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Fixed clobber problem that can occur during PHI transitions. Closes #10

This commit is contained in:
jespergravgaard 2019-03-09 18:37:23 +01:00
parent 4d8e083a21
commit 5a83c1b357
10 changed files with 897 additions and 33 deletions

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@ -79,14 +79,18 @@ public class Pass4AssertNoCpuClobber extends Pass2Base {
PhiTransitions phiTransitions = new PhiTransitions(getProgram(), statementBlock);
PhiTransitions.PhiTransition phiTransition = phiTransitions.getTransition(phiTransitionId);
for(PhiTransitions.PhiTransition.PhiAssignment phiAssignment : phiTransition.getAssignments()) {
// IF the assignment is later than the current one
if(phiAssignment.getAssignmentIdx() > transitionAssignmentIdx) {
// IF the assignment is later than the current one
RValue rValue = phiAssignment.getrValue();
Collection<VariableRef> alive = VariableReferenceInfos.getReferencedVars(rValue);
aliveVars.addAll(alive);
VariableRef assignedVar = phiAssignment.getVariable();
assignedVars.remove(assignedVar);
alive.remove(assignedVar);
} else if(phiAssignment.getAssignmentIdx() < transitionAssignmentIdx) {
// IF the assignment is before the current one
VariableRef assignedVar = phiAssignment.getVariable();
assignedVars.remove(assignedVar);
}
}
}

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@ -44,6 +44,11 @@ public class TestPrograms {
AsmFragmentTemplateUsages.logUsages(log, false, false, false, false, false, false);
}
@Test
public void testClobberProblem() throws IOException, URISyntaxException {
compileAndCompare("scrollbig-clobber");
}
@Test
public void testComparisonsSWord() throws IOException, URISyntaxException {
compileAndCompare("test-comparisons-sword");

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@ -0,0 +1,24 @@
// Clobber problem in next_char return value
byte* TEXT = "cml @";
void main() {
byte* SCREEN = $400;
for( byte i: 0..255) {
SCREEN[i] = next_char();
}
}
byte* nxt = TEXT;
// Find the next char of the text
byte next_char() {
byte c = *nxt;
if(c=='@') {
nxt = TEXT;
c = *nxt;
}
nxt++;
return c;
}

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@ -57,6 +57,7 @@ scroll_bit: {
cmp #0
bne b1
jsr next_char
txa
sta c
lda #0
sta c+1
@ -143,9 +144,10 @@ scroll_hard: {
next_char: {
ldy #0
lda (nxt),y
cmp #'@'
tax
cpx #'@'
bne b1
lda TEXT
ldx TEXT
lda #<TEXT
sta nxt
lda #>TEXT

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@ -2104,13 +2104,13 @@ Limited combination testing to 100 combinations of 512 possible.
Uplifting [scroll_hard] best 24938 combination reg byte x [ scroll_hard::i#2 scroll_hard::i#1 ]
Uplifting [] best 24626 combination zp ZP_WORD:4 [ current_chargen#27 current_chargen#11 current_chargen#19 current_chargen#5 ] zp ZP_BYTE:3 [ current_bit#29 current_bit#12 current_bit#21 current_bit#5 ] zp ZP_WORD:11 [ nxt#18 nxt#31 nxt#14 nxt#36 nxt#19 ] reg byte x [ scroll#18 scroll#10 scroll#3 ]
Uplifting [fillscreen] best 24626 combination zp ZP_WORD:14 [ fillscreen::cursor#2 fillscreen::cursor#1 ]
Uplifting [next_char] best 24608 combination reg byte a [ next_char::return#1 next_char::c#0 next_char::c#1 ] reg byte a [ next_char::return#0 ]
Uplifting [main] best 24608 combination
Uplifting [scroll_soft] best 24608 combination
Uplifting [next_char] best 24610 combination reg byte x [ next_char::return#1 next_char::c#0 next_char::c#1 ] reg byte x [ next_char::return#0 ]
Uplifting [main] best 24610 combination
Uplifting [scroll_soft] best 24610 combination
Attempting to uplift remaining variables inzp ZP_BYTE:3 [ current_bit#29 current_bit#12 current_bit#21 current_bit#5 ]
Uplifting [] best 24608 combination zp ZP_BYTE:3 [ current_bit#29 current_bit#12 current_bit#21 current_bit#5 ]
Uplifting [] best 24610 combination zp ZP_BYTE:3 [ current_bit#29 current_bit#12 current_bit#21 current_bit#5 ]
Attempting to uplift remaining variables inzp ZP_BYTE:17 [ scroll_bit::$3 ]
Uplifting [scroll_bit] best 24602 combination reg byte a [ scroll_bit::$3 ]
Uplifting [scroll_bit] best 24606 combination reg byte a [ scroll_bit::$3 ]
Coalescing zero page register with common assignment [ zp ZP_WORD:4 [ current_chargen#27 current_chargen#11 current_chargen#19 current_chargen#5 ] ] with [ zp ZP_WORD:20 [ scroll_bit::$4 ] ] - score: 1
Coalescing zero page register with common assignment [ zp ZP_WORD:4 [ current_chargen#27 current_chargen#11 current_chargen#19 current_chargen#5 scroll_bit::$4 ] ] with [ zp ZP_WORD:18 [ scroll_bit::c#0 ] ] - score: 1
