From 7384fb5357dee600080032415becff0e281d4f87 Mon Sep 17 00:00:00 2001
From: Jesper Gravgaard <jg@ramboll.com>
Date: Mon, 6 Jul 2020 17:49:41 +0200
Subject: [PATCH] Fixed problem with post increment inside conditions. Closes
 #486

---
 src/test/kc/condition-integer-2.c    |   2 +-
 src/test/ref/condition-integer-2.asm |  51 ++--
 src/test/ref/condition-integer-2.cfg |  26 +-
 src/test/ref/condition-integer-2.log | 437 ++++++++++++++++-----------
 src/test/ref/condition-integer-2.sym |  39 +--
 5 files changed, 326 insertions(+), 229 deletions(-)

diff --git a/src/test/kc/condition-integer-2.c b/src/test/kc/condition-integer-2.c
index 604f369e7..d6aee1435 100644
--- a/src/test/kc/condition-integer-2.c
+++ b/src/test/kc/condition-integer-2.c
@@ -1,5 +1,5 @@
 // Tests using integer conditions in while() / for() / do..while
-// This should produce 'ba ba ba' at the top of the screen
+// This should produce 'ba ba@ ba@' at the top of the screen
 
 byte* const SCREEN = 0x0400;
 byte idx = 0;
diff --git a/src/test/ref/condition-integer-2.asm b/src/test/ref/condition-integer-2.asm
index 743e9a312..433d63de7 100644
--- a/src/test/ref/condition-integer-2.asm
+++ b/src/test/ref/condition-integer-2.asm
@@ -1,60 +1,73 @@
 // Tests using integer conditions in while() / for() / do..while
-// This should produce 'ba ba ba' at the top of the screen
+// This should produce 'ba ba@ ba@' at the top of the screen
 .pc = $801 "Basic"
 :BasicUpstart(main)
 .pc = $80d "Program"
   .label SCREEN = $400
 main: {
-    ldy #0
-    ldx #2
+    // while()
+    .label j = 2
+    ldx #0
+    lda #2
   // for()
   __b1:
     // for( byte i=2;i;i--)
-    cpx #0
+    cmp #0
     bne __b2
     // SCREEN[idx++] = ' '
     lda #' '
-    sta SCREEN,y
+    sta SCREEN,x
     // SCREEN[idx++] = ' ';
-    iny
+    inx
     lda #3
+    sta.z j
   __b4:
     // while( j-- )
-    sec
-    sbc #1
-    cmp #0
+    ldy.z j
+    dey
+    lda #0
+    cmp.z j
     bne __b5
     // SCREEN[idx++] = ' '
     lda #' '
-    sta SCREEN,y
+    sta SCREEN,x
     // SCREEN[idx++] = ' ';
+    txa
+    tay
     iny
-    lda #2
+    ldx #2
   __b7:
     // SCREEN[idx++] = k
+    txa
     sta SCREEN,y
     // SCREEN[idx++] = k;
     iny
     // while(k--)
+    txa
     sec
     sbc #1
-    cmp #0
-    bne __b7
+    cpx #0
+    bne __b8
     // }
     rts
+  __b8:
+    tax
+    jmp __b7
   __b5:
     // SCREEN[idx++] = j
-    sta SCREEN,y
+    tya
+    sta SCREEN,x
     // SCREEN[idx++] = j;
-    iny
+    inx
+    sty.z j
     jmp __b4
   __b2:
     // SCREEN[idx++] = i
-    txa
-    sta SCREEN,y
+    sta SCREEN,x
     // SCREEN[idx++] = i;
-    iny
+    inx
     // for( byte i=2;i;i--)
-    dex
+    sec
+    sbc #1
     jmp __b1
 }
diff --git a/src/test/ref/condition-integer-2.cfg b/src/test/ref/condition-integer-2.cfg
index 8f3732c7d..22ffbce51 100644
--- a/src/test/ref/condition-integer-2.cfg
+++ b/src/test/ref/condition-integer-2.cfg
@@ -14,31 +14,35 @@ main::@3: scope:[main]  from main::@1
   to:main::@4
 main::@4: scope:[main]  from main::@3 main::@5
   [5] (byte) idx#11 ← phi( main::@3/(byte) idx#1 main::@5/(byte) idx#2 )
-  [5] (byte) main::j#2 ← phi( main::@3/(byte) 3 main::@5/(byte) main::j#1 )
+  [5] (byte) main::j#2 ← phi( main::@3/(byte) 3 main::@5/(byte) main::j#4 )
   [6] (byte) main::j#1 ← -- (byte) main::j#2
-  [7] if((byte) 0!=(byte) main::j#1) goto main::@5
+  [7] if((byte) 0!=(byte) main::j#2) goto main::@5
   to:main::@6
 main::@6: scope:[main]  from main::@4
   [8] *((const nomodify byte*) SCREEN + (byte) idx#11) ← (byte) ' '
   [9] (byte) idx#3 ← ++ (byte) idx#11
   to:main::@7
-main::@7: scope:[main]  from main::@6 main::@7
-  [10] (byte) idx#13 ← phi( main::@6/(byte) idx#3 main::@7/(byte) idx#14 )
-  [10] (byte) main::k#2 ← phi( main::@6/(byte) 2 main::@7/(byte) main::k#1 )
+main::@7: scope:[main]  from main::@6 main::@8
+  [10] (byte) idx#13 ← phi( main::@6/(byte) idx#3 main::@8/(byte) idx#14 )
+  [10] (byte) main::k#2 ← phi( main::@6/(byte) 2 main::@8/(byte) main::k#3 )
   [11] *((const nomodify byte*) SCREEN + (byte) idx#13) ← (byte) main::k#2
   [12] (byte) idx#14 ← ++ (byte) idx#13
   [13] (byte) main::k#1 ← -- (byte) main::k#2
-  [14] if((byte) 0!=(byte) main::k#1) goto main::@7
+  [14] if((byte) 0!=(byte) main::k#2) goto main::@8
   to:main::@return
 main::@return: scope:[main]  from main::@7
   [15] return 
   to:@return
+main::@8: scope:[main]  from main::@7
+  [16] (byte) main::k#3 ← (byte) main::k#1
+  to:main::@7
 main::@5: scope:[main]  from main::@4
-  [16] *((const nomodify byte*) SCREEN + (byte) idx#11) ← (byte) main::j#1
-  [17] (byte) idx#2 ← ++ (byte) idx#11
+  [17] *((const nomodify byte*) SCREEN + (byte) idx#11) ← (byte) main::j#1
+  [18] (byte) idx#2 ← ++ (byte) idx#11
+  [19] (byte) main::j#4 ← (byte) main::j#1
   to:main::@4
 main::@2: scope:[main]  from main::@1
-  [18] *((const nomodify byte*) SCREEN + (byte) idx#10) ← (byte) main::i#2
-  [19] (byte) idx#0 ← ++ (byte) idx#10
-  [20] (byte) main::i#1 ← -- (byte) main::i#2
+  [20] *((const nomodify byte*) SCREEN + (byte) idx#10) ← (byte) main::i#2
+  [21] (byte) idx#0 ← ++ (byte) idx#10
+  [22] (byte) main::i#1 ← -- (byte) main::i#2
   to:main::@1
diff --git a/src/test/ref/condition-integer-2.log b/src/test/ref/condition-integer-2.log
index c8999b24b..5bfe0f725 100644
--- a/src/test/ref/condition-integer-2.log
+++ b/src/test/ref/condition-integer-2.log
@@ -10,8 +10,8 @@ main: scope:[main]  from __start::@1
 main::@1: scope:[main]  from main main::@2
   (byte) idx#17 ← phi( main/(byte) idx#20 main::@2/(byte) idx#0 )
   (byte) main::i#2 ← phi( main/(byte) main::i#0 main::@2/(byte) main::i#1 )
-  (bool~) main::$0 ← (number) 0 != (byte) main::i#2
-  if((bool~) main::$0) goto main::@2
+  (bool~) main::$2 ← (number) 0 != (byte) main::i#2
+  if((bool~) main::$2) goto main::@2
   to:main::@3
 main::@2: scope:[main]  from main::@1
   (byte) idx#9 ← phi( main::@1/(byte) idx#17 )
@@ -29,9 +29,10 @@ main::@3: scope:[main]  from main::@1
 main::@4: scope:[main]  from main::@3 main::@5
   (byte) idx#18 ← phi( main::@3/(byte) idx#1 main::@5/(byte) idx#2 )
   (byte) main::j#2 ← phi( main::@3/(byte) main::j#0 main::@5/(byte) main::j#3 )
+  (byte~) main::$0 ← (byte) main::j#2
   (byte) main::j#1 ← -- (byte) main::j#2
-  (bool~) main::$1 ← (number) 0 != (byte) main::j#1
-  if((bool~) main::$1) goto main::@5
+  (bool~) main::$3 ← (number) 0 != (byte~) main::$0
+  if((bool~) main::$3) goto main::@5
   to:main::@6
 main::@5: scope:[main]  from main::@4
   (byte) idx#11 ← phi( main::@4/(byte) idx#18 )
@@ -50,9 +51,10 @@ main::@7: scope:[main]  from main::@6 main::@7
   (byte) main::k#2 ← phi( main::@6/(byte) main::k#0 main::@7/(byte) main::k#1 )
   *((const nomodify byte*) SCREEN + (byte) idx#13) ← (byte) main::k#2
   (byte) idx#4 ← ++ (byte) idx#13
+  (byte~) main::$1 ← (byte) main::k#2
   (byte) main::k#1 ← -- (byte) main::k#2
-  (bool~) main::$2 ← (number) 0 != (byte) main::k#1
-  if((bool~) main::$2) goto main::@7
+  (bool~) main::$4 ← (number) 0 != (byte~) main::$1
+  if((bool~) main::$4) goto main::@7
   to:main::@return
 main::@return: scope:[main]  from main::@7
   (byte) idx#14 ← phi( main::@7/(byte) idx#4 )
@@ -110,9 +112,11 @@ SYMBOL TABLE SSA
 (byte) idx#8
 (byte) idx#9
 (void()) main()
-(bool~) main::$0
-(bool~) main::$1
+(byte~) main::$0
+(byte~) main::$1
 (bool~) main::$2
+(bool~) main::$3
+(bool~) main::$4
 (label) main::@1
 (label) main::@2
 (label) main::@3
@@ -136,9 +140,9 @@ SYMBOL TABLE SSA
 (byte) main::k#1
 (byte) main::k#2
 
