From 9502a6f59014dec173cfc19d9413b39e707d6f08 Mon Sep 17 00:00:00 2001
From: Irmen de Jong <irmen@razorvine.net>
Date: Fri, 13 Mar 2026 21:49:55 +0100
Subject: [PATCH] fix invalid augmented assignment optimization, and a call to
 pop() that crashed a symbol prefix test because the call wasn't defined as a
 builtin

---
 .../compiler/astprocessing/CodeDesugarer.kt   | 22 +++++++++++--------
 .../prog8/compiler/astprocessing/Utility.kt   |  2 +-
 docs/source/todo.rst                          |  3 ---
 examples/test.p8                              | 11 ++++++++--
 4 files changed, 23 insertions(+), 15 deletions(-)

diff --git a/compiler/src/prog8/compiler/astprocessing/CodeDesugarer.kt b/compiler/src/prog8/compiler/astprocessing/CodeDesugarer.kt
index 8da2f641f..44f4a3ca5 100644
--- a/compiler/src/prog8/compiler/astprocessing/CodeDesugarer.kt
+++ b/compiler/src/prog8/compiler/astprocessing/CodeDesugarer.kt
@@ -946,21 +946,25 @@ _after:
         // consolidates simple assignment followed by augmented assignment into a single combined assignment.
         // a = simplevalue  |  a += expression  -->   a = simplevalue + expression  (for all augmented operators)
         // NOTE: this is NOT SAFE to do when dealing with pointer arithmetic because the semantics of the combined expression is different!
+        // NOTE: this is also NOT SAFE when the augmented assignment's RHS references the target variable (e.g., a = b; a *= a)
         if(!assignment.isAugmentable && assignment.value.isSimple) {
             val next = assignment.nextSibling() as? Assignment
             if(next?.isAugmentable==true && next.value is BinaryExpression && next.target.isSameAs(assignment.target, program)) {
                 val combined = next.value as BinaryExpression
                 if(combined.left isSameAs assignment.target) {
-                    if(!assignment.target.inferType(program).isPointer && (assignment.value.inferType(program).isPointer || combined.right.inferType(program).isPointer)) {
-                        // avoid pointer arithmetic:  a = (simplevalue as uword) + expression
-                        combined.left = TypecastExpression(assignment.value, DataType.UWORD, true, combined.left.position)
-                    } else {
-                        // no pointer arithmetic done, just transform it into   a = simplevalue + expression
-                        combined.left = assignment.value
+                    // Check if RHS also references the target variable - if so, can't optimize
+                    if(!(combined.right isSameAs assignment.target)) {
+                        if(!assignment.target.inferType(program).isPointer && (assignment.value.inferType(program).isPointer || combined.right.inferType(program).isPointer)) {
+                            // avoid pointer arithmetic:  a = (simplevalue as uword) + expression
+                            combined.left = TypecastExpression(assignment.value, DataType.UWORD, true, combined.left.position)
+                        } else {
+                            // no pointer arithmetic done, just transform it into   a = simplevalue + expression
+                            combined.left = assignment.value
+                        }
+                        assignment.value = combined
+                        combined.linkParents(assignment)
+                        return listOf(IAstModification.Remove(next, parent as IStatementContainer))
                     }
-                    assignment.value = combined
-                    combined.linkParents(assignment)
-                    return listOf(IAstModification.Remove(next, parent as IStatementContainer))
                 }
             }
         }
diff --git a/compiler/src/prog8/compiler/astprocessing/Utility.kt b/compiler/src/prog8/compiler/astprocessing/Utility.kt
index 05ab6788d..07df84bb9 100644
--- a/compiler/src/prog8/compiler/astprocessing/Utility.kt
+++ b/compiler/src/prog8/compiler/astprocessing/Utility.kt
@@ -50,7 +50,7 @@ internal fun makePushPopFunctionCalls(value: PtExpression): Pair<PtFunctionCall,
     val popCall = if(popTypecast!=null) {
         PtTypeCast(popTypecast, true, value.position).also {
             val returnDt = if(pushWord) DataType.UWORD else if(pushLong) DataType.LONG else if(pushFloat) DataType.FLOAT else DataType.UBYTE
-            it.add(PtFunctionCall(popFunc, false, false, arrayOf(returnDt), value.position))
+            it.add(PtFunctionCall(popFunc, true, false, arrayOf(returnDt), value.position))
         }
     } else
         PtFunctionCall(popFunc, true, false, arrayOf(value.type), value.position)
diff --git a/docs/source/todo.rst b/docs/source/todo.rst
index f0fa3555f..e2694b1f5 100644
--- a/docs/source/todo.rst
+++ b/docs/source/todo.rst
@@ -1,9 +1,6 @@
 TODO
 ====
 
-BUG in unzip: lookup error p8s_pop  [unzip.p8: line 262 col 16-24]
-
-
 Known bugs:
 - fix chained aliasing errors see test "chained aliasing"
 - fix crash in ir loader/vm for deeply nested symbol reference, see test "deeply scoped variable references"
diff --git a/examples/test.p8 b/examples/test.p8
index 1c9fb1677..948077351 100644
--- a/examples/test.p8
+++ b/examples/test.p8
@@ -6,9 +6,16 @@ main {
     sub start() {
         long @shared z1, z2
         z1=1111
-
-        z2 = z1*z1
+        z2=z1
+        z2*=z2
         txt.print_l(z2)
+        txt.nl()
+
+        z1=-1111
+        z2=z1
+        z2*=z2
+        txt.print_l(z2)
+        txt.nl()
     }
 }