Coalescing zero page register [ zp ZP_WORD:4 [ current_chargen#27 current_chargen#11 current_chargen#19 current_chargen#5 scroll_bit::$4 scroll_bit::c#0 ] ] with [ zp ZP_WORD:14 [ fillscreen::cursor#2 fillscreen::cursor#1 ] ]
@ -2274,7 +2274,8 @@ scroll_bit: {
jmp b8
//SEG60 scroll_bit::@8
b8:
//SEG61 [24] (byte~) scroll_bit::$3 ← (byte) next_char::return#0
//SEG61 [24] (byte~) scroll_bit::$3 ← (byte) next_char::return#0 -- vbuaa=vbuxx
txa
//SEG62 [25] (word) scroll_bit::c#0 ← ((word)) (byte~) scroll_bit::$3 -- vwuz1=_word_vbuaa
sta c
lda #0
@ -2447,17 +2448,18 @@ scroll_hard: {
//SEG123 next_char
// Find the next char of the scroll text
next_char: {
//SEG124 [58] (byte) next_char::c#0 ← *((byte*) nxt#31) -- vbuaa=_deref_pbuz1
//SEG124 [58] (byte) next_char::c#0 ← *((byte*) nxt#31) -- vbuxx=_deref_pbuz1
ldy #0
lda (nxt),y
//SEG125 [59] if((byte) next_char::c#0!=(byte) '@') goto next_char::@1 -- vbuaa_neq_vbuc1_then_la1
cmp #'@'
tax
//SEG125 [59] if((byte) next_char::c#0!=(byte) '@') goto next_char::@1 -- vbuxx_neq_vbuc1_then_la1
cpx #'@'
bne b1_from_next_char
jmp b2
//SEG126 next_char::@2
b2:
//SEG127 [60] (byte) next_char::c#1 ← *((const byte*) TEXT#0) -- vbuaa=_deref_pbuc1
lda TEXT
//SEG127 [60] (byte) next_char::c#1 ← *((const byte*) TEXT#0) -- vbuxx=_deref_pbuc1
ldx TEXT
//SEG128 [61] phi from next_char::@2 to next_char::@1 [phi:next_char::@2->next_char::@1]
b1_from_b2:
//SEG129 [61] phi (byte) next_char::return#1 = (byte) next_char::c#1 [phi:next_char::@2->next_char::@1#0] -- register_copy
@ -2670,11 +2672,11 @@ FINAL SYMBOL TABLE
(label) next_char::@2
(label) next_char::@return
(byte) next_char::c
(byte) next_char::c#0 reg byte a 3.0
(byte) next_char::c#1 reg byte a 4.0
(byte) next_char::c#0 reg byte x 3.0
(byte) next_char::c#1 reg byte x 4.0
(byte) next_char::return
(byte) next_char::return#0 reg byte a 4.0
(byte) next_char::return#1 reg byte a 1.5
(byte) next_char::return#0 reg byte x 4.0
(byte) next_char::return#1 reg byte x 1.5
(byte*) nxt
(byte*) nxt#14 nxt zp ZP_WORD:7 3.0
(byte*) nxt#18 nxt zp ZP_WORD:7 4.0
@ -2729,15 +2731,15 @@ zp ZP_WORD:5 [ scroll_bit::sc#2 scroll_bit::sc#1 ]
reg byte a [ scroll_bit::b#2 ]
reg byte x [ scroll_hard::i#2 scroll_hard::i#1 ]
zp ZP_WORD:7 [ nxt#18 nxt#31 nxt#14 nxt#36 nxt#19 ]
reg byte a [ next_char::return#1 next_char::c#0 next_char::c#1 ]
reg byte a [ next_char::return#0 ]
reg byte x [ next_char::return#1 next_char::c#0 next_char::c#1 ]
reg byte x [ next_char::return#0 ]
reg byte a [ scroll_bit::$3 ]
reg byte a [ scroll_bit::bits#0 ]
reg byte a [ scroll_bit::$9 ]
FINAL ASSEMBLER
Score: 20822
Score: 20826
//SEG0 File Comments
// An 8x8 char letter scroller
@ -2859,7 +2861,8 @@ scroll_bit: {
jsr next_char
//SEG59 [23] (byte) next_char::return#0 ← (byte) next_char::return#1
//SEG60 scroll_bit::@8
//SEG61 [24] (byte~) scroll_bit::$3 ← (byte) next_char::return#0
//SEG61 [24] (byte~) scroll_bit::$3 ← (byte) next_char::return#0 -- vbuaa=vbuxx
txa
//SEG62 [25] (word) scroll_bit::c#0 ← ((word)) (byte~) scroll_bit::$3 -- vwuz1=_word_vbuaa
sta c
lda #0
@ -3006,15 +3009,16 @@ scroll_hard: {
//SEG123 next_char
// Find the next char of the scroll text
next_char: {
//SEG124 [58] (byte) next_char::c#0 ← *((byte*) nxt#31) -- vbuaa=_deref_pbuz1
//SEG124 [58] (byte) next_char::c#0 ← *((byte*) nxt#31) -- vbuxx=_deref_pbuz1
ldy #0
lda (nxt),y
//SEG125 [59] if((byte) next_char::c#0!=(byte) '@') goto next_char::@1 -- vbuaa_neq_vbuc1_then_la1
cmp #'@'
tax
//SEG125 [59] if((byte) next_char::c#0!=(byte) '@') goto next_char::@1 -- vbuxx_neq_vbuc1_then_la1
cpx #'@'
bne b1
//SEG126 next_char::@2
//SEG127 [60] (byte) next_char::c#1 ← *((const byte*) TEXT#0) -- vbuaa=_deref_pbuc1
lda TEXT
//SEG127 [60] (byte) next_char::c#1 ← *((const byte*) TEXT#0) -- vbuxx=_deref_pbuc1
ldx TEXT
//SEG128 [61] phi from next_char::@2 to next_char::@1 [phi:next_char::@2->next_char::@1]
//SEG129 [61] phi (byte) next_char::return#1 = (byte) next_char::c#1 [phi:next_char::@2->next_char::@1#0] -- register_copy
//SEG130 [61] phi (byte*) nxt#18 = (const byte*) TEXT#0 [phi:next_char::@2->next_char::@1#1] -- pbuz1=pbuc1

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@ -44,11 +44,11 @@
(label) next_char::@2
(label) next_char::@return
(byte) next_char::c
(byte) next_char::c#0 reg byte a 3.0
(byte) next_char::c#1 reg byte a 4.0
(byte) next_char::c#0 reg byte x 3.0
(byte) next_char::c#1 reg byte x 4.0
(byte) next_char::return
(byte) next_char::return#0 reg byte a 4.0
(byte) next_char::return#1 reg byte a 1.5
(byte) next_char::return#0 reg byte x 4.0
(byte) next_char::return#1 reg byte x 1.5
(byte*) nxt