-Adding number conversion cast (unumber) 0 in (bool~) main::$0 ← (number) 0 != (byte) main::i#2
-Adding number conversion cast (unumber) 0 in (bool~) main::$1 ← (number) 0 != (byte) main::j#1
-Adding number conversion cast (unumber) 0 in (bool~) main::$2 ← (number) 0 != (byte) main::k#1
+Adding number conversion cast (unumber) 0 in (bool~) main::$2 ← (number) 0 != (byte) main::i#2
+Adding number conversion cast (unumber) 0 in (bool~) main::$3 ← (number) 0 != (byte~) main::$0
+Adding number conversion cast (unumber) 0 in (bool~) main::$4 ← (number) 0 != (byte~) main::$1
 Successful SSA optimization PassNAddNumberTypeConversions
 Simplifying constant pointer cast (byte*) 1024
 Simplifying constant integer cast 0
@@ -151,8 +155,10 @@ Finalized unsigned number type (byte) 0
 Successful SSA optimization PassNFinalizeNumberTypeConversions
 Alias main::i#2 = main::i#3 
 Alias idx#10 = idx#9 idx#17 
+Alias main::j#2 = main::$0 
 Alias main::j#1 = main::j#3 
 Alias idx#11 = idx#18 idx#12 
+Alias main::k#2 = main::$1 
 Alias idx#14 = idx#4 idx#5 
 Alias idx#19 = idx#6 
 Alias idx#15 = idx#7 idx#16 idx#8 
@@ -160,9 +166,9 @@ Successful SSA optimization Pass2AliasElimination
 Identical Phi Values (byte) idx#20 (byte) idx#19
 Identical Phi Values (byte) idx#15 (byte) idx#14
 Successful SSA optimization Pass2IdenticalPhiElimination
-Simple Condition (bool~) main::$0 [4] if((byte) 0!=(byte) main::i#2) goto main::@2
-Simple Condition (bool~) main::$1 [14] if((byte) 0!=(byte) main::j#1) goto main::@5
-Simple Condition (bool~) main::$2 [25] if((byte) 0!=(byte) main::k#1) goto main::@7
+Simple Condition (bool~) main::$2 [4] if((byte) 0!=(byte) main::i#2) goto main::@2
+Simple Condition (bool~) main::$3 [14] if((byte) 0!=(byte) main::j#2) goto main::@5
+Simple Condition (bool~) main::$4 [25] if((byte) 0!=(byte) main::k#2) goto main::@7
 Successful SSA optimization Pass2ConditionalJumpSimplification
 Constant (const byte) main::i#0 = 2
 Constant (const byte) main::j#0 = 3
@@ -192,14 +198,13 @@ CALL GRAPH
 Created 6 initial phi equivalence classes
 Coalesced [5] idx#22 ← idx#1
 Coalesced [11] idx#24 ← idx#3
-Coalesced [18] main::k#3 ← main::k#1
+Not coalescing [18] main::k#3 ← main::k#1
 Coalesced [19] idx#25 ← idx#14
-Coalesced [22] main::j#4 ← main::j#1
+Not coalescing [22] main::j#4 ← main::j#1
 Coalesced [23] idx#23 ← idx#2
 Coalesced [27] main::i#4 ← main::i#1
 Coalesced [28] idx#21 ← idx#0
-Coalesced down to 6 phi equivalence classes
-Culled Empty Block (label) main::@8
+Coalesced down to 8 phi equivalence classes
 Adding NOP phi() at start of main
 
