diff --git a/src/main/java/dk/camelot64/kickc/passes/Pass4RegisterUpliftPotentialRegisterAnalysis.java b/src/main/java/dk/camelot64/kickc/passes/Pass4RegisterUpliftPotentialRegisterAnalysis.java
index c5a6be49a..ead0111ec 100644
--- a/src/main/java/dk/camelot64/kickc/passes/Pass4RegisterUpliftPotentialRegisterAnalysis.java
+++ b/src/main/java/dk/camelot64/kickc/passes/Pass4RegisterUpliftPotentialRegisterAnalysis.java
@@ -5,11 +5,9 @@ import dk.camelot64.kickc.asm.AsmProgram;
 import dk.camelot64.kickc.fragment.AsmFragmentInstance;
 import dk.camelot64.kickc.fragment.AsmFragmentTemplateSynthesizer;
 import dk.camelot64.kickc.model.*;
+import dk.camelot64.kickc.model.statements.*;
 import dk.camelot64.kickc.model.values.LValue;
 import dk.camelot64.kickc.model.values.VariableRef;
-import dk.camelot64.kickc.model.statements.Statement;
-import dk.camelot64.kickc.model.statements.StatementAssignment;
-import dk.camelot64.kickc.model.statements.StatementPhiBlock;
 
 import java.util.*;
 
@@ -39,8 +37,8 @@ public class Pass4RegisterUpliftPotentialRegisterAnalysis extends Pass2Base {
             variableRefs.add(phiVariable.getVariable());
          }
          return variableRefs;
-      } else if(statement instanceof StatementAssignment) {
-         LValue lValue = ((StatementAssignment) statement).getlValue();
+      } else if(statement instanceof StatementLValue) {
+         LValue lValue = ((StatementLValue) statement).getlValue();
          if(lValue instanceof VariableRef) {
             variableRefs.add((VariableRef) lValue);
          }
diff --git a/src/test/java/dk/camelot64/kickc/test/TestPrograms.java b/src/test/java/dk/camelot64/kickc/test/TestPrograms.java
index 34cfcf980..9ae8ceaf7 100644
--- a/src/test/java/dk/camelot64/kickc/test/TestPrograms.java
+++ b/src/test/java/dk/camelot64/kickc/test/TestPrograms.java
@@ -57,7 +57,7 @@ public class TestPrograms {
 
    @Test
    public void testProcedureCallingConventionStack0() throws IOException, URISyntaxException {
-      compileAndCompare("procedure-callingconvention-stack-0"); //, log().verboseCreateSsa().verboseParse().verboseStatementSequence().verboseUplift().verboseLiveRanges().verboseSSAOptimize());
+      compileAndCompare("procedure-callingconvention-stack-0");
    }
 
    @Test
diff --git a/src/test/ref/procedure-callingconvention-stack-0.asm b/src/test/ref/procedure-callingconvention-stack-0.asm
index f770b0722..b061638cc 100644
--- a/src/test/ref/procedure-callingconvention-stack-0.asm
+++ b/src/test/ref/procedure-callingconvention-stack-0.asm
@@ -5,7 +5,6 @@
   .label SCREEN = $400
   .const STACK_BASE = $103
 main: {
-    .label _0 = 2
     lda #'0'
     pha
     lda #7
@@ -13,7 +12,6 @@ main: {
     jsr plus
     pla
     pla
-    sta.z _0
     sta SCREEN
     rts
 }
diff --git a/src/test/ref/procedure-callingconvention-stack-0.log b/src/test/ref/procedure-callingconvention-stack-0.log
index 49790fbe9..121a292ec 100644
--- a/src/test/ref/procedure-callingconvention-stack-0.log
+++ b/src/test/ref/procedure-callingconvention-stack-0.log
@@ -262,14 +262,11 @@ Uplift Scope [main] 2: zp ZP_BYTE:2 [ main::$0 ]
 Uplift Scope [] 
 