(byte*) nxt#14 nxt zp ZP_WORD:7 3.0
(byte*) nxt#18 nxt zp ZP_WORD:7 4.0
@ -103,8 +103,8 @@ zp ZP_WORD:5 [ scroll_bit::sc#2 scroll_bit::sc#1 ]
reg byte a [ scroll_bit::b#2 ]
reg byte x [ scroll_hard::i#2 scroll_hard::i#1 ]
zp ZP_WORD:7 [ nxt#18 nxt#31 nxt#14 nxt#36 nxt#19 ]
reg byte a [ next_char::return#1 next_char::c#0 next_char::c#1 ]
reg byte a [ next_char::return#0 ]
reg byte x [ next_char::return#1 next_char::c#0 next_char::c#1 ]
reg byte x [ next_char::return#0 ]
reg byte a [ scroll_bit::$3 ]
reg byte a [ scroll_bit::bits#0 ]
reg byte a [ scroll_bit::$9 ]

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@ -0,0 +1,41 @@
// Clobber problem in next_char return value
.pc = $801 "Basic"
:BasicUpstart(main)
.pc = $80d "Program"
.label nxt = 2
main: {
.label SCREEN = $400
ldx #0
lda #<TEXT
sta nxt
lda #>TEXT
sta nxt+1
b1:
jsr next_char
tya
sta SCREEN,x
inx
cpx #0
bne b1
rts
}
// Find the next char of the text
next_char: {
ldy #0
lda (nxt),y
tay
cpy #'@'
bne b1
ldy TEXT
lda #<TEXT
sta nxt
lda #>TEXT
sta nxt+1
b1:
inc nxt
bne !+
inc nxt+1
!:
rts
}
TEXT: .text "cml @"

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@ -0,0 +1,42 @@
@begin: scope:[] from
[0] phi()
to:@2
@2: scope:[] from @begin
[1] phi()
[2] call main
to:@end
@end: scope:[] from @2
[3] phi()
main: scope:[main] from @2
[4] phi()
to:main::@1
main::@1: scope:[main] from main main::@3
[5] (byte) main::i#2 ← phi( main/(byte/signed byte/word/signed word/dword/signed dword) 0 main::@3/(byte) main::i#1 )
[5] (byte*) nxt#13 ← phi( main/(const byte*) TEXT#0 main::@3/(byte*) nxt#11 )
[6] call next_char
[7] (byte) next_char::return#0 ← (byte) next_char::return#1
to:main::@3
main::@3: scope:[main] from main::@1
[8] (byte~) main::$0 ← (byte) next_char::return#0
[9] *((const byte*) main::SCREEN#0 + (byte) main::i#2) ← (byte~) main::$0
[10] (byte) main::i#1 ← ++ (byte) main::i#2
[11] if((byte) main::i#1!=(byte/signed byte/word/signed word/dword/signed dword) 0) goto main::@1
to:main::@return
main::@return: scope:[main] from main::@3
[12] return
to:@return
next_char: scope:[next_char] from main::@1
[13] (byte) next_char::c#0 ← *((byte*) nxt#13)
[14] if((byte) next_char::c#0!=(byte) '@') goto next_char::@1
to:next_char::@2
next_char::@2: scope:[next_char] from next_char
[15] (byte) next_char::c#1 ← *((const byte*) TEXT#0)
to:next_char::@1
next_char::@1: scope:[next_char] from next_char next_char::@2
[16] (byte) next_char::return#1 ← phi( next_char/(byte) next_char::c#0 next_char::@2/(byte) next_char::c#1 )
[16] (byte*) nxt#10 ← phi( next_char/(byte*) nxt#13 next_char::@2/(const byte*) TEXT#0 )
[17] (byte*) nxt#11 ← ++ (byte*) nxt#10
to:next_char::@return
next_char::@return: scope:[next_char] from next_char::@1
[18] return
to:@return

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@ -0,0 +1,707 @@
CONTROL FLOW GRAPH SSA
@begin: scope:[] from
(byte*) TEXT#0 ← (const string) $0
to:@1
main: scope:[main] from @2
(byte*) TEXT#5 ← phi( @2/(byte*) TEXT#7 )
(byte*) nxt#15 ← phi( @2/(byte*) nxt#14 )
(byte*) main::SCREEN#0 ← ((byte*)) (word/signed word/dword/signed dword) $400
(byte) main::i#0 ← (byte/signed byte/word/signed word/dword/signed dword) 0
to:main::@1
main::@1: scope:[main] from main main::@3
(byte*) TEXT#4 ← phi( main/(byte*) TEXT#5 main::@3/(byte*) TEXT#6 )
(byte) main::i#3 ← phi( main/(byte) main::i#0 main::@3/(byte) main::i#1 )
(byte*) main::SCREEN#2 ← phi( main/(byte*) main::SCREEN#0 main::@3/(byte*) main::SCREEN#1 )
(byte*) nxt#13 ← phi( main/(byte*) nxt#15 main::@3/(byte*) nxt#0 )
call next_char
(byte) next_char::return#0 ← (byte) next_char::return#2
to:main::@3
main::@3: scope:[main] from main::@1
(byte*) TEXT#6 ← phi( main::@1/(byte*) TEXT#4 )
(byte) main::i#2 ← phi( main::@1/(byte) main::i#3 )
(byte*) main::SCREEN#1 ← phi( main::@1/(byte*) main::SCREEN#2 )
(byte*) nxt#7 ← phi( main::@1/(byte*) nxt#5 )
(byte) next_char::return#3 ← phi( main::@1/(byte) next_char::return#0 )
(byte~) main::$0 ← (byte) next_char::return#3
(byte*) nxt#0 ← (byte*) nxt#7
*((byte*) main::SCREEN#1 + (byte) main::i#2) ← (byte~) main::$0
(byte) main::i#1 ← (byte) main::i#2 + rangenext(0,$ff)
(bool~) main::$1 ← (byte) main::i#1 != rangelast(0,$ff)
if((bool~) main::$1) goto main::@1
to:main::@return
main::@return: scope:[main] from main::@3
(byte*) nxt#8 ← phi( main::@3/(byte*) nxt#0 )
(byte*) nxt#1 ← (byte*) nxt#8
return
to:@return
@1: scope:[] from @begin
(byte*) TEXT#1 ← phi( @begin/(byte*) TEXT#0 )
(byte*) nxt#2 ← (byte*) TEXT#1
to:@2
next_char: scope:[next_char] from main::@1
(byte*) TEXT#3 ← phi( main::@1/(byte*) TEXT#4 )