 FINAL CONTROL FLOW GRAPH
@@ -219,33 +224,37 @@ main::@3: scope:[main]  from main::@1
   to:main::@4
 main::@4: scope:[main]  from main::@3 main::@5
   [5] (byte) idx#11 ← phi( main::@3/(byte) idx#1 main::@5/(byte) idx#2 )
-  [5] (byte) main::j#2 ← phi( main::@3/(byte) 3 main::@5/(byte) main::j#1 )
+  [5] (byte) main::j#2 ← phi( main::@3/(byte) 3 main::@5/(byte) main::j#4 )
   [6] (byte) main::j#1 ← -- (byte) main::j#2
-  [7] if((byte) 0!=(byte) main::j#1) goto main::@5
+  [7] if((byte) 0!=(byte) main::j#2) goto main::@5
   to:main::@6
 main::@6: scope:[main]  from main::@4
   [8] *((const nomodify byte*) SCREEN + (byte) idx#11) ← (byte) ' '
   [9] (byte) idx#3 ← ++ (byte) idx#11
   to:main::@7
-main::@7: scope:[main]  from main::@6 main::@7
-  [10] (byte) idx#13 ← phi( main::@6/(byte) idx#3 main::@7/(byte) idx#14 )
-  [10] (byte) main::k#2 ← phi( main::@6/(byte) 2 main::@7/(byte) main::k#1 )
+main::@7: scope:[main]  from main::@6 main::@8
+  [10] (byte) idx#13 ← phi( main::@6/(byte) idx#3 main::@8/(byte) idx#14 )
+  [10] (byte) main::k#2 ← phi( main::@6/(byte) 2 main::@8/(byte) main::k#3 )
   [11] *((const nomodify byte*) SCREEN + (byte) idx#13) ← (byte) main::k#2
   [12] (byte) idx#14 ← ++ (byte) idx#13
   [13] (byte) main::k#1 ← -- (byte) main::k#2
-  [14] if((byte) 0!=(byte) main::k#1) goto main::@7
+  [14] if((byte) 0!=(byte) main::k#2) goto main::@8
   to:main::@return
 main::@return: scope:[main]  from main::@7
   [15] return 
   to:@return
+main::@8: scope:[main]  from main::@7
+  [16] (byte) main::k#3 ← (byte) main::k#1
+  to:main::@7
 main::@5: scope:[main]  from main::@4
-  [16] *((const nomodify byte*) SCREEN + (byte) idx#11) ← (byte) main::j#1
-  [17] (byte) idx#2 ← ++ (byte) idx#11
+  [17] *((const nomodify byte*) SCREEN + (byte) idx#11) ← (byte) main::j#1
+  [18] (byte) idx#2 ← ++ (byte) idx#11
+  [19] (byte) main::j#4 ← (byte) main::j#1
   to:main::@4
 main::@2: scope:[main]  from main::@1
-  [18] *((const nomodify byte*) SCREEN + (byte) idx#10) ← (byte) main::i#2
-  [19] (byte) idx#0 ← ++ (byte) idx#10
-  [20] (byte) main::i#1 ← -- (byte) main::i#2
+  [20] *((const nomodify byte*) SCREEN + (byte) idx#10) ← (byte) main::i#2
+  [21] (byte) idx#0 ← ++ (byte) idx#10
+  [22] (byte) main::i#1 ← -- (byte) main::i#2
   to:main::@1
 
 
@@ -256,46 +265,54 @@ VARIABLE REGISTER WEIGHTS
 (byte) idx#10 9.25
 (byte) idx#11 7.8
 (byte) idx#13 17.5
-(byte) idx#14 7.333333333333333
-(byte) idx#2 22.0
+(byte) idx#14 5.5
+(byte) idx#2 11.0
 (byte) idx#3 4.0
 (void()) main()
 (byte) main::i
 (byte) main::i#1 22.0
 (byte) main::i#2 11.0
 (byte) main::j
-(byte) main::j#1 11.0
-(byte) main::j#2 22.0
+(byte) main::j#1 8.25
+(byte) main::j#2 16.5
+(byte) main::j#4 22.0
 (byte) main::k
-(byte) main::k#1 16.5
+(byte) main::k#1 11.0
 (byte) main::k#2 11.0
+(byte) main::k#3 22.0
 
 Initial phi equivalence classes
 [ main::i#2 main::i#1 ]
 [ idx#10 idx#0 ]
-[ main::j#2 main::j#1 ]
+[ main::j#2 main::j#4 ]
 [ idx#11 idx#1 idx#2 ]
-[ main::k#2 main::k#1 ]
+[ main::k#2 main::k#3 ]
 [ idx#13 idx#3 idx#14 ]
+Added variable main::j#1 to live range equivalence class [ main::j#1 ]
+Added variable main::k#1 to live range equivalence class [ main::k#1 ]
 Complete equivalence classes
 [ main::i#2 main::i#1 ]
 [ idx#10 idx#0 ]
-[ main::j#2 main::j#1 ]
+[ main::j#2 main::j#4 ]
 [ idx#11 idx#1 idx#2 ]
-[ main::k#2 main::k#1 ]
+[ main::k#2 main::k#3 ]
 [ idx#13 idx#3 idx#14 ]
+[ main::j#1 ]
+[ main::k#1 ]
 Allocated zp[1]:2 [ main::i#2 main::i#1 ]
 Allocated zp[1]:3 [ idx#10 idx#0 ]
-Allocated zp[1]:4 [ main::j#2 main::j#1 ]
+Allocated zp[1]:4 [ main::j#2 main::j#4 ]
 Allocated zp[1]:5 [ idx#11 idx#1 idx#2 ]
-Allocated zp[1]:6 [ main::k#2 main::k#1 ]
+Allocated zp[1]:6 [ main::k#2 main::k#3 ]
 Allocated zp[1]:7 [ idx#13 idx#3 idx#14 ]
+Allocated zp[1]:8 [ main::j#1 ]
+Allocated zp[1]:9 [ main::k#1 ]
 