 Uplifting [plus] best 84 combination reg byte a [ plus::b#0 ] zp ZP_BYTE:3 [ plus::a#0 ] reg byte a [ plus::return#0 ] 
-Uplifting [main] best 84 combination zp ZP_BYTE:2 [ main::$0 ] 
-Uplifting [] best 84 combination 
-Attempting to uplift remaining variables inzp ZP_BYTE:2 [ main::$0 ]
-Uplifting [main] best 84 combination zp ZP_BYTE:2 [ main::$0 ] 
+Uplifting [main] best 78 combination reg byte a [ main::$0 ] 
+Uplifting [] best 78 combination 
 Attempting to uplift remaining variables inzp ZP_BYTE:3 [ plus::a#0 ]
-Uplifting [plus] best 84 combination zp ZP_BYTE:3 [ plus::a#0 ] 
-Coalescing zero page register [ zp ZP_BYTE:3 [ plus::a#0 ] ] with [ zp ZP_BYTE:2 [ main::$0 ] ]
-Allocated (was zp ZP_BYTE:3) zp ZP_BYTE:2 [ plus::a#0 main::$0 ]
+Uplifting [plus] best 78 combination zp ZP_BYTE:3 [ plus::a#0 ] 
+Allocated (was zp ZP_BYTE:3) zp ZP_BYTE:2 [ plus::a#0 ]
 
 ASSEMBLER BEFORE OPTIMIZATION
   // File Comments
@@ -299,7 +296,6 @@ bend_from_b1:
 bend:
   // main
 main: {
-    .label _0 = 2
     // [5] callprepare plus (byte) '0' (byte) 7 
     // [5] callprepare plus (byte) '0' (byte) 7  -- _stackpushbyte_=vbuc1 
     lda #'0'
@@ -313,11 +309,9 @@ main: {
     // [7] (byte~) main::$0 ← callfinalize plus 
     // [7] (byte~) main::$0 ← callfinalize plus  -- _stackpullbyte_1 
     pla
-    // [7] (byte~) main::$0 ← callfinalize plus  -- vbuz1=_stackpullbyte_ 
+    // [7] (byte~) main::$0 ← callfinalize plus  -- vbuaa=_stackpullbyte_ 
     pla
-    sta.z _0
-    // [8] *((const byte*) SCREEN#0) ← (byte~) main::$0 -- _deref_pbuc1=vbuz1 
-    lda.z _0
+    // [8] *((const byte*) SCREEN#0) ← (byte~) main::$0 -- _deref_pbuc1=vbuaa 
     sta SCREEN
     jmp breturn
     // main::@return
@@ -355,8 +349,6 @@ Removing instruction jmp bend
 Removing instruction jmp breturn
 Removing instruction jmp breturn
 Succesful ASM optimization Pass5NextJumpElimination
-Removing instruction lda.z _0
-Succesful ASM optimization Pass5UnnecesaryLoadElimination
 Removing instruction b1_from_bbegin:
 Removing instruction b1:
 Removing instruction main_from_b1:
@@ -380,7 +372,7 @@ FINAL SYMBOL TABLE
 (const byte*) SCREEN#0 SCREEN = (byte*) 1024
 (const word) STACK_BASE STACK_BASE = (word) $103
 (void()) main()
-(byte~) main::$0 $0 zp ZP_BYTE:2 2.0
+(byte~) main::$0 reg byte a 2.0
 (label) main::@return
 __stackcall (byte()) plus((byte) plus::a , (byte) plus::b)
 (label) plus::@return
@@ -393,13 +385,14 @@ __stackcall (byte()) plus((byte) plus::a , (byte) plus::b)
 (byte) plus::return
 (byte) plus::return#0 reg byte a 2.0
 
-zp ZP_BYTE:2 [ plus::a#0 main::$0 ]
+reg byte a [ main::$0 ]
+zp ZP_BYTE:2 [ plus::a#0 ]
 reg byte a [ plus::b#0 ]
 reg byte a [ plus::return#0 ]
 