(byte*) nxt#9 ← phi( main::@1/(byte*) nxt#13 )
(byte) next_char::c#0 ← *((byte*) nxt#9)
(bool~) next_char::$0 ← (byte) next_char::c#0 == (byte) '@'
(bool~) next_char::$1 ← ! (bool~) next_char::$0
if((bool~) next_char::$1) goto next_char::@1
to:next_char::@2
next_char::@1: scope:[next_char] from next_char next_char::@2
(byte) next_char::c#2 ← phi( next_char/(byte) next_char::c#0 next_char::@2/(byte) next_char::c#1 )
(byte*) nxt#10 ← phi( next_char/(byte*) nxt#9 next_char::@2/(byte*) nxt#4 )
(byte*) nxt#3 ← ++ (byte*) nxt#10
(byte) next_char::return#1 ← (byte) next_char::c#2
to:next_char::@return
next_char::@2: scope:[next_char] from next_char
(byte*) TEXT#2 ← phi( next_char/(byte*) TEXT#3 )
(byte*) nxt#4 ← (byte*) TEXT#2
(byte) next_char::c#1 ← *((byte*) nxt#4)
to:next_char::@1
next_char::@return: scope:[next_char] from next_char::@1
(byte*) nxt#11 ← phi( next_char::@1/(byte*) nxt#3 )
(byte) next_char::return#4 ← phi( next_char::@1/(byte) next_char::return#1 )
(byte) next_char::return#2 ← (byte) next_char::return#4
(byte*) nxt#5 ← (byte*) nxt#11
return
to:@return
@2: scope:[] from @1
(byte*) TEXT#7 ← phi( @1/(byte*) TEXT#1 )
(byte*) nxt#14 ← phi( @1/(byte*) nxt#2 )
call main
to:@3
@3: scope:[] from @2
(byte*) nxt#12 ← phi( @2/(byte*) nxt#1 )
(byte*) nxt#6 ← (byte*) nxt#12
to:@end
@end: scope:[] from @3
SYMBOL TABLE SSA
(const string) $0 = (string) "cml @"
(label) @1
(label) @2
(label) @3
(label) @begin
(label) @end
(byte*) TEXT
(byte*) TEXT#0
(byte*) TEXT#1
(byte*) TEXT#2
(byte*) TEXT#3
(byte*) TEXT#4
(byte*) TEXT#5
(byte*) TEXT#6
(byte*) TEXT#7
(void()) main()
(byte~) main::$0
(bool~) main::$1
(label) main::@1
(label) main::@3
(label) main::@return
(byte*) main::SCREEN
(byte*) main::SCREEN#0
(byte*) main::SCREEN#1
(byte*) main::SCREEN#2
(byte) main::i
(byte) main::i#0
(byte) main::i#1
(byte) main::i#2
(byte) main::i#3
(byte()) next_char()
(bool~) next_char::$0
(bool~) next_char::$1
(label) next_char::@1
(label) next_char::@2
(label) next_char::@return
(byte) next_char::c
(byte) next_char::c#0
(byte) next_char::c#1
(byte) next_char::c#2
(byte) next_char::return
(byte) next_char::return#0
(byte) next_char::return#1
(byte) next_char::return#2
(byte) next_char::return#3
(byte) next_char::return#4
(byte*) nxt
(byte*) nxt#0
(byte*) nxt#1
(byte*) nxt#10
(byte*) nxt#11
(byte*) nxt#12
(byte*) nxt#13
(byte*) nxt#14
(byte*) nxt#15
(byte*) nxt#2
(byte*) nxt#3
(byte*) nxt#4
(byte*) nxt#5
(byte*) nxt#6
(byte*) nxt#7
(byte*) nxt#8
(byte*) nxt#9
Inversing boolean not [22] (bool~) next_char::$1 ← (byte) next_char::c#0 != (byte) '@' from [21] (bool~) next_char::$0 ← (byte) next_char::c#0 == (byte) '@'
Successful SSA optimization Pass2UnaryNotSimplification
Alias (byte) next_char::return#0 = (byte) next_char::return#3
Alias (byte*) main::SCREEN#1 = (byte*) main::SCREEN#2
Alias (byte) main::i#2 = (byte) main::i#3
Alias (byte*) TEXT#4 = (byte*) TEXT#6
Alias (byte*) nxt#0 = (byte*) nxt#7 (byte*) nxt#8 (byte*) nxt#1
Alias (byte*) TEXT#0 = (byte*) TEXT#1 (byte*) nxt#2 (byte*) nxt#14 (byte*) TEXT#7
Alias (byte) next_char::return#1 = (byte) next_char::c#2 (byte) next_char::return#4 (byte) next_char::return#2
Alias (byte*) TEXT#2 = (byte*) TEXT#3 (byte*) nxt#4
Alias (byte*) nxt#11 = (byte*) nxt#3 (byte*) nxt#5
Alias (byte*) nxt#12 = (byte*) nxt#6
Successful SSA optimization Pass2AliasElimination
Self Phi Eliminated (byte*) main::SCREEN#1
Self Phi Eliminated (byte*) TEXT#4
Successful SSA optimization Pass2SelfPhiElimination
Redundant Phi (byte*) nxt#15 (byte*) TEXT#0
Redundant Phi (byte*) TEXT#5 (byte*) TEXT#0
Redundant Phi (byte*) main::SCREEN#1 (byte*) main::SCREEN#0
Redundant Phi (byte*) TEXT#4 (byte*) TEXT#5
Redundant Phi (byte*) nxt#0 (byte*) nxt#11
Redundant Phi (byte*) nxt#9 (byte*) nxt#13
Redundant Phi (byte*) TEXT#2 (byte*) TEXT#4
Redundant Phi (byte*) nxt#12 (byte*) nxt#0
Successful SSA optimization Pass2RedundantPhiElimination
Simple Condition (bool~) main::$1 [13] if((byte) main::i#1!=rangelast(0,$ff)) goto main::@1
Simple Condition (bool~) next_char::$1 [23] if((byte) next_char::c#0!=(byte) '@') goto next_char::@1
Successful SSA optimization Pass2ConditionalJumpSimplification
Constant (const byte*) TEXT#0 = $0
Constant (const byte*) main::SCREEN#0 = ((byte*))$400
Constant (const byte) main::i#0 = 0
Successful SSA optimization Pass2ConstantIdentification
Resolved ranged next value main::i#1 ← ++ main::i#2 to ++
Resolved ranged comparison value if(main::i#1!=rangelast(0,$ff)) goto main::@1 to (byte/signed byte/word/signed word/dword/signed dword) 0
Culled Empty Block (label) @1
Culled Empty Block (label) @3