 INITIAL ASM
 Target platform is c64basic / MOS6502X
   // File Comments
 // Tests using integer conditions in while() / for() / do..while
-// This should produce 'ba ba ba' at the top of the screen
+// This should produce 'ba ba@ ba@' at the top of the screen
   // Upstart
 .pc = $801 "Basic"
 :BasicUpstart(main)
@@ -309,9 +326,13 @@ Target platform is c64basic / MOS6502X
 main: {
     .label i = 2
     // while()
-    .label j = 4
+    .label j = 8
     // do...while()
-    .label k = 6
+    .label k = 9
+    // while()
+    .label j_1 = 4
+    // do...while()
+    .label k_1 = 6
     // [1] phi from main to main::@1 [phi:main->main::@1]
   __b1_from_main:
     // [1] phi (byte) idx#10 = (byte) 0 [phi:main->main::@1#0] -- vbuz1=vbuc1 
@@ -344,15 +365,17 @@ main: {
     // [5] phi (byte) idx#11 = (byte) idx#1 [phi:main::@3->main::@4#0] -- register_copy 
     // [5] phi (byte) main::j#2 = (byte) 3 [phi:main::@3->main::@4#1] -- vbuz1=vbuc1 
     lda #3
-    sta.z j
+    sta.z j_1
     jmp __b4
     // main::@4
   __b4:
-    // [6] (byte) main::j#1 ← -- (byte) main::j#2 -- vbuz1=_dec_vbuz1 
-    dec.z j
-    // [7] if((byte) 0!=(byte) main::j#1) goto main::@5 -- vbuc1_neq_vbuz1_then_la1 
+    // [6] (byte) main::j#1 ← -- (byte) main::j#2 -- vbuz1=_dec_vbuz2 
+    ldy.z j_1
+    dey
+    sty.z j
+    // [7] if((byte) 0!=(byte) main::j#2) goto main::@5 -- vbuc1_neq_vbuz1_then_la1 
     lda #0
-    cmp.z j
+    cmp.z j_1
     bne __b5
     jmp __b6
     // main::@6
@@ -370,54 +393,64 @@ main: {
     // [10] phi (byte) idx#13 = (byte) idx#3 [phi:main::@6->main::@7#0] -- register_copy 
     // [10] phi (byte) main::k#2 = (byte) 2 [phi:main::@6->main::@7#1] -- vbuz1=vbuc1 
     lda #2
-    sta.z k
-    jmp __b7
-    // [10] phi from main::@7 to main::@7 [phi:main::@7->main::@7]
-  __b7_from___b7:
-    // [10] phi (byte) idx#13 = (byte) idx#14 [phi:main::@7->main::@7#0] -- register_copy 
-    // [10] phi (byte) main::k#2 = (byte) main::k#1 [phi:main::@7->main::@7#1] -- register_copy 
+    sta.z k_1
     jmp __b7
     // main::@7
   __b7:
     // [11] *((const nomodify byte*) SCREEN + (byte) idx#13) ← (byte) main::k#2 -- pbuc1_derefidx_vbuz1=vbuz2 
-    lda.z k
+    lda.z k_1
     ldy.z idx_2
     sta SCREEN,y
     // [12] (byte) idx#14 ← ++ (byte) idx#13 -- vbuz1=_inc_vbuz1 
     inc.z idx_2
-    // [13] (byte) main::k#1 ← -- (byte) main::k#2 -- vbuz1=_dec_vbuz1 
-    dec.z k
-    // [14] if((byte) 0!=(byte) main::k#1) goto main::@7 -- vbuc1_neq_vbuz1_then_la1 
+    // [13] (byte) main::k#1 ← -- (byte) main::k#2 -- vbuz1=_dec_vbuz2 
+    ldy.z k_1
+    dey
+    sty.z k
+    // [14] if((byte) 0!=(byte) main::k#2) goto main::@8 -- vbuc1_neq_vbuz1_then_la1 
     lda #0
-    cmp.z k
-    bne __b7_from___b7
+    cmp.z k_1
+    bne __b8
     jmp __breturn
     // main::@return
   __breturn:
     // [15] return 
     rts
+    // main::@8
+  __b8:
+    // [16] (byte) main::k#3 ← (byte) main::k#1 -- vbuz1=vbuz2 
+    lda.z k
+    sta.z k_1
+    // [10] phi from main::@8 to main::@7 [phi:main::@8->main::@7]
+  __b7_from___b8:
+    // [10] phi (byte) idx#13 = (byte) idx#14 [phi:main::@8->main::@7#0] -- register_copy 
+    // [10] phi (byte) main::k#2 = (byte) main::k#3 [phi:main::@8->main::@7#1] -- register_copy 
+    jmp __b7
     // main::@5
   __b5:
-    // [16] *((const nomodify byte*) SCREEN + (byte) idx#11) ← (byte) main::j#1 -- pbuc1_derefidx_vbuz1=vbuz2 
+    // [17] *((const nomodify byte*) SCREEN + (byte) idx#11) ← (byte) main::j#1 -- pbuc1_derefidx_vbuz1=vbuz2 
     lda.z j
     ldy.z idx_1
     sta SCREEN,y
-    // [17] (byte) idx#2 ← ++ (byte) idx#11 -- vbuz1=_inc_vbuz1 
+    // [18] (byte) idx#2 ← ++ (byte) idx#11 -- vbuz1=_inc_vbuz1 
     inc.z idx_1
+    // [19] (byte) main::j#4 ← (byte) main::j#1 -- vbuz1=vbuz2 
+    lda.z j
+    sta.z j_1
     // [5] phi from main::@5 to main::@4 [phi:main::@5->main::@4]
   __b4_from___b5:
     // [5] phi (byte) idx#11 = (byte) idx#2 [phi:main::@5->main::@4#0] -- register_copy 
-    // [5] phi (byte) main::j#2 = (byte) main::j#1 [phi:main::@5->main::@4#1] -- register_copy 
+    // [5] phi (byte) main::j#2 = (byte) main::j#4 [phi:main::@5->main::@4#1] -- register_copy 
     jmp __b4
     // main::@2
   __b2:
-    // [18] *((const nomodify byte*) SCREEN + (byte) idx#10) ← (byte) main::i#2 -- pbuc1_derefidx_vbuz1=vbuz2 
+    // [20] *((const nomodify byte*) SCREEN + (byte) idx#10) ← (byte) main::i#2 -- pbuc1_derefidx_vbuz1=vbuz2 
     lda.z i
     ldy.z idx
     sta SCREEN,y
-    // [19] (byte) idx#0 ← ++ (byte) idx#10 -- vbuz1=_inc_vbuz1 
+    // [21] (byte) idx#0 ← ++ (byte) idx#10 -- vbuz1=_inc_vbuz1 
     inc.z idx
-    // [20] (byte) main::i#1 ← -- (byte) main::i#2 -- vbuz1=_dec_vbuz1 
+    // [22] (byte) main::i#1 ← -- (byte) main::i#2 -- vbuz1=_dec_vbuz1 
     dec.z i
     // [1] phi from main::@2 to main::@1 [phi:main::@2->main::@1]
   __b1_from___b2:
@@ -436,22 +469,32 @@ Statement [3] *((const nomodify byte*) SCREEN + (byte) idx#10) ← (byte) ' ' [
 Statement [8] *((const nomodify byte*) SCREEN + (byte) idx#11) ← (byte) ' ' [ idx#11 ] (  [ idx#11 ] { }  ) always clobbers reg byte a 
 Potential registers zp[1]:2 [ main::i#2 main::i#1 ] : zp[1]:2 , reg byte a , reg byte x , reg byte y , 
 Potential registers zp[1]:3 [ idx#10 idx#0 ] : zp[1]:3 , reg byte x , reg byte y , 
-Potential registers zp[1]:4 [ main::j#2 main::j#1 ] : zp[1]:4 , reg byte a , reg byte x , reg byte y , 
+Potential registers zp[1]:4 [ main::j#2 main::j#4 ] : zp[1]:4 , reg byte a , reg byte x , reg byte y , 
 Potential registers zp[1]:5 [ idx#11 idx#1 idx#2 ] : zp[1]:5 , reg byte x , reg byte y , 
-Potential registers zp[1]:6 [ main::k#2 main::k#1 ] : zp[1]:6 , reg byte a , reg byte x , reg byte y , 
+Potential registers zp[1]:6 [ main::k#2 main::k#3 ] : zp[1]:6 , reg byte a , reg byte x , reg byte y , 
 Potential registers zp[1]:7 [ idx#13 idx#3 idx#14 ] : zp[1]:7 , reg byte a , reg byte x , reg byte y , 
+Potential registers zp[1]:8 [ main::j#1 ] : zp[1]:8 , reg byte a , reg byte x , reg byte y , 
+Potential registers zp[1]:9 [ main::k#1 ] : zp[1]:9 , reg byte a , reg byte x , reg byte y , 
 