 
 FINAL ASSEMBLER
-Score: 63
+Score: 60
 
   // File Comments
 // Test a procedure with calling convention stack
@@ -419,7 +412,6 @@ Score: 63
   // @end
   // main
 main: {
-    .label _0 = 2
     // plus('0', 7)
     // [5] callprepare plus (byte) '0' (byte) 7 
     // [5] callprepare plus (byte) '0' (byte) 7  -- _stackpushbyte_=vbuc1 
@@ -434,11 +426,10 @@ main: {
     // [7] (byte~) main::$0 ← callfinalize plus 
     // [7] (byte~) main::$0 ← callfinalize plus  -- _stackpullbyte_1 
     pla
-    // [7] (byte~) main::$0 ← callfinalize plus  -- vbuz1=_stackpullbyte_ 
+    // [7] (byte~) main::$0 ← callfinalize plus  -- vbuaa=_stackpullbyte_ 
     pla
-    sta.z _0
     // SCREEN[0] = plus('0', 7)
-    // [8] *((const byte*) SCREEN#0) ← (byte~) main::$0 -- _deref_pbuc1=vbuz1 
+    // [8] *((const byte*) SCREEN#0) ← (byte~) main::$0 -- _deref_pbuc1=vbuaa 
     sta SCREEN
     // main::@return
     // }
diff --git a/src/test/ref/procedure-callingconvention-stack-0.sym b/src/test/ref/procedure-callingconvention-stack-0.sym
index 1d1338bbe..3f16225e7 100644
--- a/src/test/ref/procedure-callingconvention-stack-0.sym
+++ b/src/test/ref/procedure-callingconvention-stack-0.sym
@@ -5,7 +5,7 @@
 (const byte*) SCREEN#0 SCREEN = (byte*) 1024
 (const word) STACK_BASE STACK_BASE = (word) $103
 (void()) main()
-(byte~) main::$0 $0 zp ZP_BYTE:2 2.0
+(byte~) main::$0 reg byte a 2.0
 (label) main::@return
 __stackcall (byte()) plus((byte) plus::a , (byte) plus::b)
 (label) plus::@return
@@ -18,6 +18,7 @@ __stackcall (byte()) plus((byte) plus::a , (byte) plus::b)
 (byte) plus::return
 (byte) plus::return#0 reg byte a 2.0
 
-zp ZP_BYTE:2 [ plus::a#0 main::$0 ]
+reg byte a [ main::$0 ]
+zp ZP_BYTE:2 [ plus::a#0 ]
 reg byte a [ plus::b#0 ]
 reg byte a [ plus::return#0 ]
diff --git a/src/test/ref/procedure-callingconvention-stack-1.asm b/src/test/ref/procedure-callingconvention-stack-1.asm
index f770b0722..b061638cc 100644
--- a/src/test/ref/procedure-callingconvention-stack-1.asm
+++ b/src/test/ref/procedure-callingconvention-stack-1.asm
@@ -5,7 +5,6 @@
   .label SCREEN = $400
   .const STACK_BASE = $103
 main: {
-    .label _0 = 2
     lda #'0'
     pha
     lda #7
@@ -13,7 +12,6 @@ main: {
     jsr plus
     pla
     pla
-    sta.z _0
     sta SCREEN
     rts
 }
diff --git a/src/test/ref/procedure-callingconvention-stack-1.log b/src/test/ref/procedure-callingconvention-stack-1.log
index 49790fbe9..121a292ec 100644
--- a/src/test/ref/procedure-callingconvention-stack-1.log
+++ b/src/test/ref/procedure-callingconvention-stack-1.log
@@ -262,14 +262,11 @@ Uplift Scope [main] 2: zp ZP_BYTE:2 [ main::$0 ]
 Uplift Scope [] 
 