Successful SSA optimization Pass2CullEmptyBlocks
Inlining constant with var siblings (const byte) main::i#0
Constant inlined $0 = (const byte*) TEXT#0
Constant inlined main::i#0 = (byte/signed byte/word/signed word/dword/signed dword) 0
Successful SSA optimization Pass2ConstantInlining
Added new block during phi lifting main::@4(between main::@3 and main::@1)
Added new block during phi lifting next_char::@4(between next_char and next_char::@1)
Adding NOP phi() at start of @begin
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
Calls in [main] to next_char:6
Created 4 initial phi equivalence classes
Coalesced [13] nxt#16 ← nxt#11
Coalesced [14] main::i#4 ← main::i#1
Coalesced [18] next_char::return#6 ← next_char::c#1
Coalesced [22] nxt#17 ← nxt#13
Coalesced [23] next_char::return#5 ← next_char::c#0
Coalesced down to 3 phi equivalence classes
Culled Empty Block (label) main::@4
Culled Empty Block (label) next_char::@4
Adding NOP phi() at start of @begin
Adding NOP phi() at start of @2
Adding NOP phi() at start of @end
Adding NOP phi() at start of main
FINAL CONTROL FLOW GRAPH
@begin: scope:[] from
[0] phi()
to:@2
@2: scope:[] from @begin
[1] phi()
[2] call main
to:@end
@end: scope:[] from @2
[3] phi()
main: scope:[main] from @2
[4] phi()
to:main::@1
main::@1: scope:[main] from main main::@3
[5] (byte) main::i#2 ← phi( main/(byte/signed byte/word/signed word/dword/signed dword) 0 main::@3/(byte) main::i#1 )
[5] (byte*) nxt#13 ← phi( main/(const byte*) TEXT#0 main::@3/(byte*) nxt#11 )
[6] call next_char
[7] (byte) next_char::return#0 ← (byte) next_char::return#1
to:main::@3
main::@3: scope:[main] from main::@1
[8] (byte~) main::$0 ← (byte) next_char::return#0
[9] *((const byte*) main::SCREEN#0 + (byte) main::i#2) ← (byte~) main::$0
[10] (byte) main::i#1 ← ++ (byte) main::i#2
[11] if((byte) main::i#1!=(byte/signed byte/word/signed word/dword/signed dword) 0) goto main::@1
to:main::@return
main::@return: scope:[main] from main::@3
[12] return
to:@return
next_char: scope:[next_char] from main::@1
[13] (byte) next_char::c#0 ← *((byte*) nxt#13)
[14] if((byte) next_char::c#0!=(byte) '@') goto next_char::@1
to:next_char::@2
next_char::@2: scope:[next_char] from next_char
[15] (byte) next_char::c#1 ← *((const byte*) TEXT#0)
to:next_char::@1
next_char::@1: scope:[next_char] from next_char next_char::@2
[16] (byte) next_char::return#1 ← phi( next_char/(byte) next_char::c#0 next_char::@2/(byte) next_char::c#1 )
[16] (byte*) nxt#10 ← phi( next_char/(byte*) nxt#13 next_char::@2/(const byte*) TEXT#0 )
[17] (byte*) nxt#11 ← ++ (byte*) nxt#10
to:next_char::@return
next_char::@return: scope:[next_char] from next_char::@1
[18] return
to:@return
VARIABLE REGISTER WEIGHTS
(byte*) TEXT
(void()) main()
(byte~) main::$0 22.0
(byte*) main::SCREEN
(byte) main::i
(byte) main::i#1 16.5
(byte) main::i#2 6.6000000000000005
(byte()) next_char()
(byte) next_char::c
(byte) next_char::c#0 3.0
(byte) next_char::c#1 4.0
(byte) next_char::return
(byte) next_char::return#0 22.0
(byte) next_char::return#1 3.75
(byte*) nxt
(byte*) nxt#10 4.0
(byte*) nxt#11 1.625
(byte*) nxt#13 5.0
Initial phi equivalence classes
[ main::i#2 main::i#1 ]
[ nxt#10 nxt#13 nxt#11 ]
[ next_char::return#1 next_char::c#0 next_char::c#1 ]
Added variable next_char::return#0 to zero page equivalence class [ next_char::return#0 ]
Added variable main::$0 to zero page equivalence class [ main::$0 ]
Complete equivalence classes
[ main::i#2 main::i#1 ]
[ nxt#10 nxt#13 nxt#11 ]
[ next_char::return#1 next_char::c#0 next_char::c#1 ]
[ next_char::return#0 ]
[ main::$0 ]
Allocated zp ZP_BYTE:2 [ main::i#2 main::i#1 ]
Allocated zp ZP_WORD:3 [ nxt#10 nxt#13 nxt#11 ]
Allocated zp ZP_BYTE:5 [ next_char::return#1 next_char::c#0 next_char::c#1 ]
Allocated zp ZP_BYTE:6 [ next_char::return#0 ]
Allocated zp ZP_BYTE:7 [ main::$0 ]
INITIAL ASM
//SEG0 File Comments
// Clobber problem in next_char return value
//SEG1 Basic Upstart
.pc = $801 "Basic"
:BasicUpstart(bbegin)
.pc = $80d "Program"
//SEG2 Global Constants & labels
.label nxt = 3
//SEG3 @begin
bbegin:
//SEG4 [1] phi from @begin to @2 [phi:@begin->@2]
b2_from_bbegin:
jmp b2
//SEG5 @2
b2:
//SEG6 [2] call main
//SEG7 [4] phi from @2 to main [phi:@2->main]
main_from_b2:
jsr main
//SEG8 [3] phi from @2 to @end [phi:@2->@end]
bend_from_b2:
jmp bend
//SEG9 @end
bend:
//SEG10 main
main: {
.label SCREEN = $400
.label _0 = 7
.label i = 2
//SEG11 [5] phi from main to main::@1 [phi:main->main::@1]
b1_from_main:
//SEG12 [5] phi (byte) main::i#2 = (byte/signed byte/word/signed word/dword/signed dword) 0 [phi:main->main::@1#0] -- vbuz1=vbuc1