 REGISTER UPLIFT SCOPES
-Uplift Scope [main] 33: zp[1]:2 [ main::i#2 main::i#1 ] 33: zp[1]:4 [ main::j#2 main::j#1 ] 27.5: zp[1]:6 [ main::k#2 main::k#1 ] 
-Uplift Scope [] 33.8: zp[1]:5 [ idx#11 idx#1 idx#2 ] 28.83: zp[1]:7 [ idx#13 idx#3 idx#14 ] 20.25: zp[1]:3 [ idx#10 idx#0 ] 
+Uplift Scope [main] 38.5: zp[1]:4 [ main::j#2 main::j#4 ] 33: zp[1]:2 [ main::i#2 main::i#1 ] 33: zp[1]:6 [ main::k#2 main::k#3 ] 11: zp[1]:9 [ main::k#1 ] 8.25: zp[1]:8 [ main::j#1 ] 
+Uplift Scope [] 27: zp[1]:7 [ idx#13 idx#3 idx#14 ] 22.8: zp[1]:5 [ idx#11 idx#1 idx#2 ] 20.25: zp[1]:3 [ idx#10 idx#0 ] 
 
-Uplifting [main] best 1067 combination reg byte x [ main::i#2 main::i#1 ] reg byte a [ main::j#2 main::j#1 ] reg byte a [ main::k#2 main::k#1 ] 
-Uplifting [] best 839 combination reg byte y [ idx#11 idx#1 idx#2 ] reg byte y [ idx#13 idx#3 idx#14 ] reg byte y [ idx#10 idx#0 ] 
+Uplifting [main] best 1417 combination zp[1]:4 [ main::j#2 main::j#4 ] zp[1]:2 [ main::i#2 main::i#1 ] reg byte x [ main::k#2 main::k#3 ] reg byte a [ main::k#1 ] zp[1]:8 [ main::j#1 ] 
+Limited combination testing to 100 combinations of 1024 possible.
+Uplifting [] best 1193 combination reg byte y [ idx#13 idx#3 idx#14 ] reg byte x [ idx#11 idx#1 idx#2 ] reg byte x [ idx#10 idx#0 ] 
+Attempting to uplift remaining variables inzp[1]:4 [ main::j#2 main::j#4 ]
+Uplifting [main] best 1193 combination zp[1]:4 [ main::j#2 main::j#4 ] 
+Attempting to uplift remaining variables inzp[1]:2 [ main::i#2 main::i#1 ]
+Uplifting [main] best 1093 combination reg byte a [ main::i#2 main::i#1 ] 
+Attempting to uplift remaining variables inzp[1]:8 [ main::j#1 ]
+Uplifting [main] best 1023 combination reg byte y [ main::j#1 ] 
+Allocated (was zp[1]:4) zp[1]:2 [ main::j#2 main::j#4 ]
 
