diff --git a/lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/BytecodeCompiler.kt b/lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/BytecodeCompiler.kt
index 43a4b7f..cfbeb06 100644
--- a/lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/BytecodeCompiler.kt
+++ b/lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/BytecodeCompiler.kt
@@ -1683,12 +1683,12 @@ class BytecodeCompiler(
         val left = ensureObjSlot(a)
         val right = ensureObjSlot(b)
         val opcode = when {
-            isExactNonNullSlotClass(left.slot, ObjString.type) &&
-                isExactNonNullSlotClass(right.slot, ObjString.type) -> stringOp
-            isExactNonNullSlotClass(left.slot, ObjInt.type) &&
-                isExactNonNullSlotClass(right.slot, ObjInt.type) -> intOp
-            isExactNonNullSlotClass(left.slot, ObjReal.type) &&
-                isExactNonNullSlotClass(right.slot, ObjReal.type) -> realOp
+            isExactNonNullSlotClassOrTemp(left.slot, ObjString.type) &&
+                isExactNonNullSlotClassOrTemp(right.slot, ObjString.type) -> stringOp
+            isExactNonNullSlotClassOrTemp(left.slot, ObjInt.type) &&
+                isExactNonNullSlotClassOrTemp(right.slot, ObjInt.type) -> intOp
+            isExactNonNullSlotClassOrTemp(left.slot, ObjReal.type) &&
+                isExactNonNullSlotClassOrTemp(right.slot, ObjReal.type) -> realOp
             else -> objOp
         }
         builder.emit(opcode, left.slot, right.slot, out)
diff --git a/notes/fast_ops_optimizations_plan.md b/notes/fast_ops_optimizations_plan.md
index b43af54..a040538 100644
--- a/notes/fast_ops_optimizations_plan.md
+++ b/notes/fast_ops_optimizations_plan.md
@@ -4,8 +4,9 @@ Baseline
 - See `notes/nested_range_baseline.md`
 
 Candidates (not started)
-1) Primitive comparisons
-   - Emit fast CMP variants for known ObjString/ObjInt/ObjReal/ObjBool across all comparison operators.
+1) Primitive comparisons (done)
+   - Emit fast CMP variants for known ObjString/ObjInt/ObjReal using temp/stable slots.
+   - MixedCompareBenchmarkTest: 374 ms -> 347 ms.
 2) Mixed numeric ops
    - Ensure INT+REAL arithmetic uses INT_TO_REAL + REAL op with no extra moves/boxing.
 3) Boolean conversion