lda #0
sta i
//SEG13 [5] phi (byte*) nxt#13 = (const byte*) TEXT#0 [phi:main->main::@1#1] -- pbuz1=pbuc1
lda #<TEXT
sta nxt
lda #>TEXT
sta nxt+1
jmp b1
//SEG14 [5] phi from main::@3 to main::@1 [phi:main::@3->main::@1]
b1_from_b3:
//SEG15 [5] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@3->main::@1#0] -- register_copy
//SEG16 [5] phi (byte*) nxt#13 = (byte*) nxt#11 [phi:main::@3->main::@1#1] -- register_copy
jmp b1
//SEG17 main::@1
b1:
//SEG18 [6] call next_char
jsr next_char
//SEG19 [7] (byte) next_char::return#0 ← (byte) next_char::return#1 -- vbuz1=vbuz2
lda next_char.return_1
sta next_char.return
jmp b3
//SEG20 main::@3
b3:
//SEG21 [8] (byte~) main::$0 ← (byte) next_char::return#0 -- vbuz1=vbuz2
lda next_char.return
sta _0
//SEG22 [9] *((const byte*) main::SCREEN#0 + (byte) main::i#2) ← (byte~) main::$0 -- pbuc1_derefidx_vbuz1=vbuz2
lda _0
ldy i
sta SCREEN,y
//SEG23 [10] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuz1=_inc_vbuz1
inc i
//SEG24 [11] if((byte) main::i#1!=(byte/signed byte/word/signed word/dword/signed dword) 0) goto main::@1 -- vbuz1_neq_0_then_la1
lda i
cmp #0
bne b1_from_b3
jmp breturn
//SEG25 main::@return
breturn:
//SEG26 [12] return
rts
}
//SEG27 next_char
// Find the next char of the text
next_char: {
.label return = 6
.label c = 5
.label return_1 = 5
//SEG28 [13] (byte) next_char::c#0 ← *((byte*) nxt#13) -- vbuz1=_deref_pbuz2
ldy #0
lda (nxt),y
sta c
//SEG29 [14] if((byte) next_char::c#0!=(byte) '@') goto next_char::@1 -- vbuz1_neq_vbuc1_then_la1
lda c
cmp #'@'
bne b1_from_next_char
jmp b2
//SEG30 next_char::@2
b2:
//SEG31 [15] (byte) next_char::c#1 ← *((const byte*) TEXT#0) -- vbuz1=_deref_pbuc1
lda TEXT
sta c
//SEG32 [16] phi from next_char::@2 to next_char::@1 [phi:next_char::@2->next_char::@1]
b1_from_b2:
//SEG33 [16] phi (byte) next_char::return#1 = (byte) next_char::c#1 [phi:next_char::@2->next_char::@1#0] -- register_copy
//SEG34 [16] phi (byte*) nxt#10 = (const byte*) TEXT#0 [phi:next_char::@2->next_char::@1#1] -- pbuz1=pbuc1
lda #<TEXT
sta nxt
lda #>TEXT
sta nxt+1
jmp b1
//SEG35 [16] phi from next_char to next_char::@1 [phi:next_char->next_char::@1]
b1_from_next_char:
//SEG36 [16] phi (byte) next_char::return#1 = (byte) next_char::c#0 [phi:next_char->next_char::@1#0] -- register_copy
//SEG37 [16] phi (byte*) nxt#10 = (byte*) nxt#13 [phi:next_char->next_char::@1#1] -- register_copy
jmp b1
//SEG38 next_char::@1
b1:
//SEG39 [17] (byte*) nxt#11 ← ++ (byte*) nxt#10 -- pbuz1=_inc_pbuz1
inc nxt
bne !+
inc nxt+1
!:
jmp breturn
//SEG40 next_char::@return
breturn:
//SEG41 [18] return
rts
}
TEXT: .text "cml @"
REGISTER UPLIFT POTENTIAL REGISTERS
Statement [13] (byte) next_char::c#0 ← *((byte*) nxt#13) [ nxt#13 next_char::c#0 ] ( main:2::next_char:6 [ main::i#2 nxt#13 next_char::c#0 ] ) always clobbers reg byte a reg byte y
Removing always clobbered register reg byte a as potential for zp ZP_BYTE:2 [ main::i#2 main::i#1 ]
Removing always clobbered register reg byte y as potential for zp ZP_BYTE:2 [ main::i#2 main::i#1 ]
Statement [13] (byte) next_char::c#0 ← *((byte*) nxt#13) [ nxt#13 next_char::c#0 ] ( main:2::next_char:6 [ main::i#2 nxt#13 next_char::c#0 ] ) always clobbers reg byte a reg byte y
Potential registers zp ZP_BYTE:2 [ main::i#2 main::i#1 ] : zp ZP_BYTE:2 , reg byte x ,
Potential registers zp ZP_WORD:3 [ nxt#10 nxt#13 nxt#11 ] : zp ZP_WORD:3 ,
Potential registers zp ZP_BYTE:5 [ next_char::return#1 next_char::c#0 next_char::c#1 ] : zp ZP_BYTE:5 , reg byte a , reg byte x , reg byte y ,
Potential registers zp ZP_BYTE:6 [ next_char::return#0 ] : zp ZP_BYTE:6 , reg byte a , reg byte x , reg byte y ,
Potential registers zp ZP_BYTE:7 [ main::$0 ] : zp ZP_BYTE:7 , reg byte a , reg byte x , reg byte y ,
REGISTER UPLIFT SCOPES
Uplift Scope [main] 23.1: zp ZP_BYTE:2 [ main::i#2 main::i#1 ] 22: zp ZP_BYTE:7 [ main::$0 ]
Uplift Scope [next_char] 22: zp ZP_BYTE:6 [ next_char::return#0 ] 10.75: zp ZP_BYTE:5 [ next_char::return#1 next_char::c#0 next_char::c#1 ]
Uplift Scope [] 10.62: zp ZP_WORD:3 [ nxt#10 nxt#13 nxt#11 ]
Uplifting [main] best 587 combination reg byte x [ main::i#2 main::i#1 ] reg byte a [ main::$0 ]
Uplifting [next_char] best 510 combination reg byte a [ next_char::return#0 ] reg byte y [ next_char::return#1 next_char::c#0 next_char::c#1 ]
Uplifting [] best 510 combination zp ZP_WORD:3 [ nxt#10 nxt#13 nxt#11 ]
Allocated (was zp ZP_WORD:3) zp ZP_WORD:2 [ nxt#10 nxt#13 nxt#11 ]
ASSEMBLER BEFORE OPTIMIZATION
//SEG0 File Comments
// Clobber problem in next_char return value
//SEG1 Basic Upstart