 ASSEMBLER BEFORE OPTIMIZATION
   // File Comments
 // Tests using integer conditions in while() / for() / do..while
-// This should produce 'ba ba ba' at the top of the screen
+// This should produce 'ba ba@ ba@' at the top of the screen
   // Upstart
 .pc = $801 "Basic"
 :BasicUpstart(main)
@@ -460,97 +503,112 @@ ASSEMBLER BEFORE OPTIMIZATION
   .label SCREEN = $400
   // main
 main: {
+    // while()
+    .label j = 2
     // [1] phi from main to main::@1 [phi:main->main::@1]
   __b1_from_main:
-    // [1] phi (byte) idx#10 = (byte) 0 [phi:main->main::@1#0] -- vbuyy=vbuc1 
-    ldy #0
-    // [1] phi (byte) main::i#2 = (byte) 2 [phi:main->main::@1#1] -- vbuxx=vbuc1 
-    ldx #2
+    // [1] phi (byte) idx#10 = (byte) 0 [phi:main->main::@1#0] -- vbuxx=vbuc1 
+    ldx #0
+    // [1] phi (byte) main::i#2 = (byte) 2 [phi:main->main::@1#1] -- vbuaa=vbuc1 
+    lda #2
     jmp __b1
   // for()
     // main::@1
   __b1:
-    // [2] if((byte) 0!=(byte) main::i#2) goto main::@2 -- vbuc1_neq_vbuxx_then_la1 
-    cpx #0
+    // [2] if((byte) 0!=(byte) main::i#2) goto main::@2 -- vbuc1_neq_vbuaa_then_la1 
+    cmp #0
     bne __b2
     jmp __b3
     // main::@3
   __b3:
-    // [3] *((const nomodify byte*) SCREEN + (byte) idx#10) ← (byte) ' ' -- pbuc1_derefidx_vbuyy=vbuc2 
+    // [3] *((const nomodify byte*) SCREEN + (byte) idx#10) ← (byte) ' ' -- pbuc1_derefidx_vbuxx=vbuc2 
     lda #' '
-    sta SCREEN,y
-    // [4] (byte) idx#1 ← ++ (byte) idx#10 -- vbuyy=_inc_vbuyy 
-    iny
+    sta SCREEN,x
+    // [4] (byte) idx#1 ← ++ (byte) idx#10 -- vbuxx=_inc_vbuxx 
+    inx
     // [5] phi from main::@3 to main::@4 [phi:main::@3->main::@4]
   __b4_from___b3:
     // [5] phi (byte) idx#11 = (byte) idx#1 [phi:main::@3->main::@4#0] -- register_copy 
-    // [5] phi (byte) main::j#2 = (byte) 3 [phi:main::@3->main::@4#1] -- vbuaa=vbuc1 
+    // [5] phi (byte) main::j#2 = (byte) 3 [phi:main::@3->main::@4#1] -- vbuz1=vbuc1 
     lda #3
+    sta.z j
     jmp __b4
     // main::@4
   __b4:
-    // [6] (byte) main::j#1 ← -- (byte) main::j#2 -- vbuaa=_dec_vbuaa 
-    sec
-    sbc #1
-    // [7] if((byte) 0!=(byte) main::j#1) goto main::@5 -- vbuc1_neq_vbuaa_then_la1 
-    cmp #0
+    // [6] (byte) main::j#1 ← -- (byte) main::j#2 -- vbuyy=_dec_vbuz1 
+    ldy.z j
+    dey
+    // [7] if((byte) 0!=(byte) main::j#2) goto main::@5 -- vbuc1_neq_vbuz1_then_la1 
+    lda #0
+    cmp.z j
     bne __b5
     jmp __b6
     // main::@6
   __b6:
-    // [8] *((const nomodify byte*) SCREEN + (byte) idx#11) ← (byte) ' ' -- pbuc1_derefidx_vbuyy=vbuc2 
+    // [8] *((const nomodify byte*) SCREEN + (byte) idx#11) ← (byte) ' ' -- pbuc1_derefidx_vbuxx=vbuc2 
     lda #' '
-    sta SCREEN,y
-    // [9] (byte) idx#3 ← ++ (byte) idx#11 -- vbuyy=_inc_vbuyy 
+    sta SCREEN,x
+    // [9] (byte) idx#3 ← ++ (byte) idx#11 -- vbuyy=_inc_vbuxx 
+    txa
+    tay
     iny
     // [10] phi from main::@6 to main::@7 [phi:main::@6->main::@7]
   __b7_from___b6:
     // [10] phi (byte) idx#13 = (byte) idx#3 [phi:main::@6->main::@7#0] -- register_copy 
-    // [10] phi (byte) main::k#2 = (byte) 2 [phi:main::@6->main::@7#1] -- vbuaa=vbuc1 
-    lda #2
-    jmp __b7
-    // [10] phi from main::@7 to main::@7 [phi:main::@7->main::@7]
-  __b7_from___b7:
-    // [10] phi (byte) idx#13 = (byte) idx#14 [phi:main::@7->main::@7#0] -- register_copy 
-    // [10] phi (byte) main::k#2 = (byte) main::k#1 [phi:main::@7->main::@7#1] -- register_copy 
+    // [10] phi (byte) main::k#2 = (byte) 2 [phi:main::@6->main::@7#1] -- vbuxx=vbuc1 
+    ldx #2
     jmp __b7
     // main::@7
   __b7:
-    // [11] *((const nomodify byte*) SCREEN + (byte) idx#13) ← (byte) main::k#2 -- pbuc1_derefidx_vbuyy=vbuaa 
+    // [11] *((const nomodify byte*) SCREEN + (byte) idx#13) ← (byte) main::k#2 -- pbuc1_derefidx_vbuyy=vbuxx 
+    txa
     sta SCREEN,y
     // [12] (byte) idx#14 ← ++ (byte) idx#13 -- vbuyy=_inc_vbuyy 
     iny
-    // [13] (byte) main::k#1 ← -- (byte) main::k#2 -- vbuaa=_dec_vbuaa 
+    // [13] (byte) main::k#1 ← -- (byte) main::k#2 -- vbuaa=_dec_vbuxx 
+    txa
     sec
     sbc #1
-    // [14] if((byte) 0!=(byte) main::k#1) goto main::@7 -- vbuc1_neq_vbuaa_then_la1 
-    cmp #0
-    bne __b7_from___b7
+    // [14] if((byte) 0!=(byte) main::k#2) goto main::@8 -- vbuc1_neq_vbuxx_then_la1 
+    cpx #0
+    bne __b8
     jmp __breturn
     // main::@return
   __breturn:
     // [15] return 
     rts
+    // main::@8
+  __b8:
+    // [16] (byte) main::k#3 ← (byte) main::k#1 -- vbuxx=vbuaa 
+    tax
+    // [10] phi from main::@8 to main::@7 [phi:main::@8->main::@7]
+  __b7_from___b8:
+    // [10] phi (byte) idx#13 = (byte) idx#14 [phi:main::@8->main::@7#0] -- register_copy 
+    // [10] phi (byte) main::k#2 = (byte) main::k#3 [phi:main::@8->main::@7#1] -- register_copy 
+    jmp __b7
     // main::@5
   __b5:
-    // [16] *((const nomodify byte*) SCREEN + (byte) idx#11) ← (byte) main::j#1 -- pbuc1_derefidx_vbuyy=vbuaa 
-    sta SCREEN,y
-    // [17] (byte) idx#2 ← ++ (byte) idx#11 -- vbuyy=_inc_vbuyy 
-    iny
+    // [17] *((const nomodify byte*) SCREEN + (byte) idx#11) ← (byte) main::j#1 -- pbuc1_derefidx_vbuxx=vbuyy 
+    tya
+    sta SCREEN,x
+    // [18] (byte) idx#2 ← ++ (byte) idx#11 -- vbuxx=_inc_vbuxx 
+    inx
+    // [19] (byte) main::j#4 ← (byte) main::j#1 -- vbuz1=vbuyy 
+    sty.z j
     // [5] phi from main::@5 to main::@4 [phi:main::@5->main::@4]
   __b4_from___b5:
     // [5] phi (byte) idx#11 = (byte) idx#2 [phi:main::@5->main::@4#0] -- register_copy 
-    // [5] phi (byte) main::j#2 = (byte) main::j#1 [phi:main::@5->main::@4#1] -- register_copy 
+    // [5] phi (byte) main::j#2 = (byte) main::j#4 [phi:main::@5->main::@4#1] -- register_copy 
     jmp __b4
     // main::@2
   __b2:
-    // [18] *((const nomodify byte*) SCREEN + (byte) idx#10) ← (byte) main::i#2 -- pbuc1_derefidx_vbuyy=vbuxx 
-    txa
-    sta SCREEN,y
-    // [19] (byte) idx#0 ← ++ (byte) idx#10 -- vbuyy=_inc_vbuyy 
-    iny
-    // [20] (byte) main::i#1 ← -- (byte) main::i#2 -- vbuxx=_dec_vbuxx 
-    dex
+    // [20] *((const nomodify byte*) SCREEN + (byte) idx#10) ← (byte) main::i#2 -- pbuc1_derefidx_vbuxx=vbuaa 
+    sta SCREEN,x
+    // [21] (byte) idx#0 ← ++ (byte) idx#10 -- vbuxx=_inc_vbuxx 
+    inx
+    // [22] (byte) main::i#1 ← -- (byte) main::i#2 -- vbuaa=_dec_vbuaa 
+    sec
+    sbc #1
     // [1] phi from main::@2 to main::@1 [phi:main::@2->main::@1]
   __b1_from___b2:
     // [1] phi (byte) idx#10 = (byte) idx#0 [phi:main::@2->main::@1#0] -- register_copy 
@@ -567,31 +625,27 @@ Removing instruction jmp __b6
 Removing instruction jmp __b7
 Removing instruction jmp __breturn
 Succesful ASM optimization Pass5NextJumpElimination
-Replacing label __b7_from___b7 with __b7
-Removing instruction __b7_from___b7:
-Succesful ASM optimization Pass5RedundantLabelElimination
 Removing instruction __b1_from_main:
 Removing instruction __b3:
 Removing instruction __b4_from___b3:
 Removing instruction __b6:
 Removing instruction __b7_from___b6:
 Removing instruction __breturn:
+Removing instruction __b7_from___b8:
 Removing instruction __b4_from___b5:
 Removing instruction __b1_from___b2:
 Succesful ASM optimization Pass5UnusedLabelElimination
-Removing instruction jmp __b7
-Succesful ASM optimization Pass5NextJumpElimination
 
 FINAL SYMBOL TABLE
 (const nomodify byte*) SCREEN = (byte*) 1024
 (byte) idx
-(byte) idx#0 reg byte y 11.0
-(byte) idx#1 reg byte y 4.0
-(byte) idx#10 reg byte y 9.25
-(byte) idx#11 reg byte y 7.8
+(byte) idx#0 reg byte x 11.0
+(byte) idx#1 reg byte x 4.0
+(byte) idx#10 reg byte x 9.25
+(byte) idx#11 reg byte x 7.8
 (byte) idx#13 reg byte y 17.5
-(byte) idx#14 reg byte y 7.333333333333333
-(byte) idx#2 reg byte y 22.0
+(byte) idx#14 reg byte y 5.5
+(byte) idx#2 reg byte x 11.0
 (byte) idx#3 reg byte y 4.0
 (void()) main()
 (label) main::@1
@@ -601,31 +655,36 @@ FINAL SYMBOL TABLE
 (label) main::@5
 (label) main::@6
 (label) main::@7
+(label) main::@8
 (label) main::@return
 (byte) main::i
-(byte) main::i#1 reg byte x 22.0
-(byte) main::i#2 reg byte x 11.0
+(byte) main::i#1 reg byte a 22.0
+(byte) main::i#2 reg byte a 11.0
 (byte) main::j
-(byte) main::j#1 reg byte a 11.0
-(byte) main::j#2 reg byte a 22.0
+(byte) main::j#1 reg byte y 8.25
+(byte) main::j#2 j zp[1]:2 16.5
+(byte) main::j#4 j zp[1]:2 22.0
 (byte) main::k
-(byte) main::k#1 reg byte a 16.5
-(byte) main::k#2 reg byte a 11.0
+(byte) main::k#1 reg byte a 11.0
+(byte) main::k#2 reg byte x 11.0
+(byte) main::k#3 reg byte x 22.0
 