 Uplifting [plus] best 84 combination reg byte a [ plus::b#0 ] zp ZP_BYTE:3 [ plus::a#0 ] reg byte a [ plus::return#0 ] 
-Uplifting [main] best 84 combination zp ZP_BYTE:2 [ main::$0 ] 
-Uplifting [] best 84 combination 
-Attempting to uplift remaining variables inzp ZP_BYTE:2 [ main::$0 ]
-Uplifting [main] best 84 combination zp ZP_BYTE:2 [ main::$0 ] 
+Uplifting [main] best 78 combination reg byte a [ main::$0 ] 
+Uplifting [] best 78 combination 
 Attempting to uplift remaining variables inzp ZP_BYTE:3 [ plus::a#0 ]
-Uplifting [plus] best 84 combination zp ZP_BYTE:3 [ plus::a#0 ] 
-Coalescing zero page register [ zp ZP_BYTE:3 [ plus::a#0 ] ] with [ zp ZP_BYTE:2 [ main::$0 ] ]
-Allocated (was zp ZP_BYTE:3) zp ZP_BYTE:2 [ plus::a#0 main::$0 ]
+Uplifting [plus] best 78 combination zp ZP_BYTE:3 [ plus::a#0 ] 
+Allocated (was zp ZP_BYTE:3) zp ZP_BYTE:2 [ plus::a#0 ]
 
 ASSEMBLER BEFORE OPTIMIZATION
   // File Comments
@@ -299,7 +296,6 @@ bend_from_b1:
 bend:
   // main
 main: {
-    .label _0 = 2
     // [5] callprepare plus (byte) '0' (byte) 7 
     // [5] callprepare plus (byte) '0' (byte) 7  -- _stackpushbyte_=vbuc1 
     lda #'0'
@@ -313,11 +309,9 @@ main: {
     // [7] (byte~) main::$0 ← callfinalize plus 
     // [7] (byte~) main::$0 ← callfinalize plus  -- _stackpullbyte_1 
     pla
-    // [7] (byte~) main::$0 ← callfinalize plus  -- vbuz1=_stackpullbyte_ 
+    // [7] (byte~) main::$0 ← callfinalize plus  -- vbuaa=_stackpullbyte_ 
     pla
-    sta.z _0
-    // [8] *((const byte*) SCREEN#0) ← (byte~) main::$0 -- _deref_pbuc1=vbuz1 
-    lda.z _0
+    // [8] *((const byte*) SCREEN#0) ← (byte~) main::$0 -- _deref_pbuc1=vbuaa 
     sta SCREEN
     jmp breturn
     // main::@return
@@ -355,8 +349,6 @@ Removing instruction jmp bend
 Removing instruction jmp breturn
 Removing instruction jmp breturn
 Succesful ASM optimization Pass5NextJumpElimination
-Removing instruction lda.z _0
-Succesful ASM optimization Pass5UnnecesaryLoadElimination
 Removing instruction b1_from_bbegin:
 Removing instruction b1:
 Removing instruction main_from_b1:
@@ -380,7 +372,7 @@ FINAL SYMBOL TABLE
 (const byte*) SCREEN#0 SCREEN = (byte*) 1024
 (const word) STACK_BASE STACK_BASE = (word) $103
 (void()) main()
-(byte~) main::$0 $0 zp ZP_BYTE:2 2.0
+(byte~) main::$0 reg byte a 2.0
 (label) main::@return
 __stackcall (byte()) plus((byte) plus::a , (byte) plus::b)
 (label) plus::@return
@@ -393,13 +385,14 @@ __stackcall (byte()) plus((byte) plus::a , (byte) plus::b)
 (byte) plus::return
 (byte) plus::return#0 reg byte a 2.0
 
-zp ZP_BYTE:2 [ plus::a#0 main::$0 ]
+reg byte a [ main::$0 ]
+zp ZP_BYTE:2 [ plus::a#0 ]
 reg byte a [ plus::b#0 ]
 reg byte a [ plus::return#0 ]
 