.pc = $801 "Basic"
:BasicUpstart(bbegin)
.pc = $80d "Program"
//SEG2 Global Constants & labels
.label nxt = 2
//SEG3 @begin
bbegin:
//SEG4 [1] phi from @begin to @2 [phi:@begin->@2]
b2_from_bbegin:
jmp b2
//SEG5 @2
b2:
//SEG6 [2] call main
//SEG7 [4] phi from @2 to main [phi:@2->main]
main_from_b2:
jsr main
//SEG8 [3] phi from @2 to @end [phi:@2->@end]
bend_from_b2:
jmp bend
//SEG9 @end
bend:
//SEG10 main
main: {
.label SCREEN = $400
//SEG11 [5] phi from main to main::@1 [phi:main->main::@1]
b1_from_main:
//SEG12 [5] phi (byte) main::i#2 = (byte/signed byte/word/signed word/dword/signed dword) 0 [phi:main->main::@1#0] -- vbuxx=vbuc1
ldx #0
//SEG13 [5] phi (byte*) nxt#13 = (const byte*) TEXT#0 [phi:main->main::@1#1] -- pbuz1=pbuc1
lda #<TEXT
sta nxt
lda #>TEXT
sta nxt+1
jmp b1
//SEG14 [5] phi from main::@3 to main::@1 [phi:main::@3->main::@1]
b1_from_b3:
//SEG15 [5] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@3->main::@1#0] -- register_copy
//SEG16 [5] phi (byte*) nxt#13 = (byte*) nxt#11 [phi:main::@3->main::@1#1] -- register_copy
jmp b1
//SEG17 main::@1
b1:
//SEG18 [6] call next_char
jsr next_char
//SEG19 [7] (byte) next_char::return#0 ← (byte) next_char::return#1 -- vbuaa=vbuyy
tya
jmp b3
//SEG20 main::@3
b3:
//SEG21 [8] (byte~) main::$0 ← (byte) next_char::return#0
//SEG22 [9] *((const byte*) main::SCREEN#0 + (byte) main::i#2) ← (byte~) main::$0 -- pbuc1_derefidx_vbuxx=vbuaa
sta SCREEN,x
//SEG23 [10] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuxx=_inc_vbuxx
inx
//SEG24 [11] if((byte) main::i#1!=(byte/signed byte/word/signed word/dword/signed dword) 0) goto main::@1 -- vbuxx_neq_0_then_la1
cpx #0
bne b1_from_b3
jmp breturn
//SEG25 main::@return
breturn:
//SEG26 [12] return
rts
}
//SEG27 next_char
// Find the next char of the text
next_char: {
//SEG28 [13] (byte) next_char::c#0 ← *((byte*) nxt#13) -- vbuyy=_deref_pbuz1
ldy #0
lda (nxt),y
tay
//SEG29 [14] if((byte) next_char::c#0!=(byte) '@') goto next_char::@1 -- vbuyy_neq_vbuc1_then_la1
cpy #'@'
bne b1_from_next_char
jmp b2
//SEG30 next_char::@2
b2:
//SEG31 [15] (byte) next_char::c#1 ← *((const byte*) TEXT#0) -- vbuyy=_deref_pbuc1
ldy TEXT
//SEG32 [16] phi from next_char::@2 to next_char::@1 [phi:next_char::@2->next_char::@1]
b1_from_b2:
//SEG33 [16] phi (byte) next_char::return#1 = (byte) next_char::c#1 [phi:next_char::@2->next_char::@1#0] -- register_copy
//SEG34 [16] phi (byte*) nxt#10 = (const byte*) TEXT#0 [phi:next_char::@2->next_char::@1#1] -- pbuz1=pbuc1
lda #<TEXT
sta nxt
lda #>TEXT
sta nxt+1
jmp b1
//SEG35 [16] phi from next_char to next_char::@1 [phi:next_char->next_char::@1]
b1_from_next_char:
//SEG36 [16] phi (byte) next_char::return#1 = (byte) next_char::c#0 [phi:next_char->next_char::@1#0] -- register_copy
//SEG37 [16] phi (byte*) nxt#10 = (byte*) nxt#13 [phi:next_char->next_char::@1#1] -- register_copy
jmp b1
//SEG38 next_char::@1
b1:
//SEG39 [17] (byte*) nxt#11 ← ++ (byte*) nxt#10 -- pbuz1=_inc_pbuz1
inc nxt
bne !+
inc nxt+1
!:
jmp breturn
//SEG40 next_char::@return
breturn:
//SEG41 [18] return
rts
}
TEXT: .text "cml @"
ASSEMBLER OPTIMIZATIONS
Removing instruction jmp b2
Removing instruction jmp bend
Removing instruction jmp b1
Removing instruction jmp b3
Removing instruction jmp breturn
Removing instruction jmp b2
Removing instruction jmp b1
Removing instruction jmp breturn
Succesful ASM optimization Pass5NextJumpElimination
Replacing label b1_from_b3 with b1
Replacing label b1_from_next_char with b1
Removing instruction b2_from_bbegin:
Removing instruction b2:
Removing instruction main_from_b2:
Removing instruction bend_from_b2:
Removing instruction b1_from_b3:
Removing instruction b1_from_next_char:
Succesful ASM optimization Pass5RedundantLabelElimination
Removing instruction bend:
Removing instruction b1_from_main:
Removing instruction b3:
Removing instruction breturn:
Removing instruction b2:
Removing instruction b1_from_b2:
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
Removing instruction jmp b1
Succesful ASM optimization Pass5NextJumpElimination
Removing instruction bbegin:
Succesful ASM optimization Pass5UnusedLabelElimination
FINAL SYMBOL TABLE
(label) @2
(label) @begin
(label) @end
(byte*) TEXT
(const byte*) TEXT#0 TEXT = (string) "cml @"
(void()) main()
(byte~) main::$0 reg byte a 22.0
(label) main::@1
(label) main::@3
(label) main::@return
(byte*) main::SCREEN
(const byte*) main::SCREEN#0 SCREEN = ((byte*))(word/signed word/dword/signed dword) $400
(byte) main::i
(byte) main::i#1 reg byte x 16.5
(byte) main::i#2 reg byte x 6.6000000000000005
(byte()) next_char()