-reg byte x [ main::i#2 main::i#1 ]
-reg byte y [ idx#10 idx#0 ]
-reg byte a [ main::j#2 main::j#1 ]
-reg byte y [ idx#11 idx#1 idx#2 ]
-reg byte a [ main::k#2 main::k#1 ]
+reg byte a [ main::i#2 main::i#1 ]
+reg byte x [ idx#10 idx#0 ]
+zp[1]:2 [ main::j#2 main::j#4 ]
+reg byte x [ idx#11 idx#1 idx#2 ]
+reg byte x [ main::k#2 main::k#3 ]
 reg byte y [ idx#13 idx#3 idx#14 ]
+reg byte y [ main::j#1 ]
+reg byte a [ main::k#1 ]
 
 
 FINAL ASSEMBLER
-Score: 629
+Score: 843
 
   // File Comments
 // Tests using integer conditions in while() / for() / do..while
-// This should produce 'ba ba ba' at the top of the screen
+// This should produce 'ba ba@ ba@' at the top of the screen
   // Upstart
 .pc = $801 "Basic"
 :BasicUpstart(main)
@@ -634,97 +693,113 @@ Score: 629
   .label SCREEN = $400
   // main
 main: {
+    // while()
+    .label j = 2
     // [1] phi from main to main::@1 [phi:main->main::@1]
-    // [1] phi (byte) idx#10 = (byte) 0 [phi:main->main::@1#0] -- vbuyy=vbuc1 
-    ldy #0
-    // [1] phi (byte) main::i#2 = (byte) 2 [phi:main->main::@1#1] -- vbuxx=vbuc1 
-    ldx #2
+    // [1] phi (byte) idx#10 = (byte) 0 [phi:main->main::@1#0] -- vbuxx=vbuc1 
+    ldx #0
+    // [1] phi (byte) main::i#2 = (byte) 2 [phi:main->main::@1#1] -- vbuaa=vbuc1 
+    lda #2
   // for()
     // main::@1
   __b1:
     // for( byte i=2;i;i--)
-    // [2] if((byte) 0!=(byte) main::i#2) goto main::@2 -- vbuc1_neq_vbuxx_then_la1 
-    cpx #0
+    // [2] if((byte) 0!=(byte) main::i#2) goto main::@2 -- vbuc1_neq_vbuaa_then_la1 
+    cmp #0
     bne __b2
     // main::@3
     // SCREEN[idx++] = ' '
-    // [3] *((const nomodify byte*) SCREEN + (byte) idx#10) ← (byte) ' ' -- pbuc1_derefidx_vbuyy=vbuc2 
+    // [3] *((const nomodify byte*) SCREEN + (byte) idx#10) ← (byte) ' ' -- pbuc1_derefidx_vbuxx=vbuc2 
     lda #' '
-    sta SCREEN,y
+    sta SCREEN,x
     // SCREEN[idx++] = ' ';
-    // [4] (byte) idx#1 ← ++ (byte) idx#10 -- vbuyy=_inc_vbuyy 
-    iny
+    // [4] (byte) idx#1 ← ++ (byte) idx#10 -- vbuxx=_inc_vbuxx 
+    inx
     // [5] phi from main::@3 to main::@4 [phi:main::@3->main::@4]
     // [5] phi (byte) idx#11 = (byte) idx#1 [phi:main::@3->main::@4#0] -- register_copy 
-    // [5] phi (byte) main::j#2 = (byte) 3 [phi:main::@3->main::@4#1] -- vbuaa=vbuc1 
+    // [5] phi (byte) main::j#2 = (byte) 3 [phi:main::@3->main::@4#1] -- vbuz1=vbuc1 
     lda #3
+    sta.z j
     // main::@4
   __b4:
     // while( j-- )
-    // [6] (byte) main::j#1 ← -- (byte) main::j#2 -- vbuaa=_dec_vbuaa 
-    sec
-    sbc #1
-    // [7] if((byte) 0!=(byte) main::j#1) goto main::@5 -- vbuc1_neq_vbuaa_then_la1 
-    cmp #0
+    // [6] (byte) main::j#1 ← -- (byte) main::j#2 -- vbuyy=_dec_vbuz1 
+    ldy.z j
+    dey
+    // [7] if((byte) 0!=(byte) main::j#2) goto main::@5 -- vbuc1_neq_vbuz1_then_la1 
+    lda #0
+    cmp.z j
     bne __b5
     // main::@6
     // SCREEN[idx++] = ' '
-    // [8] *((const nomodify byte*) SCREEN + (byte) idx#11) ← (byte) ' ' -- pbuc1_derefidx_vbuyy=vbuc2 
+    // [8] *((const nomodify byte*) SCREEN + (byte) idx#11) ← (byte) ' ' -- pbuc1_derefidx_vbuxx=vbuc2 
     lda #' '
-    sta SCREEN,y
+    sta SCREEN,x
     // SCREEN[idx++] = ' ';
-    // [9] (byte) idx#3 ← ++ (byte) idx#11 -- vbuyy=_inc_vbuyy 
+    // [9] (byte) idx#3 ← ++ (byte) idx#11 -- vbuyy=_inc_vbuxx 
+    txa
+    tay
     iny
     // [10] phi from main::@6 to main::@7 [phi:main::@6->main::@7]
     // [10] phi (byte) idx#13 = (byte) idx#3 [phi:main::@6->main::@7#0] -- register_copy 
-    // [10] phi (byte) main::k#2 = (byte) 2 [phi:main::@6->main::@7#1] -- vbuaa=vbuc1 
-    lda #2
-    // [10] phi from main::@7 to main::@7 [phi:main::@7->main::@7]
-    // [10] phi (byte) idx#13 = (byte) idx#14 [phi:main::@7->main::@7#0] -- register_copy 
-    // [10] phi (byte) main::k#2 = (byte) main::k#1 [phi:main::@7->main::@7#1] -- register_copy 
+    // [10] phi (byte) main::k#2 = (byte) 2 [phi:main::@6->main::@7#1] -- vbuxx=vbuc1 
+    ldx #2
     // main::@7
   __b7:
     // SCREEN[idx++] = k
-    // [11] *((const nomodify byte*) SCREEN + (byte) idx#13) ← (byte) main::k#2 -- pbuc1_derefidx_vbuyy=vbuaa 
+    // [11] *((const nomodify byte*) SCREEN + (byte) idx#13) ← (byte) main::k#2 -- pbuc1_derefidx_vbuyy=vbuxx 
+    txa
     sta SCREEN,y
     // SCREEN[idx++] = k;
     // [12] (byte) idx#14 ← ++ (byte) idx#13 -- vbuyy=_inc_vbuyy 
     iny
     // while(k--)
-    // [13] (byte) main::k#1 ← -- (byte) main::k#2 -- vbuaa=_dec_vbuaa 