 
 FINAL ASSEMBLER
-Score: 63
+Score: 60
 
   // File Comments
 // Test a procedure with calling convention stack
@@ -419,7 +412,6 @@ Score: 63
   // @end
   // main
 main: {
-    .label _0 = 2
     // plus('0', 7)
     // [5] callprepare plus (byte) '0' (byte) 7 
     // [5] callprepare plus (byte) '0' (byte) 7  -- _stackpushbyte_=vbuc1 
@@ -434,11 +426,10 @@ main: {
     // [7] (byte~) main::$0 ← callfinalize plus 
     // [7] (byte~) main::$0 ← callfinalize plus  -- _stackpullbyte_1 
     pla
-    // [7] (byte~) main::$0 ← callfinalize plus  -- vbuz1=_stackpullbyte_ 
+    // [7] (byte~) main::$0 ← callfinalize plus  -- vbuaa=_stackpullbyte_ 
     pla
-    sta.z _0
     // SCREEN[0] = plus('0', 7)
-    // [8] *((const byte*) SCREEN#0) ← (byte~) main::$0 -- _deref_pbuc1=vbuz1 
+    // [8] *((const byte*) SCREEN#0) ← (byte~) main::$0 -- _deref_pbuc1=vbuaa 
     sta SCREEN
     // main::@return
     // }
diff --git a/src/test/ref/procedure-callingconvention-stack-1.sym b/src/test/ref/procedure-callingconvention-stack-1.sym
index 1d1338bbe..3f16225e7 100644
--- a/src/test/ref/procedure-callingconvention-stack-1.sym
+++ b/src/test/ref/procedure-callingconvention-stack-1.sym
@@ -5,7 +5,7 @@
 (const byte*) SCREEN#0 SCREEN = (byte*) 1024
 (const word) STACK_BASE STACK_BASE = (word) $103
 (void()) main()
-(byte~) main::$0 $0 zp ZP_BYTE:2 2.0
+(byte~) main::$0 reg byte a 2.0
 (label) main::@return
 __stackcall (byte()) plus((byte) plus::a , (byte) plus::b)
 (label) plus::@return
@@ -18,6 +18,7 @@ __stackcall (byte()) plus((byte) plus::a , (byte) plus::b)
 (byte) plus::return
 (byte) plus::return#0 reg byte a 2.0
 
-zp ZP_BYTE:2 [ plus::a#0 main::$0 ]
+reg byte a [ main::$0 ]
+zp ZP_BYTE:2 [ plus::a#0 ]
 reg byte a [ plus::b#0 ]
 reg byte a [ plus::return#0 ]
diff --git a/src/test/ref/procedure-callingconvention-stack-4.asm b/src/test/ref/procedure-callingconvention-stack-4.asm
index e30da2ff6..cc0338948 100644
--- a/src/test/ref/procedure-callingconvention-stack-4.asm
+++ b/src/test/ref/procedure-callingconvention-stack-4.asm
@@ -6,7 +6,6 @@
   .label SCREEN = $400
   .const STACK_BASE = $103
 main: {
-    .label w = 2
     ldy #0
   b1:
     tya
@@ -19,10 +18,9 @@ main: {
     jsr plus
     pla
     pla
-    sta.z w
-    tya
+    sty.z $ff
     clc
-    adc.z w
+    adc.z $ff
     sta SCREEN
     iny
     cpy #2
diff --git a/src/test/ref/procedure-callingconvention-stack-4.log b/src/test/ref/procedure-callingconvention-stack-4.log
index 7a3b632a4..3cb2fd89f 100644
--- a/src/test/ref/procedure-callingconvention-stack-4.log
+++ b/src/test/ref/procedure-callingconvention-stack-4.log
@@ -403,16 +403,13 @@ Uplift Scope [main] 22.79: zp ZP_BYTE:2 [ main::a#2 main::a#1 ] 22: zp ZP_BYTE:5
 Uplift Scope [plus] 4: zp ZP_BYTE:7 [ plus::b#0 ] 2: zp ZP_BYTE:6 [ plus::a#0 ] 2: zp ZP_BYTE:8 [ plus::return#0 ] 
 Uplift Scope [] 
 