(label) next_char::@1
(label) next_char::@2
(label) next_char::@return
(byte) next_char::c
(byte) next_char::c#0 reg byte y 3.0
(byte) next_char::c#1 reg byte y 4.0
(byte) next_char::return
(byte) next_char::return#0 reg byte a 22.0
(byte) next_char::return#1 reg byte y 3.75
(byte*) nxt
(byte*) nxt#10 nxt zp ZP_WORD:2 4.0
(byte*) nxt#11 nxt zp ZP_WORD:2 1.625
(byte*) nxt#13 nxt zp ZP_WORD:2 5.0
reg byte x [ main::i#2 main::i#1 ]
zp ZP_WORD:2 [ nxt#10 nxt#13 nxt#11 ]
reg byte y [ next_char::return#1 next_char::c#0 next_char::c#1 ]
reg byte a [ next_char::return#0 ]
reg byte a [ main::$0 ]
FINAL ASSEMBLER
Score: 366
//SEG0 File Comments
// Clobber problem in next_char return value
//SEG1 Basic Upstart
.pc = $801 "Basic"
:BasicUpstart(main)
.pc = $80d "Program"
//SEG2 Global Constants & labels
.label nxt = 2
//SEG3 @begin
//SEG4 [1] phi from @begin to @2 [phi:@begin->@2]
//SEG5 @2
//SEG6 [2] call main
//SEG7 [4] phi from @2 to main [phi:@2->main]
//SEG8 [3] phi from @2 to @end [phi:@2->@end]
//SEG9 @end
//SEG10 main
main: {
.label SCREEN = $400
//SEG11 [5] phi from main to main::@1 [phi:main->main::@1]
//SEG12 [5] phi (byte) main::i#2 = (byte/signed byte/word/signed word/dword/signed dword) 0 [phi:main->main::@1#0] -- vbuxx=vbuc1
ldx #0
//SEG13 [5] phi (byte*) nxt#13 = (const byte*) TEXT#0 [phi:main->main::@1#1] -- pbuz1=pbuc1
lda #<TEXT
sta nxt
lda #>TEXT
sta nxt+1
//SEG14 [5] phi from main::@3 to main::@1 [phi:main::@3->main::@1]
//SEG15 [5] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@3->main::@1#0] -- register_copy
//SEG16 [5] phi (byte*) nxt#13 = (byte*) nxt#11 [phi:main::@3->main::@1#1] -- register_copy
//SEG17 main::@1
b1:
//SEG18 [6] call next_char
jsr next_char
//SEG19 [7] (byte) next_char::return#0 ← (byte) next_char::return#1 -- vbuaa=vbuyy
tya
//SEG20 main::@3
//SEG21 [8] (byte~) main::$0 ← (byte) next_char::return#0
//SEG22 [9] *((const byte*) main::SCREEN#0 + (byte) main::i#2) ← (byte~) main::$0 -- pbuc1_derefidx_vbuxx=vbuaa
sta SCREEN,x
//SEG23 [10] (byte) main::i#1 ← ++ (byte) main::i#2 -- vbuxx=_inc_vbuxx
inx
//SEG24 [11] if((byte) main::i#1!=(byte/signed byte/word/signed word/dword/signed dword) 0) goto main::@1 -- vbuxx_neq_0_then_la1
cpx #0
bne b1
//SEG25 main::@return
//SEG26 [12] return
rts
}
//SEG27 next_char
// Find the next char of the text
next_char: {
//SEG28 [13] (byte) next_char::c#0 ← *((byte*) nxt#13) -- vbuyy=_deref_pbuz1
ldy #0
lda (nxt),y
tay
//SEG29 [14] if((byte) next_char::c#0!=(byte) '@') goto next_char::@1 -- vbuyy_neq_vbuc1_then_la1
cpy #'@'
bne b1
//SEG30 next_char::@2
//SEG31 [15] (byte) next_char::c#1 ← *((const byte*) TEXT#0) -- vbuyy=_deref_pbuc1
ldy TEXT
//SEG32 [16] phi from next_char::@2 to next_char::@1 [phi:next_char::@2->next_char::@1]
//SEG33 [16] phi (byte) next_char::return#1 = (byte) next_char::c#1 [phi:next_char::@2->next_char::@1#0] -- register_copy
//SEG34 [16] phi (byte*) nxt#10 = (const byte*) TEXT#0 [phi:next_char::@2->next_char::@1#1] -- pbuz1=pbuc1
lda #<TEXT
sta nxt
lda #>TEXT
sta nxt+1
//SEG35 [16] phi from next_char to next_char::@1 [phi:next_char->next_char::@1]
//SEG36 [16] phi (byte) next_char::return#1 = (byte) next_char::c#0 [phi:next_char->next_char::@1#0] -- register_copy
//SEG37 [16] phi (byte*) nxt#10 = (byte*) nxt#13 [phi:next_char->next_char::@1#1] -- register_copy
//SEG38 next_char::@1
b1:
//SEG39 [17] (byte*) nxt#11 ← ++ (byte*) nxt#10 -- pbuz1=_inc_pbuz1
inc nxt
bne !+
inc nxt+1
!:
//SEG40 next_char::@return
//SEG41 [18] return
rts
}
TEXT: .text "cml @"

View File

@ -0,0 +1,35 @@
(label) @2
(label) @begin
(label) @end
(byte*) TEXT
(const byte*) TEXT#0 TEXT = (string) "cml @"
(void()) main()
(byte~) main::$0 reg byte a 22.0
(label) main::@1
(label) main::@3
(label) main::@return
(byte*) main::SCREEN
(const byte*) main::SCREEN#0 SCREEN = ((byte*))(word/signed word/dword/signed dword) $400
(byte) main::i
(byte) main::i#1 reg byte x 16.5
(byte) main::i#2 reg byte x 6.6000000000000005
(byte()) next_char()
(label) next_char::@1
(label) next_char::@2
(label) next_char::@return
(byte) next_char::c
(byte) next_char::c#0 reg byte y 3.0
(byte) next_char::c#1 reg byte y 4.0
(byte) next_char::return
(byte) next_char::return#0 reg byte a 22.0
(byte) next_char::return#1 reg byte y 3.75
(byte*) nxt
(byte*) nxt#10 nxt zp ZP_WORD:2 4.0
(byte*) nxt#11 nxt zp ZP_WORD:2 1.625
(byte*) nxt#13 nxt zp ZP_WORD:2 5.0
reg byte x [ main::i#2 main::i#1 ]
zp ZP_WORD:2 [ nxt#10 nxt#13 nxt#11 ]
reg byte y [ next_char::return#1 next_char::c#0 next_char::c#1 ]
reg byte a [ next_char::return#0 ]
reg byte a [ main::$0 ]