+    // [13] (byte) main::k#1 ← -- (byte) main::k#2 -- vbuaa=_dec_vbuxx 
+    txa
     sec
     sbc #1
-    // [14] if((byte) 0!=(byte) main::k#1) goto main::@7 -- vbuc1_neq_vbuaa_then_la1 
-    cmp #0
-    bne __b7
+    // [14] if((byte) 0!=(byte) main::k#2) goto main::@8 -- vbuc1_neq_vbuxx_then_la1 
+    cpx #0
+    bne __b8
     // main::@return
     // }
     // [15] return 
     rts
+    // main::@8
+  __b8:
+    // [16] (byte) main::k#3 ← (byte) main::k#1 -- vbuxx=vbuaa 
+    tax
+    // [10] phi from main::@8 to main::@7 [phi:main::@8->main::@7]
+    // [10] phi (byte) idx#13 = (byte) idx#14 [phi:main::@8->main::@7#0] -- register_copy 
+    // [10] phi (byte) main::k#2 = (byte) main::k#3 [phi:main::@8->main::@7#1] -- register_copy 
+    jmp __b7
     // main::@5
   __b5:
     // SCREEN[idx++] = j
-    // [16] *((const nomodify byte*) SCREEN + (byte) idx#11) ← (byte) main::j#1 -- pbuc1_derefidx_vbuyy=vbuaa 
-    sta SCREEN,y
+    // [17] *((const nomodify byte*) SCREEN + (byte) idx#11) ← (byte) main::j#1 -- pbuc1_derefidx_vbuxx=vbuyy 
+    tya
+    sta SCREEN,x
     // SCREEN[idx++] = j;
-    // [17] (byte) idx#2 ← ++ (byte) idx#11 -- vbuyy=_inc_vbuyy 
-    iny
+    // [18] (byte) idx#2 ← ++ (byte) idx#11 -- vbuxx=_inc_vbuxx 
+    inx
+    // [19] (byte) main::j#4 ← (byte) main::j#1 -- vbuz1=vbuyy 
+    sty.z j
     // [5] phi from main::@5 to main::@4 [phi:main::@5->main::@4]
     // [5] phi (byte) idx#11 = (byte) idx#2 [phi:main::@5->main::@4#0] -- register_copy 
-    // [5] phi (byte) main::j#2 = (byte) main::j#1 [phi:main::@5->main::@4#1] -- register_copy 
+    // [5] phi (byte) main::j#2 = (byte) main::j#4 [phi:main::@5->main::@4#1] -- register_copy 
     jmp __b4
     // main::@2
   __b2:
     // SCREEN[idx++] = i
-    // [18] *((const nomodify byte*) SCREEN + (byte) idx#10) ← (byte) main::i#2 -- pbuc1_derefidx_vbuyy=vbuxx 
-    txa
-    sta SCREEN,y
+    // [20] *((const nomodify byte*) SCREEN + (byte) idx#10) ← (byte) main::i#2 -- pbuc1_derefidx_vbuxx=vbuaa 
+    sta SCREEN,x
     // SCREEN[idx++] = i;
-    // [19] (byte) idx#0 ← ++ (byte) idx#10 -- vbuyy=_inc_vbuyy 
-    iny
+    // [21] (byte) idx#0 ← ++ (byte) idx#10 -- vbuxx=_inc_vbuxx 
+    inx
     // for( byte i=2;i;i--)
-    // [20] (byte) main::i#1 ← -- (byte) main::i#2 -- vbuxx=_dec_vbuxx 
-    dex
+    // [22] (byte) main::i#1 ← -- (byte) main::i#2 -- vbuaa=_dec_vbuaa 
+    sec
+    sbc #1
     // [1] phi from main::@2 to main::@1 [phi:main::@2->main::@1]
     // [1] phi (byte) idx#10 = (byte) idx#0 [phi:main::@2->main::@1#0] -- register_copy 
     // [1] phi (byte) main::i#2 = (byte) main::i#1 [phi:main::@2->main::@1#1] -- register_copy 
diff --git a/src/test/ref/condition-integer-2.sym b/src/test/ref/condition-integer-2.sym
index f86749717..089e80857 100644
--- a/src/test/ref/condition-integer-2.sym
+++ b/src/test/ref/condition-integer-2.sym
@@ -1,12 +1,12 @@
 (const nomodify byte*) SCREEN = (byte*) 1024
 (byte) idx
-(byte) idx#0 reg byte y 11.0
-(byte) idx#1 reg byte y 4.0
-(byte) idx#10 reg byte y 9.25
-(byte) idx#11 reg byte y 7.8
+(byte) idx#0 reg byte x 11.0
+(byte) idx#1 reg byte x 4.0
+(byte) idx#10 reg byte x 9.25
+(byte) idx#11 reg byte x 7.8
 (byte) idx#13 reg byte y 17.5
-(byte) idx#14 reg byte y 7.333333333333333
-(byte) idx#2 reg byte y 22.0
+(byte) idx#14 reg byte y 5.5
+(byte) idx#2 reg byte x 11.0
 (byte) idx#3 reg byte y 4.0
 (void()) main()
 (label) main::@1
@@ -16,20 +16,25 @@
 (label) main::@5
 (label) main::@6
 (label) main::@7
+(label) main::@8
 (label) main::@return
 (byte) main::i
-(byte) main::i#1 reg byte x 22.0
-(byte) main::i#2 reg byte x 11.0
+(byte) main::i#1 reg byte a 22.0
+(byte) main::i#2 reg byte a 11.0
 (byte) main::j
-(byte) main::j#1 reg byte a 11.0
-(byte) main::j#2 reg byte a 22.0
+(byte) main::j#1 reg byte y 8.25
+(byte) main::j#2 j zp[1]:2 16.5
+(byte) main::j#4 j zp[1]:2 22.0
 (byte) main::k
-(byte) main::k#1 reg byte a 16.5
-(byte) main::k#2 reg byte a 11.0
+(byte) main::k#1 reg byte a 11.0
+(byte) main::k#2 reg byte x 11.0
+(byte) main::k#3 reg byte x 22.0
 
-reg byte x [ main::i#2 main::i#1 ]
-reg byte y [ idx#10 idx#0 ]
-reg byte a [ main::j#2 main::j#1 ]
-reg byte y [ idx#11 idx#1 idx#2 ]
-reg byte a [ main::k#2 main::k#1 ]
+reg byte a [ main::i#2 main::i#1 ]
+reg byte x [ idx#10 idx#0 ]
+zp[1]:2 [ main::j#2 main::j#4 ]
+reg byte x [ idx#11 idx#1 idx#2 ]
+reg byte x [ main::k#2 main::k#3 ]
 reg byte y [ idx#13 idx#3 idx#14 ]
+reg byte y [ main::j#1 ]
+reg byte a [ main::k#1 ]