-Uplifting [main] best 671 combination reg byte y [ main::a#2 main::a#1 ] reg byte a [ main::$2 ] reg byte x [ main::v#0 ] zp ZP_BYTE:4 [ main::w#0 ] 
+Uplifting [main] best 651 combination reg byte y [ main::a#2 main::a#1 ] reg byte a [ main::$2 ] reg byte x [ main::v#0 ] reg byte a [ main::w#0 ] 
 Limited combination testing to 100 combinations of 128 possible.
-Uplifting [plus] best 662 combination reg byte a [ plus::b#0 ] zp ZP_BYTE:6 [ plus::a#0 ] reg byte a [ plus::return#0 ] 
-Uplifting [] best 662 combination 
-Attempting to uplift remaining variables inzp ZP_BYTE:4 [ main::w#0 ]
-Uplifting [main] best 662 combination zp ZP_BYTE:4 [ main::w#0 ] 
+Uplifting [plus] best 642 combination reg byte a [ plus::b#0 ] zp ZP_BYTE:6 [ plus::a#0 ] reg byte a [ plus::return#0 ] 
+Uplifting [] best 642 combination 
 Attempting to uplift remaining variables inzp ZP_BYTE:6 [ plus::a#0 ]
-Uplifting [plus] best 662 combination zp ZP_BYTE:6 [ plus::a#0 ] 
-Coalescing zero page register [ zp ZP_BYTE:6 [ plus::a#0 ] ] with [ zp ZP_BYTE:4 [ main::w#0 ] ]
-Allocated (was zp ZP_BYTE:6) zp ZP_BYTE:2 [ plus::a#0 main::w#0 ]
+Uplifting [plus] best 642 combination zp ZP_BYTE:6 [ plus::a#0 ] 
+Allocated (was zp ZP_BYTE:6) zp ZP_BYTE:2 [ plus::a#0 ]
 
 ASSEMBLER BEFORE OPTIMIZATION
   // File Comments
@@ -443,7 +440,6 @@ bend_from_b1:
 bend:
   // main
 main: {
-    .label w = 2
     // [5] phi from main to main::@1 [phi:main->main::@1]
   b1_from_main:
     // [5] phi (byte) main::a#2 = (byte) 0 [phi:main->main::@1#0] -- vbuyy=vbuc1 
@@ -472,13 +468,12 @@ main: {
     // [9] (byte) main::w#0 ← callfinalize plus 
     // [9] (byte) main::w#0 ← callfinalize plus  -- _stackpullbyte_1 
     pla
-    // [9] (byte) main::w#0 ← callfinalize plus  -- vbuz1=_stackpullbyte_ 
+    // [9] (byte) main::w#0 ← callfinalize plus  -- vbuaa=_stackpullbyte_ 
     pla
-    sta.z w
-    // [10] (byte~) main::$2 ← (byte) main::w#0 + (byte) main::a#2 -- vbuaa=vbuz1_plus_vbuyy 
-    tya
+    // [10] (byte~) main::$2 ← (byte) main::w#0 + (byte) main::a#2 -- vbuaa=vbuaa_plus_vbuyy 
+    sty.z $ff
     clc
-    adc.z w
+    adc.z $ff
     // [11] *((const byte*) SCREEN#0) ← (byte~) main::$2 -- _deref_pbuc1=vbuaa 
     sta SCREEN
     // [12] (byte) main::a#1 ← ++ (byte) main::a#2 -- vbuyy=_inc_vbuyy 
@@ -561,7 +556,7 @@ FINAL SYMBOL TABLE
 (byte) main::v
 (byte) main::v#0 reg byte x 11.0
 (byte) main::w
-(byte) main::w#0 w zp ZP_BYTE:2 11.0
+(byte) main::w#0 reg byte a 11.0
 __stackcall (byte()) plus((byte) plus::a , (byte) plus::b)
 (label) plus::@return
 (const byte) plus::OFFSET_STACK_A OFFSET_STACK_A = (byte) 0
@@ -575,14 +570,15 @@ __stackcall (byte()) plus((byte) plus::a , (byte) plus::b)
 
