b1: // for (byte k = 0; k <= 2; k++) // [10] if((byte) popup_selector::k#2<(byte) 2+(byte) 1) goto popup_selector::@2 -- vbuxx_lt_vbuc1_then_la1 cpx #2+1 bcc b2 // popup_selector::@return // } // [11] return rts // popup_selector::@2 b2: // screen[k] = opcode // [12] *((const byte*) screen + (byte) popup_selector::k#2) ← (byte) 'b' -- pbuc1_derefidx_vbuxx=vbuc2 lda #'b' sta screen,x // for (byte k = 0; k <= 2; k++) // [13] (byte) popup_selector::k#1 ← ++ (byte) popup_selector::k#2 -- vbuxx=_inc_vbuxx inx // [9] phi from popup_selector::@2 to popup_selector::@1 [phi:popup_selector::@2->popup_selector::@1] // [9] phi (byte) opcode#12 = (byte) 'b' [phi:popup_selector::@2->popup_selector::@1#0] -- vbuaa=vbuc1 // [9] phi (byte) popup_selector::k#2 = (byte) popup_selector::k#1 [phi:popup_selector::@2->popup_selector::@1#1] -- register_copy jmp b1 } // File Data