 reg byte y [ main::a#2 main::a#1 ]
 reg byte x [ main::v#0 ]
+reg byte a [ main::w#0 ]
 reg byte a [ main::$2 ]
-zp ZP_BYTE:2 [ plus::a#0 main::w#0 ]
+zp ZP_BYTE:2 [ plus::a#0 ]
 reg byte a [ plus::b#0 ]
 reg byte a [ plus::return#0 ]
 
 
 FINAL ASSEMBLER
-Score: 557
+Score: 537
 
   // File Comments
 // Test a procedure with calling convention stack
@@ -603,7 +599,6 @@ Score: 557
   // @end
   // main
 main: {
-    .label w = 2
     // [5] phi from main to main::@1 [phi:main->main::@1]
     // [5] phi (byte) main::a#2 = (byte) 0 [phi:main->main::@1#0] -- vbuyy=vbuc1 
     ldy #0
@@ -630,14 +625,13 @@ main: {
     // [9] (byte) main::w#0 ← callfinalize plus 
     // [9] (byte) main::w#0 ← callfinalize plus  -- _stackpullbyte_1 
     pla
-    // [9] (byte) main::w#0 ← callfinalize plus  -- vbuz1=_stackpullbyte_ 
+    // [9] (byte) main::w#0 ← callfinalize plus  -- vbuaa=_stackpullbyte_ 
     pla
-    sta.z w
     // w+a
-    // [10] (byte~) main::$2 ← (byte) main::w#0 + (byte) main::a#2 -- vbuaa=vbuz1_plus_vbuyy 
-    tya
+    // [10] (byte~) main::$2 ← (byte) main::w#0 + (byte) main::a#2 -- vbuaa=vbuaa_plus_vbuyy 
+    sty.z $ff
     clc
-    adc.z w
+    adc.z $ff
     // SCREEN[i] = w+a
     // [11] *((const byte*) SCREEN#0) ← (byte~) main::$2 -- _deref_pbuc1=vbuaa 
     sta SCREEN
diff --git a/src/test/ref/procedure-callingconvention-stack-4.sym b/src/test/ref/procedure-callingconvention-stack-4.sym
index 5b2d1ff34..05f95ff24 100644
--- a/src/test/ref/procedure-callingconvention-stack-4.sym
+++ b/src/test/ref/procedure-callingconvention-stack-4.sym
@@ -15,7 +15,7 @@
 (byte) main::v
 (byte) main::v#0 reg byte x 11.0
 (byte) main::w
-(byte) main::w#0 w zp ZP_BYTE:2 11.0
+(byte) main::w#0 reg byte a 11.0
 __stackcall (byte()) plus((byte) plus::a , (byte) plus::b)
 (label) plus::@return
 (const byte) plus::OFFSET_STACK_A OFFSET_STACK_A = (byte) 0
@@ -29,7 +29,8 @@ __stackcall (byte()) plus((byte) plus::a , (byte) plus::b)
 
 reg byte y [ main::a#2 main::a#1 ]
 reg byte x [ main::v#0 ]
+reg byte a [ main::w#0 ]
 reg byte a [ main::$2 ]
-zp ZP_BYTE:2 [ plus::a#0 main::w#0 ]
+zp ZP_BYTE:2 [ plus::a#0 ]
 reg byte a [ plus::b#0 ]
 reg byte a [ plus::return#0 ]